bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhodium(III)‐Catalyzed Alkenylation–Annulation of closo‐Dodecaborate Anions through Double B−H Activation at Room Temperature
Authors: Zhang Yuanbin , Sun Yuji , Lin Furong , Liu Jiyong , Duttwyler Simon
Published: November 2016

1,2,3‐Trisubstituted closo‐dodecaborates with B−O, B−N, and B−C bonds as well as a fused borane oxazole ring have been synthesized by rhodium‐catalyzed direct cage B−H alkenylation and annulation of ureido boranes in the first reported example of regioselective B−H bond functionalization of the [B12H12]2− cage by transition‐metal catalysis. This reaction proceeded at room temperature under ambient conditions and exhibited excellent selectivity for efficient monoalkenylation with good functional‐group tolerance. The urea moiety enabled B−H activation by acting as a directing group, was incorporated in the oxazole ring in situ, and also avoided multiple alkenylation. A possible mechanism is proposed on the basis of the isolation of a rhodium agostic intermediate and control experiments.
Practical Photocatalytic Trifluoromethylation and Hydrotrifluoromethylation of Styrenes in Batch and Flow
Authors: Straathof Natan J. W. , Cramer Sten E. , Hessel Volker , Noël Timothy
Published: November 2016

Styrenes represent a challenging class of substrates for current radical trifluoromethylation and hydrotrifluoromethylation methods due to a myriad of potential side reactions. Herein, we describe the development of mild, selective and broadly applicable photocatalytic trifluoromethylation and hydrotrifluoromethylation protocols for these challenging substrates. The methods use fac‐Ir(ppy)3, visible light and inexpensive CF3I and can be applied to a diverse set of vinylarene substrates. The use of continuous‐flow photochemical reaction conditions allowed to reduce the reaction time and increase the reaction selectivity.
Symmetry‐Breaking Charge Transfer and Hydrogen Bonding: Toward Asymmetrical Photochemistry
Authors: Dereka Bogdan , Rosspeintner Arnulf , Krzeszewski Maciej , Gryko Daniel T. , Vauthey Eric
Published: November 2016

Symmetry‐breaking charge transfer upon photoexcitation of a linear A‐π‐D‐π‐A molecule (D and A being electron donating and accepting groups) could be visualized using ultrafast time‐resolved infrared spectroscopy by monitoring the CN stretching modes on the A units. Whereas in apolar solvents, the S1 state remains symmetric and quadrupolar, symmetry breaking occurs within ca. 100 fs in polar solvents as shown by the presence of two CN bands, instead of one in apolar solvents, with a splitting that increases with polarity. In protic solvents, symmetry breaking is significantly amplified by H‐bonding interactions, which are the strongest at the CN group with the highest basicity. In strongly protic solvents, the two CN bands transform in about 20 ps into new bands with a larger splitting, and the lifetime of the S1 state is substantially reduced. This is attributed to the formation of an excited asymmetric tight H‐bond complex.
Macroscopic Hexagonal Tubes of 3 d–4 f Metallocycles
Authors: Wu Jianfeng , Zhao Lang , Zhang Li , Li Xiao‐Lei , Guo Mei , Powell Annie K. , Tang Jinkui
Published: November 2016

The self‐assembly of three giant hexagonal 3d–4f metallocycles with inner diameters of 16.4, 16.5, and 16.4 Å, is described. Hexagonal metallocycles were stacked along the crystallographic c axis, producing unique hexagonal macroscopic tubular single crystals. The assembly mechanism of the tubular crystals was investigated. Remarkably, all three hexagonal metallocycles show typical single‐molecule magnet behavior, benefiting from the ferromagnetic couplings between the 3d and 4f ions.
Short Enantioselective Total Synthesis of Tatanan A and 3‐epi‐Tatanan A Using Assembly‐Line Synthesis
Authors: Noble Adam , Roesner Stefan , Aggarwal Varinder K.
Published: November 2016

Short and highly stereoselective total syntheses of the sesquilignan natural product tatanan A and its C3 epimer are described. An assembly‐line synthesis approach, using iterative lithiation–borylation reactions, was applied to install the three contiguous stereocenters with high enantio‐ and diastereoselectivity. One of the stereocenters was installed using a configurationally labile lithiated primary benzyl benzoate, resulting in high levels of substrate‐controlled (undesired) diastereoselectivity. However, reversal of selectivity was achieved by using a novel diastereoselective Matteson homologation. Stereospecific alkynylation of a hindered secondary benzylic boronic ester enabled completion of the synthesis in a total of eight steps.
Explaining the Size Dependence in Platinum‐Nanoparticle‐Catalyzed Hydrogenation Reactions
Authors: Bai Licheng , Wang Xin , Chen Qiang , Ye Yifan , Zheng Haoquan , Guo Jinghua , Yin Yadong , Gao Chuanbo
Published: November 2016

