bluuebunny/crossref_metadata_2025 huggingface dataset:
Rate‐limiting step analysis of the microbial desulfurization of dibenzothiophene in a model oil system
Authors: Abin‐Fuentes Andres , Leung James C. , Mohamed Magdy El‐Said , Wang Daniel I.C. , Prather Kristala L.J.
Published: November 2013

A mechanistic analysis of the various mass transport and kinetic steps in the microbial desulfurization of dibenzothiophene (DBT) by Rhodococcus erythropolis IGTS8 in a model biphasic (oil–water), small‐scale system was performed. The biocatalyst was distributed into three populations, free cells in the aqueous phase, cell aggregates and oil–adhered cells, and the fraction of cells in each population was measured. The power input per volume (P/V) and the impeller tip speed (vtip) were identified as key operating parameters in determining whether the system is mass transport controlled or kinetically controlled. Oil–water DBT mass transport was found to not be limiting under the conditions tested. Experimental results at both the 100 mL and 4 L (bioreactor) scales suggest that agitation leading to P/V greater than 10,000 W/ m3 and/or vtip greater than 0.67 m/s is sufficient to overcome the major mass transport limitation in the system, which was the diffusion of DBT within the biocatalyst aggregates. Biotechnol. Biotechnol. Bioeng. 2014;111: 876–884. © 2013 Wiley Periodicals, Inc.
Primary hepatocellular carcinoma (“hepatoid” carcinoma) of the pancreas: a case report and review of the literature
Authors: Steen Shawn , Wolin Edward , Geller Stephen A. , Colquhoun Steven
Published: November 2013

Key Clinical Message

We present a case of hepatocellular carcinoma located within the pancreas. These tumors occur in the body and tail of the pancreas, with a male predominance, and at a younger age. Tumors with pure hepatocellular histopathology have better survival and recurrence rates and should be offered surgical therapy if possible.
Enhancement of Promiscuous Amidase Activity of a Bacillus subtilis Esterase by Formation of a π–π Network
Authors: Hackenschmidt Silke , Moldenhauer Eva J. , Behrens Geoffrey A. , Gand Martin , Pavlidis Ioannis V. , Bornscheuer Uwe T.
Published: November 2013

Over the past decade, researchers have tried to decipher the borderline between serine proteases and carboxylic ester hydrolases; although they share the same catalytic triad, the factor that distinguishes their substrate preference still remains unknown. So far, the total inversion of the catalytic character has not yet been fulfilled; only minor improvements of the promiscuous amidase activity have been achieved for the carboxylic ester hydrolases compared to their natural activities, even though different sophisticated approaches of rational design have been applied. In the present study we used a combination of directed evolution and rational design to improve the promiscuous amidase activity of a Bacillus subtilis esterase. A double mutant was identified with 7.5 fold higher relative reaction specificity for the promiscuous amidase reaction with both aromatic and aliphatic substrates, whereas the esterase activity was not significantly affected. The mutation that resulted from the directed evolution experiments was not in the direct vicinity of the active site but affected the substrate binding through a π–π stacking network.
Interplay of α,α‐ versus α,β‐Conjugation in the Excited States and Charged Defects of Branched Oligothiophenes as Models for Dendrimeric Materials
Authors: González‐Cano Rafael C. , Saini Geeta , Jacob Josemon , López Navarrete Juan T. , Casado Juan , Ruiz Delgado M. Carmen
Published: November 2013

This article investigates the excited and charged states of three branched oligothiophenes with methyl–thienyl side groups as models to promote 3D arrangements. A comparison with the properties of the parent systems, linear all‐α,α‐oligothiophenes, is proposed. A wide variety of spectroscopic methods (i.e., absorption, emission, triplet–triplet transient absorption, and spectroelectrochemistry) in combination with DFT calculations have been used for this purpose. Whereas the absorption spectra are slightly blueshifted upon branching, both the emission spectra and triplet–triplet absorption spectra are moderately redshifted; this indicates a larger contribution of the β‐linked thienyl groups in the delocalization of the S1 and T1 states rather than into the S0 state. The delocalization through the α,β‐conjugated path was found to be crucial for the stabilization of the trication species in the larger branched systems, whereas the linear sexithiophene homologue can only be stabilized up to the dication species.
Social Isomers of Picolines in a Small Space
Authors: Ajami Dariush , Theodorakopoulos Giannoula , Petsalakis Ioannis D. , Rebek Julius
Published: November 2013

Encapsulation complexes permit the observation of molecules under conditions of limited motion. Inside capsules, molecular encounters are prolonged, prearranged, and protected from the medium, in contrast to the short‐lived and random encounters that occur in bulk solution. Herein, the interaction of α‐, β‐, and γ‐picolines in a cylindrical capsule is described. Two picolines were taken up, and NMR spectra indicated dynamic combinations of various social isomers. The stabilities of the complexes are interpreted through computational methods. The shape of the space in the capsule allowed the alignment of molecules and revealed delicate, atom‐to‐atom interactions and attractive forces that elude observation in dilute solution. These weak forces were amplified in the isolated small space of the capsule.
In Situ Formation of Semichelating Ligands: A Strategy for Tuning the Magnetic Coupling in Azide‐Bridged Copper(II) Complexes
Authors: Shi Wen‐Bo , Cui Ai‐Li , Kou Hui‐Zhong
Published: November 2013

