bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic and molecular modelling analysis of the interaction between ethane‐1,2‐diyl bis(N,N‐dimethyl‐N‐hexadecylammoniumacetoxy)dichloride and bovine serum albumin
Authors: Patel Rajan , Mir Muzaffar Ul Hassan , Maurya Jitendra Kumar , Singh Upendra Kumar , Maurya Neha , Parray Mehraj ud din , Khan Abbul Bashar , Ali Anwar
Published: April 2015

Several spectroscopic approaches namely fluorescence, time‐resolved fluorescence, UV‐visible, and Fourier transform infra‐red (FT‐IR) spectroscopy were employed to examine the interaction between ethane‐1,2‐diyl bis(N,N‐dimethyl‐N‐hexadecylammoniumacetoxy)dichloride (16‐E2‐16) and bovine serum albumin (BSA). Fluorescence studies revealed that 16‐E2‐16 quenched the BSA fluorescence through a static quenching mechanism, which was further confirmed by UV–visible and time‐resolved fluorescence spectroscopy. In addition, the binding constant and the number of binding sites were also calculated. The thermodynamic parameters at different temperatures (298 K, 303 K, 308 K and 313 K) indicated that 16‐E2‐16 binding to BSA is entropy driven and that the major driving forces are electrostatic interactions. Decrease of the α‐helix from 53.90 to 46.20% with an increase in random structure from 22.56 to 30.61% were also observed by FT‐IR. Furthermore, the molecular docking results revealed that 16‐E2‐16 binds predominantly by electrostatic and hydrophobic forces to some residues in the BSA sub‐domains IIA and IIIA. Copyright © 2015 John Wiley & Sons, Ltd.
Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide
Authors: Mhareb M. H. A. , Hashim S. , Ghoshal S. K. , Alajerami Y. S. M. , Saleh M. A. , Razak N. A. B. , Azizan S. A. B.
Published: April 2015

We report the impact of dysprosium (Dy3+) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy3+. An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy3+ ions. Good linearity in the range of 0.01–4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O–MgO–B2O3 radiation dosimeters. Copyright © 2015 John Wiley & Sons, Ltd.
Structural, morphological and steady state photoluminescence spectroscopy studies of red Eu3+‐doped Y2O3 nanophosphors prepared by the sol‐gel method
Authors: Lamiri Lyes , Guerbous Lakhdar , Samah Madani , Boukerika Allaoua , Ouhenia Salim
Published: April 2015

Europium trivalent (Eu3+)‐doped Y2O3 nanopowders of different concentrations (0.5, 2.5, 5 or 7 at.%) were synthesized by the sol‐gel method, at different pH values (pH 2, 5 or 8) and annealing temperatures (600°C, 800°C or 1000°C). The nanopowders samples were characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared spectroscopy (FT‐IR) and steady state photoluminescence spectroscopy. The effect of pH of solution and annealing temperatures on structural, morphological and photoluminescence properties of Eu3+‐doped Y2O3 were studied and are discussed. It was found that the average crystallite size of the nanopowders increased with increasing pH and annealing temperature values. The Y2O3:Eu3+ material presented different morphology and its evolution depended on the pH value and the annealing temperature. Activation energies at different pH values were determined and are discussed. Under ultraviolet (UV) light excitation, Y2O3:Eu3+ showed narrow emission peaks corresponding to the 5D0–7FJ (J = 0, 1, 2 and 3) transitions of the Eu3+ ion, with the most intense red emission at 611 assigned to forced electric dipole 5D0→7F2. The emission intensity became more intense with increasing annealing temperature and pH values, related to the improvement of crystalline quality. For the 1000°C annealing temperature, the emission intensity presented a maximum at pH 5 related to the uniform cubic‐shaped particles. It was found that for lower annealing temperatures (small crystallite size) the CTB (charge transfer band) position presented a red shift. Copyright © 2015 John Wiley & Sons, Ltd.
Binding properties of palmatine to DNA: spectroscopic and molecular modeling investigations
Authors: Mi Ran , Tu Bao , Bai Xiao‐Ting , Chen Jun , Ouyang Yu , Hu Yan‐Jun
Published: April 2015

Palmatine, an isoquinoline alkaloid, is an important medicinal herbal extract with diverse pharmacological and biological properties. In this work, spectroscopic and molecular modeling approaches were employed to reveal the interaction between palmatine and DNA isolated from herring sperm. The absorption spectra and iodide quenching results indicated that groove binding was the main binding mode of palmatine to DNA. Fluorescence studies indicated that the binding constant (K) of palmatine and DNA was ~ 104 L·mol−1. The associated thermodynamic parameters, ΔG, ΔH, and ΔS, indicated that hydrogen bonds and van der Waals forces played major roles in the interaction. The effects of chemical denaturant, thermal denaturation and pH on the interaction were investigated and provided further support for the groove binding mode. In addition to experimental approaches, molecular modeling was conducted to verify binding pattern of palmatine–DNA. Copyright © 2015 John Wiley & Sons, Ltd.
Enhancement of the binding affinity of methylene blue to site I in human serum albumin by cupric and ferric ions
Authors: He Ling‐Ling , Wang Yong‐Xia , Wu Xiao‐Xia , Liu Xian‐Ping , Wang Xin , Liu Bin , Wang Xin
Published: April 2015

In this work, the binding characteristics of methylene blue (MB) to human serum albumin (HSA) and the influence of Cu2+ and Fe3+ on the binding affinity of MB to HSA were investigated using fluorescence, absorption, circular dichroism (CD) spectroscopy and molecular modelling. The results of competitive binding experiments using the site probes ketoprofen and ibuprofen as specific markers suggested that MB was located in site I within sub‐domain IIA of HSA. The molecular modelling results agreed with the results of competitive site marker experiments and the results of CD spectra indicated that the interaction between MB and HSA caused the conformational changes in HSA. The binding affinity of MB to HSA was enhanced but to a different extent in the presence of Cu2+ and Fe3+, respectively, which indicated that the influence of different metal ions varied. Enhancement of the binding affinity of MB to HSA in the presence of Cu2+ is due to the formation of Cu2+–HSA complex leading to the conformational changes in HSA, whereas in the presence of Fe3+, enhancement of the binding affinity is due to the greater stability of the Fe3+–HSA–MB complex compared with the MB–HSA complex. Copyright © 2015 John Wiley & Sons, Ltd.
Lebensraum Seegraswiese
Authors: Molenkamp Miriam
Published: April 2015

