bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural Observations of Heterometallic Uranyl Copper(II) Carboxylates and Their Solid‐State Topotactic Transformation upon Dehydration
Authors: Olchowka Jakub , Falaise Clément , Volkringer Christophe , Henry Natacha , Loiseau Thierry 
Published: December 2012

AbstractThe hydrothermal reactions of uranyl nitrate and metallic copper with aromatic polycarboxylic acids gave rise to the formation of five heterometallic UO22+Cu2+ coordination polymers: (UO2)Cu(H2O)2(1,2‐bdc)2 (1; 1,2‐bdc=phthalate), (UO2)Cu(H2O)2(btec)⋅4 H2O (2) and (UO2)Cu(btec) (2′; btec=pyromellitate), (UO2)2Cu(H2O)4(mel) (3; mel=mellitate), and (UO2)2O(OH)2Cu(H2O)2(1,3‐bdc)⋅H2O (4; 1,3‐bdc=isophthlalate). Single‐crystal X‐ray diffraction (XRD) analysis of compound 1 revealed 2D layers of chains of UO8 and CuO4(H2O)2 units that were connected through the phthalate ligands. In compound 2, these sheets were connected to each other through the two additional carboxylate arms of the pyromellitate, thus resulting in a 3D open‐framework with 1D channels that trapped water molecules. Upon heating, free and bonded water species (from CuOH2) were evacuated from the structure. This thermal transition was followed by in situ XRD and IR spectroscopy. Heating induced a solid‐state topotactic transformation with the formation of a new set of CuO interactions in the crystalline anhydrous structure (2′), in order to keep the square‐planar environment around the copper centers. The structure of compound 3 was built up from trinuclear motifs, in which one copper center, CuO4(OH2)2, was linked to two uranium units, UO5(H2O)2. The assembly of this trimer, “U2Cu”, with the mellitate generated a 3D network. Complex 4 contained a tetranuclear uranyl core of UO5(OH)2 and UO6(OH) units that were linked to two copper centers, CuO(OH)2(H2O)2, which were then connected to each other through isophthalate ligands and UOCu interactions to create a 3D structure. The common structural feature of these different compounds is a bridging oxo group of UOCu type, which is reflected by apical CuO distances in the range 2.350(3)–2.745(5) Å. In the case of a shorter CuO distance, a slight lengthening of the uranyl bond (UO) is observed (e.g., 1.805(3) Å in complex 4).
Decarboxylative Alkylation of β‐Keto Acids with Isochromans under Oxidative Conditions
Authors: Chen Yan , Tian Shi‐Kai 
Published: December 2012

AbstractAn unprecedented decarboxylative alkylation reaction of β‐keto acids with isochromans has been developed under oxidative conditions. A range of β‐keto acids smoothly undergo decarboxylative alkylation with isochromans in the presence of 2,2,6,6‐tetramethylpiperdine‐1‐oxoammonium hexafluorophosphate to give structurally diverse 1‐acylmethylisochromans in moderate to excellent yields with extremely high regioselectivity.
A Scalable Synthesis of 6,19‐Dihydroxyandrostenedione
Authors: Yan Yubo , Li Ting , Liu Tao , Dou Qingyu , Ding Kai , Tian Weisheng 
Published: December 2012

AbstractStarting from the commercially available 19‐hydroxyandrostenedione, a practical protocol for the preparation of 6,19‐dihydroxyandrostenedione is reported. This compound is a key intermediate for the synthesis of cyclocitrinols. With the stereospecific epoxidation and following isomerization to allylic alcohol as key steps, a six‐step procedure provided desired product in high yield. The sequence is easy to scale‐up without the need of laborious chromatography.
Design and Rationale of the PRAGUE‐12 Trial: A Large, Prospective, Randomized, Multicenter Trial That Compares Cardiac Surgery With Left Atrial Surgical Ablation With Cardiac Surgery Without Ablation in Patients With Coronary and/or Valvular Heart Disease Plus Atrial Fibrillation
Authors: Straka Zbyněk , Budera Petr , Osmančík Pavel , Vaněk Tomáš , Hulman Michal , Šmíd Michal , Malý Marek , Widimský Petr 
Published: December 2012

