bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative characterization of the regulation of iron metabolism in glioblastoma stem‐like cells using magnetophoresis
Authors: Park Kyoung‐Joo J. , Kim James , Testoff Thomas , Adams Joseph , Poklar Miranda , Zborowski Maciej , Venere Monica , Chalmers Jeffrey J. 
Published: March 2019

AbstractThis study focuses on different iron regulation mechanisms of glioblastoma (GBM) cancer stem‐like cells (CSCs) and non‐stem tumor cells (NSTCs) using multiple approaches: cell viability, density, and magnetophoresis. GBM CSCs and NSTCs were exposed to elevated iron concentration, and their magnetic susceptibility was measured using single cell magnetophoresis (SCM), which tracks the magnetic and settling velocities of thousands of individual cells passing through the magnetic field with a constant energy gradient. Our results consistently demonstrate that GBM NSTCs have higher magnetic susceptibility distribution at increased iron concentration compared with CSCs, and we speculate that it is because CSCs have the ability to store a high amount of iron in ferritin, whereas the free iron ions inside the NSTCs lead to higher magnetic susceptibility and reduced cell viability and growth. Further, their difference in magnetic susceptibility has led us to pursue a separate experiment using a quadrupole magnetic separator (QMS), a novel microfluidic device that uses a concentric channel and permanent magnets in a special configuration to separate samples based on their magnetic susceptibilities. GBM CSCs and NSTCs were exposed to elevated iron concentration, stained with two different trackers, mixed and introduced into QMS; subsequently, the separated fractions were analyzed by fluorescent microscopy. The separation results portray a successful label‐less magnetic separation of the two populations.
Direct capture and conversion of CO2from air by growing a cyanobacterial consortium at pH up to 11.2
Authors: Ataeian Maryam , Liu Yihua , Canon‐Rubio Karen Andrea , Nightingale Michael , Strous Marc , Vadlamani Agasteswar 
Published: March 2019

AbstractBioenergy with carbon capture and storage (BECCS) is recognized as a potential negative emission technology, needed to keep global warming within safe limits. With current technologies, large‐scale implementation of BECCS would compromise food production. Bioenergy derived from phototrophic microorganisms, with direct capture of CO2from air, could overcome this challenge and become a sustainable way to realize BECCS.Here we present an alkaline capture and conversion system that combines high atmospheric CO2transfer rates with high and robust phototrophic biomass productivity (15.2 ± 1.0 g/m2/d). The system is based on a cyanobacterial consortium, that grows at high alkalinity (0.5 mol/L) and a pH swing between 10.4 and 11.2 during growth and harvest cycles.
Meta-analysis of risk factors and complications associated with atrial fibrillation after oesophagectomy
Authors: Schizas D , Kosmopoulos M , Giannopoulos S , Giannopoulos S , Kokkinidis D G , Karampetsou N , Papanastasiou C A , Rouvelas I , Liakakos T 
Published: March 2019

Abstract

Background
Oesophagectomy is associated with high morbidity and mortality rates. New-onset atrial fibrillation (AF) is a frequent complication following oesophagectomy. Several studies have explored whether new-onset AF is associated with adverse events after oesophagectomy.

Methods
This review was performed according to PRISMA guidelines. Eligible studies were identified through a search of PubMed, Scopus and Cochrane CENTRAL databases up to 25 November 2018. A meta-analysis was conducted with the use of random-effects modelling. The I2 statistic was used to assess for heterogeneity.

Results
In total, 53 studies including 9087 patients were eligible for analysis. The overall incidence of postoperative AF was 16·5 per cent. Coronary artery disease and hypertension were associated with AF, whereas diabetes, smoking and chronic obstructive pulmonary disease were not. Patients with AF had a significantly higher risk of overall postoperative adverse events than those without fibrillation (odds ratio (OR) 5·50, 95 per cent c.i. 3·51 to 8·30), including 30-day mortality (OR 2·49, 1·70 to 3·64), anastomotic leak (OR 2·65, 1·53 to 4·59) and pneumonia (OR 3·42, 2·39 to 4·90).