Seegraswiesen besitzen eine vielseitige ökologische Bedeutung. Neben ihrer Rolle als Produzenten bieten sie Dank ihrer komplexen räumlichen Struktur und reichen Diversität einer Vielzahl von Organismen Schutz und eine Nahrungsgrundlage. Viele Arten zeigen hoch spezialisierte Anpassungen an den Lebensraum Seegraswiese. Dieser Artikel präsentiert eine Auswahl dieser Spezialisten im Roten Meer und ihre verschiedenen Überlebensstrategien: Symbiose, Mimikry und Tarntracht.
Genomische Prägung: Abgestempelt von Mutter oder Vater
Authors: Kronberg Inge
Published: April 2015

In der Vererbung ist es nicht immer gleichgültig, von welchem Elternteil ein Gen stammt. Die Stilllegung von Genen kann zu einem funktionell hemizygoten Zustand führen, bei dem nur das vom Vater stammende oder nur das von der Mutter stammende Allel am betreffenden Genlokus aktiv ist. Die molekularbiologischen Mechanismen und der adaptive Wert dieses als Genomische Prägung oder Genomic Imprinting bezeichneten Phänomens stehen im Fokus epigenetischer Forschung.
Ernst Mayr (1904–2005) und das Primat der Biologie
Authors: Junker Thomas , Hoßfeld Uwe
Published: April 2015

Der deutsch‐amerikanische Biologe Ernst Mayr war einer der bedeutendsten Evolutionsbiologen des 20. Jahrhunderts. Er war ein führender Ornithologe und Systematiker, ein streitbarer Verfechter einer neuen Philosophie der Biologie sowie einer der einflussreichsten Historiker der Biologie der letzten Jahrzehnte. Seine zahlreichen Artikel und Bücher, vor allem sein monumentales Werk “The Growth of Biological Thought” (1982), wurden für eine ganze Generation von Biologiehistorikern zum Orientierungspunkt.
Diagnostik mit Teststreifen: Wie der Schwangerschaftstest funktioniert
Authors: Hauk Andrea
Published: April 2015

Seit Beginn der 1960er Jahre werden Labortests auf Teststreifen für diagnostische Zwecke entwickelt, man nennt dies auch “Trocken‐Chemie”. Der Schwangerschaftstest ist wohl die bekannteste Anwendung dieser so genannten Lateral Flow assays. Hier wird das hCG‐Hormon (Human‐Choriongonadotropin) im Urin nachgewiesen. Der fragile Teststreifen, auf dem die Reaktion abläuft, wird üblicherweise mit einem Plastikgehäuse ummantelt. Haben Sie sich schon einmal gefragt, was sich hinter dem Plastikgehäuse befindet und welche Reaktion dort im stillen Kämmerchen abläuft, bis das Farbsignal im Sichtfenster erscheint?
Randomized clinical trial of adjuvant chemotherapy with S-1 versus gemcitabine after pancreatic cancer resection
Authors: Shimoda M , Kubota K , Shimizu T , Katoh M
Published: April 2015

Background

Randomized studies of adjuvant chemotherapy using gemcitabine suggest a survival benefit after resection of pancreatic cancer. S-1 has also been shown to prolong survival in patients with unresectable pancreatic cancer. This study compared the effects of adjuvant chemotherapy with S-1 or gemcitabine after resection of pancreatic cancer in a randomized trial.

Methods

Patients who had undergone resection of pancreatic cancer were registered in this randomized clinical trial. The primary endpoint was disease-free survival (DFS). Expression levels of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) mRNAs in cancer tissues were measured as indicators of fluoropyrimidine sensitivity.

Results

Of 57 patients registered, 29 were allocated to the S-1 group and 28 to gemcitabine. DFS tended to be better with S-1 (median 14·6 (90 per cent c.i. 8·8 to 28·4) months versus 10·5 (7·0 to 28·4) months in the gemcitabine group; P = 0·188), with a similar pattern for overall survival: 21·5 (95 per cent c.i. 14·4 to 42·3) and 18·0 (13·3 to 42·8) months respectively (P = 0·293). When patients were divided into subgroups based on high or low DPD and TS expression, those with a DPD level below the median of 0·88 or a TS level of at least 2·00 had a significant prolongation of DFS after S-1 treatment compared with gemcitabine (P = 0·008 and P = 0·035 respectively).

Conclusion

Overall, S-1 did not improve DFS compared with gemcitabine after pancreatic cancer resection, but there seemed to be a DFS advantage in patients with low expression of DPD or high expression of TS. Reference number: UMIN000009118 (http://www.umin.ac.jp/ctr/).
Systematic review of experimental studies on intestinal anastomosis
Authors: Yauw S T K , Wever K E , Hoesseini A , Ritskes-Hoitinga M , van Goor H
Published: April 2015

Background

The contribution of animal research to a reduction in clinical intestinal anastomotic leakage is unknown, despite numerous experimental studies. In view of the current societal call to replace, reduce and refine animal experiments, this study examined the quality of animal research related to anastomotic healing and leakage.

Methods

Animal studies on intestinal anastomotic healing were retrieved systematically from PubMed and Embase. Study objective, conclusion and animal model were recorded. Reporting quality and internal validity (reporting of randomization and blinding) were assessed.