AbstractSurgical ablation procedure can restore sinus rhythm (SR) in patients with atrial fibrillation (AF) undergoing cardiac surgery. However, it is not known whether it has any impact on clinical outcomes. There is a need for a randomized trial with long‐term follow‐up to study the outcome of surgical ablation in patients with coronary and/or valve disease and AF. Patients are prospectively enrolled and randomized either to group A (cardiac surgery with left atrial ablation) or group B (cardiac surgery alone). The primary efficacy outcome is the SR presence (without any AF episode) during a 24‐hour electrocardiogram after 1 year. The primary safety outcome is the combined end point of death, myocardial infarction, stroke, and renal failure at 30 days. Long‐term outcomes are a composite of total mortality, stroke, bleeding, and heart failure at 1 and 5 years. We finished the enrollment with a total of 224 patients from 3 centers in 2 countries in December 2011. Currently, the incomplete 1‐year data are available, and the patients who enrolled first will have their 5‐year visits shortly. PRAGUE‐12 is the largest study to be conducted so far comparing cardiac surgery with surgical ablation of AF to cardiac surgery without ablation in an unselected population of patients who are operated on for coronary and/or valve disease. Its long‐term results will lead to a better recognition of ablation's potential clinical benefits.The PRAGUE‐12 trial is partially funded by the Charles University Research Projects MSM0021620817 and UNCE 204010/2012.The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Milestones in Pediatric Cardiology: Making Possible the Impossible
Authors: Mormile Raffaella , Quadrini Ilaria , Squarcia Umberto 
Published: December 2012

AbstractPediatric Cardiology as a discipline has been proposed to have been born on August 26, 1938, when Robert Gross at the age of 33 years, successfully ligated a patent ductus arteriosus of a 7 years girl at the Children's Hospital in Boston. In November 1944, Helen Taussig convinced Alfred Blalock to anastomose the left subclavian artery to the left pulmonary artery after Robert Gross had declined to cooperate with her. About the 1950s, at the University of Minneapolis, Clarence Walton Lillehei worked on a controlled “crossed circulation” in which the cardiopulmonary bypass machine was another human, generally one of the patient's parents. In 1966 Williams Rashkind introduced ballon septostomy as a palliative approach to complete transposition of the Great Arteries, followed later by Jean Kan's balloon valvuloplasty to open the pulmonary valve. During the 1960s Giancarlo Rastelli developed a new classification of the Atrio Ventricular Canal defect which allowed to have a strikingly better surgical results. Today, even the hypoplastic left heart syndrome (HLHS), at one time a fatal condition, is operable. The completion of the Human Genome Project has been an enormous help in the understanding the genetic causes of cardiac anomalies. However, there are very few approved application for stem cells, and stem cells will not likely replace organ transplantation any time soon. Recently, the protein survivin has been described as a novel player in cardioprotection against myocardial ischemia/reperfusion injury. The science needs to be made with love to warrant the humanity of Research.The authors have no funding, financial relationships, or conflicts of interest to disclose.
Infarct‐like Acute Myocarditis: Relation Between Electrocardiographic Findings and Myocardial Damage as Assessed by Cardiac Magnetic Resonance Imaging
Authors: Nucifora Gaetano , Miani Daniela , Di Chiara Antonio , Piccoli Gianluca , Artico Jessica , Puppato Michela , Slavich Gianaugusto , De Biasio Marzia , Gasparini Daniele , Proclemer Alessandro 
Published: December 2012

