bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: MULTIPLE METAL‐CARBON BONDS. 20. TUNGSTEN METHYLIDYNE COMPLEXES
Authors: SHARP P. R. , HOLMES S. J. , SCHROCK R. R. , CHURCHILL M. R. , WASSERMAN H. J. 
Published: April 2016

AbstractAus der Reaktionslösung des W‐Komplexes (I) und zwei Molen AlMe3 wird nach Zugabe von N,N,N′,N′‐Tetramethylethylendiamin der Komplex (II) isoliert, für den eine trans‐Stellung des Methylidin‐ und des Chlorid‐Liganden röntgenographisch bestätigt wird.
ChemInform Abstract: PREPARATION AND REACTIVITY OF THE (CYCLOHEXADIENE)MANGANESE TRICARBONYL ANION. POTENTIALLY USEFUL METHODS OF ARENE AND CARBON‐HYDROGEN BOND ACTIVATION
Authors: LAMANNA W. , BROOKHART M. 
Published: April 2016

AbstractÜberschüssiges Li‐triethylhydridoborat oder K‐triisopropoxyhydridoborat reagieren mit dem Benzol‐ Mn‐Komplex (I) zu dem Titelkomplexion (II), das auch quantitativ durch Hydridreduktion der Cyclohexadienylverbindung (III) dargestellt werden kann, die IR‐ spektroskopisch als Intermediärprodukt bei der Reaktion von (I) zu (II) nachgewiesen wurde.
ChemInform Abstract: OXIDATION OF MANGANESE(II) PHTHALOCYANINE BY MOLECULAR OXYGEN
Authors: LEVER A. B. P. , WILSHIRE J. P. , QUAN S. K. 
Published: April 2016

AbstractDer Mn(II)‐ Komplex (I) reagiert in gereinigtem, wasserfreiem Pyridin nicht mit Sauerstoff.
ChemInform Abstract: PREPARATION OF TRIS(μ2‐HYDRO)‐NONACARBONYL‐μ3‐ETHYLIDYNE‐TRIIRON FROM PENTACARBONYLIRON
Authors: WONG K. S. , FEHLNER T. P. 
Published: April 2016

AbstractNeben den Ferraboranen B3H7 Fe,(CO)6 und B2H6Fe2(CO)6 wird die Titelverbindung (I) aus der 2:1:2‐molaren Reaktion von Fe‐pentacarbonyl, Pentaboran(9) und Na‐dihydrido‐bis‐[2‐methoxy ethoxy]‐aluminat isoliert.
ChemInform Abstract: OXIDATION OF SUBSTITUTED IRON CARBONYL COMPLEXES IN ACETONITRILE, ACETONE, AND DICHLOROMETHANE AT MERCURY AND PLATINUM ELECTRODES
Authors: BLANCH S. W. , BOND A. M. , COLTON R. 
Published: April 2016

AbstractDie elektrochemische Oxidation von Fe(CO)5‐n(EPh3)n (E: As, Sb, P; n: 1,2) an Pt‐Elektroden führt zu den entsprechenden 17‐Elektronen‐Kationen [Fe(CO)5‐n(EPh3)n]+, von denen die Arsin‐ und Stibin‐Derivate in allen obigen Lösungsmitteln instabil sind, während das Phosphin‐Derivat n:2 in Dichlormethan geringe Stabilität zeigt Die Reaktionen führen wahrscheinlich zur Zersetzung An Hg‐Elektroden dagegen scheinen die Kationen wesentlich stabiler zu sein, vermutlich sind sie "Hg‐stabilisiert" Chemisches reversibles Verhalten kann dort beobachtet werden, wo die Reaktion am Pt vollständig irreversibel ist.
ChemInform Abstract: THE SYNTHESIS OF A METAL COMPLEX OF BENZENETHIOL, (FE(C5H5)(CO)2(PHSH))BF4, AND ITS CHARACTERIZATION AS A STRONG ACID
Authors: TREICHEL P. M. , ROSENHEIN L. D. 
Published: April 2016

