bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence of a LNOX influence on middle/upper troposphere ozone‐mixing ratios at Dakar, Senegal during Northern Hemisphere summer season
Authors: Jenkins Gregory S. , Gueye Moussa , Drame Mamadou S. , Ndiaye Seydi A. 
Published: February 2014

AbstractWe present results for the vertical distribution of tropospheric ozone from 40 measurements at Dakar, Senegal (14.59°N, 17.5°W) from June to September of 2008, 2010, 2011 and 2012. Under pre‐monsoon conditions (June), many dry air intrusions are found in the lower troposphere transitioning to humid conditions during July, August and September. Measurements show the highest ozone‐mixing ratios (50–100 ppb) in the 400–200 hPa layer and easterly wind flow during each month. Lightning‐NOX (LNOX) is the only viable source to explain the vertical distribution of ozone, with a large amount of upstream lightning over West Africa during summer.
George Box and Bayesian inference
Authors: Meyer R. Daniel 
Published: February 2014

AbstractThe Bayesian paradigm was fundamental to George Box's philosophy of statistics. Box's scholarship in statistics was driven by his engagement with other scientists in the process of scientific discovery. In his view, scientific discovery was represented elegantly by Bayes' theorem, in which information from the latest experiment is combined with current knowledge. Applications to real problems was the focus of his research in Bayesian methods, especially problems that were less accessible to classical methods based on sampling theory. These problems typically related to the design of experiments and analysis of experimental data, hierarchical models, the sensitivity of inferences to assumptions about the data, and the use of non‐informative priors. His work with a network of collaborators laid the groundwork for widespread application of Bayesian methods facilitated by later advances in computational methods. Copyright © 2014 John Wiley & Sons, Ltd.
Natural products – learning chemistry from plants
Authors: Staniek Agata , Bouwmeester Harro , Fraser Paul D. , Kayser Oliver , Martens Stefan , Tissier Alain , van der Krol Sander , Wessjohann Ludger , Warzecha1 Heribert 
Published: February 2014

AbstractPlant natural products (PNPs) are unique in that they represent a vast array of different structural features, ranging from relatively simple molecules to very complex ones. Given the fact that many plant secondary metabolites exhibit profound biological activity, they are frequently used as fragrances and flavors, medicines, as well as industrial chemicals. As the intricate structures of PNPs often cannot be mimicked by chemical synthesis, the original plant providers constitute the sole source for their industrial, large‐scale production. However, sufficient supply is not guaranteed for all molecules of interest, making the development of alternative production systems a priority. Modern techniques, such as genome mining and thorough biochemical analysis, have helped us gain preliminary understanding of the enzymatic formation of the valuable ingredients in planta. Herein, we review recent advances in the application of biocatalytical processes, facilitating generation of complex PNPs through utilization of plant‐derived specific enzymes and combinatorial biochemistry. We further evaluate the options of employing heterologous organisms harboring PNP biosynthetic pathways for the production of secondary metabolites of interest.
Peptide microarrays enable rapid mimotope optimization for pharmacokinetic analysis of the novel therapeutic antibody IMAB362
Authors: Schnatbaum Karsten , Schmoldt Hans‐Ulrich , Daneschdar Matin , Plum Laura M. , Jansong Janina , Zerweck Johannes , Kühne Yvonne , Masch Antonia , Wenschuh Holger , Fiedler Markus , Türeci Özlem , Sahin Ugur , Reimer Ulf 
Published: February 2014

AbstractAs membrane proteins play an important role in a variety of life‐threatening diseases, the development of therapeutic monoclonal antibodies against membrane proteins is of significant interest. Among many other requirements, the process of antibody drug development requires a set of tailor‐made assays for the characterization of the antibodies and for monitoring their activity. Designing assays to characterize antibodies directed to membrane proteins is challenging, because the natural targets are often not available in a format that is compatible with a biochemical assay setup. Thus, alternatives that mimic the targeted membrane proteins are needed. In this study, we developed optimal peptidic mimotopes for the ELISA‐based detection of the novel therapeutic antibody IMAB362 in biological samples. Initial hits were identified using phage display and these hits were optimized with the help of structure‐activity relationship analysis on peptide microarrays. The optimized peptides showed binding constants in the low nanomolar to picomolar range, an improvement by a factor of up to 30 compared to the initial hits. The best mimotope (apparent KD = 0.15 nM) was successfully used for the ELISA‐based quantification of IMAB362 in samples from a mouse pharmacokinetic study. The process described allows the rapid discovery of mimotopes for target proteins that are difficult to produce or handle, which can then be used in pre‐clinical and clinical assays or for the purification of biological products.
Lanthanoid–Transition‐Metal Bonding in Bismetallocenes
Authors: Butovskii Mikhail V. , Oelkers Benjamin , Bauer Tobias , Bakker Jacinta M. , Bezugly Viktor , Wagner Frank R. , Kempe Rhett 
Published: February 2014