AbstractBackground:Acute myocarditis (AM) may occasionally have an infarct‐like presentation. The aim of the present study was to investigate the relation between electrocardiographic (ECG) findings in this group of patients and myocardial damage assessed by cardiac magnetic resonance imaging (MRI) with the late gadolinium enhancement (LGE) technique.Hypothesis:Myocardial damage may be associated with ECG changes in infarct‐like AM.Methods:Forty‐one consecutive patients (36 males; mean age, 36 ± 12 years) with diagnosis of AM according to cardiac MRI Lake Louise criteria and infarct‐like presentation were included. The relation between site of ST‐segment elevation (STE), sum of STE (sumSTE), time to normalization of STE, and development of negative T wave with the extent of LGE (expressed as % of left ventricular mass [%LV LGE]), was evaluated.Results:Most (80%) patients presented with inferolateral STE; mean sumSTE was 5 ± 3 mm. Normalization of STE occurred within 24 hours in 20 (49%) patients. Development of negative T wave occurred in 28 (68%) patients. Cardiac MRI showed LGE in all patients; mean %LV LGE was 9.6 ± 7.2%. Topographic agreement between site of STE and LGE was 68%. At multivariate analysis, sumSTE (β = 0.42, P < 0.001), normalization of STE >24 hours (β = 0.39, P < 0.001), and development of negative T wave (β = 0.49, P < 0.001) were independently related to %LV LGE.Conclusions:Analysis of the site of STE underestimates the extent of myocardial injury among patients with infarct‐like myocarditis. However, some ECG features (ie, sumSTE, normalization of STE >24 hours, and development of negative T wave) may help to identify patients with larger areas of myocardial damage.The authors have no funding, financial relationships, or conflicts of interest to disclose.
Synthesis and Biological Evaluation of Diaryl‐Substituted Carboranes as Inhibitors of Hypoxia Inducible Factor (HIF)‐1 Transcriptional Activity
Authors: Minegishi Hidemitsu , Matsukawa Takuya , Nakamura Hiroyuki 
Published: December 2012

AbstractDiaromatic‐substituted ortho‐ and meta‐carboranes were synthesized as mimics of manassantin A. Among the carboranes synthesized, compounds 1 and 2 showed significant inhibition of hypoxia‐induced HIF‐1 transcriptional activity, with IC50 values of 3.2 and 2.2 μM, respectively. Compounds 1 and 2 similarly suppressed hypoxia‐induced HIF‐1α accumulation in a concentration‐dependent manner without affecting the expression level of HIF‐1α mRNA. The hypoxia‐induced accumulation and translocation of HIF‐1α into nuclei were not observed in HeLa cells treated with compounds 1 and 2 by immunofluorescence analysis, revealing that the inhibition of hypoxia‐induced HIF‐1 transcriptional activity is induced by compounds 1 and 2 through a degradation pathway of the HIF‐1α protein under hypoxic conditions.
Butyltin(IV) Benzoates: Inhibition of Thioredoxin Reductase, Tumor Cell Growth Inhibition, and Interactions with Proteins
Authors: Navakoski de Oliveira Kely , Andermark Vincent , von Grafenstein Susanne , Onambele Liliane A. , Dahl Gregor , Rubbiani Riccardo , Wolber Gerhard , Gabbiani Chiara , Messori Luigi , Prokop Aram , Ott Ingo 
Published: December 2012

AbstractThioredoxin reductase (TrxR) is overexpressed in cancer cells and is therefore a putative cancer target. Inhibition of this enzyme is considered an important strategy for the development of new chemotherapeutic agents with a specific mechanism of action. Organotin compounds have been described as experimental antitumor agents, yet their mechanism of action remains largely unknown. Based on the outcome of a virtual screening study, various di‐ and tri‐n‐butyltin(IV) carboxylates were synthesized, and their biological properties were evaluated. All synthesized compounds were able to inhibit TrxR selectively within the micromolar range and showed potent antitumor activity against HT‐29 and MCF‐7 cancer cell lines. Moreover, tin(IV) organometallics were found to strongly induce apoptosis in the BJAB lymphoma cell line. Mass spectrometry and atomic absorption spectroscopy experiments revealed metal binding to proteins, and efficient cellular uptake was observed using a di‐n‐butyltin(IV) complex as an example.
How to Tickle Spins with a Fourier Transform NMR Spectrometer
Authors: Segawa Takuya F. , Carnevale Diego , Bodenhausen Geoffrey 
Published: December 2012