Hydrogenation reactions are industrially important reactions that typically require unfavorably high H2 pressure and temperature for many functional groups. Herein we reveal surprisingly strong size‐dependent activity of Pt nanoparticles (PtNPs) in catalyzing this reaction. Based on unambiguous spectral analyses, the size effect has been rationalized by the size‐dependent d‐band electron structure of the PtNPs. This understanding enables production of a catalyst with size of 1.2 nm, which shows a sixfold increase in turnover frequency and 28‐fold increase in mass activity in the regioselective hydrogenation of quinoline, compared with PtNPs of 5.3 nm, allowing the reaction to proceed under ambient conditions with unprecedentedly high reaction rates. The size effect and the synthesis strategy developed herein may provide a general methodology in the design of metal‐nanoparticle‐based catalysts for a broad range of organic syntheses.
Aluminum Hydride Catalyzed Hydroboration of Alkynes
Authors: Bismuto Alessandro , Thomas Stephen P. , Cowley Michael J.
Published: November 2016

An aluminum‐catalyzed hydroboration of alkynes using either the commercially available aluminum hydride DIBAL‐H or bench‐stable Et3Al⋅DABCO as the catalyst and H‐Bpin as both the boron reagent and stoichiometric hydride source has been developed. Mechanistic studies revealed a unique mode of reactivity in which the reaction is proposed to proceed through hydroalumination and σ‐bond metathesis between the resultant alkenyl aluminum species and HBpin, which acts to drive turnover of the catalytic cycle.
Experimental and Computational Studies of the Copper Borate Complexes [(NHC)Cu(HBEt3)] and [(NHC)Cu(HB(C6F5)3)]
Authors: Collins Lee R. , Rajabi Nasir A. , Macgregor Stuart A. , Mahon Mary F. , Whittlesey Michael K.
Published: November 2016

The synthesis of the Cu‐borate complexes [(6Mes)Cu(HBR3)] featuring the unusual [HBEt3]− (5) and [HB(C6F5)3]− (6) ligands is described. Experimental and computational studies show both compounds feature a direct Cu–H interaction, but that while 5 is two‐coordinate, 6 displays an additional, stabilizing Cu–Cipso(C6F5) interaction.
Hollow Nanotubes of N‐Doped Carbon on CoS
Authors: Chen Yuming , Li Xiaoyan , Park Kyusung , Zhou Limin , Huang Haitao , Mai Yiu‐Wing , Goodenough John B.
Published: November 2016

Low‐cost, single‐step synthesis of hollow nanotubes of N‐doped carbon deposited on CoS is enabled by the simultaneous use of three functionalities of polyacrylonitrite (PAN) nanofibers: 1) a substrate for loading active materials, 2) a sacrificial template for creating hollow tubular structures, and 3) a precursor for in situ nitrogen doping. The N‐doped carbon in hollow tubes of CoS provides a high‐capacity anode of long cycle life for a rechargeable Li‐ion or Na‐ion battery cell that undergoes the conversion reaction 2 A++2 e−+CoS →Co+A2S with A=Li or Na.
A Hyperpolarizable 1H Magnetic Resonance Probe for Signal Detection 15 Minutes after Spin Polarization Storage
Authors: Roy Soumya S. , Norcott Philip , Rayner Peter J. , Green Gary G. R. , Duckett Simon B.
Published: November 2016

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are two extremely important techniques with applications ranging from molecular structure determination to human imaging. However, in many cases the applicability of NMR and MRI are limited by inherently poor sensitivity and insufficient nuclear spin lifetime. Here we demonstrate a cost‐efficient and fast technique that tackles both issues simultaneously. We use the signal amplification by reversible exchange (SABRE) technique to hyperpolarize the target 1H nuclei and store this polarization in long‐lived singlet (LLS) form after suitable radiofrequency (rf) pulses. Compared to the normal scenario, we achieve three orders of signal enhancement and one order of lifetime extension, leading to 1H NMR signal detection 15 minutes after the creation of the detected states. The creation of such hyperpolarized long‐lived polarization reflects an important step forward in the pipeline to see such agents used as clinical probes of disease.
Rhodium‐Catalyzed Diastereoselective Cyclization of Allenyl‐Sulfonylcarbamates: A Stereodivergent Approach to 1,3‐Aminoalcohol Derivatives
Authors: Spreider Pierre A. , Haydl Alexander M. , Heinrich Marc , Breit Bernhard
Published: November 2016

A diastereoselective and stereodivergent rhodium‐catalyzed intramolecular coupling of sulfonylcarbamates with terminal allenes is described and it provides selective access to 1,3‐aminoalcohol derivatives, scaffolds found in bioactive compounds. The reaction is compatible with a large range of different functional groups, thus furnishing products with high diastereoselectivities and yields. Moreover, multigram scale reactions, as well as the application of suitable product transformations were demonstrated.
Organocatalytic Enantioselective Vinylogous Pinacol Rearrangement Enabled by Chiral Ion Pairing
Authors: Wu Hua , Wang Qian , Zhu Jieping
Published: November 2016

An enantioselective pinacol rearrangement of functionalized (E)‐2‐butene‐1,4‐diols was developed. In the presence of a catalytic amount of a chiral BINOL‐derived N‐triflyl phosphoramide, these 1,4‐diols rearranged to β,γ‐unsaturated ketones in excellent yields and enantioselectivities. The formation of a chiral ion pair between the intermediary allylic cation and the chiral phosphoramide anion was postulated to be responsible for the highly efficient chirality transfer. These chiral building blocks were further converted into enantioenriched polysubstituted tetrahydrofuran and tetrahydronaphthalene derivatives.
Wall slip velocity measurement of molten polypropylene in capillary flow based on length‐corrected Mooney technique
Authors: Ren Zhong , Huang Xingyuan , Liu Hesheng
Published: November 2016