Five CuII complexes of trinuclear [Cu3(L1)2(N3)6] (1), one‐dimensional chain [Cu5(L2)2(N3)10]n (2), trinuclear [Cu3(L3)2(N3)6] (3) and dinuclear [Cu2(L4)2(N3)2Cl2] (4) and [Cu2(L5)2(N3)2Cl2] (5) (L1–5=RCH2OR′, R=substituted pyrazole or imidazole, R′=Me, Et or nPr) were synthesized by the reaction of CuCl2⋅2 H2O, sodium azide with RCH2Cl in CH3OH, C2H5OH or n‐C3H7OH. The ether ligands L1 and L2 can be alternatively prepared by the alcoholysis of RCH2Cl in the presence of sodium azide, whereas the ligands L3–5 form in corresponding alcohols without azide. For complexes 1–5, the oxygen atom of the ether ligands is located at the Jahn–Teller axis of CuII with the long CuO separations of 2.377(3)–2.830(3) Å. The nitrogen atoms of bridging azides are located in the equatorial or basal planes of CuII ions, favoring strong magnetic coupling. The Cu‐Nazido‐Cu bridging angles in complexes 1–3 are 98.8(2)°–101.6(1)°, leading to ferromagnetic coupling, whereas the Cu‐Nazido‐Cu angles in complexes 4 and 5 are close to 103°, leading to antiferromagnetic coupling.
A Hierarchical Nanoporous PtCu Alloy as an Oxygen‐Reduction Reaction Electrocatalyst with High Activity and Durability
Authors: Xu Caixia , Zhang Huan , Hao Qin , Duan Huimei
Published: November 2013

A hierarchical nanoporous (HNP) PtCu alloy was successfully fabricated by two‐step dealloying of a well‐designed PtCuAl precursor alloy combined with an annealing operation. The as‐made PtCu alloy has an interconnected hierarchical network architecture with controllable bimodal ligament/pore distributions obtained by adjusting the annealing temperature and the redealloying time. HNP‐PtCu exhibits superior specific and mass activities for the oxygen‐reduction reaction (ORR) compared with single‐modal nanoporous PtCu and commercial Pt/C catalysts. More importantly, the HNP‐PtCu alloy shows much higher structure stability with less loss of the electrochemical surface area of Pt and ORR activity upon long‐term potential scans in acid solution. The excellent electrocatalytic performance for ORR makes the HNP‐PtCu alloy attractive as efficient cathode electrocatalysts in fuel‐cell‐related technologies.
A Mesoporous Carbon‐Supported Pt Nanocatalyst for the Conversion of Lignocellulose to Sugar Alcohols
Authors: Park Dae Sung , Yun Danim , Kim Tae Yong , Baek Jayeon , Yun Yang Sik , Yi Jongheop
Published: November 2013

The conversion of lignocellulose is a crucial topic in the renewable and sustainable chemical industry. However, cellulose from lignocellulose is not soluble in polar solvents, and is, therefore, difficult to convert into value‐added chemicals. A strategy to overcome this drawback is the use of mesoporous carbon, which enhances the affinity between the cellulose and the catalyst through its abundant functional groups and large uniform pores. Herein, we report on the preparation of a Pt catalyst supported on a type of 3D mesoporous carbon inspired by Echinometra mathae (Pt/CNE) to enhance the interaction between the catalyst and a nonsoluble reactant. In the hydrolytic hydrogenation of cellulose, the abundant oxygen groups of CNE facilitated the access of cellulose to the surface of the catalyst, and the open pore structure permits cello‐oligomers to effectively diffuse to the active sites inside the pore. The highly dispersed Pt performed dual roles: hydrolysis by in situ generating protons from H2 or water as well as effective hydrogenation. The use of the Pt/CNE catalyst resulted in an approximately 80 % yield of hexitol, the best performance reported to date. In direct conversion of hardwood powder, the Pt/CNE shows good performance in the production of sugar alcohols (23 % yield). We expect that the open‐structured 3D carbon will be widely applied to the conversion of various lignocellulosic materials.
The effects of maternal eating disorders on offspring childhood and early adolescent psychiatric disorders
Authors: Micali Nadia , De Stavola Bianca , Ploubidis George B , Simonoff Emily , Treasure Janet
Published: November 2013

Objective

There is evidence that parental psychiatric disorders are associated with offspring psychiatric disorder. Very few small studies have investigated the effect of maternal eating disorders on offspring psychopathology throughout childhood and early adolescence. We aimed to investigate psychiatric disorders at age 7, 10, and 13 years in offspring of women with eating disorders prior to pregnancy and investigate the relative contribution of other psychiatric disorders.

Method

Women (N = 12,035) from a large population‐based longitudinal cohort: the Avon Longitudinal Study of Parents and Children (ALSPAC). A brief prepregnancy psychiatric history was obtained at enrollment to determine exposure. Offspring psychiatric disorder was measured using the developmental and well‐being assessment at ages 7, 10, and 13.

Results

Maternal eating disorders were associated with a psychiatric diagnosis in the offspring at age 7 and 10, particularly emotional disorders (Odds ratio = 1.9, 95%CI: 1.1–2.8). Maternal psychiatric disorders other than eating disorders predicted psychiatric diagnoses across ages, and acted in an additive fashion with maternal eating disorders.

