External carbon source
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The identification of a suitable stationary phase in supercritical fluid chromatography (SFC) is a major source of difficulty for those with little experience in this technique. Several protocols have been suggested for column classification in high-performance liquid chromatography (HPLC), gas chromatography (GC), and SFC. However, none of the proposed classification schemes received general acceptance. A fair way to compare columns was proposed with the sum of ranking differences (SRD). In this project, we used the retention data obtained for 86 test compounds with varied polarity and structure, analyzed on 71 different stationary phases encompassing the full range in polarity of commercial packed columns currently available to the SFC chromatographer, with a single set of mobile phase and operating conditions (carbon dioxide-methanol mobile phase, 25°C, 150bar outlet pressure, 3ml/min). First, a reference column was selected and the 70 remaining columns were ranked based on this reference column and the retention data obtained on the 86 analytes. As these analytes previously served for the calculation of linear solvation energy relationships (LSER) on the 71 columns, SRD ranks were compared to LSER methodology. Finally, an external comparison based on the analysis of 10 other analytes (UV filters) related the observed selectivity to SRD ranking. Comparison of elution orders of the UV filters to the SRD rankings is highly supportive of the adequacy of SRD methodology to select similar and dissimilar columns.
Clearwater Mesa (James Ross Island, northeast Antarctic Peninsula) provides a unique opportunity to study solute dynamics and geochemical weathering in the pristine lacustrine systems of a high latitude environment. In order to determine major controls on the solute composition of these habitats, a geochemical survey was conducted on 35 lakes. Differences between lakes were observed based on measured physico-chemical parameters, revealing neutral to alkaline waters with total dissolved solids (TDS) < 2500 mg L-1. Katerina and Trinidad-Tatana systems showed an increase in their respective TDS, total organic carbon values, and finner sediments from external to internal lakes, indicating an accumulation of solutes due to weathering. Norma and Florencia systems exhibited the most diluted and circumneutral waters, likely from the influence of glacier and snow melt. Finally, isolated lakes presented large variability in TDS values, indicating weathering and meltwater contributions at different proportions. Trace metal abundances revealed a volcanic mineral weathering source, except for Pb and Zn, which could potentially indicate atmospheric inputs. Geochemical modelling was also conducted on a subset of connected lakes to gain greater insight into processes determining solute composition, resulting in the weathering of salts, carbonates and silicates with the corresponding generation of clays. We found CO2 consumption accounted for 20-30% of the total species involved in weathering reactions. These observations allow insights into naturally occurring geochemical processes in a pristine environment, while also providing baseline data for future research assessing the impacts of anthropogenic pollution and the effects of climate change.
- MeSH
- ekosystém MeSH
- geologické sedimenty chemie MeSH
- jezera chemie MeSH
- klimatické změny MeSH
- ledový příkrov chemie MeSH
- minerály analýza MeSH
- monitorování životního prostředí metody MeSH
- olovo analýza MeSH
- organické látky analýza MeSH
- počasí MeSH
- stopové prvky analýza MeSH
- uhličitany analýza MeSH
- zinek analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Antarktida MeSH
- Trinidad a Tobago MeSH
The accumulation of glycerol is essential for yeast viability upon hyperosmotic stress. Here we show that the osmotolerant yeast Zygosaccharomyces rouxii has two genes, ZrSTL1 and ZrSTL2, encoding transporters mediating the active uptake of glycerol in symport with protons, contributing to cell osmotolerance and intracellular pH homeostasis. The growth of mutants lacking one or both transporters is affected depending on the growth medium, carbon source, strain auxotrophies, osmotic conditions and the presence of external glycerol. These transporters are localised in the plasma membrane, they transport glycerol with similar kinetic parameters and besides their expected involvement in the cell survival of hyperosmotic stress, they surprisingly both contribute to an efficient survival of hypoosmotic shock and to the maintenance of intracellular pH homeostasis under non-stressed conditions. Unlike STL1 in Sa. cerevisiae, the two Z. rouxii STL genes are not repressed by glucose, but their expression and activity are downregulated by fructose and upregulated by non-fermentable carbon sources, with ZrSTL1 being more influenced than ZrSTL2. In summary, both transporters are highly important, though Z. rouxii CBS 732(T) cells do not use external glycerol as a source of carbon.
- MeSH
- biologický transport MeSH
- delece genu MeSH
- fyziologický stres MeSH
- glycerol metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- mikrobiální viabilita MeSH
- organické látky metabolismus MeSH
- osmoregulace * MeSH
- osmotický tlak MeSH
- regulace genové exprese u hub účinky léků MeSH
- symportéry genetika metabolismus MeSH
- Zygosaccharomyces genetika růst a vývoj metabolismus fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
... Characterizing inter-individual variability 237 -- 10.4.2 Efficacy of use 238 -- 10.4.3 Internal exposure sources ... ... 239 -- 10.5 Limitations of biological markers for exposure assessment 240 -- 10.5.1 Source identification ... ... Detection limits 263 -- 11.5.2 Internal quality control 265 -- 11.5.2.1 Control charts 265 -- 11.5.3 External ... ... Exposure studies 280 -- 12.3 Air pollution exposure studies 280 -- 12.3.1 Particle studies 280 -- 12.3.2 Carbon ...
