Effects of prior short multiple-sprint exercises with different intersprint recoveries on the slow component of oxygen uptake during high-intensity exercise.

This study compares the effects of two short multiple-sprint exercise (MSE) (6 × 6 s) sessions with two different recovery durations (30 s or 180 s) on the slow component of oxygen uptake ([Formula: see text]O(2)) during subsequent high-intensity exercise. Ten male subjects performed a 6-min cycling test at 50% of the difference between the gas exchange threshold and [Formula: see text]O(2peak) (Δ50). Then, the subjects performed two MSEs of 6 × 6 s separated by two intersprint recoveries of 30 s (MSE(30)) and 180 s (MSE(180)), followed 10 min later by the Δ50 (Δ50(30) and Δ50(180), respectively). Electromyography (EMG) activities of the vastus medialis and lateralis were measured throughout each exercise bout. During MSE(30), muscle activity (root mean square) increased significantly (p ≤ 0.04), with a significant leftward-shifted median frequency of the power density spectrum (MDF; p ≤ 0.01), whereas MDF was significantly rightward-shifted during MSE(180) (p = 0.02). The mean [Formula: see text]O(2) value was significantly higher in MSE(30) than in MSE(180) (p < 0.001). During Δ50(30), [Formula: see text]O(2) and the deoxygenated hemoglobin ([HHb]) slow components were significantly reduced (-27%, p = 0.02, and -34%, p = 0.003, respectively) compared with Δ50. There were no significant modifications of the [Formula: see text]O(2) slow component in Δ50(180) compared with Δ50 (p = 0.32). The neuromuscular and metabolic adaptations during MSE(30) (preferential activation of type I muscle fibers evidenced by decreased MDF and a greater aerobic metabolism contribution to the required energy demands), but not during MSE(180), may lead to reduced [Formula: see text]O(2) and [HHb] slow components, suggesting an alteration in motor units recruitment profile (i.e., change in the type of muscle fibers recruited) and (or) an improved muscle O(2) delivery during subsequent exercise.

In-line Monitoring of Precipitation Process using Raman Spectroscopy and ATR-FTIR

Polymorfian jatkuva seuranta saostuksessa on hyödyllistä suunnittelun ja kidetuotteen ominaisuuksien sekä kiteytystä seuraavan jatkoprosessoinnin kannalta. Tässä diplomityössä on tutkittu L-glutamiinihapon kahden (- ja ß) polymorfimuodon liukoisuuden riippuvuutta pH:sta ja lämpötilasta.Tulokseksi saatiin, että kummankin polymorfin liukoisuus kasvoi sekä pH:ta ettälämpötilaa kasvatettaessa. ¿¿muodon liukoisuus oli korkeampi kuin ß-muodon liukoisuus valituilla pH-arvoilla eri lämpötiloissa. Lisäksi seurattiin puolipanostoimisen saostuksen aikana 1-litraisella laboratoriokiteyttimellä muodostuvan kiteisen polymorfiseoksen koostumusta hyödyntäen in-line Raman-spektroskopiaa. Myös liuoksen pH-muutosta seurattiin sekä liuoksen koostumusta ATR FTIR-spektroskopian (Attenuated Total Reflection Fourier Transform Infrared Spectrometer) avulla. Tutkittavina muuttujina olivat mm. sekoitusintensiteetti, sekoitintyyppi, reaktanttien (natriumglutamaatti ja rikkihappo) konsentraatiot sekä syötetyn rikkihapon syöttökohta kiteyttimessä. Työhön sisältyi 36 koetta ja osa kokeista toistettiin tulosten oikeellisuuden tarkistamiseksi. Inline-mittaustulosten verifioimiseksi kidenäytteet analysoitiin myös käyttämällä konfokaali Raman-mikroskooppia. Kidemorfologiaa tutkittiin SEM-kuvien (Scanning Eletronic Microscope) avulla. Työ osoitti, että Raman-spektroskopia on joustava ja luotettava menetelmä saostusprosessin jatkuvaan seurantaan L-glutamiinihapolla. Alhaiset lähtöainepitoisuudet tuottivat pääasiassa ¿¿muotoa, kun taas alhainen sekoitusteho edisti ß-muodon muodostumista. Syöttökohta vaikutti merkittävästi polymorfiaan. Kun rikkihapon syöttökohta oli epäideaalisesti sekoitetulla vyöhykkeellä, nousi ylikylläisyystaso korkeaksi ja päätuote oli tällöin ß-muotoa. 6-lapainen vinolapaturbiini (nousukulma 45o) ja 6-lapainen levyturbiini eivät merkittävästi poikenneet toisistaan muodostuvien polymorfien osalta.

