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Search results for: LOW PH
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Inhibition of amyloid fibril formation of hen egg white lysozyme by trimethylamine N-oxide at low pH
PublicationIn vitro inhibition of the formation of fibrous aggregates of proteins (amyloids) has gained increasing attention due to the number of diseases associated with protein misfolding and fibrillation. An interesting group of compounds for which pronounced activity against this phenomenon can be expected consists of low molecular weight substances (osmolytes) which have the ability to change protein stability. Here we investigate the...
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Influence of pH and low-molecular weight organic compounds in solution on selected spectroscopic and analytical parameters of flowing liquid anode atmospheric pressure glow discharge (FLA-APGD) for the optical emission spectrometric (OES) determination of Ag, Cd, and Pb
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Laboratory bioreactor with pH control system for investigations of hydrogen production in the dark fermentation process
PublicationThe work presents the construction of a low-cost research bioreactor equipped with a pH control sys-tem. The developed bioreactor was applied for hydrogen production in the dark fermentation process using Enterobacter aerogenes ATCC 13048. Presented paper compares the results obtained during the process without and with pH regulation for different feed materials: glucose, energetic poplar hydro-lysates, acid whey and glycerol....
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Importance of the combined effects of dissolved oxygen and pH on optimization of nitrogen removal in anammox-enriched granular sludge
PublicationThe combined effects of dissolved oxygen (DO) and pH on nitrogen removal were investigated in a laboratory-scale sequencing batch reactor (SBR) with anammox-enriched granular sludge obtained from a nitritation/anammox system. The highest specific nitrogen removal rate (SNRR) (1.1 gN gVSS−1 d−1) was observed under non-aerated conditions, resulting in the nitrogen removal efficiency of 81.6%. Although nitrogen removal was readily...
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Fibre-Optic pH Sensor
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The crystal structures of (<i>O</i>-silyl)thiobenzoates (<sup><i>t</i></sup>BuO)<sub>3</sub>SiOC(S)Ph, Ph<sub>3</sub>SiOC(S)Ph, (2,6-XyO)<sub>3</sub>SiOC(S)Ph, and PhC(O)SSSC(O)Ph
PublicationChlorek benzylu reaguje z silanotiolanami sodu R3SiSNa dając wyłącznie pochodne sililowe kwasu monotiobenzoesowego R3SiOC(S)Ph, R=t-Bu, Ph lub 2,6-XyO w postaci pomarańczowych kryształów. Wymienione produkty zostały poddane rentgenowskiej analizie strukturalnej. Badania NMR roztworów tych substancji wskazują, że te same izomery są obecne w roztworze i w ciele stałym.
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Treatment of bitumen post oxidative effluents by sulfate radicals based advanced oxidation processes (S-AOPs) under alkaline pH conditions
PublicationSulfate radicals based Advanced Oxidation Processes (S-AOPs), namely Persulfate and peroxymonosulfate, were used for the treatment of post oxidative effluents from a production of petroleum bitumens under alkaline pH. Studies on the identification and monitoring of the volatile organic compounds (VOCs) along with COD, BOD and sulfide ions reduction were performed. Persulfate with a ratio between the oxygen from the oxidant and...
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pH Gradient Reversed-Phase HPLC
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pH-tunable equilibria in azocrown ethers with histidine moieties
PublicationEtery koronowe posiadające elektro- i fotoaktywne reszty azowe oraz ugrupowania z ruchliwymi protonami jak w grupie COOH histydyny charakteryzują się unikalnym, zależnym od pH, efektem stymulowania pozornej obecności/nieobecności ugrupowania azowego. Obserwowane różnice właściwości elektrochemicznych eterów azokoronowych z resztą N-acetylohistydyny lub resztami imidazolu uwidaczniają się przebiegiem chemicznej redukcji w silnie...
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An Application Supporting Gastroesophageal Multichannel Intraluminal Impedance-pH Analysis
PublicationDue to a significant rise in the number of patients diagnosed with diseases of the upper gastrointestinal tract and the high cost of treatment, there is a need to further research on one of the most popular diagnostic tests used in this case – esophageal Multichannel Intraluminal Impedance and pH measurement. This may lead to finding new diagnostically relevant information, used to quicken and improve the diagnostic procedure....
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Justyna Signerska-Rynkowska dr inż.
PeopleI am currently an assistant professor (adjunct) at Gdansk University of Technology (Department of Differential Equations and Mathematics Applications). My scientific interests include dynamical systems theory, chaos theory and their applications to modeling of biological phenomena, especially to neurosciences. In June 2013 I completed PhD in Mathematics at the Institute of Mathematics of Polish Academy of Sciences (IMPAN) (thesis...