AbstractDer durch 1:2‐molare Umsetzung des THF‐ Analogen (I) mit Thiophenol gebildete Titelkomplex (II) wird IR‐ und NMR‐spektroskopisch charakterisiert.
ChemInform Abstract: SYNTHESIS AND CHARACTERIZATION OF 1,1′‐BIS(6‐FULVENYL)FERROCENE
Authors: CASSENS A. , EILBRACHT P. , MUELLER‐WESTERHOFF U. T. , NAZZAL A. , NEUENSCHWANDER M. , PROESSDORF W. + 
Published: April 2016

AbstractDimethylaminofulven (I) wird mit Natriumcyclopentadienid (II) zum Fulvenylcyclopentadienid‐Anion (III) umgesetzt, das mit Eisen(II)‐chlorid (IV) zum Bis‐(fulvenyl)‐ferrocen (V) reagiert.
ChemInform Abstract: AN EFFICIENT SYNTHESIS OF (1,1)FERROCENOPHANE VIA 1,1′‐BIS(6‐FULVENYL)FERROCENE
Authors: MUELLER‐WESTERHOFF U. T. , NAZZAL A. , PROESSDORF W. + 
Published: April 2016

AbstractDas Bis‐(fulvenyl)‐ferrocen (I) wird mit komplexen Borhydriden (II) zum Salz (III) reduziert und anschließend mit Eisen(II)‐chlorid zum Ferrocenophan (IV) umgesetzt, das in guten Ausbeuten erhalten wird.
ChemInform Abstract: SCHIFF BASE TETRADENTATE CHELATING LIGANDS AND COBALT COMPLEXES FROM ACETYLINDANONES
Authors: DRUSIANI A. , PLESSI L. , BIGOTTO A. , PELLIZER G. , COSTA G. 
Published: April 2016

AbstractDie Acetylindanone (I), deren IR‐ und NMR‐spektroskopische Charakterisierung zeigt, daß die Keto‐enol‐Struktur vorherrscht (80‐90%), reagieren (außer Ic) mit Ethylendiamin in siedendem Methanol zu Schiffschen Basen.
ChemInform Abstract: PREPARATION AND PHYSICAL PROPERTIES OF ALKYLCOBALT COMPLEXES OF THE COENZYME B12 MODEL COMPLEX RCO(C2(DO)(DOH)PN)X
Authors: FINKE R. G. , SMITH B. L. , MCKENNA W. A. , CHRISTIAN P. A. 
Published: April 2016

AbstractAusgehend von Pentanon‐(2) (I) wurde in einer dreistufigen Synthese über (II) und (III) der Diiodo‐cobalt(III)‐Komplex (IV) mit einer Gesamtausb.
ChemInform Abstract: MERCURY‐BRIDGED COBALTACARBORANE COMPLEXES CONTAINING BORON‐MERCURY‐BORON THREE‐CENTER BONDS. SYNTHESIS AND STRUCTURE OF μμ′‐((η5‐C5R5)CO(CH3)2C2B3H4)2HG AND μ‐((η5‐C5R5)CO(CH3)2C2B3H4)HGCL (R = HYDROGEN, METHYL) AND RELATED COMPOUNDS
Authors: FINSTER D. C. , GRIMES R. N. 
Published: April 2016

AbstractDie Reaktion der nido‐Cobaltacarborane (I) mit NaH in THF liefert unter Deprotonierung die entsprechenden Anionen, die mit HgClg über ein anfangliches instabiles Addukt die isolierbaren Komplexe (II) bilden.
ChemInform Abstract: THE REACTIVITY OF ACETYLENES COORDINATED TO COBALT. III. REACTION OF THE BUTENE‐2‐OLIDE‐4 COMPLEXES, (C4O2R1,R2)CO2(CO)7 WITH ACETYLENES; FORMATION OF NEW TYPES OF ORGANIC LIGANDS
Authors: VARADI G. , HORVATH I. T. , PALYI G. , MARKO L. , SLOVOKHOTOV Y. L. , STRUCHKOV Y. T. 
Published: April 2016