AbstractBismetallocenes [Cp2LuReCp2] and [Cp*2LaReCp2] (Cp=cyclopentadienyl; Cp*=pentamethylcyclopentadienyl) were prepared using different synthetic strategies. Salt metathesis—performed in aromatic hydrocarbons to avoid degradation pathways caused by THF—were identified as an attractive alternative to alkane elimination. Although alkane elimination is more attractive in the sense of its less elaborate workup, the rate of the reaction shows a strong dependence on the ionic radius of Ln3+ (Ln=lanthanide) within a given ligand set. Steric hindrance can cause a dramatic decrease in the reaction rate of alkane elimination. In this case, salt metathesis should be considered the better alternative. Covalent bonding interactions between the Ln and transition‐metal (TM) cations has been quantified on the basis of the delocalization index. Its magnitude lies within the range characteristic for bonds between transition metals. Secondary interactions were identified between carbon atoms of the Cp ligand of the transition metal and the Ln cation. Model calculations clearly indicated that the size of these interactions depends on the capability of the TM atom to act as an electron donor (i.e., a Lewis base). The consequences can even be derived from structural details. The observed clear dependency of the LuRu and interfragment LuC bonding on the THF coordination of the Lu atom points to a tunable Lewis acidity at the Ln site, which provides a method of significantly influencing the structure and the interfragment bonding.
Aptamer‐Based Luminescence Energy Transfer from Near‐Infrared‐to‐Near‐Infrared Upconverting Nanoparticles to Gold Nanorods and Its Application for the Detection of Thrombin
Authors: Yuan Fei , Chen Hongqi , Xu Juan , Zhang Yiyan , Wu Yong , Wang Lun 
Published: February 2014

AbstractA new luminescence energy transfer (LET) system has been designed for the detection of thrombin in the near‐infrared (NIR) region by utilizing NIR‐to‐NIR upconversion lanthanide nanophosphors (UCNPs) as the donor and gold nanorods (Au NRs) as the acceptor. The use of upconverting NaYF4:Yb3+,Tm3+ nanoparticles with sharp NIR emission peaks upon NIR excitation by an inexpensive infrared continuous wave laser diode provided large spectral overlap between the donor and the acceptor. Both the Au NRs and carboxyl‐terminated NaYF4:Yb3+,Tm3+ UCNPs were first modified with different thrombin aptamers. When thrombin was added, a LET system was then formed because of the specific recognition between the thrombin aptamers and thrombin. The LET system was used to monitor thrombin concentrations in aqueous buffer and human blood samples. The limits of detection for thrombin are as low as 0.118 nM in buffer solution and 0.129 nM in human serum. The method was also successfully applied to thrombin detection in blood samples.
Palladium/Copper‐Catalyzed Oxidative Arylation of Terminal Alkenes with Aroyl Hydrazides
Authors: Zhang Yong‐Gang , Liu Xiang‐Lei , He Zeng‐Yang , Li Xi‐Ming , Kang Hong‐Jian , Tian Shi‐Kai 
Published: February 2014

AbstractAn unprecedented oxidative arylation reaction of terminal alkenes with simple aroyl hydrazides has been developed under aerobic conditions for the stereoselective synthesis of 1,2‐disubstituted alkenes. A range of aroyl hydrazides underwent palladium/copper‐catalyzed oxidative Mizoroki–Heck reaction with terminal alkenes open to air in a 1:1 mixture of dimethyl sulfoxide and acetonitrile to give structurally diverse 1,2‐disubstituted alkenes in moderate to excellent yields with excellent regio‐ and E‐selectivity. The reaction tolerated a wide variety of functional groups, such as alkoxy, hydroxy, amino, fluoro, chloro, bromo, cyano, nitro, ester, amide, imide, phosphine oxide, and sulfone groups, and, moreover, molecular oxygen and dimethyl sulfoxide were demonstrated to serve as terminal oxidants. This study provides a useful method for the stereoselective synthesis of 1,2‐disubstituted alkenes through direct transformation of the vinylic CH bonds in terminal alkenes.
Mein Weg zum Wissenschaftsjournalismus
Authors: Groß Michael 
Published: February 2014