In this study, to measure wall slip velocity of molten polypropylene (PP) by using different length‐to‐diameter (L/D) ratios of capillary dies with fixed diameter, a length‐corrected Mooney technique was proposed. Moreover, the effects of pressure, temperature, and L/D ratio were considered to better represent wall slip mechanism. To verify the feasibility of the length‐corrected Mooney technique, a series of capillary rheological experiments for molten PP were carried out. Meanwhile, the power‐law quantitative equations of slip velocity were established by shear stress. Moreover, the effects of L/D ratio and temperature on rheological properties of PP were investigated. In addition, numerical simulations for slip velocity and rheological properties of PP were performed. Numerical results validated that the length‐corrected Mooney technique, and the power‐law quantitative equations of slip velocity were available. Results showed that wall slip velocity of molten PP decreased with the capillary die's L/D ratio, but increased with the temperature and shear rate. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44589.
Development of release methods for captive‐bred freshwater pearl mussels (Margaritifera margaritifera
Authors: Kyle Rebecca , Reid Neil , O'Connor Nessa , Roberts Dai
Published: November 2016

Biodiversity loss is a global problem with freshwater bivalves considered among the most endangered biota. The freshwater pearl mussel, Margaritifera margaritifera, is declining throughout its range owing to habitat degradation and overexploitation. In most of its range, populations are regarded as reproductively non‐functional, which has led to the development of captive breeding programmes.

A novel method of releasing M. margaritifera was tested, with captive‐bred juveniles being released into the rivers caged in ‘mussel silos’ (protective concrete domes with ventilation creating upwelling to ensure water through‐flow).

In total, 240 juvenile mussels were released and survival and growth rates were monitored for 18 months after release for three size classes: A (13.01–20.00 mm); B (10.01–13.00 mm); and C (4.01–10.00 mm).

Two experimental treatments were tested: one in which sediment was added to each silo (allowing mussels to orientate and burrow) and one without sediment. Survival by the end of the experiment at month 18 was significantly higher for the largest size class at 97% (although growth was lowest in this cohort), and lowest for the smallest size class, at 61% (although growth was highest in this cohort). Survival and growth were unaffected by the experimental treatment suggesting that adding sediment offered no advantage. Growth was positively correlated both with water temperature and with particle size of suspended solids (both of which were collinear, peaking in summer).

There are many ex situ breeding programmes for freshwater pearl mussels throughout Europe and the results of this study suggest that the use of mussel silos may be a useful tool to protect juvenile mussels, allowing them to be released at a relatively early stage of development and minimizing the risk of domestication.

Copyright © 2016 John Wiley & Sons, Ltd.
Betwixt and Between: Intracranial Perspective on Zygomatic Arch Plasticity and Function in Mammals
Authors: Franks Erin M. , Holton Nathan E. , Scott Jeremiah E. , McAbee Kevin R. , Rink Jason T. , Pax Kazune C. , Pasquinelly Adam C. , Scollan Joseph P. , Eastman Meghan M. , Ravosa Matthew J.
Published: November 2016

The zygomatic arch is morphologically complex, providing a key interface between the viscerocranium and neurocranium. It also serves as an attachment site for masticatory muscles, thereby linking it to the feeding apparatus. Though morphological variation related to differential loading is well known for many craniomandibular elements, the adaptive osteogenic response of the zygomatic arch remains to be investigated. Here, experimental data are presented that address the naturalistic influence of masticatory loading on the postweaning development of the zygoma and other cranial elements. Given the similarity of bone‐strain levels among the zygoma and maxillomandibular elements, a rabbit and pig model were used to test the hypothesis that variation in cortical bone formation and biomineralization along the zygomatic arch and masticatory structures are linked to increased stresses. It was also hypothesized that neurocranial structures would be minimally affected by varying loads. Rabbits and pigs were raised for 48 weeks and 8 weeks, respectively. In both experimental models, CT analyses indicated that elevated masticatory loading did not induce differences in cortical bone thickness of the zygomatic arch, though biomineralization was positively affected. Hypotheses were supported regarding bone formation for maxillomandibular and neurocranial elements. Varying osteogenic responses in the arch suggests that skeletal adaptation, and corresponding variation in performance, may reside differentially at one level of bony architecture. Thus, it is possible that phenotypic diversity in the mammalian zygoma is due more singularly to natural selection (vs. plasticity). These findings underscore the complexity of the zygomatic arch and, more generally, determinants of skull form. Anat Rec, 299:1646–1660, 2016. © 2016 Wiley Periodicals, Inc.
Synthesis and Carbonic Anhydrase Inhibition of Novel 2‐(4‐(Aryl)thiazole‐2‐yl)‐3a,4,7,7a‐tetrahydro‐1H‐4,7‐methanoisoindole‐1,3(2H)‐dione Derivatives
Authors: Kocyigit Umit M. , Aslan Osman Nuri , Gulcin Ilhami , Temel Yusuf , Ceylan Mustafa
Published: November 2016

