bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Friedel—Crafts Arylation for the Formation of C(sp2)—C(sp2) Bonds: A Route to Unsymmetrical and Functionalized Polycyclic Aromatic Hydrocarbons from Aryl Triazenes.
Authors: Zhou Jun , Yang Weijun , Wang Binjie , Ren Hongjun
Published: May 2013

Treatment of aryltriazene substrates with the Lewis acid boron trifluoride promotes the formation of a phenyl cation and results in a regioselective intramolecular Friedel—Crafts arylation to form various title skeletons.
ChemInform Abstract: Synthesis of Trifluormethyl Substituted Oxetenes by the Reaction of Acetylenedicarboxylate with Trifluoromethyl Ketone in the Presence of Triphenylphosphine.
Authors: Fan Huafang , Wang Xiaowei , Zhao Jingwei , Li Xinjin , Gao Jinming , Zhu Shizheng
Published: May 2013

The obtained trifluoromethyl substituted oxetenes are stable in the presence of some Lewis acids.
ChemInform Abstract: Convenient Propylphosphonic Anhydride (T3P®)‐Mediated Synthesis of β‐Sultams
Authors: Zarei Maaroof
Published: May 2013

[via [2 + 2]‐cycloaddition of imines with sulfenes].
ChemInform Abstract: Highly Enantioselective Rh‐Catalyzed Carboacylation of Olefins: Efficient Syntheses of Chiral Poly‐Fused Rings.
Authors: Xu Tao , Ko Haye Min , Savage Nikolas A. , Dong Guangbin
Published: May 2013

This method can be used to prepare certain nontrivial chiral carbon frameworks.
ChemInform Abstract: First One‐Pot Organocatalytic Synthesis of α‐Methylene‐γ‐lactones.
Authors: Companyo Xavier , Mazzanti Andrea , Moyano Albert , Janecka Anna , Rios Ramon
Published: May 2013

The reaction between protected 2‐hydroxymalonates (II) and Morita—Baylis—Hillman carbonates (I) is catalyzed by chiral cinchona‐derived Lewis bases.
ChemInform Abstract: Synthesis of Thienyl‐Substituted Dihydrofuran Compounds Promoted by Manganese(III) Acetate.
Authors: Bicer Emre , Yilmaz Mehmet , Burgaz E. Vildan , Pekel A. Tarik
Published: May 2013

The radical reaction of diones with thienyl substituted alkenes gives the corresponding products in moderate to high yields.
ChemInform Abstract: Regio‐ and Stereoselective Allylation and Crotylation of Indoles at C2 Through the Use of Potassium Organotrifluoroborate Salts.
Authors: Nowrouzi Farhad , Batey Robert A.
Published: May 2013

This method proceeds with high regio‐ and diastereoselectivity.
ChemInform Abstract: Organocatalytic Asymmetric Michael Addition of Oxazolones to Arylsulfonyl Indoles: Facile Access to syn‐Configured α,β‐Disubstituted Tryptophan Derivatives.
Authors: Cai Chang‐Wu , Zhu Xing‐Li , Wu Song , Zuo Zong‐Le , Yu Liang‐Liang , Qin Da‐Bin , Liu Quan‐Zhong , Jing Lin‐Hai
Published: May 2013

For the first time the highly stereoselective title Michael addition reaction is presented.
ChemInform Abstract: Sulfoxide‐TFAA and Nucleophile Combination as New Reagent for Aliphatic C—H Functionalization at Indole 2α‐Position.
Authors: Tayu Masanori , Higuchi Kazuhiro , Inaba Masato , Kawasaki Tomomi
Published: May 2013

A new procedure for the C—H functionalization at indole 2α‐position is developed using a combination of dimethyl sulfoxide, trifluoroacetic anhydride, and a nucleophile.
ChemInform Abstract: Group 11 Metal Amide‐Catalyzed Asymmetric Cycloaddition Reactions of Azomethine Imines with Terminal Alkynes.
Authors: Imaizumi Takaki , Yamashita Yasuhiro , Kobayashi Shu
Published: May 2013

This reaction proceeds with high regioselectivity.
ChemInform Abstract: Chemoselective Synthesis of Substituted Pyrazoles Through AgOTf‐Catalyzed Cascade Propargylic Substitution—Cyclization—Aromatization.
Authors: Xu Su‐Xia , Hao Lu , Wang Tao , Ding Zong‐Cang , Zhan Zhuang‐Ping
Published: May 2013

Silver‐catalyzed reaction of propargylic alcohols (I) with tosylhydrazine leads to 3,5‐disubstituted 1H‐pyrazoles (II), whilst the analogous reaction of terminal alkynes (VII) gives rise to N‐tosyl pyrazoles (VIII).
ChemInform Abstract: Water‐Based Conditions for the Microscale Parallel Synthesis of Bicyclic Lactams.
Authors: Malaquin Sandra , Jida Mouhamad , Courtin Justin , Laconde Guillaume , Willand Nicolas , Deprez Benoit , Deprez‐Poulain Rebecca
Published: May 2013

Simple conditions are developed for the reaction of keto acids with dinucleophiles.
ChemInform Abstract: Synthesis, Antimicrobial and Antitubercular Activity of Some Novel [3‐Isonicotinoyl‐5‐(4‐substituted)‐2,3‐dihydro‐1,3,4‐oxadiazol‐2‐yl] and Substituted 5‐(Pyridin‐4‐yl)‐1,3,4‐oxadiazole‐2‐thiol Derivatives.
Authors: Pattan Shashikant , Musmade Deepak , Muluk Rekha , Pawar Sonali , Daithankar Aarati , Wabale Nikita , Bhawar Sanjay , Pattan Jayashri
Published: May 2013

A series of novel 2,5‐diaryloxadiazole (III) and mercaptooxadiazole derivatives (VIII) are synthesized, which show promising antibacterial, antifungal and antitubercular activities.
ChemInform Abstract: Asymmetric Conjugate Addition of Grignard Reagents to Pyranones.
Authors: Mao Bin , Fananas‐Mastral Martin , Feringa Ben L.
Published: May 2013