Discussion

Maternal eating disorders together with comorbid psychopathology increase risk for psychiatric disorders in childhood and early adolescence, in particular for emotional disorders. This has important implications for prevention and future research. © 2013 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:385–393)
Predicting grey‐sided vole occurrence in northern Sweden at multiple spatial scales
Authors: Magnusson Magnus , Bergsten Arvid , Ecke Frauke , Bodin Örjan , Bodin Lennart , Hörnfeldt Birger
Published: November 2013

Forestry is continually changing the habitats for many forest‐dwelling species around the world. The grey‐sided vole (Myodes rufocanus) has declined since the 1970s in forests of northern Sweden. Previous studies suggested that this might partly be caused by reduced focal forest patch size due to clear‐cutting. Proximity and access to old pine forest and that microhabitats often contains stones have also been suggested previously but never been evaluated at multiple spatial scales. In a field study in 2010–2011 in northern Sweden, we investigated whether occurrence of grey‐sided voles would be higher in (1) large focal patches of >60 years old forest, (2) in patches with high connectivity to surrounding patches, and (3) in patches in proximity to stone fields. We trapped animals in forest patches in two study areas (Västerbotten and Norrbotten). At each trap station, we surveyed structural microhabitat characteristics. Landscape‐scale features were investigated using satellite‐based forest data combined with geological maps. Unexpectedly, the vole was almost completely absent in Norrbotten. The trap sites in Norrbotten had a considerably lower amount of stone holes compared with sites with voles in Västerbotten. We suggest this might help to explain the absence in Norrbotten. In Västerbotten, the distance from forest patches with voles to stone fields was significantly shorter than from patches without voles. In addition, connectivity to surrounding patches and size of the focal forest patches was indeed related to the occurrence of grey‐sided voles, with connectivity being the overall best predictor. Our results support previous findings on the importance of large forest patches, but also highlight the importance of connectivity for occurrence of grey‐sided voles. The results further suggest that proximity to stone fields increase habitat quality of the forests for the vole and that the presence of stone fields enhances the voles' ability to move between nearby forest patches through the matrix.
STAT4 is critical for immunity but not for antileishmanial activity of antimonials in experimental visceral leishmaniasis
Authors: Oghumu Steve , Gupta Gaurav , Snider Heidi M. , Varikuti Sanjay , Terrazas César A. , Papenfuss Tracey L. , Kaplan Mark H. , Satoskar Abhay R.
Published: November 2013

We and others have previously shown that IL‐12 is indispensable for immunity and is required for the optimal antiparasitic activity of antimonials in experimental visceral leishmaniasis caused by Leishmania donovani. Here we investigated the role of STAT4 in immunity against L. donovani using STAT4 knockout mice and also determined the effect of STAT4 deficiency in response to antimonial therapy. Upon infection with L. donovani, stat4−/− BALB/c and C57BL/6 mice showed enhanced susceptibility to Leishmania during late time points of infection which was associated with a marked reduction in Th1 responses and hepatic immunopathology. Interestingly, these defects in Th1 responses in stat4−/− did not impair the antimonial chemotherapy as both stat4−/− and WT mice showed comparable levels of parasite clearance from the liver and spleen. These findings highlight the role of STAT4 in immunity to L. donovani infection and also provide evidence that STAT4 is dispensable for antimonial‐based chemotherapy.
Kinetics of malonaldehyde content in enriched chicken meat during isothermal cooking
Authors: Roux Stéphanie , Petit Matthieu , Baeza Elisabeth , Bastianelli Denis , Tillard Emmanuel , Arnaud Elodie
Published: November 2013

Lipid oxidation is a standard parameter in the evaluation of meat quality. It is most often used when the composition of the meat is modified, either by changing the animal's diet or by adding food supplements during post‐slaughter meat processing. Malonaldehyde (MA) is commonly accepted as the main lipid oxidation product in meat. In this study, changes in MA contents in chicken meat enriched with n3‐PUFA during cooking were analysed. Small samples (1.5 g) of ground chicken thighs were placed in plastic bags, wrapped in thin film, and immersed in a water bath at different temperatures (50, 70 and 100°C) for cooking times ranging from 0 to 30 min. MA content was measured by liquid chromatography. MA content first increased rapidly and then decreased. The kinetics were fitted to a model using sequential first‐order reactions including appearance and disappearance rate constants. The temperature influenced the rate constants according to Arrhenius' law, with the highest activation energy for the appearance rate constant. An increase in the vitamin E content of the meat reduced the appearance rate but not the disappearance rate constant.

Practical applications: This study investigates the possibility of modelling the MA content in n3‐PUFA enriched chicken meat during cooking in order to predict the lipid oxidation state of the meat consumers would eat. By understanding the mechanisms of MA appearance and disappearance reactions according to the level of antioxidant present in the meat, this study enables to monitor the lipid oxidation extent. The utility of vitamin E as an antioxidant in n3‐PUFA enriched chicken meat is demonstrated. This study also enlightens the behaviour of the MA, the compound most widely used in literature to characterize the lipid oxidation extent, which is a transition product and must be used with care. In fact, it is clearly shown that a single value of MA content cannot express an oxidation state due to cooking without prior focus on the complete kinetics to determine the appearance and disappearance phases of the MA.
Hydroboration of unsaturated fatty acid methyl esters and conversion of the boron adducts*
Authors: Lucas Theodor , Schäfer Hans J.
Published: November 2013

Unsaturated FAMEs can be modified to higher value compounds by hydroboration of the double bond. The added boron atom can be replaced in a subsequent oxidation by a hydroxy group. This way methyl 10‐undecenoate (1b), methyl oleate (3a), methyl ricinoleate ((9Z,12R)‐6a), and methyl linoleate (9) were converted into methyl 11‐hydroxyundecanoate and methyl hydroxyoctadecanoates in 82–92% yield. Organoboranes isomerize at higher temperatures. Hydroboration of oleic acid and subsequent heating to 220°C led after oxidative work‐up to 70% of 1,4‐octadecanediol. Presumably a 1,4‐oxaborinane intermediate is involved. Alkyl groups of organoboranes can be attached to the carbonyl‐equivalent: dichloromethyl methyl ether (DCME). With this reaction the boranes of the esters 1b and 3a were converted in 55–80% yield to dimers with an inserted ketocarbonyl group. Ester 9 afforded in the same reaction methyl nonadecanoates with an integrated cyclopentene ring.