AbstractIn the long bygone days of continuous‐wave nuclear magnetic resonance (NMR) spectroscopy, a selected transition within a multiplet of a high‐resolution spectrum could be irradiated by a highly selective continuous‐wave (CW) radio‐frequency (rf) field with a very weak amplitude ${\omega _2 }$/(2π)≤J. This causes splittings of connected transitions, allowing one to map the connectivities of all transitions within the energy‐level diagram of the spin system. Such “tickling” experiments stimulated the invention of two‐dimensional spectroscopy, but seem to have been forgotten for nearly 50 years. We show that tickling can readily be achieved in homonuclear systems with Fourier transform spectrometers by applying short pulses in the intervals between the sampling points. Extensions to heteronuclear systems are even more straightforward since they can be carried out using very weak CW rf fields.
Debinding Mechanisms in Thermoplastic processing of a Ba0.5Sr0.5Co0.8Fe0.2O3−δ‐ Stearic Acid–Polystyrene Mixture
Authors: Salehi Mehdi , Clemens Frank , Otal Eugenio H. , Ferri Davide , Graule Thomas , Grobéty Bernard 
Published: December 2012

AbstractIn the present study, we address the interaction between a thermoplastic binder system and Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) during thermal treatment of the thermoplastic feedstock. BSCF powder was coated with different amounts of stearic acid (SA) acting as a surfactant. Oxygen release from the uncoated BSCF surface changes the decomposition of polystyrene (PS) in inert atmospheres from a pyrolytic to a thermoxidative mechanism, thereby decreasing the break‐down temperature and the activation energy. In mixtures with coated BSCF powder, the decomposition products of SA carbonatize the BSCF surface, which inhibits oxygen release. Mass spectrometry of the breakdown products indicates that the decomposition of SA in the presence of BSCF also modifies the decomposition pathway of PS. The influence of BSCF on the polymer decomposition reaction in air is not as strong. Oxygen diffusion seems to be responsible for the differences to pure PS in reaction rates and the activation energies.
Structural and Photoelectrochemical Evaluation of Nanotextured Sn‐Doped AgInS2 Films Prepared by Spray Pyrolysis
Authors: Cheng Qian , Peng Xihong , Chan Candace K. 
Published: December 2012

AbstractSpray pyrolysis was used to prepare films of AgInS2 (AIS) with and without Sn as an extrinsic dopant. The photoelectrochemical performance of these films was evaluated after annealing under a N2 or S atmosphere with different amounts of the Sn dopant. DFT was used to calculate the band structure of AIS and understand the role of Sn doping in the observed properties. All AIS films were n‐type, and Sn was found to increase the photocurrent and carrier concentration of AIS with an optimum doping level of x=[Sn]/([Ag]+[In])=0.02, which gave a photocurrent of 4.85 mA cm−2. Above this level, the Sn dopants were detrimental to the photoelectrochemical performance, likely a result of a self‐compensating effect and the introduction of a deep acceptor level, which could act as a recombination site for photogenerated carriers.
Ordered Mesoporous Tungsten Suboxide Counter Electrode for Highly Efficient Iodine‐Free Electrolyte‐Based Dye‐Sensitized Solar Cells
Authors: Jeong Inyoung , Jo Changshin , Anthonysamy Arockiam , Kim Jung‐Min , Kang Eunae , Hwang Jongkook , Ramasamy Easwaramoorthi , Rhee Shi‐Woo , Kim Jin Kon , Ha Kyoung‐Su , Jun Ki‐Won , Lee Jinwoo 
Published: December 2012