Carbonic anhydrase (CA, EC 4.2.1.1) is a member of the metalloenzyme family. It catalyzes the rapid conversion of carbon dioxide (CO2) and water to bicarbonate (HCO3−) and protons (H+) and also plays an important role in biochemical and physiological processes. In this study, a number of novel 2‐(4‐(aryl)thiazole‐2‐yl)‐3a,4,7,7a‐tetrahydro‐1H‐4,7‐methanoisoindole‐1,3(2H)‐dione derivatives were synthesized and evaluated for their inhibitory characteristics against the human CA isoenzymes I and II (hCA I and hCA II). The structures of the new molecules 8a–i were confirmed by means of IR, 1H NMR, 13C NMR, and elemental analysis. These compounds exhibited excellent inhibitory effects, in the low nanomolar range, with Ki values in the range of 27.07–37.80 nM against hCA I and in the range of 11.80–25.81 nM against hCA II. Our findings suggest that the new isoindolylthiazole derivatives have superior inhibitory effect over acetazolamide (AZA), which is used as clinical CA inhibitor with Ki values of 34.50 and 28.93 nM against the hCA I and hCA II isoenzymes, respectively.
A GIS‐based method to identify cost‐effective routes for rural deviated fixed route transit
Authors: Yang Hongtai , Cherry Christopher R. , Zaretzki Russell , Ryerson Megan S. , Liu Xiaobo , Fu Zhijian
Published: November 2016

Deviated fixed route transit (DFRT) service connecting rural and urban areas is a growing transportation mode in the USA. Little research has been done to develop frameworks for route design. A methodology to explore the most cost‐effective DFRT route is presented in this paper. The inputs include potential DFRT demand distribution and a road network. A heuristic is used to build possible routes by starting at urban cores and extending in all network directions in certain length increments. All the DFRT routes falling in the length range desired by the users are selected. The cost effectiveness of those routes, defined by operating cost per passenger trip, is compared. The most cost‐effective route is selected and presented in a GIS map. A case study illustrates the methodology in several Tennessee metropolitan regions. The most cost‐effective route length is case specific; some routes (e.g. those out of our Nashville case) are most cost effective when short, while others (e.g. those out of Memphis) are most cost effective when long. Government agencies could use the method to identify routes with the lowest operating cost per passenger given a route length or an operating cost budget. Copyright © 2016 John Wiley & Sons, Ltd.
Metabolite profiling of whole murine embryos reveals metabolic perturbations associated with maternal valproate‐induced neural tube closure defects
Authors: Akimova Darya , Wlodarczyk Bogdan J. , Lin Ying , Ross M. Elizabeth , Finnell Richard H. , Chen Qiuying , Gross Steven S.
Published: November 2016

Background

Valproic acid (VPA) is prescribed therapeutically for multiple conditions, including epilepsy. When taken during pregnancy, VPA is teratogenic, increasing the risk of several birth and developmental defects including neural tube defects (NTDs). The mechanism by which VPA causes NTDs remains controversial and how VPA interacts with folic acid (FA), a vitamin commonly recommended for the prevention of NTDs, remains uncertain. We sought to address both questions by applying untargeted metabolite profiling analysis to neural tube closure (NTC) stage mouse embryos.

Methods

Pregnant SWV dams on either a 2 ppm or 10 ppm FA supplemented diet were injected with a single dose of VPA on gestational day E8.5. On day E9.5, the mouse embryos were collected and evaluated for NTC status. Liquid chromatography coupled to mass spectrometry metabolomics analysis was performed to compare metabolite profiles of NTD‐affected VPA‐exposed whole mouse embryos with profiles from embryos that underwent normal NTC from control dams.

Results

NTDs were observed in all embryos from VPA‐treated dams and penetrance was not diminished by dietary FA supplementation. The most profound metabolic perturbations were found in the 10ppm FA VPA‐exposed mouse embryos, compared with the other three treatment groups. Affected metabolites included amino acids, nucleobases and related phosphorylated nucleotides, lipids, and carnitines.

Conclusion

Maternal VPA treatment markedly perturbed purine and pyrimidine metabolism in E9.5 embryos. In combination with a high FA diet, VPA treatment resulted in gross metabolic changes, likely caused by a multiplicity of mechanisms, including an apparent disruption of mitochondrial beta‐oxidation. Birth Defects Research 109:106–119, 2017. © 2016 Wiley Periodicals, Inc.
What drives parallel evolution?
Authors: Bailey Susan F. , Blanquart François , Bataillon Thomas , Kassen Rees
Published: November 2016

Parallel evolution is the repeated evolution of the same phenotype or genotype in evolutionarily independent populations. Here, we use evolve‐and‐resequence experiments with bacteria and yeast to dissect the drivers of parallel evolution at the gene level. A meta‐analysis shows that parallel evolution is often rare, but there is a positive relationship between population size and the probability of parallelism. We present a modeling approach to estimate the contributions of mutational and selective heterogeneity across a genome to parallel evolution. We show that, for two experiments, mutation contributes between ∼10 and 45%, respectively, of the variation associated with selection. Parallel evolution cannot, therefore, be interpreted as a phenomenon driven by selection alone; it must also incorporate information on heterogeneity in mutation rates along the genome. More broadly, the work discussed here helps lay the groundwork for a more sophisticated, empirically grounded theory of parallel evolution.
Core–shell structured CdTe/CdS@SiO2@CdTe@SiO2 composite fluorescent spheres: Synthesis and application for Cd2+ detection
Authors: Liu Fang , Li Shujia , Hu Ruoxin , Shao Na
Published: November 2016