Bacterial membrane injuries induced by lactacin F and nisin

The combined action of nisin and lactacin F, two bacteriocins produced by lactic acid bacteria, is additive. In this report, the basis of this effect is examined. Channels formed by lactacin F were studied by experiments using planar lipid bilayers, and bactericidal effects were analyzed by flow cytometry. Lactacin F produced pores with a conductance of 1 ns in black lipid bilayers in 1 mM KClat 10 mV at 20°C. Pore formation was strongly dependent on voltage. Although lactacin F formed pores at very low potential (10 mV), the dependence was exponentialabov e 40 mV. The injuries induced by nisin and lactacin F in the membranes of Lactobacillus helveticus produced different flow cytometric profiles. Probably, when both bacteriocins are present, each acts separately; their cooperation may be due to an increase in the number of single membrane injuries

Potentiometric titration as a method of determining the stoichiometric dissociation constants of weak acids from the thermodynamic dissociation constants of aqueous solutions at 298.15 K

The simple single-ion activity coefficient equation originating from the Debye-Hückel theory was used to determine the thermodynamic and stoichiometric dissociation constants of weak acids from data concerning galvanic cells. Electromotive force data from galvanic cells without liquid junctions, which was obtained from literature, was studied in conjuction with the potentiometric titration data relating to aqueous solutions at 298.15 K. The dissociation constants of weak acids could be determined by the presented techniques and almost all the experimental data studied could be interpreted within the range of experimental error. Potentiometric titration has been used here and the calculation methods were developed to obtain the thermodynamic and stoichiometric dissociation constants of some weak acids in aqueous solutions at 298.15 K. The ionic strength of titrated solutions were adjusted using an inert electrolyte, namely, sodium or potassium chloride. Salt content alonedetermines the ionic strength. The ionic strength of the solutions studied varied from 0.059 mol kg-1 to 0.37 mol kg-1, and in some cases up to 1.0 mol kg-1. The following substances were investigated using potentiometric titration: aceticacid, propionic acid, L-aspartic acid, L-glutamic acid and bis(2,2-dimethyl-3-oxopropanol) amine.