Conclusion
Postoperative AF is frequently observed in patients undergoing oesophagectomy for cancer. It is associated with an increased risk of death and postoperative complications.
When both Km and Vmax are altered, Is the enzyme inhibited or activated?
Authors: Silverstein Todd P. 
Published: March 2019

AbstractEnzyme activators lower Km (the Michaelis constant) and/or raise Vmax (the asymptotic reaction velocity at infinite substrate concentration); conversely, inhibitors raise Km and/or lower Vmax. But what if an effector moves both Km and Vmax in the same direction? Uncompetitive inhibitors, which decrease both Km and Vmax by the same factor, are the most common example of this. A less well‐known example occurs often when crowding agents are added to the buffer in order to mimic the environment commonly encountered in vivo. Crowding agents tested on different enzymes have been shown to have every conceivable effect on Km or Vmax, causing them to rise, fall, or stay the same. In this article, a mathematical analysis is presented allowing biochemists to judge whether an effector that causes Km and Vmax to both move in the same direction serves as an inhibitor, an activator, or most surprising, as both. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):446–449, 2019.
Hope and challenge: Precision medicine in bladder cancer
Authors: Su Hongwei , Jiang Haitao , Tao Tao , Kang Xing , Zhang Xu , Kang Danyue , Li Shucheng , Li Chengxi , Wang Haifeng , Yang Zhao , Zhang Jinku , Li Chong 
Published: March 2019

AbstractBladder cancer (BC) is a complex disease and could be classified into nonmuscle‐invasive BC (NMIBC) or muscle‐invasive BC (MIBC) subtypes according to the distinct genetic background and clinical prognosis. Until now, the golden standard and confirmed diagnosis of BC is cystoscopy and the major problems of BC are the high rate of recurrence and high costs in the clinic. Recent molecular and genetic studies have provided perspectives on the novel biomarkers and potential therapeutic targets of BC. In this article, we provided an overview of the traditional diagnostic approaches of BC, and introduced some new imaging, endoscopic, and immunological diagnostic technology in the accurate diagnosis of BC. Meanwhile, the minimally invasive precision treatment technique, immunotherapy, chemotherapy, gene therapy, and targeted therapy of BC were also included. Here, we will overview the diagnosis and therapy methods of BC used in clinical practice, focusing on their specificity, efficiency, and safety. On the basis of the discussion of the benefits of precision medicine in BC, we will also discuss the challenges and limitations facing the non‐invasive methods of diagnosis and precision therapy of BC. The molecularly targeted and immunotherapeutic approaches, and gene therapy methods to BC treatment improved the prognosis and overall survival of BC patients.
Nucleophilic Substitution of Aliphatic Fluorides via Pseudohalide Intermediates
Authors: Jaiswal Amit K. , Prasad Pragati K. , Young Rowan D. 
Published: March 2019

AbstractA method for aliphatic fluoride functionalization with a variety of nucleophiles has been reported. Carbon–fluoride bond cleavage is thermodynamically driven by the use of silylated pseudohalides TMS‐OMs or TMS‐NTf2, resulting in the formation of TMS‐F and a trapped aliphatic pseudohalide intermediate. The rate of fluoride/pseudohalide exchange and the stability of this intermediate are such that little rearrangement is observed for terminal fluoride positions in linear aliphatic fluorides. The ability to convert organofluoride positions into pseudohalide groups allows facile nucleophilic attack by a wide range of nucleophiles. The late introduction of the nucleophiles also allows for a wide range of functional‐group tolerance in the coupling partners. Selective alkyl fluoride mesylation is observed in the presence of other alkyl halides, allowing for orthogonal synthetic strategies.
Electrocatalysis of a Europium‐Dependent Bacterial Methanol Dehydrogenase with Its Physiological Electron‐Acceptor Cytochrome cGJ
Authors: Kalimuthu Palraj , Daumann Lena J. , Pol Arjan , Op den Camp Huub J. M. , Bernhardt Paul V. 
Published: March 2019