AbstractDem Wissenschaftsjournalismus kommt angesichts der rasanten Fortschritte in Wissenschaft und Technik eine wichtige Rolle zu. Die freiberufliche Tätigkeit in diesem Bereich bietet zwar wenig finanzielle Sicherheit aber viel kreativen Spielraum. Neugier und Freude am Schreiben sind die wichtigsten Qualifikationen.
Stickstoffreduktion mit Titan‐Clustern
Authors: Jaenicke Lothar 
Published: February 2014

AbstractStickstoff (genauer Distickstoff, N2) ist ein sehr inertes Element, daher das verbreitetste auf Erden. Und doch ist es in reduzierter Form als Ammoniak (NH3) lebenswichtig zur Biosynthese der Protein‐Aminosäuren und ihrer direkten Polymerisate, den Biostrukturmaterialien (Proteine und Bindegewebe) oder indirekten Abkömmlinge, den hochmolekularen Biokatalysatoren (Enzyme) und niedermolekularen Biowirkstoffen (Vitamine, Hormone, Signalstoffe). Ohne mikrobiell oder chemisch fixierten Stickstoff geht nichts in dieser Welt.
Synthesis, Antimalarial Properties, and SAR Studies of Alkoxyurea‐Based HDAC Inhibitors
Authors: Hansen Finn K. , Skinner‐Adams Tina S. , Duffy Sandra , Marek Linda , Sumanadasa Subathdrage D. M. , Kuna Krystina , Held Jana , Avery Vicky M. , Andrews Katherine T. , Kurz Thomas 
Published: February 2014

AbstractHistone deacetylase (HDAC) inhibitors are an emerging class of potential antimalarial drugs. We investigated the antiplasmodial properties of 16 alkoxyurea‐based HDAC inhibitors containing various cap and zinc binding groups (ZBGs). Ten compounds displayed sub‐micromolar activity against the 3D7 line of Plasmodium falciparum. Structure–activity relationship studies revealed that a hydroxamic acid ZBG is crucial for antiplasmodial activity, and that the introduction of bulky alkyl substituents to cap groups increases potency against asexual blood‐stage parasites. We also demonstrate that selected compounds cause hyperacetylation of P. falciparum histone H4, indicating inhibition of one or more PfHDACs. To assess the selectivity of alkoxyurea‐based HDAC inhibitors for parasite over normal mammalian cells, the cytotoxicity of representative compounds was evaluated against neonatal foreskin fibroblast (NFF) cells. The most active compound, 6‐((3‐(4‐(tert‐butyl)phenyl)ureido)oxy)‐N‐hydroxyhexanamide (1 e, Pf3D7 IC50: 0.16 μM) was 31‐fold more toxic against the asexual blood stages than towards normal mammalian cells. Moreover, a subset of four structurally diverse HDAC inhibitors revealed moderate activity against late‐stage (IV–V) gametocytes.
Synthetic Chromatin Approaches To Probe the Writing and Erasing of Histone Modifications
Authors: Fierz Beat 
Published: February 2014

AbstractPosttranslational modifications (PTMs) of chromatin are involved in gene regulation, thereby contributing to cell differentiation, lineage determination, and organism development. Discrete chromatin states are established by the action of a large set of enzymes that catalyze the deposition, propagation, and removal of histone PTMs, thereby modulating gene expression. Given their central role in determining and maintaining cellular phenotype, as well as in controlling chromatin processes such as DNA repair, the dysregulation of these enzymes can have serious consequences, and can result in cancer and neurodegenerative diseases. Thus, such chromatin regulator proteins are promising drug targets. However, they are often present in large, modular protein complexes that specifically recognize target chromatin regions and exhibit intricate regulation through preexisting histone marks. This renders the study of their enzymatic mechanisms complex. Recent developments in the chemical production of defined chromatin substrates show great promise for improving our understanding of the activity of chromatin regulator complexes at the molecular level. Herein I discuss examples highlighting the application of synthetic chromatin to study the enzymatic mechanisms and regulatory pathways of these crucial protein complexes in detail, with potential implications for assay development in pharmacological research.
Efficient Plasmonic Dye‐Sensitized Solar Cells with Fluorescent Au‐Encapsulated C‐Dots
Authors: Narayanan Remya , Deepa Melepurath , Srivastava Avanish Kumar , Shivaprasad Sonnada Math 
Published: February 2014