Core–shell structured quantum dot (QD)–silica fluorescent nanoparticles have attracted a great deal of attention due to the excellent optical properties of QDs and the stability of silica. In this study, core–shell structured CdTe/CdS@SiO2@CdTe@SiO2 fluorescent nanospheres were synthesized based on the Stöber method using multistep silica encapsulation. The second silica layer on the CdTe QDs maintained the optical stability of nanospheres and decreased adverse influences on the probe during subsequent processing. Red‐emissive CdTe/CdS QDs (630 nm) were used as a built‐in reference signal and green‐emissive CdTe QDs (550 nm) were used as a responding probe. The fluorescence of CdTe QDs was greatly quenched by added S2−, owing to a S2−‐induced change in the CdTe QDs surface state in the shell. Upon addition of Cd2+ to the S2−‐quenched CdTe/CdS@SiO2@CdTe@SiO2 system, the responding signal at 550 nm was dramatically restored, whereas the emission at 630 nm remained almost unchanged; this response could be used as a ratiometric ‘off–on’ fluorescent probe for the detection of Cd2+. The sensing mechanism was suggested to be: the newly formed CdS‐like cluster with a higher band gap facilitated exciton/hole recombination and effectively enhanced the fluorescence of the CdTe QDs. The proposed probe shows a highly sensitive and selective response to Cd2+ and has potential application in the detection of Cd2+ in environmental or biological samples.
Online measurement of viscosity for biological systems in stirred tank bioreactors
Authors: Schelden Maximilian , Lima William , Doerr Eric Will , Wunderlich Martin , Rehmann Lars , Büchs Jochen , Regestein Lars
Published: November 2016

One of the most critical parameters in chemical and biochemical processes is the viscosity of the medium. Its impact on mixing, as well as on mass and energy transfer is substantial. An increase of viscosity with reaction time can be caused by the formation of biopolymers like xanthan or by filamentous growth of microorganisms. In either case the properties of fermentation broth are changing and frequently non‐Newtonian behavior are observed, resulting in major challenges for the measurement and control of mixing and mass transfer. This study demonstrates a method for the online determination of the viscosity inside a stirred tank reactor. The presented method is based on online measurement of heat transfer capacity from the bulk medium to the jacket of the reactor. To prove the feasibility of the method, fermentations with the xanthan producing bacterium Xanthomonas campestris pv. campestris B100 as model system were performed. Excellent correlation between offline measured apparent viscosity and online determined heat transfer capacity were found. The developed tool should be applicable to any other process with formation of biopolymers and filamentous growth. Biotechnol. Bioeng. 2017;114: 990–997. © 2016 Wiley Periodicals, Inc.
Six‐membered cyclic carbonates from trimethylolpropane: Lipase‐mediated synthesis in a flow reactor and in silico evaluation of the reaction
Authors: Bornadel Amin , Ismail Mohamed , Sayed Mahmoud , Hatti‐Kaul Rajni , Pyo Sang‐Hyun
Published: November 2016

Six‐membered cyclic carbonates with hydroxyl and methoxycarbonyloxy functional groups were prepared by transesterification of trimethylolpropane (TMP) with dimethylcarbonate (DMC) by solvent‐free lipase‐mediated flow reaction followed by thermal cyclization. The flow reaction efficiency was evaluated using different configurations of reactor consisting of packed beds of Novozym®435 (immobilized Candida antarctica lipase B—CalB—a.k.a. N435) and molecular sieves, flowrate, and biocatalyst loads. The mixed column of the biocatalyst and molecular sieves, allowing rapid and efficient removal of the by‐product—methanol—was the most efficient setup. Higher conversion (81.6%) in the flow reaction compared to batch process (72%) was obtained using same amount of N435 (20% (w/w) N435:TMP) at 12 h, and the undesirable dimer and oligomer formation were suppressed. Moreover, the product was recovered easily without extra separation steps, and the biocatalyst and the molecular sieves remained intact for subsequent regeneration and recycling. The reaction of CalB with DMC and the primary transesterification product, monocarbonated TMP, respectively, as acyl donors was evaluated by in silico modeling and empirically to determine the role of the enzyme in the formation of cyclic carbonates and other side products. DMC was shown to be the preferred acyl donor, suggesting that TMP and its carbonated derivatives serve only as acyl acceptors in the lipase‐catalyzed reaction. Subsequent cyclization to cyclic carbonate is catalyzed at increased temperature and not by the enzyme. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:375–382, 2017
Impact of phosphate and other medium components on physiological regulation of bacterial laccase production
Authors: Kaur Kavleen , Singh Gursharan , Gupta Vijaya , Capalash Neena , Sharma Prince
Published: November 2016