AbstractDie Cobalt‐carbonyl‐lacton‐Komplexe (I) reagieren mit den substituierten Acetylenen (II) zu den bekannten u‐Acetylen‐carbonyl‐cobalt‐ Komplexen (III) und zu zwei Isomeren der neuen Komplexe (IV).
ChemInform Abstract: COBALT(II) AND NICKEL(II) COMPLEXES OF 1‐METHOXY‐2‐METHYLTHIOETHANE AND 2‐METHOXYETHANETHIOL
Authors: BLOODWORTH B. C. , DEMETRIOU B. , GRZESKOWIAK R. 
Published: April 2016

AbstractUnter wasserfreien Bedingungen reagieren die Metallhalogenide mit 1‐Methoxy‐2‐methylmercaptoethan zu den Komplexen (I) und (II).
ChemInform Abstract: OXIDATIVE ADDITION OF α‐KETOIMIDOYL CHLORIDES TO PALLADIUM(0) AND PLATINUM(0) COMPLEXES
Authors: MANTOVANI A. , FACCHIN G. , BOSCHI T. , CROCIANI B. 
Published: April 2016

AbstractDie α‐Ketoimidoylchloride (I) reagieren mit den Platin(O)‐ (II) und Palladium(O)‐phosphin‐Komplexen (IV) zu den trans‐ (III) bzw. cis‐Komplexen (V).
ChemInform Abstract: OCTAFLUOROCYCLOOCTATETRAENE TRANSITION‐METAL CHEMISTRY: 1,2‐η AND 1,2,3,6‐η COMPLEXES OF IRON AND PLATINUM
Authors: BAREFOOT A. C. III , CORCORAN E. W. JUN. , HUGHES R. P. , LEMAL D. M. , SAUNDERS W. D. , LAIRD B. B. , DAVIS R. E. 
Published: April 2016

AbstractDie Reaktion des Titelliganden (II) mit überschüssigem Nonacarbonyldieisen in Hexan bei Raumtemp. führt zu dem Olefin‐Komplex (I).
ChemInform Abstract: STERIC CONTROL IN THE SYNTHESIS AND REACTIONS OF DICHLORO‐μ‐DICHLORO‐BIS(TRICYCLOHEXYLPHOSPHINE)DIPLATINUM
Authors: ANDERSON G. K. , CLARK H. C. , DAVIES J. A. 
Published: April 2016

AbstractDie langsame Zugabe einer äquimolaren Menge des sperrigen Tricyclohexylphosphins zum K‐platinat(II) (I) führt zur Bildung des dimeren Titelkomplexes (II) in hoher Ausbeute.
ChemInform Abstract: SYNTHESES OF BILE PIGMENTS. XII. SYNTHESIS OF E,Z,Z‐BILIVERDINS FROM 5(1H)‐PYRROMETHENONES OF THE SAME CONFIGURATION
Authors: GOSSAUER A. , BLACHA‐PULLER M. , ZEISBERG R. , WRAY V. 
Published: April 2016

AbstractTFA‐katalysierte Kondensation des (Z)‐Pyrromethenonaldehydes (Ia) mit (Z)‐Pyrromethenoncarbonsäureester (IIa) liefert den (Z,Z,Z)‐konfigurierten Mesobiliverdin‐IIIoz‐dimethylester (IIIa); das (Z,Z,E)‐Isomere (IIIb) entsteht unter analogen Bedingungen aus (Ib) und (IIa) oder (IIb).
ChemInform Abstract: SYNTHESIS OF PALLESCENSIN‐E: USE OF CROWN ETHER IN THE WADSWORTH PROCEDURE FOR OLEFIN FORMATION
Authors: BAKER R. , SIMS R. J. 
Published: April 2016