AbstractA simple strategy to improve the efficiency of a ZnO‐nanorod‐based dye‐sensitized solar cell (DSSC) by use of Au‐encapsulated carbon dots (Au@C‐dots) in the photoanode is presented. The localized surface plasmonic resonance of Au in the 500–550 nm range coupled with the ability of C‐dots to undergo charge separation increase the energy‐harvesting efficiency of the DSSC with ZnO/N719/Au@C‐dots photoanodes. Charge transfer from N719 dye to Au@C‐dots is confirmed by fluorescence and lifetime enhancements of Au@C‐dots. Forster resonance energy transfer (FRET) from the gap states of ZnO nanorods to N719 dye is also ratified and the energy transfer rate is 4.4×108 s−1 and the Forster radius is 1.89 nm. The overall power conversion efficiency of the plasmonic and FRET‐enabled DSSC with ZnO/N719/Au@C‐dots as the photoanode, I2/I− as the electrolyte and multiwalled carbon nanotubes as the counter electrode is 4.1 %, greater by 29 % compared to a traditional ZnO/N719 cell.
Coordinate‐Targeted and Coordinate‐Stochastic Super‐Resolution Microscopy with the Reversibly Switchable Fluorescent Protein Dreiklang
Authors: Jensen Nickels A. , Danzl Johann G. , Willig Katrin I. , Lavoie‐Cardinal Flavie , Brakemann Tanja , Hell Stefan W. , Jakobs Stefan 
Published: February 2014

AbstractDiffraction‐unlimited far‐field super‐resolution fluorescence (nanoscopy) methods typically rely on transiently transferring fluorophores between two states, whereby this transfer is usually laid out as a switch. However, depending on whether this is induced in a spatially controlled manner using a pattern of light (coordinate‐targeted) or stochastically on a single‐molecule basis, specific requirements on the fluorophores are imposed. Therefore, the fluorophores are usually utilized just for one class of methods only. In this study we demonstrate that the reversibly switchable fluorescent protein Dreiklang enables live‐cell recordings in both spatially controlled and stochastic modes. We show that the Dreiklang chromophore entails three different light‐induced switching mechanisms, namely a reversible photochemical one, off‐switching by stimulated emission, and a reversible transfer to a long‐lived dark state from the S1 state, all of which can be utilized to overcome the diffraction barrier. We also find that for the single‐molecule‐based stochastic GSDIM approach (ground‐state depletion followed by individual molecule return), Dreiklang provides a larger number of on–off localization events as compared to its progenitor Citrine. Altogether, Dreiklang is a versatile probe for essentially all popular forms of live‐cell fluorescence nanoscopy.
Contrasting responses of non‐small cell lung cancer to antiangiogenic therapies depend on histological subtype
Authors: Larrayoz Marta , Pio Ruben , Pajares María J , Zudaire Isabel , Ajona Daniel , Casanovas Oriol , Montuenga Luis M , Agorreta Jackeline 
Published: February 2014

AbstractThe vascular endothelial growth factor (VEGF) pathway is a clinically validated antiangiogenic target for non‐small cell lung cancer (NSCLC). However, some contradictory results have been reported on the biological effects of antiangiogenic drugs. In order to evaluate the efficacy of these drugs in NSCLC histological subtypes, we analyzed the anticancer effect of two anti‐VEGFR2 therapies (sunitinib and DC101) in chemically induced mouse models and tumorgrafts of lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC). Antiangiogenic treatments induced vascular trimming in both histological subtypes. In ADC tumors, vascular trimming was accompanied by tumor stabilization. In contrast, in SCC tumors, antiangiogenic therapy was associated with disease progression and induction of tumor proliferation. Moreover, in SCC, anti‐VEGFR2 therapies increased the expression of stem cell markers such as aldehyde dehydrogenase 1A1, CD133, and CD15, independently of intratumoral hypoxia. In vitro studies with ADC cell lines revealed that antiangiogenic treatments reduced pAKT and pERK signaling and inhibited proliferation, while in SCC‐derived cell lines the same treatments increased pAKT and pERK, and induced survival. In conclusion, this study evaluates for the first time the effect of antiangiogenic drugs in lung SCC murine models in vivo and sheds light on the contradictory results of antiangiogenic therapies in NSCLC.
Review of Methods for Improving the Cyclic Stability of Li–Air Batteries by Controlling Cathode Reactions
Authors: Zhao Ning , Li Chilin , Guo Xiangxin 
Published: February 2014