Laccases are multicopper oxidases known to catalyze the transformation of a wide range of phenolic and non‐phenolic substrates using oxygen as electron acceptor and forming water as the only by product. Their potential relevance in several industries requires the constant search for novel laccases. Positive outcome of the isolation of laccase producing bacteria depends on the nature and concentration of media constituents. Several attempts to isolate laccase producing bacteria failed when the phosphate‐containing M9 minimal medium was used. Shift to phosphate‐less M162 medium led to successful isolations. Seven bacterial isolates belonging to genera Bacillus, Lysinibacillus, Bhargavaea and Rheinheimera were used to study the effect of medium constituents on laccase production. Inorganic phosphate (≥50 mM) was found to regulate laccase synthesis negatively though no inhibitory effect of phosphate (10–500 mM) was seen on laccase activity. All isolates ceased laccase synthesis when grown in the presence of tryptone (0.2–1%), with R. tangshanensis as an exception, or yeast extract (1.5–2%) as the only C/N source in M162 medium. Supplementation upto 0.1% of glucose in basal M162 medium increased laccase production in five isolates but decreased at higher concentrations. The influence of medium components on laccase synthesis was further affirmed by zymographic studies. These observations offer possibilities of isolating promising laccase producers from diverse environmental sources. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:541–548, 2017
Effect of copper variation in yeast hydrolysate on C‐terminal lysine levels of a monoclonal antibody
Authors: Mitchelson Fernie G. , Mondia Jessica P. , Hughes Erik H.
Published: November 2016

The ability to control charge heterogeneity in monoclonal antibodies is important to demonstrate product quality comparability and consistency. This article addresses the control of C‐terminal lysine processing through copper supplementation to yeast hydrolysate powder, a raw material used in the cell culture process. Large‐scale production of a murine cell line exhibited variation in the C‐terminal lysine levels of the monoclonal antibody. Analysis of process data showed that this variation correlated well with shifts in cell lactate metabolism and pH levels of the production culture. Small‐scale studies demonstrated sensitivity of the cells to copper, where a single low dose of copper to the culture impacted cell lactate metabolism and C‐terminal lysine processing. Subsequent analytical tests indicated that the yeast hydrolysate powder, added to the basal media and nutrient feed in the process, contained varying levels of trace copper across lots. The measured copper concentrations in yeast hydrolysate lots correlated well with the variation in lactate and pH trends and C‐terminal lysine levels of the batches in manufacturing. Small‐scale studies further demonstrated that copper supplementation to yeast hydrolysate lots with low concentrations of copper can shift the metabolic performance and C‐terminal lysine levels of these cultures to match the control, high copper cultures. Hence, a strategy of monitoring, and if necessary supplementing, copper in yeast‐hydrolysate powders resulted in the ability to control and ensure product quality consistency. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:463–468, 2017
Independent prognostic factors for posttransplant survival in hepatocellular carcinoma patients undergoing liver transplantation
Authors: Xing Minzhi , Kim Hyun S.
Published: November 2016

The aim of this study was to investigate longitudinal trends in locoregional therapy (LRT) use in hepatocellular carcinoma (HCC) patients listed for transplant, and evaluate independent prognostic factors for overall survival (OS) in HCC patients undergoing orthotopic liver transplantation (OLT). The United Network for Organ Sharing (UNOS) database was used to identify HCC patients listed for liver transplantation from 1988 to 2014, and longitudinal rates of bridging LRT were calculated. OLT recipients listed from 2002 to 2013 and transplanted up to 2014, with ≥1 year of follow‐up were further analyzed. OS was compared between patients receiving bridging LRT versus none, high versus low wait times (HWT vs. LWT), and by geographic region. Bridging LRT use in the US has increased dramatically over 25 years, with more than 50% of listed patients receiving at least 1 LRT in 2014. Of 17,291 HCC patients listed for LT from 2002 to 2013, 14,511 received OLT, mean age 57.4 years, 76.8% male; 3889 received bridging LRT. Comparison groups were similar for gender, race, body mass index (BMI), HCC etiology, and biological MELD scores (P > 0.05). Significant differences in mean OS in regions with HWT/high LRT (122.4 months), HWT/low LRT (104.5 months), LWT/high LRT (104.2 months), and LWT/low LRT (102.3 months) were observed, P = 0.0006. Recipient age, donor age, bridging LRT, and longer wait times were independent prognostic factors of survival from OLT. Increasing longitudinal trends in bridging LRT for HCC patients were observed. Younger age, younger donor age, high wait times, and bridging LRT were significant independent prognostic factors for prolonged survival from transplant.
Atmospheric harmony in the retail environment: Its influence on store satisfaction and re‐patronage intention
Authors: Garaus Marion
Published: November 2016

To trigger positive consumer responses, retailers spend large sums of money on arousing and entertaining store environment designs that do not always produce the desired positive consumer reactions. The current research provides a theoretical framework that offers an alternate explanation for shopper preferences regarding retail environments. Drawing on consumers' need for an environment that promotes understanding, this study indicates the importance of communicating a coherent store environment to effect store satisfaction and re‐patronage intention. Harmonious store environments facilitate understanding and comprehension; they enhance information processing and pleasure judgment. One laboratory experiment and one field experiment tested the proposed research framework. Insights from evolutionary and aesthetic psychology, consumer behavior research, and the Asian practice of Feng Shui all guided the manipulation of music and aesthetic design variables to create atmospheric harmony. The findings of both studies suggest that harmonious store environments increase pleasure and positively impact shopping satisfaction and re‐patronage intent, as mediated by shopping value. These findings offer a new perspective for creating pleasant store environments. Theoretical and practical implications are discussed. Copyright © 2016 John Wiley & Sons, Ltd.
A light‐colored region of caudal fin: a niche of melanocyte progenitors in crucian carp (Cyprinus carpio L.)
Authors: Huang Yaping , Luo Yurong , Liu Jinhui , Gui Saiyu , Wang Mei , Liu Wenbin , Peng Liangyue , Xiao Yamei
Published: November 2016