Environmental health criteria, ISSN 0250-863X no. 214
xxx, 375 s. : il., tab. ; 24 cm
... and the Origins of Metabolic -- 3 Water and the Fitness of the Environment 41 Diversity 498 -- 4 Carbon ... ... Acid precipitation threatens the fitness of the environment 50 xvi DETAILED CONTENTS -- CHAPTER 4 -- Carbon ... ... and the Molecular Diversity of Life 53 -- Organic chemistry is the study of carbon compounds 53 -- Carbon ... ... atoms are the most versatile building blocks of molecules 54 -- Variation in carbon skeletons contributes ... ... to daughter cells: a closer look 210 -- Cytokinesis divides the cytoplasm: a closer look 212 -- External ...
Fourth edition 1206, 32 stran : ilustrace ; 29 cm
... - Acids, Bases, and Buffers 23 Acids and Bases 23 The pH Scale 24 Buffers 25 -- The Importance of Carbon ... ... Genetic Code 80 RNA 80 Transcription 81 Translation 82 -- Different Cells, Different Proteins 83 -- The Source ... ... Pulmonary Ventilation 288 Respiratory Control 290 -- Gas Exchange 291 -- Partial Pressure of Gases 291 External ... ... the Fabric of Life 387 From Populations to Ecosystems 387 Energy Flow 388 -- Chemical Cycling 392 Carbon ...
xx, 456 s. : il., grafy ; 32 cm
- Konspekt
- Biologické vědy
- NLK Obory
- biologie
- zdravotní výchova
- výchova a vzdělávání pracovníků ve zdravotnictví
- NLK Publikační typ
- učebnice středních škol
- učebnice středních škol
... Absorbed Dose, 24 Units of Kerma and Dose, 25 Heavy Charged Particle Interactions, 25 Protons, 25 -- Carbon ... ... Environmental Permitting (England and Wales) Regulations 2016, 58 -- High Activity Sealed Radioactive Sources ... ... 116 Implanted Kilovoltage Machine, 116 Beta-Ray Machine, 117 Gamma-Ray Machine, 117 Radioisotope Source ... ... Planning, 164 -- Magnetic Resonance-Based Planning, 164 Beam Modelling and Dose Calculations for External ... ... MV Photon Beam Treatment Planning, 164 Modelling of the Source of Radiation, 165 Modelling of Dose in ...
Eighth edition xxiii, 615 stran : ilustrace, tabulky ; 28 cm
- MeSH
- nádory radioterapie MeSH
- nukleární lékařství metody MeSH
- radioterapie metody MeSH
- Publikační typ
- učebnice MeSH
- Konspekt
- Učební osnovy. Vyučovací předměty. Učebnice
- Lékařské vědy. Lékařství
- NLK Obory
- radiologie, nukleární medicína a zobrazovací metody
- onkologie
- NLK Publikační typ
- kolektivní monografie
... with Fewer Than 500 Genes -- OF GENOMES AND THE TREE OF LIFE e lowered by a Variety of Free-Energy Sources ... ... r x Nitrogen and Carbon Dioxide for Others E ochemical Diversity Exists Among Prokaryotic Cells ~ ‘e ... ... Cell Lines Are a Widely Used Source of -emogeneous Cells -- 392 -- 392 -- 394 -- 395 -- 396 -- 398 -- ... ... -- Carbon Fixation Uses ATP and NADPH to Convert ? ... ... 02 into Sugars -- Sugars Generated by Carbon Fixation Can Be Stored as Starch or Consumed to Produce ...
Sixth edition xxxiv, 1430 stran v různém stránkování : ilustrace (převážně barevné) ; 29 cm
- Konspekt
- Biochemie. Molekulární biologie. Biofyzika
- NLK Obory
- molekulární biologie, molekulární medicína
- NLK Publikační typ
- učebnice vysokých škol
... and Proteins 112 -- Lipid Metabolism 112 -- Amino Acid Metabolism 114 -- Uses of Different Energy Sources ... ... Transport 489 -- Inherited Defects in Hemoglobin Structure and Function 490 -- Muscle Myoglobin 491 -- Carbon ... ... 608 -- Sexual Reproduction 610 -- Sex Determination 610 -- Development of Accessory Sex Organs and External ...
5th ed. xx, 704 s. : il.
- MeSH
- anatomie MeSH
- fyziologie MeSH
- Publikační typ
- monografie MeSH
- Konspekt
- Fyziologie člověka a srovnávací fyziologie
- NLK Obory
- fyziologie
- anatomie
... Smooth Muscle 286 -- 9.9 Smooth Muscle Contraction and Its Control 287 -- Cross-Bridge Activation 287 Sources ... ... Other Factors in the Blood and Different Isoforms on Hemoglobin Saturation 470 -- 13.5 Transport of Carbon ... ... Summary—Division of Labor 521 -- 14.15 Diuretics 521 section С Hydrogen Ion Regulation 524 -- 14.16 Sources ... ... Sex Differentiation 605 -- Differentiation of the Gonads 606 -- Differentiation of Internal and External ...
13th edition xxiv, 707 s. : il., tab. ; 28 sm
- Konspekt
- Fyziologie člověka a srovnávací fyziologie
- NLK Obory
- fyziologie
- NLK Publikační typ
- kolektivní monografie