The combination of cuprous bromide/dimethyl sulfide complex with reversed (R,S)‐Josiphos ligand is successfully applied as a catalytic system for the asymmetric conjugate addition of Grignard reagents (II) to dihydropyranone (I) and pyranone (IV) derivatives leading to 4‐substituted tetrahydropyranones (III) and 3,4‐dihydropyranones (V), respectively.
ChemInform Abstract: Synthesis of 4H‐Pyran Derivatives under Solvent‐Free and Grinding Conditions.
Authors: Smits Rufus , Belyakov Sergey , Plotniece Aiva , Duburs Gunars
Published: May 2013

An efficient and environmentally friendly synthesis of the title compounds (IV) is developed using a multicomponent room‐temperature grinding procedure.
ChemInform Abstract: One‐Pot Synthesis of 2‐Aryl‐3‐alkoxycarbonyl Chromones Through a Cascade Lewis Acid‐Catalyzed Aldehyde Olefination/Oxa‐Michael Addition/Oxidation.
Authors: Wang Ningning , Cai Shuying , Zhou Chao , Lu Ping , Wang Yanguang
Published: May 2013

The presented method is conducted in one‐pot with high atom efficiency compared to the previously established route to the target compounds involving four steps.
ChemInform Abstract: Organocatalytic Conjugate Addition Promoted by Multi‐Hydrogen‐Bond Cooperation: Access to Chiral 2‐Amino‐3‐nitrile‐chromenes.
Authors: Li Wenjun , Huang Jiayao , Wang Jian
Published: May 2013

A new and efficient synthesis of different substituted chromenes is presented.
ChemInform Abstract: Synthesis of ortho/ortho′‐Substituted 1,1‐Diarylethylenes Through Cross‐Coupling Reactions of Sterically Encumbered Hydrazones and Aryl Halides.
Authors: Roche Maxime , Hamze Abdallah , Provot Olivier , Brion Jean‐Daniel , Alami Mouad
Published: May 2013

Broad spectrum of both coupling partners is tolerated, regardless the electronic and steric properties.
ChemInform Abstract: Simple and Cost Effective Acid Catalysts for Efficient Synthesis of 9‐Aryl‐1,8‐dioxooctahydroxanthene.
Authors: Ilangovan A. , Muralidharan S. , Sakthivel P. , Malayappasamy S. , Karuppusamy S. , Kaushik M. P.
Published: May 2013

The condensation of dimedone with aromatic aldehydes can be catalyzed by CaCl2 or HBr.
ChemInform Abstract: N‐Heterocyclic‐Carbene‐Catalyzed Asymmetric Oxidative Hetero‐Diels—Alder Reactions with Simple Aliphatic Aldehydes.
Authors: Zhao Xiaodan , Ruhl Kyle E. , Rovis Tomislav
Published: May 2013

A NHC‐catalyzed condensation of α‐substituted acetaldehydes with α,β‐unsaturated imines or ketones is developed in the presence of organic oxidants to yield trans‐lactams and cis‐lactones highly stereoselectively.
ChemInform Abstract: Diverse Reactivity in a Rhodium(III)‐Catalyzed Oxidative Coupling of N‐Allyl Arenesulfonamides with Alkynes.
Authors: Wang Dongqi , Wang Fen , Song Guoyong , Li Xingwei
Published: May 2013

Depending on the reaction conditions, the oxidative Rh‐catalyzed and Ag(I)‐mediated process provides pyridine or sterically defined cyclopentanone scaffolds.
ChemInform Abstract: Copper‐Catalyzed Highly Regioselective 2‐Aryloxylation of 2,x‐Dihalopyridines.
Authors: Zhou Qizhong , Zhang Bin , Du Tieqi , Gu Haining , Ye Yuyuan , Jiang Huajiang , Chen Rener
Published: May 2013

The title reaction is achieved for the first time.
ChemInform Abstract: Direct C3‐Alkenylation of Pyridin‐4(1H)‐one via Oxidative Heck Coupling.
Authors: Zhang Guangling , Li Ziyuan , Huang Yue , Xu Jinyi , Wu Xiaoming , Yao Hequan
Published: May 2013

Selective C3‐alkenylation of 2,5‐disubstituted pyridin‐4(1H)‐ones succeeds via Pd‐catalyzed oxidative Heck coupling.
ChemInform Abstract: Metal‐Free Construction of Tricyclic or Tetracyclic Compounds—Acid‐Promoted Synthesis of Benzo[4,5]imidazo[2,1‐a]isoindole and 1,2‐Dialkyl‐2,3‐dihydrobenzimidazoles.
Authors: Chen Jinying , Qu Jinpeng , Zhang Yuanqing , Chen Yongxin , Liu Na , Chen Baohua
Published: May 2013

The mechanistic proposal for this reaction consists of a cycloamination involving one of the amine functionalities followed by elimination of one of the newly formed hydroxyl groups, rearomatization and a final cyclocondensation.
ChemInform Abstract: One‐Pot Ring‐Closing Metathesis/1,3‐Dipolar Cycloaddition Through Assisted Tandem Ruthenium Catalysis: Synthesis of a Dye with Isoindolo[2,1‐a]quinoline Structure.
Authors: Arisawa Mitsuhiro , Fujii Yuki , Kato Hiroshige , Fukuda Hayato , Matsumoto Takashi , Ito Mika , Abe Hiroshi , Ito Yoshihiro , Shuto Satoshi
Published: May 2013

This reaction yields chromophoric isoindolo[2,1‐α]quinoline derivatives with the color depending on the substituents.
ChemInform Abstract: A Serendipitous Conversion of Enaminolactone Nitriles with Primary Amines: A New Synthesis of Substituted 2‐Aminopyridine Derivatives.
Authors: Cheikh Nawel , Villemin Didier , Bar Nathalie , Lohier Jean‐Francois , Choukchou‐Braham Nourredine , Mostefa‐Kara Bachir , Sopkova Jana
Published: May 2013