Melanocyte stem cells are a population of immature cells which sustain the self‐renewal and replenish the differentiated melanocytes. In this research, a light‐colored region (LCR) is observed at the heel of caudal fin in juvenile crucian carp. By cutting off the caudal fin, the operated caudal fin can regenerate in accordance with the original pigment pattern from the retained LCR. As markers of stem cells, Oct4 and Sox2 have been found to be highly expressed in the LCR as well as Mitfa, a label of the melanoblasts. In vitro, Mitfa+ melanoblasts are observed in the cells which are derived from the LCR and transfected with Mitfa‐EGFP reporter by using Tol2 transposon system. Furthermore, by real‐time qPCR, it is shown that the level of sox2 mRNA is gradually decreased from the LCR to proximal and distal caudal fin, and that of mitfa mRNA in the proximal caudal fin (PCF) is higher than that in the LCR, while it is the lowest in the distal caudal fin. Hence, we propose that the LCR is a pigment progenitor niche, sending melanocytes to the distal of caudal fin, which gradually emerges as caudal fin grow. We reveal that the LCR of caudal fin might be a niche of pigment progenitors, and contribute to pigment‐producing stem cells in crucian carp.
Cost awareness decreases total percutaneous coronary intervention procedural cost: The SHOPPING (Show How Options in Price for Procedures Can Be Influenced Greatly) trial
Authors: Asher Elad , Mansour John , Wheeler Adam , Kendrick Daniel , Cunningham Michael , Parikh Sahil , Zidar David , Harford Todd , Simon Daniel I. , Kashyap Vikram S.
Published: November 2016

Objectives

We initiated the SHOPPING Trial (Show How Options in Price for Procedures can be InflueNced Greatly) to see if percutaneous coronary intervention (PCI) procedures can be performed at a lower cost in a single institution.

Background

Procedural practice variability is associated with inefficiency and increased cost. We hypothesized that announcing costs for all supplies during a catheterization procedure and reporting individual operator cost relative to peers would spur cost reduction without affecting clinical outcomes.

Methods

Baseline costs of 10 consecutive PCI procedures performed by 9 interventional cardiologists were documented during a 90‐day interval. Costs were reassessed after instituting cost announcing and peer reporting the next quarter. The intervention involved labeling of all endovascular supplies, equipment, devices, and disposables in the catheterization laboratory and announcement of the unit price for each piece when requested. For each interventionalist, procedure time and costs were measured and analyzed prior to and after the intervention.

Results

We found that total PCI procedural cost was significantly reduced by an average of $234.77 (P = 0.01), equating to a total savings of $21,129.30 over the course of 90 PCI procedures. Major Adverse Cardiac and Cerebrovascular Event (MACCE) rates were similar during both periods (2.3% vs. 3.5%, P = NS).

Conclusions

Announcing costs in the catheterization laboratory during single vessel PCI and peer reporting leads to cost reduction without affecting clinical outcomes. This intervention may have a role in more complex coronary and peripheral interventional procedures, and in other procedural areas where multiple equipment and device alternatives with variable costs are available. © 2016 Wiley Periodicals, Inc.
Incidence and predictors of permanent pacemaker implantation following treatment with the repositionable Lotus™ transcatheter aortic valve
Authors: Zaman Sarah , McCormick Liam , Gooley Robert , Rashid Hashrul , Ramkumar Satish , Jackson Damon , Hui Samuel , Meredith Ian T.
Published: November 2016

Objectives

To determine the incidence and predictors of permanent pacemaker (PPM) requirement following transcatheter aortic valve replacement (TAVR) with the mechanically expanded LotusTM Valve System (Boston Scientific).

Background

Pacemaker implantation is the most common complication following TAVR. Predictors of pacing following TAVR with the Lotus valve have not been systematically assessed.

Methods

Consecutive patients with severe aortic stenosis who underwent Lotus valve implantation were prospectively recruited at a single‐centre. Patients with a pre‐existing PPM were excluded. Baseline ECG, echocardiographic and multiple detector computed tomography as well as procedural telemetry and depth of implantation were independently analyzed in a blinded manner. The primary endpoint was 30‐day incidence of pacemaker requirement (PPM implantation or death while pacing‐dependent). Multivariate analysis was performed to identify independent predictors of the primary endpoint.

Results

A total of 104 consecutive patients underwent TAVR with the Lotus valve with 9/104 (9%) with a pre‐existing PPM excluded. New or worsened procedural LBBB occurred in 78%. Thirty‐day incidence of the primary pacing endpoint was 28%. The most common indication for PPM implantation was complete heart block (CHB) (69%). Independent predictors of the primary endpoint included pre‐existing RBBB (hazard ratio [HR] 2.8, 95% CI 1.1–7.0; P = 0.032) and depth of implantation below the noncoronary cusp (NCC) (HR 2.4, 95% CI 1.0–5.7; P = 0.045).