Results

A total of 1342 studies were identified, with a rising publication rate. The objectives of most studies were therapeutic interventions (64·8 per cent) and identification of risk factors (27·5 per cent). Of 350 articles studying experimental therapies, 298 (85·1 per cent) reported a positive effect on anastomotic healing. On average, 44·7 per cent of relevant study characteristics were not reported, in particular details on anastomotic complications (31·6 per cent), use of antibiotics (75·7 per cent), sterile surgery (83·4 per cent) and postoperative analgesia (91·4 per cent). The proportion of studies with randomization, blinding of surgery and blinding of primary outcome assessment has increased in the past two decades but remains insufficient, being included in only 62·4, 4·9 and 8·5 per cent of publications respectively. Animal models varied widely in terms of species, method to compromise healing, intestinal segment and outcome measures used.

Conclusion

Animal research on anastomotic leakage is of poor quality and still increasing, contrary to societal aims. Reporting and study quality must improve if results are to impact on patients.
Systematic review of compression following treatment for varicose veins
Authors: El-Sheikha J , Carradice D , Nandhra S , Leung C , Smith G E , Campbell B , Chetter I C
Published: April 2015

Background

Consensus regarding compression following treatment of varicose veins has yet to be reached. This systematic review aims to establish the optimal compression regimen after venous treatment.

Methods

A systematic review of MEDLINE, Embase and CENTRAL was performed to identify randomized clinical trials (RCTs) investigating different compression strategies following treatment for superficial venous insufficiency.

Results

Seven RCTs comparing different durations and methods of compression fulfilled the inclusion criteria. The treatment modality was open surgery in three trials, foam sclerotherapy in two and endovenous laser ablation (EVLA) in two trials. The quality of the studies was variable, and significant sources of potential bias were present. Both the studies and compression regimens used were heterogeneous. Ten products were used in six general regimens for a duration of 0–42 days. One study suggested that 7 days rather than 2 days of stockings following EVLA was associated with superior quality of life and less pain at 1 week. Another study reported that, following surgery, application of a compression stocking after 3 days of bandaging was associated with a slightly longer recovery than no compression after 3 days. One study recorded compliance clearly, finding it to be only 40 per cent. The quality and heterogeneity of the studies precluded meta-analysis.

Conclusion

There is currently little quality evidence upon which to base any recommendations concerning compression following treatment for varicose veins.
Identification of microRNAs associated with abdominal aortic aneurysms and peripheral arterial disease
Authors: Stather P W , Sylvius N , Sidloff D A , Dattani N , Verissimo A , Wild J B , Butt H Z , Choke E , Sayers R D , Bown M J
Published: April 2015

Background

MicroRNAs are crucial in the regulation of cardiovascular disease and represent potential therapeutic targets to decrease abdominal aortic aneurysm (AAA) expansion. The aim of this study was to identify circulating microRNAs associated with AAA.

Methods

Some 754 microRNAs in whole-blood samples from 15 men with an AAA and ten control subjects were quantified using quantitative reverse transcriptase–PCR. MicroRNAs demonstrating a significant association with AAA were validated in peripheral blood and plasma samples of men in the following groups (40 in each): healthy controls, controls with peripheral arterial disease (PAD), men with a small AAA (30–54 mm), those with a large AAA (over 54 mm), and those following AAA repair. MicroRNA expression was also assessed in aortic tissue.

Results

Twenty-nine differentially expressed microRNAs were identified in the discovery study. Validation study revealed that let-7e (fold change (FC) –1·80; P = 0·001), miR-15a (FC −2·24; P < 0·001) and miR-196b (FC −2·26; P < 0·001) were downregulated in peripheral blood from patients with an AAA, and miR-411 was upregulated (FC 5·90; P = 0·001). miR-196b was also downregulated in plasma from the same individuals (FC −3·75; P = 0·029). The same miRNAs were similarly expressed differentially in patients with PAD compared with healthy controls. Validated and predicted microRNA targets identified through miRWalk revealed that these miRNAs were all regulators of AAA-related genes (vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, DAB2 interacting protein, α1-antitrypsin, C-reactive protein, interleukin 6, osteoprotegerin, methylenetetrahydrofolate reductase, tumour necrosis factor α).

Conclusion

In this study, circulating levels of let-7e, miR-15a, miR-196b and miR-411 were differentially expressed in men with an AAA compared with healthy controls, but also differentially expressed in men with PAD. Modulation of these miRNAs and their target genes may represent a new therapeutic pathway to affect the progression of AAA and atherosclerosis.
Modulation of the ~20‐Hz motor‐cortex rhythm to passive movement and tactile stimulation
Authors: Parkkonen Eeva , Laaksonen Kristina , Piitulainen Harri , Parkkonen Lauri , Forss Nina
Published: April 2015

Background

Integration of afferent somatosensory input with motor‐cortex output is essential for accurate movements. Prior studies have shown that tactile input modulates motor‐cortex excitability, which is reflected in the reactivity of the ~20‐Hz motor‐cortex rhythm. ~20‐Hz rebound is connected to inhibition or deactivation of motor cortex whereas suppression has been associated with increased motor cortex activity. Although tactile sense carries important information for controlling voluntary actions, proprioception likely provides the most essential feedback for motor control.

Methods

To clarify how passive movement modulates motor‐cortex excitability, we studied with magnetoencephalography (MEG) the amplitudes and peak latencies of suppression and rebound of the ~20‐Hz rhythm elicited by tactile stimulation and passive movement of right and left index fingers in 22 healthy volunteers.

Results

Passive movement elicited a stronger and more robust ~20‐Hz rebound than tactile stimulation. In contrast, the suppression amplitudes did not differ between the two stimulus types.