Novel fused 2‐aminopyridines are synthesized from enaminolactone nitrile (III) and various primary amines including chiral ones.
ChemInform Abstract: An Electrochemical Nickel‐Catalyzed Arylation of 3‐Amino‐6‐chloropyridazines.
Authors: Sengmany Stephane , Vitu‐Thiebaud Arnaud , Le Gall Erwan , Condon Sylvie , Leonel Eric , Thobie‐Gautier Christine , Pipelier Muriel , Lebreton Jacques , Dubreuil Didier
Published: May 2013

The electrochemical method for the synthesis of 3‐amino‐6‐arylpyridazines is complementary to the classic Suzuki‐, Stille‐ or Nigishi‐cross‐coupling reactions and provides the products with higher yields.
ChemInform Abstract: Nano Copper Oxide Mediated Ligand‐Free C—S Cross‐Coupling and Concomitant Oxidative Aromatization of 4‐Aryl‐3,4‐dihydropyrimidin‐2(1H)‐thione with Diaryliodonium Salts.
Authors: Bhong Bhagyashree Y. , Shelke Amol V. , Karade Nandkishor N.
Published: May 2013

The optimized conditions allow the simple and efficient synthesis of a broad spectrum of synthetically and biologically important (2‐thioaryl)pyrimidine derivatives.
ChemInform Abstract: New Synthesis of 3,5‐Disubstituted‐5H‐thiazolo[3,2‐α]pyrimidine via Ring Annulation of 3,4‐Dihydropyrimidin‐2(1H)‐thione Using Alkynyl(aryl)iodonium Salts.
Authors: Shelke Amol V. , Bhong Bhagyashree Y. , Karade Nandkishor N.
Published: May 2013

The simple transition metal free protocol uses reagents (II) as synthons of alkynyl cations for the preparation of the pharmacologically important heterocyclic scaffold.
ChemInform Abstract: A Highly Facile Approach to the Synthesis of Novel 2‐(3‐Benzyl‐2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐1‐yl) ‐N‐phenylacetamides.
Authors: Novikov Mikhail S. , Babkov Denis A. , Paramonova Maria P. , Chizhov Alexander O. , Khandazhinskaya Anastasia L. , Seley‐Radtke Katherine L.
Published: May 2013

A facile and high‐yielding procedure for the preparation of N‐arylacetamides (IV) via N‐silylation is developed which avoids intractable work‐up and by‐products.
ChemInform Abstract: Efficient Synthesis of 5H‐Indazolo[3,2‐b]‐1,3,4‐benzotriazepines by a Tandem Aza‐Wittig Cyclization.
Authors: Zhao Fen‐Fen , Zhang Hao , Ding Ming‐Wu
Published: May 2013

A facile protocol allows the synthesis of new benzotriazepine derivatives from azides (I) via formation of a phosphazide intermediate and subsequent intramolecular cyclization.
ChemInform Abstract: Reductive Coupling Reactions: A New Strategy for C(sp3)—P Bond Formation.
Authors: Chen Zi‐Sheng , Zhou Zhao‐Zhao , Hua Hui‐Liang , Duan Xin‐Hua , Luo Jian‐Yi , Wang Jia , Zhou Ping‐Xin , Liang Yong‐Min
Published: May 2013

A C(sp3)‐P bond formation reaction utilizing N‐tosylhydrazones as readily available alkylating reagents is developed.
ChemInform Abstract: Germatranes and Their Quasi and Hypo Analogues with Highly Electronegative Substituent at the Ge Atom
Authors: Voronkov M. G. , Korlyukov A. A. , Samokhin G. S. , Vrazhnov D. V. , Kochina T. A.
Published: May 2013

synthesis and characterization by IR spectroscopy
ChemInform Abstract: SN2 Substitution Reaction of 2‐C‐Acetoxymethyl Glycals Catalyzed by Iodine: A Novel Synthesis of 2‐C‐N‐Arylamidomethyl Glycals.
Authors: Yadav J. S. , Narasimhulu G. , Umadevi N. , Reddy Y. Vikram , Reddy B. V. Subba
Published: May 2013

It is demonstrated that iodine is an efficient catalyst for the nucleophilic substitution of glycals with N‐aryl amides.
ChemInform Abstract: Nanoscale (111) Faceted Rock‐Salt Metal Oxides in Catalysis
Authors: Cadigan Christopher A. , Corpuz April R. , Lin Feng , Caskey Christopher M. , Finch Kenneth B. H. , Wang Xue , Richards Ryan M.
Published: May 2013

Review: 170 refs.
ChemInform Abstract: Hierarchical Assembly of Multifunctional Oxide‐Based Composite Nanostructures for Energy and Environmental Applications
Authors: Gao Pu‐Xian , Shimpi Paresh , Gao Haiyong , Liu Caihong , Guo Yanbing , Cai Wenjie , Liao Kuo‐Ting , Wrobel Gregory , Zhang Zhonghua , Ren Zheng , et al. et al.
Published: May 2013

Review: 56 refs.
ChemInform Abstract: Nanostructured Photoelectrodes Based on WO3: Applications to Photooxidation of Aqueous Electrolytes
Authors: Bignozzi Carlo Alberto , Caramori Stefano , Cristino Vito , Argazzi Roberto , Meda Laura , Tacca Alessandra
Published: May 2013

Review: 58 refs.
ChemInform Abstract: N‐Heterocyclic Carbene Ligands and Iron: An Effective Association for Catalysis
Authors: Bezier David , Sortais Jean‐Baptiste , Darcel Christophe
Published: May 2013

Review: 141 refs.
ChemInform Abstract: Applications of Asymmetric Organocatalysis in Medicinal Chemistry
Authors: Aleman Jose , Cabrera Silvia
Published: May 2013

Review: 97 refs.
ChemInform Abstract: A Dynamic Route to Structure and Function: Recent Advances in Imine‐Based Organic Nanostructured Materials
Authors: Liu Yi , Li Zhan‐Ting
Published: May 2013

Review: ca. 80 refs.
ChemInform Abstract: Polycyclic Peptide Therapeutics
Authors: Baeriswyl Vanessa , Heinis Christian
Published: May 2013