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Wpływ pH na ługowanie zwiercin łupkowych roztworami wodnymi
PublicationZwierciny wytworzone podczas poszukiwania węglowodorów w formacjach łupkowych mogą zawierać metale ciężkie i radionuklidy. Mając na uwadze zagospodarowanie zwiercin, wykonano badanie ich ługowania metodą statyczną, stosując roztwory wodne o różnych pH regulowanych HNO3 i KOH. Charakterystykę chemiczną zwiercin z otworu z Basenu Bałtyckiego przeprowadzono metodą rentgenowskiej analizy fluorescencyjnej, natomiast...
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Theoretical opportunities and actual limitations of pH gradient HPLC
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Determination of pKa by pH Gradient Reversed-Phase HPLC
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BEHAVIOUR OF TiO2/CHITOSAN DISPERSION AS A FUNCTION OF SOLUTION pH
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pH -Tunable equilibria in azocrown ethers with histidine moieties, Bioelectrochemistry
PublicationThe crown ethers with electro- and photoactive azo moieties containing substituents with mobile protons such as in the –COOH groups of histidine, show unique effect of pH switched on/off presence of the azo form. The differences observed for the electrochemical behavior of azocrown ethers with N-acetylhistidine and imidazole moieties reveal the interference of a chemical reduction pathway in strongly acidified solutions. This...
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Modeling the pH effects on nitrogen removal in the anammox-enriched granular sludge
PublicationThe aim of the study was to determine the pH effects on nitrogen removal in the anammox-enriched granular sludge. The experimental data were extracted from a 4L completely-mixed batch reactor with the granular sludge at different initial pH values (6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5) and constant temperature T=30℃. Simulations were run in GPS-X 6.4 using a comprehensive mechanistic model Mantis2. Two kinetic parameters, including...
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MODELING THE pH EFFECTS ON NITROGEN REMOVAL IN THE ANAMMOX-ENRICHED GRANULAR SLUDGE
PublicationThe aim of the study was to determine the pH effects on nitrogen removal in the anammox-enriched 10 granular sludge. The experimental data were extracted from a 4L completely-mixed batch reactor with the 11 granular sludge at different initial pH values (6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5) and constant temperature 12 T=30℃. Simulations were run in GPS-X 6.4 using a comprehensive mechanistic model Mantis2. Two 13 kinetic parameters,...
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Effect of pH on optical sensing with poly-L-lysine-modified nanodiamonds
PublicationNitrogen-vacancy (NV) centers are crystallographic defects which provide diamonds with unique physical properties. The centers are known for their intensive, time-stable fluorescence, and an electron spin, which exhibits long coherence time and may be manipulated using external stimuli. Nanodiamonds containing the NV centers are promising tools in biolabeling, biosensing, and drug delivery due to the aforementioned properties of...
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On stability of iodine doped TiO2 electrodes in pH varied aqueous electrolytes
PublicationW pracy przedstaiono charakterystykę elektrochemiczną warstwy domieszkowanego jodem TiO2 na podłożu platynowym. Wyniki badań prowadzone w elektrolitach o różnym pH pozowoliły na określenie właściwości na granicy faz elektroda - elektrolit. Wyznaczono zależność potencjału pasma płaskiego od pH elektrolitu, a charakter otrzymanej funkcji potwirdził stabilność proszku I-TiO2 w kontakcie s roztworem.
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pH-dependent composite coatings for controlled drug delivery system - Review
PublicationNowadays in case of long-term implants, the most common postoperative complications are bacterial infections, which in consequence may provoke loos- ening of the implants in the primary phase of stabilization. Bacterial infections are currently the most frequent cause of revision surgery of the implants such as hip joint endoprosthesis, knee joint endoprosthesis and dental implants. In order to provide the local and long-term antibacterial...
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ELECTRICAL CONDUCTIVITY AND pH IN SURFACE WATER AS TOOL FOR IDENTIFICATION OF CHEMICAL DIVERSITY
PublicationIn the present study, the creeks and lakes located at the western shore of Admiralty Bay were analysed. The impact of various sources of water supply was considered, based on the parameters of temperature, pH and specific electrolytic conductivity (SEC25). All measurements were conducted during a field campaign in January-February 2017. A multivariate dataset was also created and a biplot of SEC25 and pH of the investigated waters...