Practical applications: Hydroboration–oxidation allows the partially regioselective conversion of unsaturated FAMEs into hydroxy‐ and dihydroxyesters. Thermal isomerization of the boranes from methyl oleate, oleic acid, and oleyl alcohol leads after oxidative work‐up to the 1,4‐diol: 1,4‐octadecanediol as main product. These products are useful as components for polyesters, polyurethanes, and precursors for heterocycles. Reaction of organoboranes from unsaturated FAMEs with the carbonyl equivalent: DCME provides a one‐step access to 1,ω‐diesters with an internal keto group, which can be applied for coupling, cross‐linking, and further conversion. The borane · THF complex is commercially available in amounts of 0.8 mol and more to do exploratory research toward such applications.
Influence of drying on the extraction of different processed lignites
Authors: Wollmerstädt Maria , Lohmeier Reinhard , Herdegen Volker , Schröder Hans‐Werner , Repke Jens‐Uwe
Published: November 2013

Industrial extraction of montan wax from lignite requires a specific pre‐treatment of raw material concerning milling and drying aiming on particles with sufficient strength and grain size distribution. The wax or its intermediate is a basic material, for example, in foundry, asphalt, or cosmetic industry. First time, the effects of drying temperature and moisture content of lignite samples on extraction rate, extraction yield, and mechanical properties were investigated. The examination was conducted out in lab‐scale with two different mechanical pre‐treatments. The experimental conditions ranged from 85 to 135°C concerning drying temperature and 1–20% for moisture content. The kinetic analysis of analytical wax extraction was made by adopting an approach from natural material extraction by Bucić‐Kojić et al. . The extraction yield as well as the extraction rate is increasing with increasing moisture content until a constant level is reached whereas temperature of drying air showed unexpectedly no significant influence on both parameters. The mechanical properties of the solids were determined by a pressure stress test. For both investigated solids, mechanical strength increases with lowering moisture content. The solids produced with the novel pre‐treatment showed in general a favorable compression behavior than the normally used particles.

Practical applications: Industrial montan wax extraction process requires hard lignite particles, which do not decay during processing and handling. The strength of lignite is highly influenced by moisture content besides other factors such as the kind of lignite, the surface mine, drying technology, milling, and processing. The strength of lignite particles increases until a maximum in solidity is reached while drying down from deposit moisture of about 50 wt%. Lignite beds with high moisture content or wide grain size distribution offer the risk of their compression. Such compressed beds are not suitable for extraction due to a lowering or even total loss of permeability for the solvent. The selection of an adequate drying procedure and moisture content of the lignite avoids such problems. But a decrease of moisture content to 1% is known to reduce extraction yield considerably, e.g., the maximal extraction yield requires a specific moisture content of lignite particles .
Phase transition‐induced rapid permeabilization of liposome membranes composed of milk‐sphingomyelin
Authors: Yoshimoto Makoto , Todaka Yoshitaka
Published: November 2013

Milk‐sphingomyelin (SPM) liposomes encapsulating 5(6)‐carboxyfluorescein (CF) were prepared and characterized in terms of the temperature‐dependent permeability of the SPM membrane. The liposomes were monodisperse and 109 nm in mean diameter. The SPM membrane was highly permeable to CF when the temperature rapidly increases toward 35°C, exhibiting apparent permeability coefficient of 1.88 × 10−8 cm/s. The size distribution of SPM liposomes was practically unchanged at 35°C. In clear contrast, the membrane was barely permeable at lower and higher temperatures than 30–35°C. The fluorescence polarization measurement, which was performed to evaluate the membrane fluidity, indicated that the rapid membrane permeabilization of SPM liposomes was induced by its phase transition. The temperature‐dependent change in the SPM membrane fluidity was much smaller than that in the membrane composed of 1‐myristoyl‐2‐palmitoyl‐sn‐glycero‐3‐phosphocholine (MPPC) or 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC), which had comparable acyl chain properties to one of the constituents of SPM. Thus, the SPM liposomes possesses unique features that make their membrane highly permeable at the specific temperature range with moderate change in the membrane fluidity.

Practical applications: Kinetically fast permeabilization of SPM liposomes at a near physiological temperature of 35°C is a phenomenon applicable to temperature‐sensitive rapid release of cosmetic compounds from the biocompatible SPM liposomes. Furthermore, the reactions catalyzed by liposome‐encapsulated enzymes, which have been utilized as drugs and biosensors, would be controlled using the SPM liposomes based on the permeability of substrates without causing thermal deactivation of enzymes.
The Redox Chemistry of Mono‐ and Bis(acyl)phosphane Oxides
Authors: Zalibera Michal , Stébé Pierre‐Nicolas , Dietliker Kurt , Grützmacher Hansjörg , Spichty Martin , Gescheidt Georg
Published: November 2013

Mono‐ and bis(acyl)phosphane oxides are usually utilized as photoinitiators for radical polymerizations. This manuscript reveals the electrochemically reversible reductions of these molecules, leading to the corresponding radical anions. The radical anions, which have been characterized by EPR and ENDOR spectroscopy, display remarkable delocalization and ion‐pairing behavior that can be rationalized by theoretical calculations.
A De Novo Stereocontrolled Approach to syn‐ and anti‐Disubstituted Acyclic β2,3‐Amino Acid Enantiomers
Authors: Cherepanova Maria , Kiss Loránd , Forró Enikő , Fülöp Ferenc
Published: November 2013

