bluuebunny/crossref_metadata_2025 huggingface dataset:
Magneto‐convection in a rotating layer of nanofluid
Authors: Yadav Dhananjay , Bhargava R. , Agrawal G. S. , Hwang Gyeong S. , Lee Jinho , Kim M. C.
Published: February 2014

The combined effect of rotation and magnetic field on the onset of convection in a horizontal layer of electrically conducting nanofluid is studied. Three cases of free–free, rigid–free, and rigid–rigid boundaries are considered. The two important effects of Brownian motion and thermophoresis are included in the model of nanofluid. The linear stability theory is employed, and the resulting eigenvalue problem is solved analytically for free–free boundaries and numerically for rigid–free and rigid–rigid boundaries using the Galerkin technique. Numerical results are presented for alumina–water nanofluid. The effects of magnetic field, rotation, and various nanofluid parameters such as nanoparticle Rayleigh number, modified diffusive ratio, and Lewis number on the onset of convection are analyzed, and results are depicted graphically. It is found that the critical Rayleigh number is lower for nanofluid in comparison with the regular fluid at the same values of Chandrasekhar number and Taylor number. The sufficient condition for the non‐existence of overstability is also obtained. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Synthesis and Antitumor Activities of Some New N1‐(Flavon‐6‐yl)amidrazone Derivatives
Authors: Habashneh Almeqdad Y. , El‐Abadelah Mustafa M. , Zihlif Malek A. , Imraish Amer , Taha Mutasem O.
Published: February 2014

A new series of N1‐(flavon‐6‐yl)amidrazones were synthesized by reacting the hydrazonoyl chloride derived from 6‐aminoflavone with the appropriate sec‐cyclic amines. The antitumor activities of these compounds were evaluated on breast cancer (MCF‐7) and leukemic (K562) cell lines. Among the compounds tested, the N‐morpholine derivative was the most active against the MCF‐7 and K562 cell lines, with IC50 values of 5.18 and 2.89 μM, respectively. Our docking studies showed that the N‐morpholino derivative fits and blocks the oncogenic tyrosine kinases bcr/abl and epidermal growth factor receptor (EGFR) in a similar fashion to that of the potent anticancer agent imatinib.
Synergy, Compatibility, and Innovation: Merging Lewis Acids with Stereoselective Enamine Catalysis
Authors: Gualandi Andrea , Mengozzi Luca , Wilson Claire M. , Cozzi Pier Giorgio
Published: February 2014

In recent years there has been an accelerated rate of development in the field of organocatalysis, with asymmetric organocatalysis now reaching full maturity. The invention of new organocatalytic reactions and the exploration of new concepts now appear in tandem with the application of organocatalytic techniques in the synthesis of natural products and active pharmaceutical ingredients (APIs). After a “golden rush” in organocatalysis, researchers are now starting to combine different methods, thereby taking advantage of the significant benefits of synergy. Metals are used in combination with organocatalytic processes, thus reaching complexity that is found in nature, where enzymes take advantage of the presence of certain metals to increase the arsenal of organic transformations available. In this Focus review, we illustrate the possibility of a “happy marriage” between Lewis acids and organocatalytic stereoselective processes. Questions have been raised about the combination of Lewis acids and organocatalysis owing to the presence of water and/or strong bases in these processes. Some Lewis acids have been shown to be compatible with organocatalysis and concepts relating to their use will be illustrated herein. To summarize the fruitful use of Lewis acids in stereoselective organocatalytic processes, we will draw attention to the advantages and selectivity achieved using this method.
Remote Impacts of Methyl Substituents on the Guest‐Binding Ability of Self‐Assembled Cages
Authors: Fang Yu , Murase Takashi , Fujita Makoto
Published: February 2014

We synthesized self‐assembled coordination cages in which 1,10‐phenanthroline derivatives serve as capping ligands. Substituents at the 2,9‐positions of the phenanthroline ligand covered the outside of the cage but had an impact on the guest binding inside the cage. Introduction of methyl groups at the 2,9‐positions allowed the cage to accommodate tetraphenylsilane. Bulky mesityl groups overhanging the cage framework significantly shrunk the cage cavity through π–π interactions with the aromatic panels of the cage. The p‐methyl group of the mesityl substituent was a determinant of the restricted motion of 4,4′‐dimethoxybenzil inside the cage at high temperature. Thus, the presence or absence of one methyl group, which is far from the guest‐binding site, makes a significant difference in the guest species and motions inside the cage.
Synchronization of Interconnected Multi‐valued Logical Networks
Authors: Meng Min , Feng Jun‐e , Hou Zhongsheng
Published: February 2014