Review: 57 refs.
ChemInform Abstract: Synthesis of Alkaloids Using Radical Cyclizations
Authors: Taniguchi Tsuyoshi , Ishibashi Hiroyuki
Published: May 2013

Review: 33 refs.
ChemInform Abstract: The Carbon—Ferrier Rearrangement: An Approach Towards the Synthesis of C‐Glycosides
Authors: Ansari Alafia Ali , Lahiri Rima , Vankar Yashwant D.
Published: May 2013

Review: 70 refs.
ChemInform Abstract: Recent Progress in the Synthesis of Glycosyl Phosphate Derivatives
Authors: Oka Natsuhisa , Sato Kazuki , Wada Takeshi
Published: May 2013

Review: 74 refs.
ChemInform Abstract: Beyond 1,3‐Difunctionalized Imidazolium Cations
Authors: Bara Jason E. , Shannon Matthew S.
Published: May 2013

Review: 49 refs.
ChemInform Abstract: Solvent Nanostructure, the Solvophobic Effect and Amphiphile Self‐Assembly in Ionic Liquids
Authors: Greaves Tamar L. , Drummond Calum J.
Published: May 2013

Review: 224 refs.
ChemInform Abstract: Value‐Added Bioconversion of Biomass by Solid‐State Fermentation
Authors: Chen Hong‐zhang , He Qin
Published: May 2013

Review: 46 refs.
ChemInform Abstract: Fuel Cell Electrocatalyst Using Polybenzimidazole‐Modified Carbon Nanotubes as Support Materials
Authors: Fujigaya Tsuyohiko , Nakashima Naotoshi
Published: May 2013

Review: 227 refs.
ChemInform Abstract: Aquasomes: A Novel Drug Carrier System
Authors: Pavani Vengala , Dintakurthi Shwetha , Aslam Sana , Gollagudem Rekha , Pabbapi Kumaraswamy
Published: May 2013

Review: 30 refs.
ChemInform Abstract: Current Options for the Treatment and Safe Disposal of Drill Cuttings
Authors: Ball Andrew S. , Stewart Richard J. , Schliephake Kirsten
Published: May 2013

Review: 100 refs.
ChemInform Abstract: The Calculations of Excited‐State Properties with Time‐Dependent Density Functional Theory
Authors: Adamo Carlo , Jacquemin Denis
Published: May 2013

Review: 60 refs.
Guideline Adherence of Antithrombotic Treatment Initiated by General Practitioners in Patients With Nonvalvular Atrial Fibrillation: A Danish Survey
Authors: Brandes Axel , Overgaard Mikkel , Plauborg Liane , Dehlendorff Christian , Lyck Frede , Peulicke Jørgen , Poulsen Søren Vinther , Husted Steen
Published: May 2013

Background

The aim of this prospective survey was to describe the demographics, stroke risk profile, and the guideline adherence of antithrombotic treatment in a Danish primary care population of patients with nonvalvular atrial fibrillation (AF).

Hypothesis

We hypothesized that a significant proportion of patients with nonvalvular AF do not receive guideline‐adherent antithrombotic treatment in primary care.

Methods

We performed a cross‐sectional survey of antithrombotic treatment using data of AF patients from general practices.

Results

Sixty‐four general practitioners enrolled 1743 patients with a mean age of 74.8 ± 11.2 years. The mean CHADS2 and CHA2DS2‐VASc scores were 1.9 ± 1.3 and 3.5 ± 1.8, respectively. Of the patients, 12.4% and 4.04%, respectively, were at truly low risk, with a CHADS2 and CHA2DS2‐VASc score 0 (P < 0.001). A score of 1 was seen in 28.0% vs 9.0% (P < 0.001) of the patients. Of all patients, 66.3% were treated with oral anticoagulants, 18.7% with antiplatelet drugs only, and 15% received no antithrombotic therapy. Based on the CHADS2 score, 75.7% of the patients were treated in adherence with the guidelines, 16% were undertreated, and 8.4% overtreated. The corresponding numbers for the CHA2DS2‐VASc score were 75.4%, 22.7%, and 1.8%, respectively. The differences in guideline adherence applying the 2 scores were significant (P < 0.001). Of patients receiving no antithrombotic therapy, 64.1% were treated in adherence to the guidelines according to the CHADS2 score. Applying the CHA2DS2‐VASc score, this proportion was only 53.4%. Antiplatelet drug treatment was in adherence to the guidelines (CHADS2 and CHA2DS2‐VASc score of 1) in only 31% and 12% of the patients, respectively.

Conclusions

Antithrombotic treatment of AF patients is in general well performed in primary care in Denmark. Further improvements may be achieved by thorough stroke risk stratification on the basis of current evidence‐based guidelines.
Statin Therapy in the Reduction of Cardiovascular Events in Patients Undergoing Intermediate‐Risk Noncardiac, Nonvascular Surgery
Authors: Raju Manjunath G. , Pachika Ajay , Punnam Sujeeth R. , Gardiner Joseph C. , Shishehbor Mehdi H. , Kapadia Samir R. , Abela George S.
Published: May 2013

Background

Hydroxymethylglutaryl‐coenzyme A reductase inhibitors (statins) reduce perioperative cardiac events in high‐risk patients undergoing cardiovascular surgery. However, there is paucity of data on the role of statins in patients undergoing intermediate‐risk noncardiac, nonvascular surgery (NCNVS).

Hypothesis

Statins are cardioprotective in intermediate‐risk NCNVS.

Methods

We identified a retrospective cohort of patients undergoing intermediate risk NCNVS. Our composite end point (CEP) included 30‐day all‐cause mortality, atrial fibrillation (AF), and nonfatal myocardial infarction (MI). A stepwise logistic regression with adjustment using propensity scores was performed to determine if statin therapy was independently associated with the risk reduction of adverse postoperative cardiovascular outcomes.