Epäpuhtaudet sinkin uutossa

Työssä tutkittiin metalli- ja anioniepäpuhtauksien myötäuuttautumista sinkin mukana di(2-etyyliheksyyli)fosforihappoalla (D2EHPA). Laboratoriokokeissa selvitettiin pH:n vaikutusta metalliepäpuhtauksien uuttautumiseen pH-alueella -O, l... 3 sekä pesujen vaikutusta sinkillä ladatun orgaanisen faasin metallipitoisuuksiin. Kokeita tehtiin sekä synteettisillä että autenttisilla prosessiliuoksilla. Anionikokeissa tutkittiin raudan ja sinkin vaikutusta kloridin ja fluoridin uuttautumiseen. Synteettisillä liuoksilla tehdyissä kokeissa tutkittiin kadmiumin, koboltin, nikkelin, kuparin sekä antimonin uuttautumista sinkkisulfaattiliuoksesta. Kokeissa havaittiin D2EHPA:n uuttavan sinkkiä selvästi em. metalleja paremmin. Sinkki uuttautui sulfaattiliuoksesta lähes täydellisesti tasapaino-pH:n ollessa yli 2,3. Sinkin jälkeen muista metalleista uuttautui eniten kadmium ja järjestyksessä sitten kupari, koboltti ja nikkeli. Epäpuhtausmetallien myötäuuttautumista lisääntyi uuton tasapaino-pH:n kasvaessa ja väheni sinkkilatauksen kasvaessa. Kahdella peräkkäisellä pesuaskeleella, joissa ensimmäinen pesuliuos sisälsi 5 g/L rikkihappoa ja toinen sekä 15 g/L rikkihappoa että 5 g/L sinkkiä saatiin kaikkien epäpuhtausmetallien pitoisuudet jäämään alle 3 mg/L. Antimonin uuttokokeissa huomattiin antimonin uuttautuvan täydellisesti D2EHPA:lla pH:sta riippumatta pH-alueella0...3. Prosessiliuoksilla tehdyissä kokeissa todettiin D2EHPA:n pystyvän tehokkaasti erottamaan sinkin magnesiumista ßzn,Mg ˜107 ja kadmiumista ßzn,cd ˜106. Havaittiin myös, että mitä suurempi sinkki- ja rautalataus orgaanisessa faasissa on sitä vähemmän magnesiumia ja kadmiumia uuttautuu. Ensimmäisessä pesussa saatiin sekä kadmiumin että magnesiumin pitoisuudet putoamaan keskimäärin 0,1 mg/L eli 30 alkuperäisestä pitoisuudesta. Toisella pesuaskeleella ei enää ollut vaikutusta kadmiumin ja magnesiumin pitoisuuksiin orgaanisessa faasissa. Kokeissa havaittiin myös, että D2EHPA:n latausasteen ylittäessä 0,7 alkaa sinkki-D2EHPA-kompleksit polymeroitua ja faasit eivät enää selkeytyneet helposti. Anionikokeissa huomattiin, ettei D2EHPA uuttanut kloridi tai fluoridi sinkin tai raudan mukana. D2EHPA:n havaittiin myös itsessään sisältävän hieman kloridia.

Establishment of an In Vitro Photoallergy Test Using NCTC2544 Cells and IL-18 Production

Differentiation between photoallergenic and phototoxic reactions induced by low molecular weight compounds represents a current problem. The use of eratinocytes as a potential tool for the detection of photoallergens as opposed to photoirritants is considered an interesting strategy for developing in vitro methods. We have previously demonstrated the possibility to use the human keratinocyte cell line NCTC2455 and the production of interleukin-18 (IL-18) to screen low molecular weight sensitizers. The purpose of this work was to explore the possibility to use the NCTC2544 assay to identify photoallergens and discriminate from phototoxic chemicals. First, we identified suitable condition of UV-irradiation (3.5 J/cm2) by investigating the effect of UVAirradiation on intracellular IL-18 on untreated or chloropromazine (a representative phototoxic compound)- treated NCTC2544 cells. Then, the effect of UVA-irradiation over NCTC2544 cells treated with increasing concentrations of 15 compounds including photoallergens (benzophenone, 4-ter-butyl-4-methoxydibenzoylmethane, 2-ethylexyl-p-methoxycinnamate, ketoprofen, 6-methylcumarin); photoirritant and photoallergen (4-aminobenzoic acid, chlorpromazine, promethazine); photoirritants (acridine, ibuprofen, 8-methoxypsoralen, retinoic acid); and negative compounds (lactic acid, SDS and p-phenilendiamine) was investigated. Twenty-four hours after exposure, cytotoxicity was evaluated by the MTT assay or LDH leakage, while ELISA was used to measure the production of IL-18. At the maximal concentration assayed with non-cytotoxic effects (CV80 under irradiated condition), all tested photoallergens induced a significant and a dose-dependent increase of intracellular IL-18 following UVA irratiation, whereas photoirritants failed. We suggest that this system may be useful for the in vitro evaluation of the photoallergic potential of chemicals.