AbstractA disulfide/thiolate (T2/T−) redox‐couple electrolyte, which is a promising iodine‐free electrolyte owing to its transparent and noncorrosive properties, requires alternative counter‐electrode materials because conventional Pt shows poor catalytic activity in such an electrolyte. Herein, ordered mesoporous tungsten suboxide (m‐WO3−x), synthesized by using KIT‐6 silica as a hard template followed by a partial reduction, is used as a catalyst for a counter electrode in T2/T−‐electrolyte‐based dye‐sensitized solar cells (DSCs). The mesoporous tungsten suboxide, which possesses interconnected pores of 4 and 20 nm, provides a large surface area and efficient electrolyte penetration into the m‐WO3−x pores. In addition to the advantages conferred by the mesoporous structure, partial reduction of tungsten oxide creates oxygen vacancies that can function as active catalytic sites, which causes a high electrical conductivity because of intervalence charge transfer between the W5+ and W6+ ions. m‐WO3−x shows a superior photovoltaic performance (79 % improvement in the power conversion efficiency) over Pt in the T2/T− electrolyte. The superior catalytic activity of m‐WO3−x is investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization curve analysis.
Production of Hybrid Diesel Fuel Precursors from Carbohydrates and Petrochemicals Using Formic Acid as a Reactive Solvent
Authors: Zhou Xiaoyuan , Rauchfuss Thomas B. 
Published: December 2012

AbstractWe report the one‐pot alkylation of mesitylene with carbohydrate‐derived 5‐(hydroxymethyl)furfural (HMF) as a step toward diesel‐range liquids. Using FeCl3 as a catalyst, HMF is shown to alkylate toluene, xylene, and mesitylene in high yields in CH2Cl2 and MeNO2 solvents. Efforts to extend this reaction to greener or safer solvents showed that most ether‐based solvents are unsatisfactory. Acid catalysts (e.g, p‐TsOH) also proved to be ineffective. Using formic acid as a reactive solvent, mesitylene could be alkylated to give mesitylmethylfurfural (MMF) starting from fructose with yields up to approximately 70 %. The reaction of fructose with formic acid in the absence of mesitylene gave rise to low yields of the formate ester of HMF, which indicates the stabilizing effect of replacing the hydroxyl substituent with mesityl. The arene also serves as a second phase into which the product is extracted. Even by using formic acid, the mesitylation of less expensive precursors such as glucose and cellulose proceeded only in modest yields (ca. 20 %). These simpler substrates were found to undergo mesitylation by using hydrogen chloride/formic acid via the intermediate chloromethylfurfural.
Occupational exposures to aluminum and iron and risk of lung epithelium atypia in sudan
Authors: Ahmed Hussain Gadelkarim , Mahmoud Tagreed Ahmed , Ginawi Ibrahim A. 
Published: December 2012

AbstractThis study investigated the risk of lung cytological atypical changes in regards to occupational exposure to aluminum and iron. Detailed job histories were elicited from 130 incident cases with confirmed exposure to aluminum (50) or iron (80) and 157 population controls (nonexposed). Cytological atypia in sputum (dysplasia) was identified in four cases and none of controls (RR =10.8550; 95% CI = 0.5898 to 199.7815, P = 0.1086), hence, metaplasia was observed among 15 (11.5%) of the cases and 10 (6%) of controls (RR = 1.8115; 95% CI = 0.8424–3.8956; P = 0.1283). Evidences of viral infection were observed in 18 (14%) of the cases and 8 (5%) of controls (RR = 2.7173; 95% CI = 1.2213–6.0460; P = 0.0143). Moniliasis was observed in 28 (22%) of the cases and 19 (12%) of controls (RR = 1.6632; 95% CI = 0.9728–2.8435; P = 0.06). Cross‐categorizations of aluminum exposure and iron use suggest greater risk associated with iron exposure than aluminum in these workers. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.
Electrochemical Immunosensor for Ultrasensitive Detection of Human Chorionic Gonadotropin Based on Pd@SBA‐15
Authors: Wu Dan , Zhang Yong , Shi Li , Cai Yanyan , Ma Hongmin , Du Bin , Wei Qin 
Published: December 2012