AbstractWe report the first electrochemical study of a lanthanoid‐dependent methanol dehydrogenase (Eu‐MDH) from the acidophilic verrucomicrobial methanotroph Methylacidiphilum fumariolicum SolV with its own physiological cytochrome cGJ electron acceptor. Eu‐MDH harbours a redox active 2,7,9‐tricarboxypyrroloquinoline quinone (PQQ) cofactor which is non‐covalently bound but coordinates trivalent lanthanoid elements including Eu3+. Eu‐MDH and the cytochrome were co‐adsorbed with the biopolymer chitosan and cast onto a mercaptoundecanol (MU) monolayer modified Au working electrode. Cyclic voltammetry of cytochrome cGJ reveals a well‐defined quasi‐reversible FeIII/II redox couple at +255 mV vs. NHE at pH 7.5 and this response is pH independent. The reversible one‐electron response of the cytochrome cGJ transforms into a sigmoidal catalytic wave in the presence of Eu‐MDH and its substrates (methanol or formaldehyde). The catalytic current was pH‐dependent and pH 7.3 was found to be optimal. Kinetic parameters (pH dependence, activation energy) obtained by electrochemistry show the same trends as those obtained from an artificial phenazine ethosulfate/dichlorophenol indophenol assay.
Reactions of GeCl2 with the Thiolate LiSC(SiMe3)3: From thf Activation to Insertion of GeCl2 Molecules into C−S Bonds
Authors: Kunz Tanja , Schrenk Claudio , Schnepf Andreas 
Published: March 2019

AbstractThe reaction system GeCl2⋅dioxane/LiSTsi (Tsi=C(SiMe3)3) opens a fruitful area in germanium chemistry, depending on the stoichiometry and solvent used during the reaction. For example, the reaction of GeCl2⋅dioxane in toluene with two equivalents of the thiolate gives the expected germylene Ge(STsi)2 in excellent yield. This germylene readily reacts with hydrogen and acetylene, however, in a non‐selective way. By using an excess amount of the thiolate and toluene as the solvent, the germanide [Ge(STsi)3][Li(thf)] is obtained. Performing the same reaction in thf leads to a C−H activation of thf to give (H7C4O)Ge[STsi](μ2‐S)2Ge[STsi]2, in which the thf molecule is still intact. Using a sub‐stoichiometric amount of the thiolate leads to the heteroleptic compound [ClGe(STsi)]2 and to the insertion product (thf)Ge[S‐GeCl2‐Tsi]2, in which additional GeCl2 molecules insert into the C−S bonds of Ge(STsi)2. The synthesis and the experimentally determined structures of all compounds are presented together with first reactivity studies of Ge(STsi)2.
Phosphate‐Rich Biomimetic Peptides Shed Light on High‐Affinity Hyperphosphorylated Uranyl Binding Sites in Phosphoproteins
Authors: Laporte Fanny A. , Lebrun Colette , Vidaud Claude , Delangle Pascale 
Published: March 2019