Kalvon modifioinnin vaikutus pienten molekyylien nanosuodatukseen

Tässä työssä tutkittiin pienten molekyylien nanosuodatusta kolmella kalvolla. Lappeenrannan teknillisen korkeakoulun laboratoriomittakaavan nanosuodatuslaitteistolla suodatettiin glukoosin, maitohapon ja oktaanihapon vesiliuoksia 0,45 m/s virtausnopeudella. Lisäksi NF 45, NF 270 ja NTR 7450 –kalvoja modifioitiin UV-säteilytyksellä modifiointiaineen kanssa tai ilman. Modifiointiaineina olivat maito- ja oktaanihappo. Kalvon modifioinnilla pyrittiin parantamaan permeabiliteettia ilman retentiohäviöitä. Kirjallisuusosassa käsiteltiin nanosuodatuksen erottumisperiaatteita ja konsentraatiopolarisaation merkitystä liuenneiden aineiden erottumisessa. Lisäksi käsiteltiin kalvon modifioinnin merkitystä suodatuksen parantamiseen ja pienten orgaanisten molekyylien nanosuodatusta. Aluksi suodatettiin glukoosi- ja oktaanihappoliuoksia NF 270 –kalvolla. Glukoosin retentio oli 80% pitoisuudesta riippumatta, mutta oktaanihapon retentio, 70-100%, riippui pitoisuudesta. 100 ppm oktaanihapon pitoisuudessa retentio oli 100% ja suuremmilla pitoisuuksilla alhaisempi. Kun oktaanihappoa suodatettiin modifioimattomilla kalvoilla pH:n funktiona, niin retentiot olivat pH-riippuvaisia. Alhaisilla pH-arvoilla oktaanihapon retentiot olivat lähes nolla ja nousivat jyrkästi pH:ssa 6 siten, että korkeilla pH-arvoilla retentiot olivat yli 80%. Glukoosin suodatuksissa NF 270 –kalvolla modifiointi aina hieman paransi vuota, mutta retentiot huononivat. Oktaanihapon suodatuksissa vuo parani hieman, kun kalvoja (NF 270 ja NTR 7450) oli modifioitu 20 minuuttia UV-säteilytyksellä 100 ppm maitohappoliuoksessa. NTR 7450 –kalvon vuo moninkertaistui modifioimattoman kalvon vuohon verrattuna, kun kalvoa oli UV-säteilytetty 20 minuuttia 2000 ppm maitohappoliuoksessa. Oktaanihapposuodatuksissa retentiot modifioiduilla kalvoilla olivat suurimmat pH-alueella 7-10. Modifioitujen kalvojen permeabiliteetit nousivat jyrkästi pH:ssa 12 kaikilla malliaineilla, mikä viittaa siihen, että modifiointiaine irtosi pH:ssa 12. Toisaalta korkeilla pH-arvoilla kalvo muuttuu avoimemmaksi, joten modifiointiaineen irtoamista ei voitu näiden mittausten perusteella varmentaa. Kalvon modifiointi oli onnistunut, sillä malliainesuodatuksissa havaittiin vuo- ja retentiomuutoksia.

Development of an enantioselective assay for simultaneous separation of venlafaxine and O-desmethylvenlafaxine by micellar electrokinetic chromatography-tandem mass spectrometry: Application to the analysis of drug-drug interaction.

To-date, there has been no effective chiral capillary electrophoresis-mass spectrometry (CE-MS) method reported for the simultaneous enantioseparation of the antidepressant drug, venlafaxine (VX) and its structurally-similar major metabolite, O-desmethylvenlafaxine (O-DVX). This is mainly due to the difficulty of identifying MS compatible chiral selector, which could provide both high enantioselectivity and sensitive MS detection. In this work, poly-sodium N-undecenoyl-L,L-leucylalaninate (poly-L,L-SULA) was employed as a chiral selector after screening several dipeptide polymeric chiral surfactants. Baseline separation of both O-DVX and VX enantiomers was achieved in 15min after optimizing the buffer pH, poly-L,L-SULA concentration, nebulizer pressure and separation voltage. Calibration curves in spiked plasma (recoveries higher than 80%) were linear over the concentration range 150-5000ng/mL for both VX and O-DVX. The limit of detection (LOD) was found to be as low as 30ng/mL and 21ng/mL for O-DVX and VX, respectively. This method was successfully applied to measure the plasma concentrations of human volunteers receiving VX or O-DVX orally when co-administered without and with indinivar therapy. The results suggest that micellar electrokinetic chromatography electrospray ionization-tandem mass spectrometry (MEKC-ESI-MS/MS) is an effective low cost alternative technique for the pharmacokinetics and pharmacodynamics studies of both O-DVX and VX enantiomers. The technique has potential to identify drug-drug interaction involving VX and O-DVX enantiomers while administering indinivar therapy.