The stereocontrolled syntheses of functionalized acyclic β2,3‐amino acid derivatives in enantiomerically pure form were performed by starting from enantiopure cis‐ and trans‐2‐aminocyclopent‐3‐enecarboxylates, which were derived from a racemic bicyclic β‐lactam. The synthetic strategy involves the stereoselective dihydroxylaton of the C–C double bond of the cyclopentene β‐amino esters. The subsequent NaIO4‐mediated ring cleavage affords dialdehyde intermediates that undergo functionalization by a Wittig reaction.
Atropisomerization in Confined Space; Cucurbiturils as Tools to Determine the Torsional Barrier of Substituted Biphenyls
Authors: Joseph Roymon , Masson Eric
Published: November 2013

The torsional barrier of biphenyls bearing a prochiral dimethylsulfonium group at their 3‐position could be determined by variable‐temperature 1H NMR spectroscopy only after encapsulation into cucurbit[7]‐ or ‐[8]uril, which triggered the splitting of the two methyl signals. Confinement of the biphenyl units into the macrocycles amplifies the dissymmetry caused by the various ortho‐ and ortho′‐substituents and represents a new tool that can be used to access atropisomerization barriers of bi(hetero)aryl derivatives.
Application of Electrodepositing Graphene Nanosheets for Latent Fingerprint Enhancement
Authors: Zhang Meiqin , Zhu Yu , Yu Xi , Liu Shouliang , Wang Meiling , Wei Qianhui , Hu Xiaoning , Tang Qiao , Zhao Yanjun , Zhang Xueji
Published: November 2013

Fingerprints are still one of the most powerful and important means of biometric identification. This paper presents a green and fast electrochemical method for improved development of latent fingerprints (LFPs) on five kinds of commonly encountered conductive substrates by the use of spatial selective electrodeposition of graphene nanosheets. Since secretions produced in the fingerprint deposit lead the underlying surface to be electrochemically inert or less active, the electrodeposition process only occurs on the areas without fingerprint residue. As a result, a high contrast negative image of the fingerprint was achieved by the electrochemical reduction of graphene oxide (GO) after optimizing the factors (applied potential, deposition time and scan rate).
Orbital pacing of Eocene climate during the Middle Eocene Climate Optimum and the chron C19r event: Missing link found in the tropical western Atlantic
Authors: Westerhold Thomas , Röhl Ursula
Published: November 2013

A high‐resolution stratigraphy is essential toward deciphering climate variability in detail and understanding causality arguments of events in earth history. Because the middle to late Eocene provides a perfect testing ground for carbon cycle models to reconstruct the transition from a hothouse to an icehouse world, an accurate time scale is needed to decode climate‐driving mechanisms. Here we present new results from ODP Site 1260 (Leg 207) which covers a unique expanded middle Eocene section (magnetochrons C18r to C20r, late Lutetian to early Bartonian) of the tropical western Atlantic including the chron C19r transient hyperthermal event and the Middle Eocene Climate Optimum (MECO). To establish a detailed cyclostratigraphy we acquired iron intensity records by XRF scanning Site 1260 cores. We revise the shipboard composite section, establish a cyclostratigraphy and use the exceptional eccentricity modulated precession cycles for orbital tuning. The new astrochronology revises the age of magnetic polarity chrons C19n to C20n, validates the position of very long eccentricity minima at 40.2 and 43.0 Ma in the orbital solutions and extends the Astronomically Tuned Geological Timescale back to 44 Ma. For the first time the new data provide clear evidence for an orbital pacing of the chron C19r event and a likely involvement of the very long (2.4 myr) eccentricity cycle contributing to the evolution of the MECO.
The effect of attenuating noradrenergic neurotransmission by clonidine on brain activity measures of visuospatial attention
Authors: Logemann H. N. Alexander , Böcker Koen B. E. , Deschamps Peter K. H. , Kemner Chantal , Kenemans J. Leon
Published: November 2013

Objective

In the current study, we investigated the role of noradrenaline in directing (bias) and disengagement of visuospatial attention.

Methods

We assessed the effect of clonidine on event‐related brain potential (ERP) reflections of bias and disengagement in a double‐blind placebo‐controlled crossover design. An initial dose of 200‐µg clonidine was replaced by 100 µg because of marked side effects. Twenty‐one healthy male participants performed the visual‐spatial cueing task while an electroencephalogram (EEG) was recorded. The behavioral output is the validity effect (benefit of cueing in terms of reaction time to targets). ERP indices for bias were the cue‐related early directing attention negativity and late directing attention positivity, and the target‐elicited P1 and N1 modulations by validity (‘validity‐effect’). The ERP index for disengagement was the target‐elicited ‘late positive deflection’ modulation by validity. Behavioral analyses were performed on 16 participants, electrophysiological analyses on a subset (n = 9).

Results

Clonidine attenuated the N1 effect, albeit in a subsample. Neither cue‐elicited ERPs nor the behavioral validity effect were affected. Clonidine‐induced blood pressure reduction was correlated with the reduction of the late positive deflection effect under clonidine.