Conclusion

Our findings suggest that suppression and rebound represent activity of two functionally distinct neuronal populations. The ~20‐Hz rebound to passive movement could be a suitable tool to study the functional state of the motor cortex both in healthy subjects and in patients with motor disorders.
Supportive care for men with prostate cancer: why are the trials not working? A systematic review and recommendations for future trials
Authors: Moore Theresa Helen Mazzarello , King Anna Jyoti Louise , Evans Maggie , Sharp Debbie , Persad Raj , Huntley Alyson Louise
Published: April 2015

Men with prostate cancer are likely to have a long illness and experience psychological distress for which supportive care may be helpful. This systematic review describes the evidence for effectiveness and cost‐effectiveness of supportive care for men with prostate cancer, taking into account treatment pathway and components of interventions. MEDLINE, EMBASE, CINAHL, CENTRAL, and Psychinfo were searched from inception––July 2013 for randomized controlled trials and controlled trials. Two authors independently assessed risk of bias and extracted data. Twenty‐six studies were included (2740 participants). Interventions were delivered pre and during (n = 12), short‐term (n = 8), and longer term (18 months) (n = 5) after primary treatment. No interventions were delivered beyond this time. Few trials recruited ethnic minorities and none recruited men in same sex relationships. Intervention components included information, education, health professional discussion, homework, peer discussion, buddy support, cognitive behavioral therapy, cognitive restructuring, psychoeducation, Reiki and relaxation. Most interventions were delivered for 5–10 weeks. Risk of bias of trials was assessed as unclear for most domains due to lack of information. The majority of trials measuring quality of life and depression found no effect. Relatively few trials measured anxiety, coping skills and self‐efficacy, and the majority found no effect. No cost data were available. Trials of supportive care for men with prostate cancer cover a range of interventions but are limited by population diversity, inconsistent measurement and reporting of outcomes, and inability to assess risk of bias. Recommendations on design and conduct of future trials are presented.
Fluorogenic Sequencing Using Halogen‐Fluorescein‐Labeled Nucleotides
Authors: Chen Zitian , Duan Haifeng , Qiao Shuo , Zhou Wenxiong , Qiu Haiwei , Kang Li , Xie X. Sunney , Huang Yanyi
Published: April 2015

Fluorogenic sequencing is a sequencing‐by‐synthesis technology that combines the advantages of pyrosequencing and fluorescence detection. With native duplex DNA as the major product, we employ polymerase to incorporate the complement‐ arily matched terminal phosphate‐labeled fluorogenic nucleotides into the DNA template and release halogen‐fluorescein as the reporter. This red‐emitting fluorophore successfully avoids spectral overlap with the autofluorescence background of the flow chip. We fully characterized the enzymatic reaction kinetics of the new substrates, and performed a 35‐base sequencing experiment with 60 reaction cycles. Our achievement expands the substrate repertoire for fluorogenic sequencing, and extends the spectral range to obtain better signal‐to‐background performance.
Complete myocardial revascularization confers a larger clinical benefit when performed with state‐of‐the‐art techniques in high‐risk patients with multivessel coronary artery disease: A meta‐analysis of randomized and observational studies
Authors: Zimarino Marco , Ricci Fabrizio , Romanello Mattia , Di Nicola Marta , Corazzini Alessandro , De Caterina Raffaele
Published: April 2015

Objectives

To test whether a strategy of complete revascularization (CR) as compared with incomplete myocardial revascularization (IR)—both performed with current “state‐of‐the‐art” percutaneous coronary interventions (PCI) or coronary artery bypass graft (CABG)—would provide a clinical benefit in patients with multivessel coronary artery disease (MVCAD).

Background

The “optimal” extent of myocardial revascularization remains to be determined. Methods: We performed a meta‐analysis of studies reporting on clinical outcomes of MVCAD patients treated with CR and IR, with extensive (>80%) use of stents for PCI or arterial conduits in CABG. Relative risk (RR) and 95% confidence intervals (CIs) for all‐cause mortality were assessed as primary endpoint, myocardial infarction (MI) and repeat revascularization as secondary endpoints.

Results

A total of 28 studies were identified, including 83,695 patients with 4.7 ± 4.3 years of follow‐up. Compared with IR, CR was associated with reduced mortality (RR: 0.73; 95% CI 0.66–0.81) both after CABG (RR: 0.76; 95% CI 0.63–0.90) and PCI (RR: 0.73; 95% CI 0.64–0.82). The risks of MI (RR: 0.74; 95% CI 0.64–0.85) and repeat revascularization (RR: 0.77; 95% CI 0.66–0.88) were also lower after CR as compared with IR. Metaregression showed a significant RR reduction of MI associated with more recent publication (P = 0.021) and increasing prevalence of diabetes (P = 0.033).

Conclusions

In MVCAD, as compared with IR, CR confers a clinical benefit that seems larger in cohorts of patients enrolled in more recent studies and with a higher prevalence of diabetes. © 2015 Wiley Periodicals, Inc.
Identifying the Role of N‐Heteroatom Location in the Activity of Metal Catalysts for Alcohol Oxidation
Authors: Chan‐Thaw Carine E. , Villa Alberto , Veith Gabriel M. , Prati Laura
Published: April 2015

This work focuses on understanding how the proximate location and bonding of N heteroatoms affect the stability and reactivity of Pd‐based catalysts for the oxidation of alcohols in the solution. The results show that the simple adsorption of N groups, from the solution, has a detrimental effect on the catalytic activity and stability. In contrast, chemically bound N moieties within the carbon structure improve these properties, which limits the leaching of metal and coarsening of metal particles. Moreover, the benefits of N atoms are realized only if the N atom is covalently bonded to the support and not directly bonded to the Pd nanoparticles.
Controlled Formation of Nickel Oxide Nanoparticles on Mesoporous Silica using Molecular Ni4O4 Clusters as Precursors: Enhanced Catalytic Performance for Dry Reforming of Methane
Authors: Baktash Elham , Littlewood Patrick , Pfrommer Johannes , Schomäcker Reinhard , Driess Matthias , Thomas Arne
Published: April 2015

Supported NiO nanoparticles (NPs) were prepared by impregnation of mesoporous silica SBA‐15 with a molecular, metalorganic [Ni4O4] cubane cluster as precursor. By using this ligand‐stabilized Ni cluster, deposition of four Ni ions in close proximity on the silica support was achieved; this resulted in the formation of small and highly dispersed NiO NPs after heat treatment. These clusters were shown to have a significant influence on the formation of NiO NPs compared to a conventional Ni(OAc)2 precursor. After a further reduction step, the materials were used as catalysts for the dry reforming of methane, which showed that preorganization of the Ni atoms on the support surface had a beneficial effect on the methane conversion rate.
Enantioselective [3+2] Cyclization of 3‐Isothiocyanato Oxindoles with Trifluoromethylated 2‐Butenedioic Acid Diesters
Authors: Du Dan , Jiang Yu , Xu Qin , Tang Xiang‐Ying , Shi Min
Published: April 2015