The stability of right- and left-handed alpha-helices as a function of monomer chirality

Poly-L-alanine forms stable right-handed alpha-helices, whereas Poly-D-alanine is stable as left-handed alpha helices.

HYDROLYTIC DEGRADATION BEHAVIOR OF PLLA NANOCOMPOSITES REINFORCED WITH MODIFIED CELLULOSE NANOCRYSTALS

Bionanocomposites derived from poly(L-Lactide) (PLLA) were reinforced with chemically modified cellulose nanocrystals (m-CNCs). The effects of these modified cellulose nanoparticles on the mechanical and hydrolytic degradation behavior of polylactide were studied. The m-CNCs were prepared by a method in which hydrolysis of cellulose chains is performed simultaneously with the esterification of hydroxyl groups to produce modified nanocrystals with ester groups. FTIR, elemental analysis, TEM, XRD and contact angle measurements were used to confirm and characterize the chemical modifications of the m-CNCs. These bionanocomposites gave considerably better mechanical properties than neat PLLA based on an approximately 100% increase in tensile strength. Due to the hydrophobic properties of the esterified nanocrystals incorporated into a polymer matrix, it was also demonstrated that a small amount of m-CNCs could lead to a remarkable decrease in the hydrolytic degradation rate of the biopolymer. In addition, the m-CNCs considerably delay the degradation of the nanocomposite by providing a physical barrier that prevents the permeation of water, which thus hinders the overall absorption of water into the matrix. The results obtained in this study show the nanocrystals can be used to reinforce polylactides and fine-tune their degradation rates in moist or physiological environments.

Epäpuhtausmetallien talteenotto sinkkiprosessissa

There are small amounts of valuable metals, such as indium, gallium and germanium, in zinc process solutions. Their solvent extraction was studied in this work in sulphate solutions containing zinc and other metals present in industrial solutions. It was discovered, that a commercial bis(2-ethylhexyl)phosphate (D2EHPA) extractant can be used to extract indium and gallium. Indium was extracted separately at a higher acid concentration than gallium. Zinc was co-extracted faster than gallium and almost as much as gallium at the same pH. However, the scrubbing of zinc was possible using a dilute sulphuric acid and a short contact time while gallium losses were small. Both indium and gallium were stripped with sulphuric acid. Germanium was extracted with 5,8-diethyl-7-hydroxydodecane-6-oxime with the commercial name of LIX 63. Unlike other metals in the solution the extraction of germanium increased with different extractants as the acidity increased. Germanium extraction isotherm was measured for a 125 g/L sulfuric acid solution. The loaded organic phase was washed with pure water. It removed the co-extracted acid and part of the germanium and extracted impurities such as iron and copper. Germanium was stripped using a NaOH solution. A process model utilizing own experimentally determined extraction, scrubbing and stripping isotherms was made with HSC Sim software developed by Outotec Oyj. The model based on McCabe–Thiele diagrams was used in sizing the necessary amount of stages and phase ratios in a recovery process. It was concluded, that indium, gallium and germanium can be recovered in the process from a feed where their concentrations are low (<300 ppm). In an example case the feed contained also more than 20 g/L zinc and 2–8 g/L iron, aluminium and copper. The recoveries of indium, gallium and germanium were more than 90 % when 1–3 stages were used in each extraction, scrubbing and stripping section. Since the number of stages is small mixer-settlers would be well suited for this purpose.