AbstractZß‐Dimethyl‐benzonitril (Ia) wird in die Carbonsäure (Ib) übergeführt, diese zum Carbinol (Ic) reduziert und weiter mit Pyridiniumchlorchromat zum Aldehyd (Id) oxidiert.
ChemInform Abstract: REACTION OF 3‐ACETATE OF 3,5‐SECO‐4‐NORCHOLESTANE‐3,5α‐ AND ‐3,5β‐DIOLS WITH PHOSPHORUS AND HALOGEN CONTAINING REAGENTS. SKELETAL REARRANGEMENTS
Authors: ACHMATOWICZ B. 
Published: April 2016

AbstractDie Reaktion des A‐Seco‐4‐norcholestan‐3,Soz‐diol‐B‐acetates (Ia) mit PPh3 /CCl4 bzw. mit P(O‐Ph)3/ Brg verläuft unter Eliminierung zu den Olefinen (IIa) bzw. (IIb).
ChemInform Abstract: SYNTHESIS OF 7‐CHLORO‐L‐ AND 7‐CHLORO‐D‐TRYPTOPHAN; BIOSYNTHESIS OF PYRROLNITRIN
Authors: VAN PEE K.‐H. , SALCHER O. , LINGENS F. 
Published: April 2016

AbstractMichael‐Reaktion des Acetaminomalonates (I) mit Acrolein (II) gibt das Addukt (III), das mit dem Chlorphenylhydrazin (IV) zu dem Hydrazon (V) kondensiert wird.
ChemInform Abstract: 3,5‐DINITRO‐1‐(P‐NITROPHENYL)‐4‐PYRIDONE AS A NOVEL PROTECTIVE GROUP OF PRIMARY AMINES
Authors: MATSUMURA E. , ARIGA M. , TOHDA Y. , KAWASHIMA T. 
Published: April 2016

Abstract3,5‐Dinitro‐1‐p‐nitrophenyl‐pyridon (I) reagiert mit zahlreichen Aminen (II) zu p‐Nitranilin (III) und den 3,5‐Dinitro‐4‐pyridonen (IV).
ChemInform Abstract: SYNTHESIS OF CROBARBATINE ACETATE. A MACROCYCLIC PYRROLIZIDINE ALKALOID ESTER
Authors: HUANG J. , MEINWALD J. 
Published: April 2016

AbstractAus der trans‐Lactoncarbonsäure (I) und A1Me3 wird das Dimethylaluminiumsalz dargestellt und mit dem Sulfid (II) zu dem Thioester (IIIa) umgesetzt, aus dem über das Acetatanhydrid (IIIb) und die Säure (IIIc) das Imidazolid (IIId) gewonnen wird.
ChemInform Abstract: SMOOTH AND EFFICIENT DEOXYGENATION OF SECONDARY ALCOHOLS. A GENERAL PROCEDURE FOR THE CONVERSION OF RIBONUCLEOSIDES TO 2′‐DEOXYNUCLEOSIDES
Authors: ROBINS M. J. , WILSON J. S. 
Published: April 2016

AbstractBehandlung der Ribofuranosylverbindungen (I) mit dem Disilan (II) führt bei nachfolgender Thioacylierung zu den Thiocarbonylestern (III).
ChemInform Abstract: REDUCTIVE METHYLATION OF N1‐SUBSTITUTED 4‐ETHOXYCARBONYL‐5‐IMIDAZOLES
Authors: ALENIN V. V. , DOMKIN V. D. 
Published: April 2016

AbstractDas 5‐Amino‐imidazol (I) wird wie im Formelschema beschrieben zum Derivat (II) umgesetzt.
ChemInform Abstract: STRUCTURE OF HIGH‐ANGLE GRAIN BOUNDARIES IN METALS AND CERAMIC OXIDES
Authors: BALLUFFI R. W. , BRISTOWE P. D. , SUN C. P. 
Published: April 2016

AbstractReview: Kritische Übersicht unter besonderer Berücksichtigung der Einflüsse der Unterschiede im Bindungsverhalten und der Kristallstruktur.
ChemInform Abstract: HOMOGENEOUS ASYMMETRIC HYDROGENATION
Authors: CAPLAR V. , COMISSO G. , SUNJIC C. 
Published: April 2016