AbstractThe rechargeable Li–air battery (as well as the Li–O2 battery) is a promising candidate for energy storage applications, especially in application of electrical vehicles. However, many technical obstacles such as the limited cyclic stability, low electrical energy efficiency, and poor rate capability must be solved prior to its practical use. In this review, we focus on methods for extension of the cycle lifetime by controlling the key operation parameters. The important influence of working parameters on the cycle operation and the underlying mechanism related to cathode reactions are addressed. It is demonstrated that battery technology in combination with knowledge of the cathode material characteristics is essential for improvement of battery performance. Prospective utilization of battery technology for overcoming other problems of Li–air batteries is also discussed.
Impact of the introduction of rituximab in first‐line follicular lymphoma: a retrospective study of 247 unselected patients referred to a single institution with a long‐term follow‐up
Authors: Nicolas‐Virelizier Emmanuelle , Ségura‐Ferlay Céline , Ghesquières Herve , Chassagne‐Clément Catherine , Gargi Thérèse , Biron Pierre , Belhabri Amine , Rey Philippe , Faurie Pierre , Chabaud Sylvie , Sebban Catherine 
Published: February 2014

AbstractRituximab was approved in France in 2004, following randomized trials that demonstrated efficacy in newly diagnosed high tumour burden follicular lymphoma (FL). This retrospective study compared the management and outcome of FL in unselected patients treated in a single institution before and after rituximab approval. Two hundred and forty‐seven adult patients were referred with first‐line FL between 1996 and 2010 and are included in this study. The 103 pre‐rituximab patients comprising cohort 1 were diagnosed between January 1996 and December 2003; cohort 2 includes the 144 patients diagnosed after the approval of rituximab between January 2004 and December 2010. Baseline clinical and biological data, type of therapy, treatment response, progression‐free survival (PFS) and overall survival (OS) rates were compared. There were no statistically significant differences between the two cohorts with respect to baseline clinical and disease characteristics, including FL International Prognostic Index score. The major difference between the two cohorts is the use of rituximab in first line. Seventy‐one per cent of patients in cohort 2 received rituximab (19% alone, 52% with chemotherapy) versus 10% in cohort 1 (2% alone, 8% with chemotherapy;p < 0.0001). The objective response rate (ORR) was significantly higher for cohort 2 (ORR84% compared with 72% for cohort 1;p = 0.03). The PFS and OS rates were also significantly better: 3‐yearPFS72% [95% confidence interval (CI) 64–80%] versus 55% (95% CI 45–64%),p = 0.0039 and 3‐yearOS98% (95% CI 94–99%) versus 83% (95% CI 74–90%),p = 0.0007. Effect of period of study is significant when using multivariate analysis on PFS and OS and lactate dehydrogenase level (PFS and OS) and age (OS). These data from everyday practice confirm the benefit for patients with FL treated in the last decade through availability of rituximab in first line used alone or in association with various chemotherapy regimens. Copyright © 2014 John Wiley & Sons, Ltd.
ADOPTION POLICY AND EVIDENCE‐BASED DOMESTIC ADOPTION PRACTICE: A COMPARISON OF ROMANIA, UKRAINE, INDIA, GUATEMALA, AND ETHIOPIA
Authors: Groza Victor , Bunkers Kelley M. 
Published: February 2014

ABSTRACTThe United Nations Convention on the Rights of the Child (1989), The Hague Convention on the Protection of Children and Co‐operation in Respect of Intercountry Adoption (The Hague Permanent Bureau, 1993), and the Guidelines for the Alternative Care of Children (2009) have provided a comprehensive, rights‐based framework and guidance for developing domestic adoption and alternative, family based care programs. Domestic adoption is a critical component of any child‐protection system and a core part of the range of alternative care options that the United Nations and other international organizations recommend be developed, resourced, and made accessible to children without parental care. This article uses data collected from adoptive parents’ postadoption and governmental data in Romania, Ukraine, India, Guatemala, and Ethiopia to focus on domestic adoption in each of these countries. The article highlights both promising practices in domestic adoption as well as policies and practices that require additional research.