The highly efficient organocatalytic enantioselective [3+2] cyclization of 3‐isothiocyanato oxindoles with trifluoromethylated 2‐butenedioic acid diesters for the synthesis of spirooxindoles possessing a CF3‐containing quaternary carbon stereocenter was explored. An enantiodivergent approach for the synthesis of spirooxindoles by regulation of the temperature was demonstrated at different temperatures. The outcome of the reaction featured high diastereo‐ and enantioselectivities. Several interesting enantioenriched spirooxindole derivatives bearing a trifluoromethyl quaternary carbon stereocenter were synthesized from the products of this reaction.
Controlled Construction of Hierarchical Nanocomposites Consisting of MnO2 and PEDOT for High‐Performance Supercapacitor Applications
Authors: Tang Pengyi , Han Lijuan , Zhang Lin , Wang Shijie , Feng Wei , Xu Guoqing , Zhang Li
Published: April 2015

The integration of hierarchical nanostructure design and encapsulation strategies using a combination of electrochemical deposition, hydrothermal, and in situ reaction methods has been recognized as one of the most effective strategies to realize practical applications of various supercapacitor materials. Herein, a facile and scalable method is developed to synthesize a core–shell–branch hierarchical MnO2@PEDOT@MnO2 composite by using a simple electrochemical deposition strategy. The proposed synthesis method facilitates the structural integration of three‐dimensional nickel foam and the synergy of different electroactive materials, which offers several advantages including simplicity, efficiency, no binder, and low cost. The as‐prepared, freestanding, hierarchical MnO2@PEDOT@MnO2 electrodes exhibit high specific capacitance and rate capability. An asymmetric supercapacitor is fabricated with the hierarchical MnO2@PEDOT@MnO2 nanocomposite as the positive electrode, activated carbon as the negative electrode, and Na2SO4 aqueous solution as the electrolyte. The asymmetric supercapacitor can be cycled reversibly in a high‐voltage window of 0–1.8 V and exhibits a high energy density of 47.8 Wh kg−1 at a power density of 180 W kg−1, indicating remarkable rate capability as well as reasonable cycling performance with 91.3 % retention after 5000 cycles.
A wavelength selection method based on random decision particle swarm optimization with attractor for near‐infrared spectral quantitative analysis
Authors: Cao Hui , Wang Yanxia , Yang Sanchun , Zhou Yan
Published: April 2015

In this paper, we proposed a wavelength selection method based on random decision particle swarm optimization with attractor for near‐infrared (NIR) spectra quantitative analysis. The proposed method was incorporated with partial least square (PLS) to construct a prediction model. The proposed method chooses the current own optimal or the current global optimal to calculate the attractor. Then the particle updates its flight velocity by the attractor, and the particle state is updated by the random decision with the new velocity. Moreover, the root‐mean‐square error of cross‐validation is adopted as the fitness function for the proposed method. In order to demonstrate the usefulness of the proposed method, PLS with all wavelengths, uninformative variable elimination by PLS, elastic net, genetic algorithm combined with PLS, the discrete particle swarm optimization combined with PLS, the modified particle swarm optimization combined with PLS, the neighboring particle swarm optimization combined with PLS, and the proposed method are used for building the components quantitative analysis models of NIR spectral datasets, and the effectiveness of these models is compared. Two application studies are presented, which involve NIR data obtained from an experiment of meat content determination using NIR and a combustion procedure. Results verify that the proposed method has higher predictive ability for NIR spectral data and the number of selected wavelengths is less. The proposed method has faster convergence speed and could overcome the premature convergence problem. Furthermore, although improving the prediction precision may sacrifice the model complexity under a certain extent, the proposed method is overfitted slightly. Copyright © 2015 John Wiley & Sons, Ltd.
The Structural Stability of Graphene Anticorrosion Coating Materials is Compromised at Low Potentials
Authors: Ambrosi Adriano , Pumera Martin
Published: April 2015

Corrosion of engineered structures is a major problem causing an estimated economic loss of more than 2 trillion US dollars annually worldwide. Graphene has recently emerged as highly promising, low‐cost, and transparent anticorrosion coating material. Herein, it is shown that a multilayer graphene film grown on Ni by chemical vapor deposition undergoes abrupt stability failure under galvanic‐corrosion conditions. The multilayer graphene coating was examined by optical microscopy, SEM, energy dispersive X‐ray spectroscopy, Raman spectroscopy, and cyclic voltammetry after exposure to potentials between 600 and 1300 mV in alkaline solution. A fast and simple electrochemical method is proposed to sensitively quantify the damage caused by the applied potential bias. It is based on quantification of the oxidation signals generated by the underlying Ni‐metal catalyst that is exposed by damage to the graphene film. It is shown that film damage can start at potentials as low as 900 mV and that macroscopic and extensive damage can be caused at potentials above 1000 mV. In addition, once the graphene film has been damaged, the corrosion rate of the underlying metal is significantly increased. These findings are of great importance for potential applications of multilayer graphene films in coating metal structures with huge industrial and economic implications.
Computational Insight into Nickel‐Catalyzed Carbon–Carbon versus Carbon–Boron Coupling Reactions of Primary, Secondary, and Tertiary Alkyl Bromides
Authors: Cheung Man Sing , Sheong Fu Kit , Marder Todd B. , Lin Zhenyang
Published: April 2015