AbstractReview: Dieser Übersichtsartikel beschreibt die Verwendung von chiralen Rhodium‐, Ruthenium‐ und Palladium‐Phosphin‐Komplexen als Hydrierkatalysatoren.
TLR signaling in human antigen‐presenting cells regulates MR1‐dependent activation of MAIT cells
Authors: Ussher James E. , van Wilgenburg Bonnie , Hannaway Rachel F. , Ruustal Kerstin , Phalora Prabhjeet , Kurioka Ayako , Hansen Ted H. , Willberg Christian B. , Phillips Rodney E. , Klenerman Paul 
Published: April 2016

Mucosal‐associated invariant T (MAIT) cells are an abundant innate‐like T lymphocyte population that are enriched in liver and mucosal tissues. They are restricted by MR1, which presents antigens derived from a metabolic precursor of riboflavin synthesis, a pathway present in many microbial species, including commensals. Therefore, MR1‐mediated MAIT cell activation must be tightly regulated to prevent inappropriate activation and immunopathology. Using an in vitro model of MR1‐mediated activation of primary human MAIT cells, we investigated the mechanisms by which it is regulated. Uptake of intact bacteria by antigen presenting cells (APCs) into acidified endolysosomal compartments was required for efficient MR1‐mediated MAIT cell activation, while stimulation with soluble ligand was inefficient. Consistent with this, little MR1 was seen at the surface of human monocytic (THP1) and B‐cell lines. Activation with a TLR ligand increased the amount of MR1 at the surface of THP1 but not B‐cell lines, suggesting differential regulation in different cell types. APC activation and NF‐κB signaling were critical for MR1‐mediated MAIT cell activation. In primary cells, however, prolonged TLR signaling led to downregulation of MR1‐mediated MAIT cell activation. Overall, MR1‐mediated MAIT cell activation is a tightly regulated process, dependent on integration of innate signals by APCs.
Multidimensional gas chromatographic techniques applied to the analysis of lipids from wild‐caught and farmed marine species
Authors: Costa Rosaria , Albergamo Ambrogina , Piparo Marco , Zaccone Giacomo , Capillo Gioele , Manganaro Antonio , Dugo Paola , Mondello Luigi 
Published: April 2016

Comprehensive two‐dimensional gas chromatography‐mass spectrometry was exploited for the obtainment of fatty acid fingerprints in fish and molluscs from South Italy. Scope of the lipidomic investigation was to highlight differences in the fatty acid profiles of samples from aquaculture and from the wild. The fish species under investigation were Sparus aurata and Dicentrarchus labrax, typically cultivated in Italy and commonly found in the fish market. Another aim was to find a correlation between the diet fed to fish and the expression of specific fatty acids in muscle composition. Beyond fish, two species of bivalves were analyzed to assess their lipidomic composition: Mytilus galloprovincialis (mussels) and Venerupis aurea var. laeta (clams). Both species originated from two salt lakes in South Italy. GC × GC–MS analysis showed that omega‐3 fatty acids were naturally more concentrated in wild fish, whereas their presence in cultivated fish was lower and in favor of omega‐6 and oleic acids, as an evident consequence of food supplementation. Bivalves reported a consistent amount of PUFA, although presenting some differences in the quality of fatty acids. As an additional parameter of investigation, the content of mercury was determined in all the samples by means of a Direct Mercury Analyzer, based on Atomic Absorption Spectroscopy. Wild fish reported a level of mercury that was ten times higher than in aquafarmed fish, and the maximum amount tolerated by the EC regulation. On the contrary, the level of mercury in molluscs was in general very low, particularly when compared with samples from other Italian sites of collection.Practical applications: One of the possible applications of the GC × GC methodology here presented could be the detection of a common food fraud. In the Mediterranean Sea, gilthead sea bream and sea bass are today rarely found in sea open waters. Basically, fish sold in the market comes from cultivation. Due to the fact that wild fish is more appreciated by the consumer, quite often fish sellers are encouraged to lie about the real origin of fish. The bidimensional plots shown in this study represent an extraordinary tool for differentiating the two types of fish. Also, this study provides substantial support to aquafarmers, who can draw useful advice on how to tune optimal diets to be fed to fish. In fact, it was demonstrated that fish feed highly affects fatty acid composition.The fatty acid composition of aquafarmed and wild caught fish and shellfish from the Mediterranean Sea was investigated. Comprehensive gas chromatography (GC × GC) was the analytical technique that allowed obtaining highly structured fingerprints of fatty acids.
Predictability of kLa in stirred tank reactors under multiple operating conditions using an Euler–Lagrange approach
Authors: Wutz Johannes , Lapin Alexey , Siebler Flora , Schäfer Jan Erik , Wucherpfennig Thomas , Berger Martina , Takors Ralf 
Published: April 2016

