1. Assessment of kidney function : clinical indications for measured GFRNatalie Ebert, Sebastjan Bevc, Arend Bökenkamp, Francois Gaillard, Mads Hornum, Kitty Jager, Christophe Mariat, Bjørn Odvar Eriksen, Runolfur Palsson, Andrew D. Rule, 2021, pregledni znanstveni članek Opis: In the vast majority of cases, glomerular filtration rate (GFR) is estimated using serum creatinine, which is highly influenced by age, sex, muscle mass, body composition, severe chronic illness and many other factors. This often leads to misclassification of patients or potentially puts patients at risk for inappropriate clinical decisions. Possible solutions are the use of cystatin C as an alternative endogenous marker or performing direct measurement of GFR using an exogenous marker such as iohexol. The purpose of this review is to highlight clinical scenarios and conditions such as extreme body composition, Black race, disagreement between creatinine- and cystatin C–based estimated GFR (eGFR), drug dosing, liver cirrhosis, advanced chronic kidney disease and the transition to kidney replacement therapy, non-kidney solid organ transplant recipients and living kidney donors where creatinine-based GFR estimation may be invalid. In contrast to the majority of literature on measured GFR (mGFR), this review does not include aspects of mGFR for research or public health settings but aims to reach practicing clinicians and raise their understanding of the substantial limitations of creatinine. While including cystatin C as a renal biomarker in GFR estimating equations has been shown to increase the accuracy of the GFR estimate, there are also limitations to eGFR based on cystatin C alone or the combination of creatinine and cystatin C in the clinical scenarios described above that can be overcome by measuring GFR with an exogenous marker. We acknowledge that mGFR is not readily available in many centres but hope that this review will highlight and promote the expansion of kidney function diagnostics using standardized mGFR procedures as an important milestone towards more accurate and personalized medicine. Ključne besede: biomarker, chronic kidney disease, clinical indications, creatinine, cystatin C, kidney function, measured glomerular filtration rate Objavljeno v DKUM: 12.08.2024; Ogledov: 52; Prenosov: 9 Celotno besedilo (607,93 KB) Gradivo ima več datotek! Več... |
2. Development of an experimental Dead-End microfiltration layout and process repeatability analysisGorazd Bombek, Luka Kevorkijan, Grega Hrovat, Drago Kuzman, Aleks Kapun, Jure Ravnik, Matjaž Hriberšek, Aleš Hribernik, 2024, izvirni znanstveni članek Opis: Microfiltration is an important process in the pharmaceutical industry. Filter selection and validation is a time-consuming and expensive process. Quality by design approach is important for product safety. The article covers the instrumentalization and process control of a laboratory-scale dead-end microfiltration layout. The layout is a downscale model of the actual production line, and the goal is filter validation and analysis of process parameters, which may influence filter operation. Filter size, fluid pressure, valve plunger speed, and timing issues were considered. The focus is on the identification of the most influential process parameters and their influence on the repeatability of pressure oscillations caused by valve opening. The goal was to find the worst-case scenario regarding pressure oscillations and, consequently, filter energy intake. The layout was designed as compact as possible to reduce pressure losses between the filter and valve. Valve-induced pressure oscillations proved to be prevailing over the water hammer effect. Several filters in sizes between 3.5 cm2 and 6900 cm2 were tested, and some recommendations were suggested for the reduction of energy intake of the filter and to improve the repeatability of the process. Ključne besede: filtration, pressure oscillations, repeatability, processes, parameters Objavljeno v DKUM: 01.02.2024; Ogledov: 425; Prenosov: 25 Celotno besedilo (5,64 MB) Gradivo ima več datotek! Več... |
3. Evaluation of the constriction size reduction of granular filters due to upstream cohesive base-soil erosionSamira Azirou, Ahmed Benamar, Abdelkader Tahakourt, 2018, izvirni znanstveni članek Opis: This study is devoted to filter-constrictions analysis and its application with respect to void and constrictions reduction during soil filtration. The experimental investigation involves combined Hole Erosion-Filtration tests using several soils and filters. The base soils are lean clays and the granular filters are selected according to the usual filtration criteria. The combination of the experimental data for porosity variation and the analytical results from the Constriction Size Distribution (CSD) analysis was used to evaluate the constrictions size reduction subsequent to the filtration process. The filtration depth was also estimated according to the retained soil mass and the porosity reduction deduced from the measured hydraulic conductivity. An analytical model of the CSD was applied to the experimental results in order to assess the constrictions reduction. As regards the obtained results, a nonuniform constriction reduction was suggested according to the effective filtration depth, advocating a dynamic filter action. Ključne besede: granular filter, internal erosion, constriction, porosity, filtration index Objavljeno v DKUM: 11.10.2018; Ogledov: 1492; Prenosov: 601 Celotno besedilo (653,76 KB) Gradivo ima več datotek! Več... |