This paper studies the synchronization of interconnectedk‐valued logical networks, as well as that of interconnected higher orderk‐valued logical networks, based on their algebraic representations. For interconnectedk‐valued logical networks, one necessary and sufficient criterion of synchronization is established via the definition of synchronization and another equivalent condition is given by combining synchronization with fixed points and cycles. Furthermore, with some special properties of semi‐tensor product, the third necessary and sufficient condition for synchronization of interconnectedk‐valued logical networks is raised in terms of transition matrices. Then, the limit set method can be used to analyze the synchronization of interconnected higher orderk‐valued logical networks. Finally, three examples, including the Boolean model for interconnected biochemical oscillators in the cell cycle, are presented to illustrate effectiveness of the results.
Robust Ensemble Kalman Filter Based on Exponential Cost Function
Authors: Bhaumik Shovan
Published: February 2014

This paper provides an alternative point of view to the robust estimation technique for nonlinear non Gaussian systems based on exponential quadratic cost function. The proposed method, named the risk sensitive ensemble Kalman filter (RSEnKF), is based on the ensemble Kalman filter (EnKF) which may be thought of as a Monte Carlo implementation of the Kalman filter for nonlinear estimation problems. The theory and formulation of the RSEnKF are presented in this paper. The proposed method is superior to the extended risk sensitive filter (ERSF) and the quadrature based risk sensitive filters in terms of estimation accuracy, and is faster than the risk sensitive particle filter (RSPF).
Some aspects of stationary characteristics and optimal control of the BMAP ∕ G − G ∕ 1 ∕ N( ∞ ) oscillating queueing system
Authors: Banik A.D.
Published: February 2014

We consider a finite‐buffer queue where arrivals occur according to a batch Markovian arrival process (BMAP), and there are two servers present in the system. At the beginning of a busy period, the low performance server serves till queue length reaches a critical level , and when queue length is greater than or equal to b, the high performance server starts working. High performance server serves till queue length drops down to a satisfactory level a ( < b) and then low performance server begins to serve again, and the process continues in this manner. The analysis has been carried out using a combination of embedded Markov chain and supplementary variable method. We obtain queue length distributions at pre‐arrival‐, arbitrary‐ and post‐departure‐epochs, and some important performance measures, such as probability of loss for the first‐, an arbitrary‐ and the last‐customer of a batch, mean queue length and mean waiting time. The total expected cost function per unit time is derived in order to determine locally optimal values for N, a and b at a minimum cost. Both partial‐ and total‐batch rejection strategies have been analyzed. Also, we investigate the corresponding BMAP ∕ G − G ∕ 1 ∕ ∞ queue using matrix‐analytic‐ and supplementary variable‐method. We calculate previously described probabilities with performance measures for infinite‐buffer model as well. In the end, some numerical results have been presented to show the effect of model parameters on the performance measures. Copyright © 2014 John Wiley & Sons, Ltd.
Determining optimal size reduction and densification for biomass feedstock using the BioFeed optimization model
Authors: Shastri Yogendra N. , Miao Zewei , Rodríguez Luis F. , Grift Tony E. , Hansen Alan C. , Ting K.C.
Published: February 2014

The benefits of particle size reduction and mechanical densification of biomass feedstock for storage, transportation, and handling must be assessed in relation to the systemic costs and energy consumption incurred due to these operations. The goal of this work was to determine the optimal levels of size reduction and densification through a combination of modeling and experimental studies. Size reduction and densification data for Miscanthus and switchgrass were generated using a two‐stage grinding process and the energy requirement and bulk densities for the particle sizes between 1 mm and 25.4 mm were determined. Increase in bulk density through compression by a pressure of 1.2 MPa was also measured. These data were used within BioFeed, a system‐level optimization model, to simulate scenarios capturing the possibilities of performing size reduction and densification at various stages of the supply chain. Simulation results assuming size reduction at farms showed that the optimal particle size range for both Miscanthus and switchgrass was 4–6 mm, with the optimal costs of $54.65 Mg–1 and $60.77 Mg–1 for Miscanthus and switchgrass, respectively. Higher hammer mill throughput and lower storage costs strongly impacted the total costs for different particle sizes. Size reduction and densification of biomass at the county‐specific centralized storage and pre‐processing facilities could reduce the costs by as much as $6.34 Mg–1 for Miscanthus and $20.13 Mg–1 for switchgrass over the base case. These differences provided the upper bound on the investments that could be made to set‐up and operate such systems. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd
Microsecond pulsed magnetic field improves efficacy of antifungal agents on pathogenic microorganisms
Authors: Novickij Vitalij , Grainys Audrius , Švedienė Jurgita , Markovskaja Svetlana , Paškevičius Algimantas , Novickij Jurij
Published: February 2014