AbstractSome phosphoproteins such as osteopontin (OPN) have been identified as high‐affinity uranyl targets. However, the binding sites required for interaction with uranyl and therefore involved in its toxicity have not been identified in the whole protein. The biomimetic approach proposed here aimed to decipher the nature of these sites and should help to understand the role of the multiple phosphorylations in UO22+ binding. Two hyperphosphorylated cyclic peptides, pS168 and pS1368 containing up to four phosphoserine (pSer) residues over the ten amino acids present in the sequences, were synthesized with all reactions performed in the solid phase, including post‐phosphorylation. These β‐sheet‐structured peptides present four coordinating residues from four amino acid side chains pointing to the metal ion, either three pSer and one glutamate in pS168 or four pSer in pS1368. Significantly, increasing the number of pSer residues up to four in the cyclodecapeptide scaffolds produced molecules with an affinity constant for UO22+ that is as large as that reported for osteopontin at physiological pH. The phosphate‐rich pS1368 can thus be considered a relevant model of UO22+ coordination in this intrinsically disordered protein, which wraps around the metal ion to gather four phosphate groups in the UO22+ coordination sphere. These model hyperphosphorylated peptides are highly selective for UO22+ with respect to endogenous Ca2+, which makes them good starting structures for selective UO22+ complexation.
Cyclic(Alkyl)(Amino)Carbene (CAAC)‐Supported Zn Alkyls: Synthesis, Structure and Reactivity in Hydrosilylation Catalysis
Authors: Bruyere Jean‐Charles , Specklin David , Gourlaouen Christophe , Lapenta Rosita , Veiros Luis F. , Grassi Alfonso , Milione Stefano , Ruhlmann Laurent , Boudon Corinne , Dagorne Samuel 
Published: March 2019

AbstractThe reactivity of ZnII dialkyl species ZnMe2 with a cyclic(alkyl)(amino)carbene, 1‐[2,6‐bis(1‐methylethyl)phenyl]‐3,3,5,5‐tetramethyl‐2‐pyrrolidinylidene (CAAC, 1), was studied and extended to the preparation of robust CAAC‐supported ZnII Lewis acidic organocations. CAAC adduct of ZnMe2 (2), formed from a 1:1 mixture of 1 and ZnMe2, is unstable at room temperature and readily undergoes a CAAC carbene insertion into the Zn−Me bond to produce the ZnX2‐type species (CAAC‐Me)ZnMe (3), a reactivity further supported by DFT calculations. Despite its limited stability, adduct 2 was cleanly ionized to robust two‐coordinate (CAAC)ZnMe+ cation (5+) and derived into (CAAC)ZnC6F5+ (7+), both isolated as B(C6F5)4− salts, showing the ability of CAAC for the stabilization of reactive [ZnMe]+ and [ZnC6F5]+ moieties. Due to the lability of the CAAC−ZnMe2 bond, the formation of bis(CAAC) adduct (CAAC)2ZnMe+ cation (6+) was also observed and the corresponding salt [6][B(C6F5)4] was structurally characterized. As estimated from experimental and calculations data, cations 5+ and 7+ are highly Lewis acidic species and the stronger Lewis acid 7+ effectively mediates alkene, alkyne and CO2 hydrosilylation catalysis. All supporting data hints at Lewis acid type activation–functionalization processes. Despite a lower energy LUMO in 5+ and 7+, their observed reactivity is comparable to those of N‐heterocyclic carbene (NHC) analogues, in line with charge‐controlled reactions for carbene‐stabilized ZnII organocations.
The Role of Electrochemistry in Future Dynamic Bio‐Refineries: A Focus on (Non‐)Kolbe Electrolysis
Authors: Palkovits Stefan , Palkovits Regina 
Published: March 2019

AbstractThe vision of a circular economy with closed carbon dioxide cycles is inevitably connected to a change of raw materials. Non‐edible biomass is an attractive carbon source for chemical industry. Brought together with renewable energy, the electrocatalytic transformation of biomass‐based feedstocks enables to directly integrate renewable electrical energy into chemical value chains. Considering the major role of natural carboxylic acids, the well‐known Kolbe and non‐Kolbe electrolysis attract increasing interest as versatile tools to valorize renewable feedstocks providing access to both biofuels and bulk or fine chemicals. They allow via decarboxylation access either to the corresponding dimerization product or the terminal alkene. Here, the electrochemical valorization of biomass is discussed with special emphasis on the possible role of (non‐)Kolbe electrolysis in a future electrified biorefinery.
Efficacy and safety of apixaban vs warfarin in patients with atrial fibrillation and prior bioprosthetic valve replacement or valve repair: Insights from the ARISTOTLE trial
Authors: Guimarães Patricia O. , Pokorney Sean D. , Lopes Renato D. , Wojdyla Daniel M. , Gersh Bernard J. , Giczewska Anna , Carnicelli Anthony , Lewis Basil S. , Hanna Michael , Wallentin Lars , Vinereanu Dragos , Alexander John H. , Granger Christopher B. 
Published: March 2019