Effect of hydrodynamics on modelling, monitoring and control of crystallization

Crystallization is a purification method used to obtain crystalline product of a certain crystal size. It is one of the oldest industrial unit processes and commonly used in modern industry due to its good purification capability from rather impure solutions with reasonably low energy consumption. However, the process is extremely challenging to model and control because it involves inhomogeneous mixing and many simultaneous phenomena such as nucleation, crystal growth and agglomeration. All these phenomena are dependent on supersaturation, i.e. the difference between actual liquid phase concentration and solubility. Homogeneous mass and heat transfer in the crystallizer would greatly simplify modelling and control of crystallization processes, such conditions are, however, not the reality, especially in industrial scale processes. Consequently, the hydrodynamics of crystallizers, i.e. the combination of mixing, feed and product removal flows, and recycling of the suspension, needs to be thoroughly investigated. Understanding of hydrodynamics is important in crystallization, especially inlargerscale equipment where uniform flow conditions are difficult to attain. It is also important to understand different size scales of mixing; micro-, meso- and macromixing. Fast processes, like nucleation and chemical reactions, are typically highly dependent on micro- and mesomixing but macromixing, which equalizes the concentrations of all the species within the entire crystallizer, cannot be disregarded. This study investigates the influence of hydrodynamics on crystallization processes. Modelling of crystallizers with the mixed suspension mixed product removal (MSMPR) theory (ideal mixing), computational fluid dynamics (CFD), and a compartmental multiblock model is compared. The importance of proper verification of CFD and multiblock models is demonstrated. In addition, the influence of different hydrodynamic conditions on reactive crystallization process control is studied. Finally, the effect of extreme local supersaturation is studied using power ultrasound to initiate nucleation. The present work shows that mixing and chemical feeding conditions clearly affect induction time and cluster formation, nucleation, growth kinetics, and agglomeration. Consequently, the properties of crystalline end products, e.g. crystal size and crystal habit, can be influenced by management of mixing and feeding conditions. Impurities may have varying impacts on crystallization processes. As an example, manganese ions were shown to replace magnesium ions in the crystal lattice of magnesium sulphate heptahydrate, increasing the crystal growth rate significantly, whereas sodium ions showed no interaction at all. Modelling of continuous crystallization based on MSMPR theory showed that the model is feasible in a small laboratoryscale crystallizer, whereas in larger pilot- and industrial-scale crystallizers hydrodynamic effects should be taken into account. For that reason, CFD and multiblock modelling are shown to be effective tools for modelling crystallization with inhomogeneous mixing. The present work shows also that selection of the measurement point, or points in the case of multiprobe systems, is crucial when process analytical technology (PAT) is used to control larger scale crystallization. The thesis concludes by describing how control of local supersaturation by highly localized ultrasound was successfully applied to induce nucleation and to control polymorphism in reactive crystallization of L-glutamic acid.

Membraanin modifiointi happo- ja alkoholikäsittelyillä

Tässä diplomityössä tutkittiin alkoholilla ja orgaanisella hapolla tehtävien esikäsittelyiden vaikutusta nanosuodatuskalvon ominaisuuksiin. Työn tarkoituksena oli parantaa nanosuodatuskalvon fraktiointiominaisuuksia sekä kasvattaa monosakkaridien suotautuvuutta. Tarkasteluissa käytetty membraani oli GE Osmonicsin valmistamaa Desal-5 DL nanosuodatuskalvoa, jota modifioitiin erilaisilla maitohappo- ja isopropanoliesikäsittelyillä. Suodatukset tehtiin kahdella erilaisella laboratoriomittakaavan levysuotimella käyttäen malliaineina väkevää sokeriliuosta sekä laimeampaa sokeri-suola-liuosta. Happo- ja alkoholiesikäsiteltyjen kalvojen vuo- ja retentioarvoja verrattiin referensseinä käytettyjen vesiliotettujen kalvojen vastaaviin arvoihin. Puhtaat esikäsitellyt kalvot analysoitiin myös tarkemmin kalvoissa tapahtuneiden muutosten ymmärtämiseksi. Suodatusten ja analyysitulosten perusteella sekä alkoholi- että happoesikäsittelyt paransivat nanosuodatuskalvon ominaisuuksia parantaen sokerivuota, heikentämättä kuitenkaan kalvon fraktiointikykyä eri moolimassan omaavien sokereiden suhteen. Hapolla saavutettiin hieman alkoholikäsittelyä suotuisammat muutokset, mutta molemmilla käsittelyillä haluttujen komponenttien retentio monesti jopa parani referenssikalvoon verrattuna. Havaitut muutokset kalvoissa olivat pääosin fysikaalisia, mutta erityisesti happokäsittely muutti kalvon rakennetta myös kemiallisesti. Molemmat käsittelyt lisäsivät myös tarkasteltavan membraanin hydrofiilisuutta.