Control and treatment of the emerging filamentous and yeast fungal diseases are of high priority in the biomedical field. This study investigated the influence of the pulsed magnetic field combined with common antifungal agents on the viability of various pathogenic fungi such as Aspergillus fumigatus, Candida albicans, and Trychophyton rubrum. Repetitive microsecond pulsed magnetic fields up to 6.1 T were applied in the study. The synergistic effect of co‐applying drugs and magnetic treatment to different fungi species causing various human mycoses showed the potential for more effective and less toxic therapy. Bioelectromagnetics. 35:347–353, 2014. © 2014 Wiley Periodicals, Inc.
The family–school interaction: school composition and parental educational expectations in the United States
Authors: Lawrence Elizabeth
Published: February 2014

Research has shown that intersections among families, schools and communities affect children's development, but there is still much unknown about how these contexts are linked and how they jointly influence children's education. This study explores one aspect of the overlapping influence of schools and families on children's education: the relationship between parental education expectations and school composition. Extending findings from literature on how parent expectations differ across social groups and studies showing school compositional effects on student outcomes suggests that schools may affect parents' attitudes and beliefs. UsingUSnationally representative data from the Early Childhood Longitudinal Study—Kindergarten (ECLS‐K), multilevel models show an independent, positive relationship between parental educational expectations of eighth grade children and the percentage of nonwhite students in the child's school, a surprising result given the lower average achievement levels ofUSschools with higher percentages of nonwhite students. This finding persists beyond controls for a variety of family, child and school factors, including baseline expectations from fifth grade. The results also show that parents of low socioeconomic status (SES) have higher expectations in schools with greater percentages of minority students, but higherSESparents are largely unaffected by school composition. Although the study cannot rule out the possible influence of unobservables, it cautiously interprets a causal effect ofUSschools on parent expectations. The study therefore concludes that school influence may extend beyond the child to family processes and that school composition is an important but overlooked factor related to educational expectations.
Flow injection chemiluminescence determination of lercanidipine based on N‐chlorosuccinimide–eosin Y post‐chemiluminescence reaction
Authors: Wang Guowei , Zhao Fang , Gao Ying
Published: February 2014

A novel post‐chemiluminescence (PCL) reaction was discovered when lercanidipine was injected into the CL reaction mixture of N‐chlorosuccinimide with alkaline eosin Y in the presence of cetyltrimethylammonium bromide (CTAB), where eosin Y was used as the CL reagent and CTAB as the surfactant. Based on this observation, a simple and highly sensitive PCL method combined with a flow injection (FI) technique was developed for the assay of lercanidipine. Under optimum conditions, the CL signal was linearly related to the concentration of lercanidipine in the range 7.0 × 10‐10 to 3.0 × 10‐6 g/mL with a detection limit of 2.3 × 10‐10 g/mL (3σ). The relative standard deviation (RSD) was 2.1% for 1.0 × 10‐8 g/mL lercanidipine (n = 13). The proposed method had been applied to the estimation of lercanidipine in tablets and human serum samples with satisfactory results. The possible CL mechanism is also discussed briefly. Copyright © 2014 John Wiley & Sons, Ltd.
Impact of hospital volume on hospital mortality, length of stay and total costs after pancreaticoduodenectomy
Authors: Yoshioka R , Yasunaga H , Hasegawa K , Horiguchi H , Fushimi K , Aoki T , Sakamoto Y , Sugawara Y , Kokudo N
Published: February 2014

Background

High morbidity and mortality rates after pancreaticoduodenectomy (PD) have led to concentration of this surgery in high-volume centres, with improved outcomes. The extent to which better outcomes might be apparent in a healthcare system where the mortality rate is already low is unclear.

Methods

The Japanese Diagnosis Procedure Combination database was used to identify patients undergoing PD between 2007 and 2010. Patient data included age, sex, co-morbidities at admission, type of hospital, type of PD, and the year in which the patient was treated. Hospital volume was defined as the number of PDs performed annually at each hospital, and categorized into quintiles: very low-, low-, medium-, high- and very high-volume groups. The Charlson co-morbidity index was calculated using the International Classification of Diseases, tenth revision, codes of co-morbidities.

Results

A total of 10 652 patients who underwent PD in 848 hospitals were identified. The overall in-hospital mortality rate after PD was 3·3 per cent (350 of 10 652), and for the groups ranged from 5·0 per cent for the very low-volume group to 1·4 per cent for the very high-volume group (P < 0·001). Multivariable analysis revealed a significant linear relationship between higher hospital volume and shorter postoperative length of stay compared with the very low-volume group, and between increasing hospital volume and lower total costs.