Conclusion

Clonidine attenuated the result of bias in a subsample and may have a modulating effect on disengagement. Copyright © 2013 John Wiley & Sons, Ltd.
A simple auto prescan calibration method for multislice fast spin echo MRI
Authors: Lee Dong‐Hoon , Hong Cheol‐Pyo , Lee Man‐Woo , Han Bong‐Soo
Published: November 2013

The image quality of fast spin echo (FSE) is more sensitive than the typical spin echo pulse sequence caused by the eddy current effect. Microsecond‐scale misalignment of primary spin echoes produces a large spatial variation in image signal intensity. In this study, we describe an auto prescan calibration method that can improve the FSE image quality and minimize the eddy current effect on the image. We used a 0.32 T MRI system and obtained phantom and lumbar images. For FSE image correction, the optimal ranges and steps were determined to find the appropriate values, which were added to or subtracted from the gradient area values for each slice. The appropriate value of each slice could be found using the maximum signal intensity when the refocusing gradient area was changed by a number of steps in the optimal range. The determined value of each slice was applied before each slice image acquisition. The determined optimal step numbers and ranges were applied to in vivo image acquisition, and confirmed the reconstructed image quality. Based on our results, the obtained phantom and lumbar images were shown to be well corrected. The corrected images represented the image quality improvement and elimination of ghosting and blurring artifacts. In conclusion, we have proposed an FSE correction technique that automatically adjusts slice selection for the refocusing gradient balance during prescan, and confirmed that the calibration technique is very reliable even within complex in vivo images. We believe that our proposed technique will greatly benefit in MRI systems. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 289–293, 2013
An efficient method for estimating soft tissue deformation based on intraoperative stereo image features and point‐based registration
Authors: Ahmadian Alireza , Serej Nasim Dadashi , Karimifard Saeed , Farnia Parastoo
Published: November 2013

Estimation of soft tissue deformation occurring during image‐guided surgery using an easily implemented and accurate method is necessary. Using a stereo camera, this study focuses on two efficient methods for estimating soft tissue deformation. Two methods were proposed to overcome limitations associated with the typical methods used for estimating soft tissue deformation, such as dependence on accuracy of the operator and indentation of skin. The first method is based on Triclops SDK, and the second method is based on projecting a pattern to acquire P‐Lands (Projected Landmarks). Based on the proposed methods, surface information is acquired in the form of point clouds of surface point coordinates to the submillimeter accuracy. The reconstructed predeformation three‐dimensional (3D) point cloud obtained for each method is registered with a modified iterative closest point algorithm to a postdeformation 3D point cloud obtained from the same region of interest. Results were compared with an MRI–MRI registration method as a control. Results are provided as RMS differences between the initial and final coordinates of corresponding points. The average RMS difference for the typical method is 3.53 mm, that for the Triclops SDK method is 2.32 mm, and that for the P‐Lands projection method is 2.06 mm. The MRI‐MRI registration had an average RMS difference of 1.12 mm. Using MRI‐MRI registration as the gold standard, the average error obtained for the typical method was 2.41 mm, that for the first method was 1.2 mm, and that for the second method was 0.94 mm. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 294–303, 2013
An improved fast marching method and its application in Alzheimer's disease
Authors: Zhao Xiaojie , Wen Xiaotong , Shen Jiahui , Hong Hao , Yao Li
Published: November 2013

Magnetic resonance diffusion tensor imaging (DTI) provides a noninvasive approach to characterize the fiber pathways in the human brain. Among the fiber tractography algorithms in DTI analysis, the fast marching (FM) method has been widely used in quantitatively analyzing the structural connectivity of the fibers and their changes. However, standard FM only considers the similarity and the principal direction information conveyed by two neighboring voxels. It may have poor tracking performance when image noise and fiber crossing are present. To solve this problem, we introduced an improved FM method employing a memory factor (MFFM) to better characterize the directionality of fiber propagation. Simulation showed that MFFM yields higher tracking accuracy, lower computational load, and better antinoise/crossing performance compared with standard FM. Finally, we applied MFFM to Alzheimer's disease (AD) DTI data to explore the impaired regional connectivity of fiber structure. The results augment the knowledge of the pathological alteration of white matter in AD. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 346–352, 2013
Pd/C‐Mediated Alkynylation of Indazoles: Synthesis and Pharmacological Evaluation of Mono and Dialkynyl‐Substituted Indazoles
Authors: Gorja D. R. , Shiva Kumar K. , Dulla B. , Mukkanti K. , Pal M.
Published: November 2013

The combination of Pd/C–CuI–PPh3 has been identified as an efficient catalytic system for the C–C bond formation between 6‐bromo‐3‐iodo‐1H‐indazole and terminal alkynes in ethanol. Mono and/or dialkynyl‐substituted indazoles can be prepared using this general and practical methodology in good to excellent yields. Some of the compounds synthesized were tested for cytotoxic activities in vitro.
Optimization of rapid acquisition with relaxation enhancement (RARE) pulse sequence parameters for 19F‐MRI studies
Authors: Mastropietro Alfonso , De Bernardi Elisabetta , Breschi Gian Luca , Zucca Ileana , Cametti Massimo , Soffientini Chiara Dolores , de Curtis Marco , Terraneo Giancarlo , Metrangolo Pierangelo , Spreafico Roberto , Resnati Giuseppe , Baselli Giuseppe
Published: November 2013

Purpose

To optimize signal‐to‐noise ratio (SNR) in fast spin echo (rapid acquisition with relaxation enhancement [RARE]) sequences and to improve sensitivity in 19F magnetic resonance imaging (MRI) on a 7T preclinical MRI system, based on a previous experimental evaluation of T1 and T2 actual relaxation times.

Materials and Methods

Relative SNR changes were theoretically calculated at given relaxation times (T1, T2) and mapped in RARE parameter space (TR, number of echoes, flip back pulse), at fixed acquisition times. T1 and T2 of KPF6 phantom samples (solution, agar mixtures, ex vivo perfused brain) were measured and experimental SNR values were compared with simulations, at optimal and suboptimal RARE parameter values.