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Zinc(II) complexation by some biologically relevant pH buffers
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pH gradient high-performance liquid chromatography: theory and applications
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pH/Organic Solvent Double-Gradient Reversed-Phase HPLC
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Effect of pH on the Redox and Sorption Properties of Native and Phosphorylated Starches
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The Role of Specific Side Groups and pH in Magnetization Transfer in Polymers
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The Role of pH in the Mechanism of .OH Radical Induced Oxidation of Nicotine
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Wastewater treatment by means of Advanced Oxidation Processes at basic pH conditions: A review
PublicationAdvanced oxidation processes (AOPs) have been used as an alternative and effective option for treatment of industrial wastewater, especially in the case of the non-biodegradable compounds. Despite of several well developed AOPs, the majority of them are effective only at acidic or neutral pH, namely Fenton related processes, making the list of available effective advanced oxidation technologies strongly limited. In many cases,...
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Application of pH measurements for the following the course of biological treatment of wastewater and its control
PublicationZaprezentowano wyniki badań przeprowadzonych w skali laboratoryjnej w reaktorze imitującym działanie reaktora SBR. Oczyszczaniu poddano ścieki syntetyczne z dodatkiem glukozy. W trakcie oczyszczania ścieków monitorowano zmiany pH, redox, przewodności oraz stężenia azotu amonowego, azotanów i fosforanów. Stwierdzono korelację między pH i zmianami stężenia fosoranów oraz brak podobnej zależności dla związków azotowych.
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Fluorescence of nanodiamond cocktails: pH-induced effects through interactions with comestible liquids
PublicationFluorescent nanodiamonds with nitrogen-vacancy centers have become important nanoscale probes for sensing and imaging. The surface chemistry of the nanodiamonds influences their emission, interactions, and quantum properties. In this work, we propose to utilize fluorescent nanodiamonds as photostable markers for investigation of comestible liquids. We prepared nanodiamond/comestibles suspensions/cocktails with a wide range of pH...
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Interactions of dissolved dsDNA with intercalating drug by anodic voltammetry and spectroscopy. Influence of pH
PublicationOddziaływanie związku przeciwnowotworowego C-1305 z DNA było badane przy pomocy impulsowej voltametrii różnicowej oraz spektroskopii UV/Vis. Triazoloakrydon C-1305 oddziałuje z DNA na dwóch drogach: przez interkalacje pomiedzy pary zasad oraz przez wiązanie sie w małym rowku helisy. W fizjologicznym pH (7,4) stałe wiązania wynoszą: K1=3,36E+5 i K2=0,18E+5 [1/M] a wielkość miejsca wiązania: n1=2,5 i n2=4,0, odpowiednio dla pierwszego...
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Effect of pH and high pressure at sub-zero temperature on the viability of some bacteria
PublicationCelem badań było określenie przeżywalności Escherichia coli i Staphylococcus aureus zawieszonych w soku jabłkowym (pH 3,8) po działaniu ciśnienia 193MPa w temperaturze -20°C. Stwierdzono, że bezpośrednio po działaniu ciśnienia przeżywalność badanych szczepów bakterii nie zmieniała się znacząco. Jednakże liczba komórek zmniejszała się z czasem przechowywania ciśnieniowanych prób. Żywe komórki mikroorganizmów nie były wykrywane w...
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Supporting Gastroesophageal Reflux Disease Diagnostics by Using Wavelet Analysis in Esophageal pH-Metry
PublicationThis paper presents a new approach to computer supported esophageal pH-metry measurement analysis performed in order to diagnose gastroesophageal reflux disease. In this approach wavelet analysis was used to analyse the esophageal pH-metry course. The research was performed on three groups of pH-metry courses: whole 24-hour pH-metry course, sleep only pH-metry course and 20 minutes after the end of a meal pH-metry course. After...
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Biorefinery Approach for H2 and Acids Production Based on Uncontrolled pH Fermentation of an Industrial Effluent
PublicationIn this work, the feasibility of uncontrolled pH acidogenic fermentation of industrial organic effluent from corn-bioethanol production was studied and modelled by using a Monod-based mathematical model. In order to do that, several tests were carried out at different initial pH values, ranging from 4 to 6. The experimental data showed a pH reduction during the fermentation process due to the generation of short-chain acids. When...
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Effect of salinity and pH on the calibration of the extraction of pharmaceuticals from water by PASSIL
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Combined pH/organic solvent gradient HPLC in analysis of forensic material
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Influence of pH on Retention in Linear Organic Modifier Gradient RP HPLC
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Monosubstituted hydrazone β-cyclodextrin derivatives for pH-sensitive complex formation with aromatic drugs
PublicationA new and convenient synthetic pathway was developed to produce monosubstituted cyclodextrins with high yields. Each of the β-cyclodextrin derivatives described in this work has an aromatic substituent connected with cyclodextrin core by a pH-sensitive hydrazone linker and a carbon chain. Carbon chains differ in lengths having one or three carbon atoms. The correlation between water solubility and linker length was determined using...