Conclusions

Almost a third of Lotus valve recipients require pacemaker implantation within 30 days. The presence of pre‐existing RBBB and the depth of prosthesis implantation below the NCC were significant pacing predictors. © 2016 Wiley Periodicals, Inc.
Catheter ablation of ventricular ectopy with para‐hisian origin: importance of mapping both sides of the interventricular septum and understanding when to stop ablating
Authors: Madaffari Antonio , Große Anett , Raffa Santi , Frommhold Markus , Fink Agnes , Geller J. Christoph
Published: November 2016

Key Clinical Message

Catheter ablation of para‐Hisian premature ventricular contractions (PVCs) still represents a challenge and is a compromise between success and inadvertent AV block. We describe a possible strategy to address PVCs from this location with high‐amplitude His‐bundle potentials at the site of earliest activation.
Contrast‐enhanced transoral carotid ultrasonography for the evaluation of a long stenotic lesion in the internal carotid artery
Authors: Hagiwara Yuta , Yoshie Tomohide , Shimizu Takahiro , Ogura Hana , Akamatsu Masashi , Fukano Takayuki , Takada Tatsuro , Nogoshi Shinji , Ueda Toshihiro , Hasegawa Yasuhiro
Published: November 2016

Key Clinical Message

Contrast‐enhanced transoral carotid ultrasonography (CETOCU) is a novel modality for imaging the distal extracranial internal carotid artery, which is not possible with conventional carotid ultrasonography. We present a representative case that demonstrates the usefulness of CETOCU.
C‐Terminal Modification and Multimerization Increase the Efficacy of a Proline‐Rich Antimicrobial Peptide
Authors: Li Wenyi , O'Brien‐Simpson Neil M. , Yao Shenggen , Tailhades Julien , Reynolds Eric C. , Dawson Raymond M. , Otvos Laszlo , Hossain Mohammed Akhter , Separovic Frances , Wade John D.
Published: November 2016

Two series of branched tetramers of the proline‐rich antimicrobial peptide (PrAMP), Chex1‐Arg20, were prepared to improve antibacterial selectivity and potency against a panel of Gram‐negative nosocomial pathogens including Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. First, tetramerization was achieved by dithiomaleimide (DTM) conjugation of two C‐terminal‐cysteine bearing dimers that also incorporated C‐terminal peptide chemical modification. DTM‐linked tetrameric peptides containing a C‐terminal hydrazide moiety on each dimer exhibited highly potent activities in the minimum inhibitory concentration (MIC) range of 0.49–2.33 μm. A second series of tetrameric analogues with C‐terminal hydrazide modification was prepared by using alternative conjugation linkers including trans‐1,4‐dibromo‐2‐butene, α,α’‐dibromo‐p‐xylene, or 6‐bismaleimidohexane to determine the effect of length on activity. Each displayed potent and broadened activity against Gram‐negative nosocomial pathogens, particularly the butene‐linked tetrameric hydrazide. Remarkably, the greatest MIC activity is against P. aeruginosa (0.77 μm/8 μg mL−1) where the monomer is inactive. None of these peptides showed any cytotoxicity to mammalian cells up to 25 times the MIC. A diffusion NMR study of the tetrameric hydrazides showed that the more active antibacterial analogues were those with a more compact structure having smaller hydrodynamic radii. The results show that C‐terminal PrAMP hydrazidation together with its rational tetramerization is an effective means for increasing both diversity and potency of PrAMP action.
Nitrogen‐Induced Transformation of Vitamin C into Multifunctional Up‐converting Carbon Nanodots in the Visible–NIR Range
Authors: Ortega‐Liebana M. Carmen , Encabo‐Berzosa M. Mar , Ruedas‐Rama M. Jose , Hueso Jose L.
Published: November 2016

Water‐soluble, biocompatible, and photoluminescent carbon nanodots have been obtained from the rationalized carbonization of vitamin C, a well‐known antioxidant molecule in the presence of an amine co‐reactant. Herein, we describe the positive influence of N‐doping to induce a unique pH‐dependent lifetime decay response that would be potentially attractive in biological backgrounds with intrinsic fluorescence fluctuations. In addition, the selectivity and sensitivity of the N‐containing carbon nanoprobes towards the detection of copper ions at ppm levels is critically enhanced in comparison with the un‐doped counterpart, especially in the near‐infrared (NIR) range. Finally, the up‐converting properties have been also successfully applied to image tumor cells in the visible range and remarkably, in the NIR region in which minimal tissue or water absorption and maximum penetration depth are expected.
Heat‐Resistant Mechanoluminescent Chromism of the Hybrid Molecule Based on Boron Ketoiminate Modified Octasubstituted Polyhedral Oligomeric Silsesquioxane
Authors: Suenaga Kazumasa , Tanaka Kazuo , Chujo Yoshiki
Published: November 2016

The development of a heat‐resistant mechanoluminescent chromic (MLC) dye based on an organic–inorganic hybrid molecular scaffold is reported. Luminescent organoboron complexes were introduced into polyhedral oligomeric silsesquioxane (POSS) at each vertex through the rigid linker structure in the Suzuki–Miyaura cross‐coupling reaction. From optical measurements, it was found that the crystalline state of the modified POSS showed orange emission. By adding mechanical forces to the sample, regular structures collapsed. Correspondingly, the emission color turned to yellow. Interestingly, the yellow‐emissive amorphous state can be preserved during heating. By radially distributing luminescent chromophores on the rigid cube, both optical and thermal properties can be modulated to realize heat‐ resistant MLC behavior. POSS can contribute not only to expressing the MLC behavior, but also to improving thermal stability in the amorphous state. This is the first example, to the best of our knowledge, to offer the rational design of a heat‐resistant MLC material.