BackgroundThe optimal anticoagulation strategy for patients with atrial fibrillation (AF) and bioprosthetic valve (BPV) replacement or native valve repair remains uncertain.HypothesisWe evaluated the safety and efficacy of apixaban vs warfarin in patients with AF and a history of BPV replacement or native valve repair.MethodsUsing data from Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) (n = 18 201), a randomized trial comparing apixaban with warfarin in patients with AF, we analyzed the subgroup of patients (n = 251) with prior valve surgery. We contacted sites by telephone to obtain additional data about prior valve surgery. Full data were available for 156 patients. The primary efficacy endpoint was stroke/systemic embolism. The primary safety endpoint was major bleeding. Treatment groups were compared using a Cox regression model.ResultsIn ARISTOTLE, 104 (0.6%) patients had a history of BPV replacement (n = 73 [aortic], n = 26 [mitral], n = 5 [mitral and aortic]) and 52 (0.3%) had a history of valve repair (n = 50 [mitral], n = 2 [aortic]). Among patients with BPVs, 55 were randomized to apixaban and 49 to warfarin. Among those with a history of native valve repair, 32 were randomized to apixaban and 20 to warfarin. Overall clinical event rates were low, with no significant differences between apixaban and warfarin for any outcomes.ConclusionsIn patients with AF and a history of BPV replacement or repair, the safety and efficacy of apixaban compared with warfarin was consistent with results from ARISTOTLE. These data suggest that apixaban may be reasonable for patients with BPVs or prior valve repair, though future larger randomized trials are needed.ClinicalTrials.govNCT00412984.
H2O2‐Responsive Organosilica‐Doxorubicin Nanoparticles for Targeted Imaging and Killing of Cancer Cells Based on a Synthesized Silane‐Borate Precursor
Authors: Xu Yanhui , Shi Wen , Li Hongyu , Li Xiaohua , Ma Huimin 
Published: March 2019

AbstractDoxorubicin (Dox) is a widely used fluorescent chemotherapy drug. Its primary delivery systems, based on physical adsorption to silica nanoparticles, can lead to low drug loading. Direct loading of Dox via covalent bonds during the formation of silica nanoparticles has never been reported. In this work, we designed and synthesized a silane‐borate precursor, which contains not only an alkoxysilane moiety to form organosilica nanoparticles but also a phenylboronic acid moiety to react with diol‐containing compounds. Using this compound, the covalent loading of Dox during the preparation of organosilica nanoparticles was effectively realized with a high drug loading content up to 22.4 %. Further modification by hyaluronic acid (HA) bestowed the Si‐Dox@HA nanoparticles with the ability to target CD44‐overexpressing cancer cells. The Si‐Dox@HA nanoparticles exhibited H2O2‐responsive release of about 80 % Dox and displayed seven‐fold selectivity for killing cancer cells over normal cells, relative to Dox and Si‐Dox nanoparticles. Moreover, these Si‐Dox@HA nanoparticles are also suitable for targeted fluorescence imaging of CD44‐overexpressing cancer cells.
Bridging the demand and the offer in data science
Authors: Belloum Adam S.Z. , Koulouzis Spiros , Wiktorski Tomasz , Manieri Andrea 
Published: March 2019