In industrial cell culture engineering, the production process consists of a multiscale seed train from lab scale to large scale. The oxygen demand of the cells has to be satisfied in all scales. Computational fluid dynamics (CFD) simulations can provide a tool to predict the mass transfer between the gas phase and the liquid phase. In this work, CFD was applied using an Euler–Lagrange approach for the prediction of the mass transfer coefficient () in stirred tank bioreactors for a wide range of operating conditions. The turbulent dissipation was studied for two different scales that show similar flow behavior. Breakup and coalescence of bubbles was not considered. A standard model was used for the simulation of turbulence and the mass transfer was assumed to be isotropic and turbulence driven. A minimalistic model was found, which was able to successfully predict the mass transfer behavior with high accuracy for the lab‐scale bioreactor (2.3 L) covering a wide range of typical operating conditions. In the given setup, bubbles remained close to the sparger, almost not interfering with the impellers. This supports the assumption of monodisperse bubbles for stirrer speeds between 140 and 260 rpm. Simulation results of an 80 L stirred tank reactor (STR) revealed the need to integrate physical phenomena like breakup and coalescence and a more sophisticated prediction of the initial bubble size distribution. Two‐phase Euler–Lagrange CFD simulations were performed for two differently scaled STRs and the mass transfer coefficient was calculated and compared to experiments in order to evaluate the applied models.
Prunella vulgaris L. hairy roots: Culture, growth, and elicitation by ethephon and salicylic acid
Authors: Ru Mei , An Yuyan , Wang Kunru , Peng Liang , Li Bo , Bai Zhenqin , Wang Bangqing , Liang Zongsuo 
Published: April 2016

Hairy roots have gained popularity as an alternative source for secondary metabolites not only because of their biosynthetic and bioactive potentials, but also because of studies of experimental systems aiming to understand secondary metabolic pathways. While many secondary metabolites have been identified in Prunella vulgaris, a comprehensive understanding of the metabolic pathways has remained elusive. Here, Agrobacterium rhizogenes (ATCC15834)‐mediated hairy root induction of P. vulgaris resulted in 15–30 times more rosmarinic acid (RA) than in the intact plant. After the growth and RA biosynthesis of P. vulgaris, hairy roots were investigated over a 1‐month period, we studied elicitation by ethephon (Eth) and salicylic acid (SA) and found 200 μg L−1 Eth and 6.9 mg L−1 SA exhibited the optimum induction efficiency. These concentrations were further selected for a time‐course assay of hairy root cultures to assess exposure to these compounds over 8 days. During that period, RA reached maximum accumulations of 1.66‐fold 8 days after Eth elicitation and 1.48‐fold 2 days post‐SA addition. We also examined the transcripts of genes involved in the RA biosynthesis pathway, and found the expression of tyrosine aminotransferase (TAT) and phenylalanine ammonia‐lyase (PAL) were increased by Eth, and SA heightened the expression of TAT, 4‐hydroxyphenylpyruvate reductase (HPPR), PAL, 4‐coumaric acid CoA‐ligase 1 (4CL1), and cytochrome P450‐dependent monooxygenase (CYP). Altogether, our results indicate that the convenient hairy root culture system of P. vulgaris can provide an alternate source for RA production and would be conducive for the engineering of secondary metabolic pathways in P. vulgaris.
Downstream process development strategies for effective bioprocesses: Trends, progress, and combinatorial approaches
Authors: Baumann Pascal , Hubbuch Jürgen 
Published: April 2016