Results

We identified 752 patients. Seventy‐five of them (9.97%) developed composite end points; 10 (1.33%) had in‐hospital nonfatal MI, 44 (5.85%) developed AF, and 35 (4.65%) died within 30 days. The 30‐day all‐cause mortality was 31/478 (6.48%) among statin nonusers vs 4/274 (1.45%) for statin users (P < 0.002). As compared with nonusers, patients on statin therapy had a 5‐fold reduced risk of 30‐day all‐cause mortality. Statin therapy was associated with decreased CEP after adjusting for baseline characteristics, with a propensity score to predict use of statins (odds ratio [OR]: 0.54, 95% confidence interval [CI]: 0.30–0.97, P = 0.039). After further adjustment for propensity score, diabetes mellitus, percutaneous coronary intervention, and prior coronary artery bypass grafting, statin therapy proved beneficial (OR: 0.51, 95% CI: 0.28–0.92, P = 0.026).

Conclusions

Statin use in the perioperative period was associated with a reduction in cardiovascular adverse events and 30‐day all‐cause mortality in patients undergoing intermediate‐risk NCNVS.
Can Statins Improve Outcomes After Isolated Cardiac Valve Surgery? A Systematic Literature Review
Authors: Chacko Jacob , Harling Leanne , Ashrafian Hutan , Athanasiou Thanos
Published: May 2013

Background

HMG CoA (3‐hydroxy‐3‐methylglutaryl coenzyme A) reductase inhibitors, or statins, have been associated with an improvement in outcomes after coronary artery surgery for some time; however, their role in isolated valve surgery (IVS) remains undetermined.

Hypothesis

The pleiotropic effects of statins may produce similar beneficial effects on outcomes after IVS.

Methods

A systematic review of the literature was performed investigating the role of statins in bioprosthetic valve replacement.

Results

Nine observational studies (7 retrospective, 2 prospective) incorporating a total of 18 154 patients were found investigating the role of statin therapy in bioprosthetic valve replacement.

Conclusions

There is presently insufficient evidence to recommend routine statin therapy in IVS, unless concomitant hypercholesterolemia or coronary artery disease is present. A prospective study clearly defining the dose, type, and duration of therapy is now required to finally clarify whether statins alone confer a postoperative benefit in these patients.
Impacts of Mitral E/e′ on Myocardial Contractile Motion and Synchronicity in Heart Failure Patients With Reduced Ejection Fraction: An Exercise–Echocardiography Study
Authors: Wang Yi‐Chih , Yu Chih‐Chieh , Chiu Fu‐Chun , Tsai Chia‐Ti , Lai Ling‐Ping , Hwang Juey‐Jen , Lin Jiunn‐Lee
Published: May 2013

Background

The association between diastolic abnormality and postexercise contractile decompensation is uncertain in heart failure (HF) patients with reduced left ventricular ejection fraction (LVEF).

Hypothesis

The higher mitral E/annular early diastolic velocity (E/e′) is relevant to postexercise regional myocardial contractile maladaptation.

Methods

Seventy HF patients with LVEF <50 % (56 males, 58 ± 15 years) were studied pre‐ and postexercise using tissue Doppler echocardiography. We evaluated the mean and standard deviation of systolic myocardial velocity (Sm) and electromechanical delay (Ts) of 12 left ventricular segments, and further analyzed the corresponding changes of septal and posterolateral segments.

Results

The higher mitral E/e′ was associated with more blunted heterogeneity of Sm and greater ventricular dyssynchrony after exercise. This is due to the posterolateral wall not being able to increase Sm with exercise to the same degree as the septum (decreased posterolateral/septal Sm ratio). Furthermore, the postexercise aggravated difference of Ts between septum and posterolateral segments leads to more dyssynchronous contraction in the higher E/e′ groups. An E/e′ ≥10 predicted a postexercise posterolateral/septal Sm ≤ 1 (odds ratio [OR]: 5.8, 95% confidence interval [CI]: 1.5‐22.6, P = 0.011), and a difference of Ts between septum and posterolateral segments >65 ms (OR: 64, 95% CI: = 6–651, P < 0.001) in HF patients with reduced LVEF in multivariate analysis.

Conclusions

The higher mitral E/e′‐related postexercise maladaptation of myocardial contractile motion and synchronicity suggests the involvement of systolic abnormality in exercise pathophysiology in HF patients with reduced LVEF.
Design and Synthesis of 4‐(2,4,5‐Trifluorophenyl)butane‐1,3‐diamines as Dipeptidyl Peptidase IV Inhibitors
Authors: Zhu Linrong , Li Yuanyuan , Qiu Ling , Su Mingbo , Wang Xin , Xia Chunmei , Qu Yi , Li Jingya , Li Jia , Xiong Bing , Shen Jingkang
Published: May 2013

The worldwide prevalence of diabetes has spurred numerous studies on the development of new antidiabetic medicines. As a result, dipeptidyl peptidase IV (DPP4) has been recognized as a validated target. In our efforts to discover new DPP4 inhibitors, we analyzed the complexed structures of DPP4 available in Protein Data Bank and designed a series of triazole compounds. After enzyme activity assays and crystallographic verification of the binding interaction patterns, we found that the triazole compounds can inhibit DPP4 with micromolar IC50 values. Liver microsome stability and cytochrome P450 metabolic tests were performed on this series, revealing undesirable pharmacokinetic profiles for the triazole compounds. To overcome this liability, we substituted the triazole ring with an amide or urea group to produce a new series of DPP4 inhibitors. Based on its enzyme activity, metabolic stability, and selectivity over DPP8 and DPP9, we selected compound 21 r for further study of its in vivo effects in mice using an oral glucose tolerance test (OGTT). The results show that 21 r has efficacy similar to that of sitagliptin at a dose of 3 mg kg−1. The crystal structure of 21 r bound to DPP4 also reveals that the trifluoromethyl group is directed toward a subpocket different from the subsite bound by sitagliptin, providing clues for the design of new DPP4 inhibitors.
Series Circuit of Organic Thin‐Film Solar Cells for Conversion of Water into Hydrogen
Authors: Aoki Atsushi , Naruse Mitsuru , Abe Takayuki
Published: May 2013