Kullan talteenotto takaisinuuttoliuoksista

Työssä tutkittiin kirjallisuuden ja laboratoriomittausten avulla vaihtoehtoja kullan pelkistämiseen ja talteenottoon kultauuton takaisinuuttoliuoksista. Tavoitteena oli löytää menetelmä, jolla saadaan puhdasta kiinteää lopputuotetta ilman kullan häviöitä. Käytettyjä pelkistimiä olivat D-(+)-glukoosi, natriumboorihydridi, L-askorbiinihappo, D-(-)-isoaskorbiinihappo ja aktiivihiili. Laboratoriokokeiden perusteella D-(-)-isoaskorbiinihappo sekä aktiivihiili olivat sopivimmat pelkistimet kokeissa käytetylle kultaliuokselle. Isoaskorbiinihapolla suoritettiin panoskokeita lasireaktorissa eri alku-pH:ssa sekä erilaisilla pelkistimen ja kullan moolisuhteilla. Tulosten perusteella havaittiin pH:n ja pelkistimen ylimäärän vaikuttavan merkittävästi lopputuotteen puhtauteen. Myös redox-potentiaalia säätämällä ja happopesulla pelkistyksen jälkeen voidaan vaikuttaa lopputuotteen puhtauteen. Aktiivihiilellä suoritettiin panoskokeita adsorptiotasapainojen (latausisotermi) ja kinetiikan tutkimiseksi. Hiileen on mahdollista saada kultaa 383 mg/g kuivaa hiiltä. Suurempi lataus voitaisiin saavuttaa käyttämällä hiiltä, jolla on pienempi partikkelikoko. Kolonnikokeita tehtiin eri virtausnopeuksilla. Kolonnikokeissa kullan dynaaminen adsorptiokapasiteetti hiileen odotetusti kasvoi virtausnopeuden laskiessa. Pienin käytetty virtausnopeus oli 2,40 BV/h, jolloin kapasiteetti oli 75,4 mg/g kuivaa hiiltä (c (Au feed) = 129 mg/L). Kullasta voidaan poistaa myös kolonnipelkistyksen jälkeen epäpuhtauksia happopesulla. Isoaskorbiinihapolla pelkistyksen kinetiikka on nopea ja sillä saatiin pelkistettyä puhdasta lopputuotetta. Sekä isoaskorbiinihappo, että aktiivihiili ovat potentiaalisia menetelmiä kullan talteenottoon.

Galactosaminoglycans from normal myometrium and leiomyoma

In many tumors, the amount of chondroitin sulfate in the extracellular matrix has been shown to be elevated when compared to the corresponding normal tissue. Nevertheless, the degree of chondroitin sulfate increase varies widely. In order to investigate a possible correlation between the amount of chondroitin sulfate and tumor size, several individual specimens of human leiomyoma, a benign uterine tumor, were analyzed. The glycosaminoglycans from eight tumors were extracted and compared with those from the respective adjacent normal myometrium. The main glycosaminoglycan found in normal myometrium was dermatan sulfate, with small amounts of chondroitin sulfate and heparan sulfate. In leiomyoma, both dermatan sulfate and chondroitin sulfate were detected and the total amounts of the two galactosaminoglycans was increased in all tumors when compared to normal tissue. In contrast, the heparan sulfate concentration decreased in the tumor. To assess the disaccharide composition of galactosaminoglycans, these compounds were incubated with bacterial chondroitinases AC and ABC. The amounts of L-iduronic acid-containing disaccharides remained constant, whereas the concentration of D-glucuronic acid-containing disaccharides increased from 2 to 10 times in the tumor, indicating that D-glucuronic acid-containing disaccharides are responsible for the elevation in galactosaminoglycan concentration. This increase is positively correlated with tumor size.