AbstractThe biopharmaceutical industry is at a turning point moving toward a more customized and patient‐oriented medicine (precision medicine). Straightforward routines such as the antibody platform process are extended to production processes for a new portfolio of molecules. As a consequence, individual and tailored productions require generic approaches for a fast and dedicated purification process development. In this article, different effective strategies in biopharmaceutical purification process development are reviewed that can analogously be used for the new generation of antibodies. Conventional approaches based on heuristics and high‐throughput process development are discussed and compared to modern technologies such as multivariate calibration and mechanistic modeling tools. Such approaches constitute a good foundation for fast and effective process development for new products and processes, but their full potential becomes obvious in a correlated combination. Thus, different combinatorial approaches are presented, which might become future directions in the biopharmaceutical industry.
Chemical depletion of sediment under the Greenland Ice Sheet
Authors: Graly Joseph A. , Humphrey Neil F. , Harper Joel T. 
Published: April 2016

AbstractThe chemical composition of sediment sampled from a network of ice boreholes contacting the bed of the ablation zone of the Greenland Ice Sheet is compared to the composition of intact bedrock clasts. This sediment is enriched in silica and depleted in reactive cations compared to the underlying bedrock. In order to test whether these differences result from grain size biases either in sample collection or due to natural sorting, sediment samples were analyzed by grain size aliquots. Enrichment of silicon and depletion of cations is consistent across grain size classes and the compositions of bedrock and subglacial sediment are statistically separate. The difference in composition between subglacial sediment and rock aligns closely with the composition of dissolved solutes in waters sampled from the same field sites and is dissimilar to the composition of the sites' suspended sediment. This implies that chemical weathering rather than disproportionate physical removal of friable minerals is responsible for the compositional differences between rock and sediment. Mass balance analysis implies 3–10% of the sediment's mass is lost to solute dissolution, with approximately double that amount precipitated as clay minerals (a large portion of which may have been physically expelled). This result implies that temperate ice sheet subglacial environments may be more chemically active than previously realized. Copyright © 2016 John Wiley & Sons, Ltd.
Simulation of moisture content in alpine rockwalls during freeze–thaw events
Authors: Rode Matthias , Schnepfleitner Harald , Sass Oliver 
Published: April 2016

AbstractRock moisture during freeze–thaw events is a key factor for frost weathering. Data on moisture levels of natural rockwalls are scarce and difficult to obtain. To close this gap, we can benefit from the extensive knowledge of moisture‐related phenomena in building materials, which is incorporated into simulation software, for example the WUFI® package of the Fraunhofer Institute of Building Physics. In this paper we applied and adapted this type of simulation to natural rockwalls to gain new insights on which moisture‐related weathering mechanisms may be important under which conditions.We collected the required input data on physical rock properties and local climate for two study areas in the eastern European Alps with different elevation [Sonnblick, 3106 m above sea level (a.s.l.) and Johnsbach, 700 m a.s.l.] and different lithologies (gneiss and dolomite, respectively). From this data, moisture profiles with depth and fluctuations in the course of a typical year were calculated. The results were cross‐checked with different thermal conditions for frost weathering reported in the literature (volumetric expansion and ice segregation theories). The analyses show that in both study areas the thresholds for frost cracking by volumetric expansion of ice (90% pore saturation, temperature < −1 °C) are hardly ever reached (in one year only 0.07% of the time in Johnsbach and 0.4% at Sonnblick, mostly in north‐exposed walls). The preconditions for weathering by ice segregation (−3 to −8 °C, > 60% saturation) prevail over much longer periods; the time spent within this ‘frost cracking window‘ is also higher for north‐facing sites. The influence of current climate warming will reduce effective frost events towards 2100; however the increase of liquid precipitation and rock moisture will promote weathering processes like ice segregation at least at the Sonnblick site. Copyright © 2016 John Wiley & Sons, Ltd.