A series circuit of bulk hetero‐junction (BHJ) organic thin‐film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. The BHJ OSCs applied consist of poly(3‐hexylthiophene) as a donor and [6,6]‐phenyl C61 butyric acid methyl ester as an acceptor. A series circuit of six such OSC units has an open circuit voltage (Voc) of 3.4 V, which is enough to electrolyze water. The short circuit current (Jsc), fill factor (FF), and energy conversion efficiency (η) are independent of the number of unit cells. A maximum electric power of 8.86 mW cm−2 is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mW cm−2, AM1.5G), and in one hour 0.65 mL hydrogen is generated.
Versatile Fluorescent Conjugated Polyelectrolyte‐Capped Mesoporous Silica Nanoparticles for Controlled Drug Delivery and Imaging
Authors: Pu Fang , Liu Xia , Yang Xinjian , Liu Zhen , Ren Jinsong , Wang Shu , Qu Xiaogang
Published: May 2013

Fluorescent conjugated polyelectrolytes (CPEs) with a large extinction coefficient, high quantum efficiency, good photostability, and efficient intramolecular/intermolecular exciton migration have recently received great research attention as a new generation of fluorescent probes. Herein, the unique properties of fluorescent conjugated polyelectrolyte and mesoporous silica nanoparticles (MSNs) are combined to prepare a pH‐sensitive drug delivery and cellular imaging system using a simple and more general method. To the best of our knowledge, this is the first proof‐of‐concept investigation on the use of fluorescent conjugated polyelectrolyte as both the capping agent of MSNs and the cellular imaging probe in parallel. Moreover, the bifunctional nanomaterial exhibits low cytotoxicity and good biocompatibility demonstrated by a cytotoxicity assay against HepG2 cells and a hemolysis assay against human red‐blood cells. It is a promising candidate for simultaneous diagnostics and therapeutics and can also provide a general strategy to develop novel multifunctional nanomedical systems.
Structural Characterization of Anion–Calcium–Humate Complexes in Phosphate‐based Fertilizers
Authors: Baigorri Roberto , Urrutia Oscar , Erro Javier , Mandado Marcos , Pérez‐Juste Ignacio , Garcia‐Mina José María
Published: May 2013

Fertilizers based on phosphate–metal–humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid31P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the31P NMR peaks. Computational chemistry methods allowed the characterization of phosphate–calcium–humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate–calcium–humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate–metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental31P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the31P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate–calcium interactions within the crystals.
Magnetism in Lithium–Oxygen Discharge Product
Authors: Lu Jun , Jung Hun‐Ji , Lau Kah Chun , Zhang Zhengcheng , Schlueter John A. , Du Peng , Assary Rajeev S. , Greeley Jeffrey , Ferguson Glen A. , Wang Hsien‐Hau , Hassoun Jusef , Iddir Hakim , Zhou Jigang , Zuin Lucia , Hu Yongfeng , Sun Yang‐Kook , Scrosati Bruno , Curtiss Larry A. , Amine Kahlil
Published: May 2013

Nonaqueous lithium–oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium‐ion batteries, and thus could render long‐range electric vehicles a reality. A molecular‐level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium–oxygen batteries. We demonstrate that the major discharge product formed in the lithium–oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc‐magnetization measurements and a lithium–oxygen cell containing an ether‐based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide‐type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide‐type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.
Sulfocerebrosides upregulate liposome uptake in human astrocytes without inducing a proinflammatory response
Authors: Suesca Elizabeth , Alejo Jose Luis , Bolaños Natalia I. , Ocampo Jackson , Leidy Chad , González John M.
Published: May 2013

Astrocytes are involved in the pathogenesis of demyelinating diseases, where they actively regulate the secretion of proinflammatory factors, and trigger the recruitment of immune cells in the central nervous system (CNS). Antigen presentation of myelin‐derived proteins has been shown to trigger astrocyte response, suggesting that astrocytes can directly sense demyelination. However, the direct response of astrocytes to lipid‐debris generated during demyelination has not been investigated. The lipid composition of the myelin sheath is distinct, presenting significant amounts of cerebrosides, sulfocerebrosides (SCB), and ceramides. Studies have shown that microglia are activated in the presence of myelin‐derived lipids, pointing to the possibility of lipid‐induced astrocyte activation. In this study, a human astrocyte cell line was exposed to liposomes enriched in each myelin lipid component. Although liposome uptake was observed for all compositions, astrocytes had augmented uptake for liposomes containing sulfocerebroside (SCB). This enhanced uptake did not modify their expression of human leukocyte antigen (HLA) molecules or secretion of chemokines. This was in contrast to changes observed in astrocyte cells stimulated with IFNγ. Contrary to human monocytes, astrocytes did not internalize beads in the size‐range of liposomes, indicating that liposome uptake is lipid specific. Epifluorescence microscopy corroborated that liposome uptake takes place through endocytosis. Soluble SCB were found to partially block uptake of liposomes containing this same lipid. Endocytosis was not decreased when cells were treated with cytochalasin D, but it was decreased by cold temperature incubation. The specific uptake of SCB in the absence of a proinflammatory response indicates that astrocytes may participate in the trafficking and regulation of sulfocerebroside metabolism and homeostasis in the CNS. © 2013 International Society for Advancement of Cytometry
A Computational Investigation of the Insertion of Carbon Dioxide into Four‐ and Five‐Coordinate Iridium Hydrides
Authors: Bernskoetter Wesley H. , Hazari Nilay
Published: May 2013

Recently, it has been demonstrated that the insertion of CO2 into iridium hydrides is a crucial step in the catalytic conversion of CO2 and H2 into formic acid. We and others have elucidated the mechanism by which CO2 inserts into six‐coordinate iridium(III) trihydrides supported by pincer ligands; these complexes are very active catalysts for CO2 hydrogenation. However, it has also been demonstrated that five‐coordinate iridium(III) dihydrides can react with CO2 and catalyze both thermal and electrochemical CO2 hydrogenation. In this work, we study the mechanism of CO2 insertion into pincer‐supported five‐coordinate iridium(III) dihydrides and four‐coordinate iridium(I) hydrides using density functional theory. The mechanisms differ slightly between the two cases. Insertion into the five‐coordinate species is a multistep process involving initial CO2 precoordination, whereas insertion into the four‐coordinate species proceeds via a single step with no prior CO2 coordination. Both of these mechanisms are different from the pathway that was recently proposed for CO2 insertion into six‐coordinate iridium(III) trihydrides. In addition, a complete pathway for catalytic CO2 hydrogenation using a five‐coordinate iridium(III) dihydride has been calculated.
Aroma characterization of flaxseed oils using headspace solid‐phase microextraction and gas chromatography‐olfactometry
Authors: Wei Changqing , Xi Wanpeng , Nie Xinyan , Liu Wenyu , Wang Qiang , Yang Beibei , Cao Dong
Published: May 2013