4. Wastewater treatment after reactive printingSonja Šostar-Turk, Marjana Simonič, Irena Petrinić, 2005, izvirni znanstveni članek Opis: Membrane filtration of wastewater after textile printing with reactive dyes isdescribed. The wastewater from a Slovenian factory, whose output is approx. 80% reactive dyes printed and dyed on cotton, was studied. In particular, the presence of urea, sodium alginate, oxidation agent and reactive dyes, used forthe printing paste preparation, in the wastewater was studied. Chemical analyses of actual, non-purified, wastewater showed that many Slovenian regulations were exceeded. The study of membrane filtration is based on a pilot wastewater treatment plantČ ultrafiltration (UF) and reverse osmosis (RO) units. The quality of the wastewater was improved by ultrafiltration, butits effluent still does not conform to the specification of concentration limits for emission into water. Permeate coming from RO meets the required specification and, therefore, could be re-used in the washing process of printed textiles. Ključne besede: textile printing, reactive dyes, wastewater treatment, membrane filtration, pilot plant Objavljeno v DKUM: 01.06.2012; Ogledov: 3369; Prenosov: 92 Povezava na celotno besedilo |
5. Laundry wastewater treatment using coagulation and membrane filtrationSonja Šostar-Turk, Irena Petrinić, Marjana Simonič, 2005, izvirni znanstveni članek Opis: This paper presents the results obtained from laundry wastewater treatment using conventional methods namely precipitation/coagulation and the flocculation process with adsorption on granular-activated carbon (GAC) and an alternative method, membrane filtrations, namely ultrafiltration (UF) and reverse osmosis (RO). Chemical analyses showed that parameter values of untreated wastewater like temperature, pH, sediment substances, total nitrogen and phosphorous, COD, BOD5, and the amount of anion surfactants had been exceeded in regard to Slovenian regulation. These regulations can be used as requirements for wastewater reuse and make treated wastewater an available source for the existing water supply. The study of conventional treatment was based on a flocculation with Al2(SO4)3 18H2O and adsorption on GAC. Membrane filtrations were studied on a pilot wastewater treatment plant: ultrafiltration (UF) and reverse osmosis (RO) units. The membranes used in this experiment were ceramic UF membrane and spiral wounded - polyethersulfone- RO membranes. The quality of the wastewater was improved by both methods and the specifications of a concentration limit for emission into water were confirmed. The disadvantage of GAC is that there is no possibility of any kind of selection, which is essential for recycling and re-use, while permeate coming from RO met the required regulation as well as requirements for reusing in washing process. However, the economical analyses showed that the membrane filtrations are more expensive compared to the GAC treatment process. Ključne besede: laundries, washing of textiles, waste waters, advanced oxidation processes, membrane technology, membrane filtration, coagulation Objavljeno v DKUM: 01.06.2012; Ogledov: 2938; Prenosov: 120 Povezava na celotno besedilo |
6. Removal efficiency of COD, total P and total N components from municipal wastewater using hollow-fibre MBRIrena Petrinić, Mirjana Čurlin, Jasmina Korenak, Marjana Simonič, 2011, strokovni članek Opis: The membrane bioreactor (MBR) integrates well within the conventionally activated sludge system regarding advanced membrane separation for wastewater treatment. Over the last decade, a number of MBR systems have been constructed worldwide and this system is now accepted as a technology of choice for wastewater treatment especially for municipal wastewater. The aim of this work was to investigate and compare submerged MBR with conventionally-activated sludge system for the treatment of municipal wastewater in Maribor, Slovenia. It can be concluded from the results, that the efficiencies being determined by the parameters were satisfied, such as, chemical oxygen demand, total phosphorous, and total nitrogen, which were 97%,75%, and 90%, respectively. The efficiencies of ultrafiltration membrane for the same parameters were also determined, and compared with biological treatment. The results of this analysis show an additional effect regarding an improvement in the quality of the permeate but primary treatment is also very important. For successfully application of MBR system smaller grid for primary treatment is needed. Ključne besede: municipal wastewater treatment, membrane bioreactor, membrane filtration, biological treatment Objavljeno v DKUM: 01.06.2012; Ogledov: 2098; Prenosov: 123 Celotno besedilo (337,63 KB) Gradivo ima več datotek! Več... |