The nickel‐catalyzed alkyl–alkyl cross‐coupling (CC bond formation) and borylation (CB bond formation) of unactivated alkyl halides reported in the literature show completely opposite reactivity orders in the reactions of primary, secondary, and tertiary alkyl bromides. The proposed NiI/NiIII catalytic cycles for these two types of bond‐formation reactions were studied computationally by means of DFT calculations at the B3LYP level. These calculations indicate that the rate‐determining step for alkyl–alkyl cross‐coupling is the reductive elimination step, whereas for borylation the rate is determined mainly by the atom‐transfer step. In borylation reactions, the boryl ligand involved has an empty p orbital, which strongly facilitates the reductive elimination step. The inability of unactivated tertiary alkyl halides to undergo alkyl–alkyl cross‐coupling is mainly due to the moderately high reductive elimination barrier.
Isostrychnine Synthesis Mediated by Hypervalent Iodine Reagent
Authors: Jacquemot Guillaume , Maertens Gaëtan , Canesi Sylvain
Published: April 2015

Althought there are several reported synthetic routes to strychnine, one of the most widely recognized alkaloids, we report an unexplored route with an oxidative dearomatizing process mediated by hypervalent iodine as the key step. The new syntheses of isostrychnine and strychnine have been achieved from an readily available phenol in nine and ten steps. In addition to the key step, these syntheses involve an aza Michael‐ether‐enol tandem transformation, two heck type cyclizations, a reductive isomerization, and a double reductive amination in cascade leading to the alkaloid main core.
Imidazolium Salt Ion Pairs in Solution
Authors: Stassen Hubert K. , Ludwig Ralf , Wulf Alexander , Dupont Jairton
Published: April 2015

The formation, stabilisation and reactivity of contact ion pairs of non‐protic imidazolium ionic liquids (ILs) in solution are conceptualized in light of selected experimental evidence as well theoretical calculations reported mainly in the last ten years. Electric conductivity, NMR, ESI‐MS and IR data as well as theoretical calculations support not only the formation of contact ion pairs in solution, but also the presence of larger ionic and neutral aggregates even when dissolved in solvents with relatively high dielectric constants, such as acetonitrile and DMSO. The presence of larger imidazolium supramolecular aggregates is favoured at higher salt concentrations in solvents of low dielectric constant for ILs that contain shorter N‐alkyl side chains associated with anions of low coordination ability. The stability and reactivity of neutral contact species are also dependent on the nature of the anion, imidazolium substituents, and are more abundant in ILs containing strong coordinating anions, in particular those that can form charge transfer complexes with the imidazolium cation. Finally, some ILs display reactivities as contact ion pairs rather than solvent‐separated ions.
ChemInform Abstract: Growth and Characterization of Acentric BaHf(BO3)2 and BaZr(BO3)2.
Authors: Maczka Miroslaw , Szymborska‐Malek Katarzyna , Gagor Anna , Majchrowski Andrzej
Published: April 2015

Single crystals of BaHf(BO3)2 are grown on a Pt wire from BaHfO3 (3.5 mol%) solved in a BaB4O7 melt (1050 °C soaking temperature, 1000‐940 °C crystallization temperature gradient).
ChemInform Abstract: Rare‐Earth Manganese Copper Phosphides REMnCu4P3 (RE: Gd—Ho): The First Quaternary Ordered Variants of the YCo5P3‐Type Structure.
Authors: Ramachandran Krishna K. , Stoyko Stanislav S. , Mullen C. Scott , Mar Arthur
Published: April 2015

The title compounds are prepared from the elements (800 °C, 10 d) and characterized by powder and single crystal XRD, electrical resistivity measurements, and TB‐LMTO‐ASA band structure calculations.
ChemInform Abstract: Crystalline and Liquid Structure of Zinc Chloride Trihydrate: A Unique Ionic Liquid.
Authors: Wilcox Robert J. , Losey Bradley P. , Folmer Jacob C. W. , Martin James D. , Zeller Matthias , Sommer Roger
Published: April 2015

The H2O/ZnCl2 phase diagram is re‐investigated in the vicinity of 75 mol% H2O.
ChemInform Abstract: Thermoelectric Properties of the Quaternary Chalcogenides BaCu5.9STe6 and BaCu5.9SeTe6.
Authors: Oudah Mohamed , Kleinke Katja M. , Kleinke Holger
Published: April 2015

The title compounds are prepared from the elements by heating to 773 K within 24 h, followed by cooling to 673 K over 200 h and finally to room temperature.
ChemInform Abstract: Preparation and Stability of a New Compound SrCe0.9Lu0.1O2.95.
Authors: Matskevich N. I. , Wolf Th. , Vyazovkin I. V. , Adelmann P.
Published: April 2015

SrCe0.9Lu0.1O2.95 is prepared by solid‐state reaction of ball milled powders of SrCO3, CeO2 and Lu2O3 (1100‐1800 °C).
ChemInform Abstract: Distorted Phosphorus and Copper Square‐Planar Layers in LaCu1+xP2 and LaCu4P3: Synthesis, Crystal Structure, and Physical Properties.
Authors: Wang Jian , Lee Kathleen , Kovnir Kirill
Published: April 2015

Single crystals of LaCu1.093P2.00 (I) and LaCu4P3 (II) are prepared from mixtures of the elements in the ratio La:Cu:P = 1:1:2.2 and La:Cu:P:KCl = 4:9:14:60, respectively (silica ampule, 1073 K, 144—168 h).
ChemInform Abstract: β‐CuN3: The Overlooked Ground‐State Polymorph of Copper Azide with Heterographene‐Like Layers.
Authors: Liu Xiaohui , George Janine , Maintz Stefan , Dronskowski Richard
Published: April 2015

α‐CuN3 precipitates from aqueous solutions of CuCl2, Na2SO3, and NaN3.
ChemInform Abstract: Crystal Structure and Bonding in BaAu5Ga2 and AeAu4+xGa3‐x (Ae: Ba and Eu): Hexagonal Diamond‐Type Au Frameworks and Remarkable Cation/Anion Partitioning in the Ae—Au—Ga Systems.
Authors: Smetana Volodymyr , Steinberg Simon , Card Nathan , Mudring Anja‐Verena , Miller Gordon J.
Published: April 2015