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Reactions of (Ph)tBuP-P(SiMe3)Li·3THF with [(PNP)TiCl2] and [MeNacNacTiCl2·THF]. Synthesis of first PNP titanium(IV) complex with phosphanylphosphinidene ligand [(PNP)Ti(Cl){η2-P-P(Ph)tBu}]
PublicationLithium derivative of diphosphane (Ph)tBuP-P(SiMe3)Li (1) was isolated for the first time and investigated in reactions with β-diketiminate (MeNacnac− = [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2C6H3) and PNP-pincer (PNP = N[2-PiPr2-4-methylphenyl]2) Ti(III) complexes. The β-diketiminate titanium(III) complex containing phosphanylphosphido ligand [MeNacNacTi(Cl){η2-P(SiMe3)-P(Ph)tBu}] (2) was prepared in reaction of [MeNacNacTiCl2·THF]...
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Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
PublicationLipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For...
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Salinity and pH as factors affecting the passive sampling and extraction of pharmaceuticals from water
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The pH Value as a Factor Modifying Bacterial Colonization of Sinonasal Mucosa in Healthy Persons
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pH-Responsive Drug Delivery Nanoplatforms as Smart Carriers of Unsymmetrical Bisacridines for Targeted Cancer Therapy
PublicationSelective therapy and controlled drug release at an intracellular level remain key challenges for effective cancer treatment. Here, we employed folic acid (FA) as a self-navigating molecule in nanoconjugates containing quantum dots (QDs) and β-cyclodextrin (β-CD) for the delivery of antitumor unsymmetrical bisacridine compound (C-2028) to lung and prostate cancers as well as normal cells. The bisacridine derivative can form the...
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pH-Induced modification to stratum corneum lipids investigated using thermal, spectroscopic, and chromatographic techniques
PublicationZbadano jakim zmianom jakościowym i ilościowym ulegają indywidualne klasy lipidów w Stratum Corneum (tkanka rogowa skóry) pod wpływem środowiska o zmiennym pH.
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Myrosinase activity in different plant samples; optimisation of measurement conditions for spectrophotometric and pH-stat methods
PublicationMyrosinase found in Brassicaceae plants, is the enzyme responsible for hydrolysis of glucosinolates. As a result a variety of biologically active metabolites are liberated, whose importance in crop protection and especially in cancer chemoprevention is rapidly gaining recognition. The growing practical application of glucosinolate degradation products requires that sensitive and reliable methods of myrosinase activity determination...
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Impact of inorganic ions and pH variations on toxicity and endocrine potential of selected environmentally relevant pharmaceuticals
PublicationAssessment of the impact of pharmaceutical residues on living organisms is a very complex subject. Apart from taking into account the toxicity of individual compounds, environmental factors should also be taken into account. In this paper, attempts were made to assess the impact of coexisting inorganic ions and changes in pH on the toxicity of ten selected pharmaceuticals. Two bioassays were used to measure the estrogenic and androgenic...
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Modyfikacja β-cyklodekstryny w celu uzyskania pH czułego nośnika leków antracyklinowych
PublicationW 2012 roku 68% zgonów było spowodowanych przez choroby niezakaźne takie, jak nowotwory, choroby układu krążenia, przewlekłe choroby układu oddechowego [1]. Zgodnie z danymi Światowej Organizacji Zdrowia (ang. World Health Organization, WHO) w 2012 roku 32,6 miliona osób cierpiało z powodu chorób nowotworowych, a 8,2 miliona zmarło z ich powodu [2]. Szacowane jest, że z roku na rok odsetek osób chorujących na choroby nowotworowe...
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Photosensitive and pH-dependent activity of pyrazine-functionalized carbazole derivative as promising antifungal and imaging agent
PublicationCarbazole skeleton plays a significant role as a structural scaffold of many pharmacologically active compounds. Pyrazine-functionalized carbazole derivative was constructed by coupling 2-amino-5-bromo-3-methylaminepyrazine (ABMAP) into 3 and 6 positions of the carbazole ring. Multi-experimental methods were used, e.g., potentiometric, spectroscopic (ATR, UV, XRD powder,1H and13C NMR), electrochemical (cyclic voltammetry), and...
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Studies on treatment of bitumen effluents by means of Advanced Oxidation Processes (AOPs) in basic pH conditions
PublicationThe paper presents the results of studies on chemical treatment of effluents from production of bitumen of petroleum origin. Due to the presence of sulfide ions, the pH of these effluents is strongly alkaline. Several Advanced Oxidation Processes (AOPs) were studied, including the use of hydroxyl and sulfate radicals oxidants, the hydrodynamic cavitation as well as sonocavitation. The best processes allow to obtain 45% reduction...