Flaxseed oil (FSO) has a distinct flavor among various types of vegetable oil. However, molecular information on FSO volatiles remains limited. In this study, a total of 60 compounds of FSO pressed from three main cultivars in Xinjiang, China, were tentatively identified and then semi‐quantified by the headspace solid phase micro‐extraction gas chromatography‐mass spectrometry (HS‐SPME‐GC‐MS) technique. Thirty of them were previously unknown as volatiles in FSO. These compounds could be categorized into eight groups (with the total numbers and numbers of new compounds per group between brackets): aldehydes (20; 10), ketones (7; 4), alcohols (13; 6), carboxylic acids (8; 3), esters (3; 1), alkanes (3; 3), heterocyclic compounds (4; 2), and other compounds (2; 1). Odor‐specific magnitude estimation (OSME) analysis revealed 53 aroma active compounds in three kinds of FSO in a consensus by using GC‐O, of which (E, E)‐2,4‐pentadienal (green, oily), (E, E)‐2,4‐heptadienal (sweet, hazelnut, woody), 5‐ethyldihydro‐2(3H)‐furanone (cereal‐like), 1‐hexanol (herbaceous, woody, green), acetic acid (sour, pungent, strong), and butyrolactone (sweet, caramel), perceived with high intensity (3.0, OSME values), and are therefore considered as major contributors to the characteristic FSO odor in Xinjiang, China.

Practical applications: Volatile compounds, whether major or minor, are crucial to FSO quality. Some of them make no direct contribution to the aroma, could be of important help to understand the formation and degradation of the volatiles with significant contribution to aroma, and they may additionally provide useful quality markers. The flavor of FSO varies widely, depending on fruit variety, degree of fruit ripeness, environmental conditions, growing region, and techniques of processing and storage. Therefore, the present study might be useful to identify purity or blending of FSO and may provide information for the producing conditions and the origin of the basic raw material.
The Disubstitution of Acetals to Prepare δ,δ‐Bis(aryl) β‐Keto Esters
Authors: Priebbenow Daniel L. , Zou Liang‐Hua , Becker Peter , Bolm Carsten
Published: May 2013

An efficient catalytic protocol for the synthesis of δ,δ‐bis(aryl)‐substituted β‐keto esters has been developed. This method involves the Lewis acid catalysed disubstitution reaction of ester‐substituted silyl enol ether acetals with a series of aromatic nucleophiles to afford valuable functionalized β‐keto esters with several sites available for further derivatisation.
Pressurized CEC with amperometric detection using mixed‐mode monolithic column for rapid analysis of chlorophenols and phenol
Authors: Lu Lanxiang , Chen Yankai , Yu Xiaowei , Wu Xiangzong , Tang Fengxiang , Wu Xiaoping
Published: May 2013

A simple analysis of chlorophenols (2‐chlorophenol, 2,4‐dichlorophenol, 2,4,6‐trichlorophenol, and pentachlorophenol) and phenol was accomplished by coupling a pressurized CEC with amperometric detection (AD). Efficient and reproducible separation of these compounds was achieved within 9 min on a capillary monolithic stationary phase bonded with octadecyl ligands and sulfonate groups, where the selectivity and the retention of analytes can be functionally controlled by optimizing experimental variables, including organic modifier content, mobile phase pH, ionic strength, working electrode potential, separation voltage, and supplementary pressure. A mixed‐mode retention mechanism consisting of reverse‐phase chromatographic partition, electrostatic repulsion, and electrophoresis is considered to play roles in the separation. The use of ACN‐based media seems effectual in preventing the unfavorable irreversible adsorption on both wall and electrode, and offer higher sensitivity and less electrode fouling in AD of phenols. The LODs were in the range from 0.02 to 0.2 μg/mL with a wide linear dynamic range of 5000‐fold, while the peak area precision ranged from 3.2 to 7.5%. The feasibility of using this method in real analysis was evaluated by recovery estimates and comparative experiment on spiked tap water samples. Good recoveries of 80–110% were achieved. Additionally, a paired t‐test was used to correlate the two methods.
On‐line sample preconcentration technique based on a dynamic pH junction in CE‐amperometric detection for the analysis of biogenic amines in urine
Authors: Tang Wanrong , Ge Shuli , Gao Fan , Wang Guan , Wang Qingjiang , He Pingang , Fang Yuzhi
Published: May 2013

It is difficult to detect biogenic amines (BAs) in biological fluids because of their very low concentrations. In this paper, we reported an on‐line sample preconcentration method in CE‐amperometric detection (CE‐AD) based on a dynamic pH junction, and a concentration enhancement of approximately 100‐fold was achieved compared with the classical CE‐AD methods in the simultaneous analysis of six BAs in urine (dopamine, epinephrine, norepinephrine, tyramine, tryptamine, and serotonin). The technique is proposed based on the sharp pH change generated at the boundary between an acidic sample and the basic BGE zone. Under optimized conditions, all analytes were successfully focused and well separated within 20 min with high efficiency and sensitivity (LODs at S/N = 3 ranging from 5.34 to 68.3 nM). For the analysis of urine samples by this method, satisfactory recoveries were obtained without a complicated pretreatment step or derivatization process. Therefore, it is self‐evident that this approach for the analysis of real biological samples has great potential in the future.
Relating sulfate and methane dynamics to geology: Accretionary prism offshore SW Taiwan
Authors: Chuang Pei‐Chuan , Dale Andrew W. , Wallmann Klaus , Haeckel Matthias , Yang Tsanyao Frank , Chen Nai‐Chen , Chen Hsiao‐Chi , Chen Hsuan‐Wen , Lin Saulwood , Sun Chih‐Hsien , You Chen‐Feng , Horng Chorng‐Shern , Wang Yunshuen , Chung San‐Hsiung
Published: May 2013