Results

The optimized setting largely depended on T1, T2 times and the use of flip back pulse improved SNR up to 30% in case of low T1/T2 ratios. Relaxation times in different conditions showed negligible changes in T1 (below 14%) and more evident changes in T2 (−95% from water solution to ex vivo brain). Experimental data confirmed theoretical forecasts, within an error margin always below 4.1% at SNR losses of ∼20% and below 8.8% at SNR losses of ∼40%. The optimized settings permitted a detection threshold at a concentration of 0.5 mM, corresponding to 6.22 × 1016 fluorine atoms per voxel.

Conclusion

Optimal settings according to measured relaxation times can significantly improve the sensitivity threshold in 19F MRI studies. They were provided in a wide range of (T1, T2) values and experimentally validated showing good agreement. J. Magn. Reson. Imaging 2014;40:162–170. © 2013 Wiley Periodicals, Inc.
Supra‐aortic arteries: Three‐dimensional time‐resolved k‐t BLAST contrast‐enhanced MRA using a nondedicated body coil at 3 tesla in acute ischemic stroke
Authors: Ferré Jean‐Christophe , Raoult Hélène , Breil Stéphane , Carsin‐Nicol Béatrice , Ronzière Thomas , Gauvrit Jean‐Yves
Published: November 2013

Purpose

To assess the image quality and diagnostic performance achieved by using supra‐aortic 3D‐TR‐CE‐k‐t BLAST MRA and a nondedicated body coil as compared with conventional CE‐MRA in patients with acute ischemic stroke.

Materials and Methods

In this prospective study, 36 consecutive patients with a suspected acute ischemic stroke underwent both k‐t BLAST MRA and conventional CE‐MRA. Image quality was assessed using visual and quantitative criteria and the techniques were compared. Both techniques were compared for degree of visual and quantitative measurement of carotid stenosis.

Results

Delineation of vessel lumen and overall diagnostic confidence were significantly better with CE‐MRA, respectively 3.4 ± 0.5 and 3.3 ± 0.6 (mean score ± SD), than with k‐t BLAST MRA, respectively 2.8 ± 0.4 and 2.9 ± 0.5 (P < 0.02). SNR and CNR were significantly higher for k‐t BLAST MRA, respectively 33.5 ± 19.3 and 27.9 ± 19.3, than for CE‐MRA, respectively 25.7 ± 10 and 20.4 ± 8.4 (P < 0.03). Intertechnique agreement was good for carotid stenosis characterization (κ = .763). For the 14 relevant stenosis, stenosis measurements were highly correlated between techniques (0.96; P < 0.0001). The Bland‐Altman plot showed a low bias in assessment of the degree of stenosis (mean bias 2.1% ± 7.7).

Conclusion

k‐t BLAST MRA using a nondedicated coil offering and dynamic information was a effective diagnostic tool for detection and characterization of carotid stenosis.J. Magn. Reson. Imaging 2014;40:1056–1063. © 2013 Wiley Periodicals, Inc.
Pulse wave velocity and flow in the carotid artery versus the aortic arch: Effects of aging
Authors: Kröner Eleanore S.J. , Lamb Hildo J. , Siebelink Hans‐Marc J. , Cannegieter Suzanne C. , van den Boogaard Pieter J. , van der Wall Ernst E. , de Roos Albert , Westenberg Jos J.M.
Published: November 2013

Purpose

To explore differences in arterial stiffness of the aorta and carotid artery, assessed by pulse wave velocity (PWV), to evaluate the blood flow volume distribution towards the carotid circulation and to assess the effect of aging on the coupling between aortic and carotid PWV using velocity‐encoded magnetic resonance imaging (MRI).

Materials and Methods

Sixteen adult younger volunteers (age <30 years) and 16 older volunteers (age >45 years) underwent 3T MRI examination to assess aortic and carotid flow volumes and PWV using the transit time method.

Results

Aortic versus carotid PWV‐ratio was 1.2 for younger volunteers and 0.95 for older volunteers, demonstrating leveling of wall stiffness. Furthermore, flow volume per minute in the internal carotid artery was lower for older versus younger volunteers (mean volume 177 ± 42 mL/min/m2 vs. 147 ± 32 mL/min/m2, P = 0.028), whereas aorta and common carotid artery flow volumes were not different. Consequently, the fraction of blood flow volume towards the brain was smaller for older versus younger volunteers (61 ± 9% versus 71 ± 8%, P = 0.002).

Conclusion

PWV‐leveling between aorta and carotid artery at older age is associated with a reduction in blood flow volume towards the brain. Velocity‐encoded MRI can be used to evaluate PWV and flow volume distribution in the aortic arch and the carotid circulation. J. Magn. Reson. Imaging 2014;40:287–293. © 2013 Wiley Periodicals, Inc.
Gannet: A batch‐processing tool for the quantitative analysis of gamma‐aminobutyric acid–edited MR spectroscopy spectra
Authors: Edden Richard A.E. , Puts Nicolaas A.J. , Harris Ashley D. , Barker Peter B. , Evans C. John
Published: November 2013

Purpose

The purpose of this study is to describe the Gannet toolkit for the quantitative batch analysis of gamma‐aminobutyric acid (GABA) ‐edited MRS data.