The new polar intermetallic compounds BaAu5Ga2 (I), BaAu4.3Ga2.7 (II), Ba1.0Au4.5Ga2.4 (III), EuAu4.8Ga2.2 (IV), and Eu1.1Au4.4Ga2.2 (V) are prepared from the elements (Ta ampules, 500—1000 °C, 3 h—7 d) and characterized by single crystal XRD, magnetic measurements, and TB‐LMTO‐ASA electronic structure calculations.
ChemInform Abstract: Diastereoselective Alkylation Reactions Employing a New Camphor‐Based 2‐Phenylimino‐2‐oxazolidine Chiral Auxiliary.
Authors: Zhang Long‐Duo , Lu Cui‐Fen , Chen Zu‐Xing , Yang Gui‐Chun , Nie Jun‐Qi
Published: April 2015

A new camphor‐based chiral auxiliary (I) is synthesized, which displays great potential for asymmetric alkylation reactions [→ (V)].
ChemInform Abstract: Asymmetric Allylation of Sulfonyl Imines Catalyzed by in situ Generated Cu(II) Complexes of Chiral Amino Alcohol Based Schiff Bases.
Authors: Ghosh Debashis , Bera Prasanta Kumar , Kumar Manish , Abdi Sayed H. R. , Khan Noor‐ul H. , Kureshy Rukhsana I. , Bajaj Hari C.
Published: April 2015

The enantioselective synthesis of homoallyl amines by Cu(II)‐Schiff base catalyzed reaction of allyltin with aryl or alkenyl‐substituted N‐sulfonylimines is described.
ChemInform Abstract: Microwave‐Assisted Oxidation of Alcohols Using Zinc Polyoxometalate.
Authors: Kasprzyk Wiktor , Galica Mateusz , Bednarz Szczepan , Bogdal Dariusz
Published: April 2015

A sandwich type Zn‐W polyoxometalate is used as an oxidation catalyst in aqueous biphasic reaction media to effect oxidation of alcohols.
ChemInform Abstract: Direct Catalytic N‐Alkylation of Amines with Carboxylic Acids.
Authors: Sorribes Ivan , Junge Kathrin , Beller Matthias
Published: April 2015

The N‐alkylation of a variety of primary and secondary amines with a wide range of carboxylic acids is efficiently achieved in the presence of phenylsilane as reducing agent and Karstedt′s Pt catalyst.
ChemInform Abstract: Stereospecific Pd‐Catalyzed Cross‐Coupling Reactions of Secondary Alkylboron Nucleophiles and Aryl Chlorides.
Authors: Li Ling , Zhao Shibin , Joshi‐Pangu Amruta , Diane Mohamed , Biscoe Mark R.
Published: April 2015

The Pd‐catalyzed cross‐coupling of aryl chlorides with secondary alkylboronic acids and secondary alkyl trifluoroborates is developed.
ChemInform Abstract: Reductive Acylation of Nitroarenes to Anilides by Sodium Sulfite in Carboxylic Acids.
Authors: Ghaffarzadeh Mohammad , Akhavan Pegah
Published: April 2015

The method is applied in the synthesis of different drugs with amide structures: propanil (IIIb) (herbicide), acetaminophen (Vc) (analgesic, antipyretic) and the main intermediate (VII) of anticancer drug flutamide
ChemInform Abstract: Rhodium(II)‐Catalyzed Stereocontrolled Synthesis of 2‐Tetrasubstituted Saturated Heterocycles from 1‐Sulfonyl‐1,2,3‐triazoles.
Authors: Boyer Alistair
Published: April 2015

Rhodium‐catalyzed transformation to tetrahydrofuran or tetrahydrothiophene derivatives proceeds with high to excellent diastereoselectivity and yields in the reactions of alkyl‐substituted alkyne precursors.
ChemInform Abstract: Novel Radical Tandem 1,6‐Enynes Thioacylation/Cyclization: Au—Pd Nanoparticles Catalysis versus Thermal Activation as a Function of the Substrate Specificity.
Authors: Notar Francesco Irene , Giauffret Justine , Fontaine‐Vive Fabien , Edwards Jennifer K. , Kiely Christopher J. , Hutchings Graham J. , Antoniotti Sylvain
Published: April 2015

The thioacylation/cyclization in the presence of the nanosized catalyst alloy proceeds under mild conditions.
ChemInform Abstract: Recyclable Bi2WO6‐Nanoparticle Mediated One‐Pot Multicomponent Reactions in Aqueous Medium at Room Temperature.
Authors: Paplal Banoth , Nagaraju S. , Veerabhadraiah Palakollu , Sujatha Kodam , Kanvah Sriram , Vijaya Kumar B. , Kashinath Dhurke
Published: April 2015

Functionalized dihydropyridine (III), polyhydroquinoline (V), 4H‐chromene (VII), and 1H‐benzochromene (IX) derivatives are synthesized with good yields in short periods of time.
ChemInform Abstract: Microwave‐Assisted Heteropolyanion‐Based Ionic Liquids Catalyzed Transamidation of Non‐Activated Carboxamides with Amines under Solvent‐Free Conditions.
Authors: Fu Renzhong , Yang Yang , Chen Zhikai , Lai Wenchen , Ma Yongfeng , Wang Quan , Yuan Rongxin
Published: April 2015

The environmentally friendly and operationally simple transamidation reaction is performed with primary, secondary, and tertiary amides as well as phthalimide with a variety of primary and secondary amines.
ChemInform Abstract: Migratory Dynamic Kinetic Resolution of Carbocyclic Allylic Alcohols.
Authors: Manzuna Sapu Chicco , Goerbe Tamas , Lihammar Richard , Baeckvall Jan‐E. , Deska Jan
Published: April 2015

Application of vinyl acyl donors other than caprates, such as acetate or butyrate may deliver the corresponding products with higher yield, but lower enantiomeric excess.
ChemInform Abstract: Thiol‐Promoted Selective Addition of Ketones to Aldehydes.
Authors: Parnes Regev , Narute Sachin , Pappo Doron
Published: April 2015

This simple and efficient method provides access to important β‐thioketone building blocks.
ChemInform Abstract: Immobilized Iron Oxide Nanoparticles as Stable and Reusable Catalysts for Hydrazine‐Mediated Nitro Reductions in Continuous Flow.
Authors: Moghaddam Mojtaba Mirhosseini , Pieber Bartholomaeus , Glasnov Toma , Kappe C. Oliver
Published: April 2015