SummaryDuring the last several years, we have observed an exponential increase in the demand for Data Scientists in the job market. As a result, a number of trainings, courses, books, and university educational programs (both at undergraduate, graduate and postgraduate levels) have been labeled as “Big data” or “Data Science”; the fil‐rouge of each of them is the aim at forming people with the right competencies and skills to satisfy the business sector needs. In this paper, we report on some of the exercises done in analyzing current Data Science education offer and matching with the needs of the job markets to propose a scalable matching service, ie, COmpetencies ClassificatiOn (E‐CO‐2), based on Data Science techniques. The E‐CO‐2 service can help to extract relevant information from Data Science–related documents (course descriptions, job Ads, blogs, or papers), which enable the comparison of the demand and offer in the field of Data Science Education and HR management, ultimately helping to establish the profession of Data Scientist.
The Effect of Crucible Rotation and Crucible Size in Top‐Seeded Solution Growth of Single‐Crystal Silicon Carbide
Authors: Horiuchi Takashi , Wang Lei , Sekimoto Atsushi , Okano Yasunori , Yamamoto Takuya , Ujihara Toru , Dost Sadik 
Published: March 2019

AbstractThe top‐seeded solution growth method is a promising technique for growing high‐quality silicon carbide single crystal. Some inherent issues in this growth process, such as morphological instability, polycrystalline growth, and low growth rate, should be clarified. A high temperature difference between the seed and the crucible wall in this system is needed to enhance growth. However, such a high temperature gradient makes the radial growth rate profile non‐uniform due to the effect of Marangoni convection below the seed crystal, which leads to poor crystal quality. In the present work, the effects of crucible size and crucible rotation are numerically investigated to minimize the effect of Marangoni convection. The possibilities of the occurrence of growth‐rate non‐uniformity and undesired impurity incorporation are examined. A smaller crucible (in radius) leads to a more uniform growth rate profile. However, it gives rise to a higher possibility of impurity incorporation. It is also predicted that crucible rotation is ineffective in suppressing the Marangoni flow near the seed edge. This leads to a flow stagnation in the center of the melt, and consequently, it does not enhance the carbon transport below the seed. It also does not reduce the possibility of undesired impurity incorporation.
High‐Performance Jet Fuels Derived from Bio‐Based Alkenes by Iron‐Catalyzed [2+2] Cycloaddition
Authors: Morris David M. , Quintana Roxanne L. , Harvey Benjamin G. 
Published: March 2019

AbstractA series of high‐performance cycloparaffinic fuels have been generated by [2+2] cycloaddition of the bio‐derived alkenes 1‐hexene, isoprene, and 1‐pentene, catalyzed by a low‐valent iron pyridine(diimine) complex [(MePDI)Fe(N2)2(μ‐N2)] [MePDI=N,N′‐(2,6‐pyridinediyldiethylidyne)bis(2,6‐dimethylbenzenamine)]. Reactions with 1‐pentene and 1‐hexene resulted in 85 % selectivity to 1,2‐cyclobutanes, and 12 % selectivity to acyclic alkenes generated by β‐hydride elimination. Self‐dimerization of isoprene was sluggish and generated heavier oligomer products, but cross‐dimerization of isoprene with 1‐hexene afforded primarily a 1,3‐cyclobutane product, along with isomers of acyclic C11 mixed dimers. Hydrocarbon mixtures were hydrogenated and fractionally distilled to yield finished fuel mixtures in overall yields of 83–93 % at the multigram scale. The fuels exhibited densities ranging between 0.767 and 0.783 g mL−1, and net heats of combustion (NHOC) of up to 120.6 kBtu gal−1 (43.8 MJ kg−1). These values are higher than conventional synthetic paraffinic kerosenes owing to the higher density and ring strain afforded by the cyclobutane rings. The fuel mixtures also exhibited extremely low viscosities ranging from 2.38 to 4.78 mm2 s−1 at −20 °C, due in part to the presence of the acyclic dimers. The excellent fuel properties of the product mixtures, selectivity for dimer products, high yields, and the ability to use simple bio‐derived alkenes as substrates, make the [Fe]‐catalyzed [2+2] cycloaddition of unactivated alkenes a compelling route to the synthesis of sustainable high‐performance fuels.