AbstractA simple and sensitive electrochemical immunosensor was conducted for the determination of human chorionic gonadotropin (hCG) with Pd@SBA‐15. Thionine (TH) was selected as an electron transfer mediator, and modified onto the electrode together with functionalized graphene nanomaterial (HSO3−GS) through electrostatic adsorption. Then Pd@SBA‐15 was immobilized onto the as‐prepared film for biomolecules anchoring. Pd@SBA‐15 composites not only retain the good biocompatibility of the SBA‐15, but also exhibit an excellent catalytic activity of Pd and low Pd leaching. hCG antibody was immobilized onto the composite film for the detection of hCG. hCG can be determined in the range of 0.01–16.00 ng/mL and the detection limit is 8.60 pg/mL. The method has been applied to the analysis of hCG in human serum samples with satisfactory results.
Multiwalled Carbon Nanotubes Modified by NTA‐Copper Complex for Label‐Free Electrochemical Immunosensor Detection
Authors: Chebil S. , Macauley N. , Hianik T. , Korri‐Youssoufi H. 
Published: December 2012

AbstractA biomaterial based on multiwalled carbon nanotubes (MWCNTs) modified with His‐tagged single chain D‐dimer antibody trough nitrilo‐triacetic‐acid (NTA)/copper complex was designed for monitoring D‐dimers, which were used as biomarkers of Deep Vein Thrombosis (DVT). The immunosensing evaluation of D‐Dimer was followed by measuring the redox process of such complex. We demonstrate that using simple chemistry and exploiting the high surface area, electronic properties of MWCNTs and redox signal of the NTA/Cu2+ complex an efficient electrochemical immunosensor for the evaluation of wide range of D‐dimer concentrations was obtained.
Hybridization Detection of Osmium Tetroxide Bipyridine‐Labeled DNA and RNA on Heated Gold Wire Electrodes
Authors: Jacobsen Martin , Flechsig Gerd‐Uwe 
Published: December 2012

AbstractWe report about hybridization detection of different nucleic acids on capture probe‐modified heated gold wire electrodes. We have compared three kinds of nucleic acid targets: DNA, uracil‐conjugated DNA, and RNA. All three sorts of nucleic acids targets could be labeled with osmium tetroxide bipyridine, hybridized with immobilized DNA capture probes and then detected by square‐wave voltammetry. Heating the gold electrode instead of the entire bulk hybridization solution leads to improved hybridization efficiency in most cases. The reason could be found in a thermal micro‐stirring effect around the heated wire electrode. Also selectivity was improved. Mismatches could be discriminated for DNA and uracil‐conjugated DNA targets. Mismatches in RNA strands, however, are more difficult to detect due to relatively stable secondary structures.
Simultaneous Determination of Antimony(III) and Molybdenum(VI) by Adsorptive Stripping Voltammetry Using Quercetin as Complexing Agent
Authors: Rojas Carlos , Arancibia Verónica , Gómez Marisol , Nagles Edgar 
Published: December 2012

AbstractA sensitive and selective voltammetric method for simultaneous determination of Sb(III) and Mo(VI) using Quercetin (Q) as complexing agent is described. Optimal conditions were found to be: pH 3.7, CQ=6.0 µmol L−1 and Eacc=−0.10 V. The LOD (3σ) for Sb(III) are 0.076 and 0.040 µg L−1, whereas for Mo(VI) are 0.086 and 0.048 µg L−1 with tacc of 60 and 120 s, respectively. The method was validated using synthetic sea water (ASTM D665) and was applied to the determination of Sb(III) and Mo(VI) in natural waters with satisfactory results.
Label‐Free Analysis of Thrombin or Hg2+ Ions by Nucleic Acid‐Functionalized Graphene Oxide Matrices Assembled on Field‐Effect Transistors
Authors: Sharon Etery , Liu Xiaoqing , Freeman Ronit , Yehezkeli Omer , Willner Itamar 
Published: December 2012

AbstractGraphene oxide (GO) is deposited onto the Al2O3 gates of field‐effect transistor devices to yield a functional matrix for the sensing of thrombin or Hg2+ ions. The deposition of an aptamer subunit against thrombin or a tailored nucleic acid with appropriate T mismatches on the GO, yield active surfaces for the analysis of thrombin or Hg2+ ions. The desorption of the aptamer‐subunit from GO, through the formation of the aptamer‐thrombin complex, or the desorption of the T–Hg2+–T‐bridged duplex DNA alter the gate potential, thus providing a signal for the sensing events.