Geochemical data (CH4, SO42−, I−, Cl−, particulate organic carbon (POC), δ13C‐CH4, and δ13C‐CO2) are presented from the upper 30 m of marine sediment on a tectonic submarine accretionary wedge offshore southwest Taiwan. The sampling stations covered three ridges (Tai‐Nan, Yung‐An, and Good Weather), each characterized by bottom simulating reflectors, acoustic turbidity, and different types of faulting and anticlines. Sulfate and iodide concentrations varied little from seawater‐like values in the upper 1–3 m of sediment at all stations; a feature that is consistent with irrigation of seawater by gas bubbles rising through the soft surface sediments. Below this depth, sulfate was rapidly consumed within 5–10 m by anaerobic oxidation of methane (AOM) at the sulfate‐methane transition. Carbon isotopic data imply a mainly biogenic methane source. A numerical transport‐reaction model was used to identify the supply pathways of methane and estimate depth‐integrated turnover rates at the three ridges. Methane gas ascending from deep layers, facilitated by thrusts and faults, was by far the dominant term in the methane budget at all sites. Differences in the proximity of the sampling sites to the faults and anticlines mainly accounted for the variability in gas fluxes and depth‐integrated AOM rates. By comparison, methane produced in situ by POC degradation within the modeled sediment column was unimportant. This study demonstrates that the geochemical trends in the continental margins offshore SW Taiwan are closely related to the different geological settings.
Longitudinal and day‐to‐day variability in the ionosphere from lower atmosphere tidal forcing
Authors: Fang Tzu‐Wei , Akmaev Rashid , Fuller‐Rowell Tim , Wu Fei , Maruyama Naomi , Millward George
Published: May 2013

Simulations with the global ionosphere plasmasphere model driven by whole atmosphere model winds show significant longitudinal and day‐to‐day variations in the ionospheric parameters. Under fixed solar and geomagnetic activity levels, the contributions of lower atmosphere tides to the longitudinal and day‐to‐day variability in the upper atmosphere are estimated. Larger relative variability is found in the nighttime than in the daytime, which is consistent with observations. The perturbations from the lower atmosphere contribute about half of the observed variability in the ionospheric F2 peak plasma density under moderate solar activity and geomagnetic quiet conditions. The daily variability of the equatorial vertical plasma drifts is primarily driven by the day‐to‐day amplitude changes of the migrating semidiurnal tide, while the wave‐4 and wave‐3 longitudinal variations during September are dominated by the nonmigrating diurnal eastward propagating tides with zonal wave numbers 3 and 2, respectively.
Rapid ice melting drives Earth's pole to the east
Authors: Chen J. L. , Wilson C. R. , Ries J. C. , Tapley B. D.
Published: May 2013

Space geodetic observations of polar motion show that around 2005, the average annual pole position began drifting toward the east, an abrupt departure from the drift direction seen over the past century. Satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) show that about 90% of this change is due to accelerated melting of polar ice sheets and mountain glaciers and related sea level rise. The close relationship between long‐term polar motion and climate‐related mass redistribution established using GRACE data indicates that accurately measured polar motion data offer an additional tool for monitoring global‐scale ice melting and sea level rise and should be useful in bridging the anticipated gap between GRACE and follow‐on satellite gravity missions.
Storage and Processing of Information Using Molecules: The All‐Photonic Approach with Simple and Multi‐Photochromic Switches
Authors: Andréasson Joakim , Pischel Uwe
Published: May 2013

The use of photochromes for the implementation of molecular logic operations is a very promising approach toward molecular computing. This statement is based on a) the possibility of operating such molecular devices exclusively with photonic signals and b) spatiotemporally and remotely controlled switching, which is characteristic for photochromes. Herein, a brief overview of the application of simple photochromes and multi‐photochromic conjugates for the small‐scale functional integration of complicated logic circuits is given. This complements and extends efforts to design molecular photochromic memories for data storage described by many research groups worldwide.
Beginning to “Unpack” Early Childhood Mental Health Consultation: Types of Consultation Services and Their Impact on Teachers
Authors: Conners‐Burrow Nicola , McKelvey Lorraine , Sockwell Latunja , Harman Ehrentraut Jennifer , Adams Skye , Whiteside‐Mansell Leanne
Published: May 2013

The goal of the current study was to examine the impact of the frequency of two types of early childhood mental health consultation (ECMHC) activities (time spent in the class and time spent meeting with teachers) on teacher–child interactions, use of positive classroom‐management techniques, and the intent to quit the childcare profession. We addressed these questions with a sample of 115 teachers from private childcare settings participating in a midlength (6–8 months) consultation partnership, using pre‐ and posttest data collected from structured classroom observations and teacher surveys. Results suggest that ECMHC time spent in the classroom was associated with less teacher punitiveness, permissiveness, and detachment, and more use of positive classroom‐management strategies at the posttest assessment (controlling for baseline teacher behaviors). The frequency of meetings with teachers did not impact teacher–child interactions; however, in an exploratory analysis, the frequency of meetings with the teacher was associated with a reduction in teachers’ intent to leave the profession of childcare.
Documenting Instructional Practices in a Literacy‐Infused Arts Program
Authors: Brooks Wanda , Smith Michael W.
Published: May 2013

This study examines the instructional practices around literacy that characterized the work of a community based arts program designed for urban adolescents. Two primary sources of data were collected: field notes on approximately 35 hours of instruction spread across seven months and interviews with the program's staff and students. Four distinct instructional episodic structures were observed: explicit instruction, collaborative or individual construction that provided time for students to engage in creative literacy and artistic activity, serial performance in which teachers are on as equal a footing as possible as students, and scaffolded practice that is informed by a belief that all can succeed can foster deep engagement in literate activity.