Materials and Methods

Using MEGA‐PRESS editing and standard acquisition parameters, four MEGA‐PRESS spectra were acquired in three brain regions in 10 healthy volunteers. These 120 datasets were processed without user intervention with Gannet, a Matlab‐based tool that takes raw time‐domain data input, processes it to generate the frequency‐domain edited spectrum, and applies a simple modeling procedure to estimate GABA concentration relative to the creatine or, if provided, the unsuppressed water signal. A comparison of four modeling approaches is also presented.

Results

All data were successfully processed by Gannet. Coefficients of variation across subjects ranged from 11% for the occipital region to 17% for the dorsolateral prefrontal region. There was no clear difference in fitting performance between the simple Gaussian model used by Gannet and the other more complex models presented.

Conclusion

Gannet, the GABA Analysis Toolkit, can be used to process and quantify GABA‐edited MRS spectra without user intervention. J. Magn. Reson. Imaging 2014;40:1445–1452. © 2013 Wiley Periodicals, Inc.
Variable spatiotemporal resolution three‐dimensional dixon sequence for rapid dynamic contrast‐enhanced breast MRI
Authors: Saranathan Manojkumar , Rettmann Dan W. , Hargreaves Brian A. , Lipson Jafi A. , Daniel Bruce L.
Published: November 2013

Purpose

To investigate a new variable spatiotemporal resolution dynamic contrast‐enhanced (DCE) MRI method termed DIfferential Subsampling with Cartesian Ordering (DISCO), for imaging of breast cancer.

Materials and Methods

DISCO combines variable density, pseudorandom k‐space segmentation and two‐point Dixon fat–water separation for high spatiotemporal resolution breast DCE MRI. During the contrast wash‐in phase, view sharing is used to achieve high temporal resolution. Forty patients referred for breast MRI were imaged, 26 using the proposed DISCO sequence and 14 using a conventional low‐spatial‐resolution dynamic sequence (VIBRANT‐FLEX) on a 3 Tesla scanner. DISCO dynamic images from 14 patients were compared with VIBRANT‐FLEX images from 14 other patients. The image quality assessed by radiologist image ranking in a blinded manner, and the temporal characteristics of the two sequences were compared.

Results

A spatial resolution of 1.1 × 1.1 × 1.2 mm3 (160 slices, 28 cm field of view) was achieved with axial bilateral coverage in 120 s. Dynamic images with ∼9 s effective temporal resolution were generated during the 2‐min contrast wash‐in phase. The image quality of DISCO dynamic images ranked significantly higher than low spatial resolution VIBRANT‐FLEX images (19.5 versus 9.5, Mann‐Whitney U‐test P = 0.00914), with no significant differences in the maximum slope of aortic enhancement.

Conclusion

DISCO is a promising variable‐spatiotemporal‐resolution imaging sequence for capturing the dynamics of rapidly enhancing tumors as well as structural features postcontrast. A near 1‐mm isotropic spatial resolution was achieved with postcontrast static phase images in 120 s and dynamic phase images acquired in 9 s per phase. J. Magn. Reson. Imaging 2014;40:1392–1399. © 2013 Wiley Periodicals, Inc.
Boundaries for algebras of analytic functions on function module Banach spaces
Authors: Acosta M. D. , Galindo P. , Lourenço M. L.
Published: November 2013

We consider the uniform algebra of continuous and bounded functions that are analytic on the interior of the closed unit ball of a complex Banach function module X. We focus on norming subsets of , i.e., boundaries, for such algebra. In particular, if X is a dual complex Banach space whose centralizer is infinite‐dimensional, then the intersection of all closed boundaries is empty. This also holds in case that X is an ‐sum of infinitely many Banach spaces and further, the torus is a boundary.
Molecular cross‐talk between members of distinct families of selenium containing proteins
Authors: Ansong Emmanuel , Yang Wancai , Diamond Alan M.
Published: November 2013

Dietary intake of selenium has been associated with reduced risk of several cancer types, and this is likely due to its role as a specific constituent of selenium containing proteins. One of these, selenium‐binding protein 1 (SBP1), is a protein of unknown function that has been shown to be reduced in tumors of diverse tissue types as compared to the corresponding normal tissue. More importantly, SBP1 has also been reported to be a predictor of clinical outcome. Levels of SBP1 are inversely associated with the levels of another protein representative of a different class of selenoproteins, glutathione peroxidase1 (GPx‐1). GPx‐1 is an anti‐oxidant, selenocysteine containing enzyme implicated in several diseases, including cancer, due to the association of specific alleles with disease risk. The relationship between SBP1 and GPx‐1 represents a unique example of a molecular interaction between selenium containing proteins with a likely significant impact on human health and disease.
Walking on Eggshells: A Study of Egg Use in Anglo‐Scandinavian York Based on Eggshell Identification Using ZooMS
Authors: Stewart John R. M. , Allen Richard B. , Jones Andrew K. G. , Kendall T. , Penkman K. E. H. , Demarchi B. , O'Connor T. , Collins M. J.
Published: November 2013

Eggshell is a potentially common archaeological resource, but it tends to be ignored. The recent development of ZooMS (zooarchaeology by mass spectrometry) as a rapid and robust system for taxonomic identification of preserved eggshell fragments has facilitated new insights into patterns of egg use in the past. This paper presents a case study of egg use at two sites in Anglo‐Scandinavian York (Hungate and Coppergate). The results described below suggest that the relative prevalence of goose eggshell may become a useful indicator of status, consistent with other characteristics of the two sites, and also demonstrate an apparent lack of exploitation of eggs of wild birds in York during the Anglo‐Scandinavian period. These results highlight the interpretative potential of eggshell, which can now begin to be more fully explored. Copyright © 2013 John Wiley & Sons, Ltd.