The extremely rapid and selective method tolerates multiple functional groups except the ones reacting with the reducing agent, hydrazine.
ChemInform Abstract: Room‐Temperature Enantioselective C—H Iodination via Kinetic Resolution.
Authors: Chu Ling , Xiao Kai‐Jiong , Yu Jing‐Quan
Published: April 2015

A kinetic resolution via palladium‐catalyzed enantioselective C—H iodination is reported wherein one of the enantiomers of a racemic benzylic amine undergoes faster aryl C—H insertion with the chiral catalyst than the other.
ChemInform Abstract: Enantioselective Allylation of Selected ortho‐Substituted Benzaldehydes: A Comparative Study.
Authors: Hessler Filip , Betik Robert , Kadlcikova Aneta , Belle Roman , Kotora Martin
Published: April 2015

The asymmetric catalytic alkylation of ortho‐substituted benzaldehydes proceeds under Lewis basic and acidic catalyst conditions to give homoallylic alcohols.
ChemInform Abstract: Oxa‐Michael Addition Promoted by the Aqueous Sodium Carbonate.
Authors: Guo Shi‐Huan , Xing Sheng‐Zhu , Mao Shuai , Gao Ya‐Ru , Chen Wen‐Liang , Wang Yong‐Qiang
Published: April 2015

The method is even applicable to α,β‐unsaturated substrates which are highly reactive, prone to polymerization or tend to hydrolyze with only the latter requiring exclusion of moisture.
ChemInform Abstract: Copper‐Catalyzed Aerobic Oxidations of 3‐N‐Hydroxyaminoprop‐1‐ynes to Form 3‐Substituted 3‐Amino‐2‐en‐1‐ones: Oxidative Mannich Reactions with a Skeletal Rearrangement.
Authors: Kawade Rahul Kisan , Tseng Chang‐Chin , Liu Rai‐Shung
Published: April 2015

The starting alkynes are treated with H2O, thiols and alcohols to produce β‐oxamides or (E)‐configurated 3‐amino‐2‐en‐1‐ones.
ChemInform Abstract: Ruthenium(II)‐Catalyzed C—H Activation with Isocyanates: A Versatile Route to Phthalimides.
Authors: De Sarkar Suman , Ackermann Lutz
Published: April 2015

Amides bearing a pyrrolidinyl leaving group are found to be optimal as starting compounds.
ChemInform Abstract: First Palladium‐Catalyzed Denitrated Coupling of Nitroarenes with Sulfinates.
Authors: Tian Heng , Cao Aijuan , Qiao Lijun , Yu Ajuan , Chang Junbiao , Wu Yangjie
Published: April 2015

Halogenated nitroarenes like (VII) react via nucleophilic displacement of the halogen atom under the present conditions.
ChemInform Abstract: Visible Light‐Mediated Dehydrogenative β‐Arylsulfonylation of Tertiary Aliphatic Amines with Arylsulfonyl Chlorides.
Authors: Chen Min , Huang Zhi‐Tang , Zheng Qi‐Yu
Published: April 2015

A novel method for the synthesis of β‐arylsulfonyl enamines (III), (VI) and (VIII)/(IX) via photoredox catalysis is reported.
ChemInform Abstract: Polystyrene Anchored Ruthenium(II) Complex Catalyzed Carbonylation of Nitrobenzene and Amines for the Synthesis of Disubstituted Ureas.
Authors: Islam Sk Manirul , Ghosh Kajari , Roy Anupam Singha , Molla Rostam Ali , Salam Noor , Chatterjee Tanmay , Iqubal Md. Asif
Published: April 2015

11 Disubstituted ureas are prepared by the ruthenium(II)‐catalyzed reaction of CO, nitrobenzenes and amines.
ChemInform Abstract: Catalytic Asymmetric Povarov Reaction of Isatin‐Derived 2‐Azadienes with 3‐Vinylindoles.
Authors: Zhang Hong‐Hao , Sun Xiao‐Xue , Liang Jing , Wang Yue‐Ming , Zhao Chang‐Chun , Shi Feng
Published: April 2015

The title reaction, the first catalytic asymmetric Povarov reaction of isatin‐derived 2‐azadienes with 3‐vinylindoles, proceeds in the presence of an axially chiral phosphoric acid furnishing spiro compounds (III) (21 examples) in generally high diastereoselectivity and good enantioselectivity.
ChemInform Abstract: Transition‐Metal‐Catalyzed Selective Cyclization Strategy to 2‐Substituted Benzofurans and Indoles en Route to the Oxa Analogues of Isocryptolepine.
Authors: Indu Satrajit , Subramanian Parthasarathi , Kaliappan Krishna P.
Published: April 2015

The title strategy works well in the case of the benzofuran skeleton (III).
ChemInform Abstract: A Domino Approach for the Synthesis of Naphtho[2,1‐b]furan‐2(1H)‐ones from Azlactones.
Authors: Salami‐Ranjbaran Elmira , Khosropour Ahmad R. , Mohammadpoor‐Baltork Iraj
Published: April 2015

PTSA‐catalyzed reaction between naphthols and azlactones provides the title compounds in moderate to good yields under solvent‐free conditions.
ChemInform Abstract: Hetaryl Thioketones: Synthesis and Selected Reactions.
Authors: Mloston Grzegorz , Urbaniak Katarzyna , Gebicki Krzysztof , Grzelak Paulina , Heimgartner Heinz
Published: April 2015

A straightforward methodology for the formation of both symmetrical and non‐symmetrical hetaryl thioketones is given.
ChemInform Abstract: Cinchona‐Based Primary Amine‐Catalyzed Enantioselective Aza‐Michael Reactions of Pyrroles with α,β‐Unsaturated Aldehydes.
Authors: Lee Su‐Jeong , Ahn Jun‐Gi , Cho Chang‐Woo
Published: April 2015

The products of the title reaction are not isolated and are further chemoselectively reduced to the corresponding alcohols.