Conclusion

A significant relationship exists between increasing hospital volume, lower in-hospital mortality, shorter length of stay and lower costs for patients undergoing PD in Japan. Centralization of PD in this healthcare system is therefore justified.
Propensity score analysis of oesophageal cancer treatment with surgery or definitive chemoradiotherapy
Authors: Karran A , Blake P , Chan D , Reid T D , Davies I L , Kelly M , Roberts S A , Crosby T , Lewis W G
Published: February 2014

Background

The role of treatments involving surgery versus definitive chemoradiotherapy (dCRT) for oesophageal cancer remains controversial.

Methods

Consecutive patients with oesophageal cancer were studied. Those whose treatment involved surgery alone or who received neoadjuvant chemotherapy or chemoradiotherapy were compared with those receiving dCRT. Multiple regression models, including propensity scores, were developed to assess confounding factors associated with undergoing surgery or dCRT, and the risk-adjusted association between treatment and survival.

Results

From a total of 727 patients, regression adjustment to control for bias created a cohort of 521 patients available for comparison (277 in the surgery group and 244 in the dCRT group). Local and distant recurrence rates were 10·1 and 22·0 per cent respectively after surgery, compared with 26·2 and 11·9 per cent following dCRT (P < 0·001). Median survival, and 2- and 5-year survival rates after surgery were 27 months, 53·8 and 31·0 per cent respectively, compared with 28 months, 54·2 and 31·9 per cent after dCRT (P = 0·918). On multivariable analysis, disease-free survival was related to endosonographic tumour category (hazard ratio (HR) 0·76, 95 per cent confidence interval 0·10 to 6·04 for T1; HR 1·57, 0·21 to 11·58 for T2; HR 2·12, 0·29 to 15·49 for T3; HR 3·07, 0·41 to 23·16 for T4; P = 0·003, in relation to T0 as reference), lymph node metastasis count (HR 1·10, 1·04 to 1·15; P < 0·001) and total disease length (HR 0·96, 0·93 to 1·00; P = 0·041).

Conclusion

There was no difference in survival after oesophageal cancer treatment involving surgery or dCRT.
Quantitative determination of euphol in rat plasma by LC‐MS/MS and its application to a pharmacokinetic study
Authors: Xie Xu , Li Yongning , Gao Dongna , Zhang Yu , Ren Yanbo
Published: February 2014

Euphol is a potential pharmacologically active ingredient isolated from Euphorbia kansui. A simple, rapid, and sensitive method to determine euphol in rat plasma was developed based on liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) for the first time. The analyte and internal standard (IS), oleanic acid, were extracted from plasma with methanol and chromatographied on a C18 short column eluted with a mobile phase of methanol–water–formic acid (95:5:0.1, v/v/v). Detection was performed by positive ion atmospheric pressure chemical ionization in selective reaction monitoring mode. This method monitored the transitions m/z 409.0 → 109.2 and m/z 439.4 → 203.2 for euphol and IS, respectively. The assay was linear over the concentration range 27–9000 ng/mL, with a limit of quantitation of 27 ng/mL. The accuracy was between –7.04 and 4.11%, and the precision was <10.83%. This LC‐MS/MS method was successfully applied to investigate the pharmacokinetic study of euphol in rats after intravenous (6 mg/kg) and oral (48 mg/kg) administration. Results showed that the absolute bioavailability of euphol was approximately 46.01%. Copyright © 2014 John Wiley & Sons, Ltd.
Venous drainage of the spine and spinal cord: A comprehensive review of its history, embryology, anatomy, physiology, and pathology
Authors: Griessenauer Christoph J. , Raborn Joel , Foreman Paul , Shoja Mohammadali M. , Loukas Marios , Tubbs R. Shane
Published: February 2014

Venous drainage of the spine and spinal cord is accomplished through a complex network of venous structures compartmentalized to intrinsic, extrinsic, and extradural systems. As the literature on this topic is scarce, the following review was performed to summarize the available literature into a single coherent format. The medical literature on the spinal venous system was reviewed using online sources as well as historical documents that were not available online in regard to history, embryology, anatomy, and physiology with a particular emphasis on the pathology affecting this system. The spinal venous system is complex and variable. Proper understanding of all aspects is critical for the management of the pathology that results from its failure. Clin. Anat. 28:75–87, 2015. © 2014 Wiley Periodicals, Inc.
Superior rectal artery origin from the median sacral artery—angiographic appearance, developmental anatomy, and clinical implications
Authors: Pearl Monica S. , Gest Thomas R. , Gailloud Philippe
Published: February 2014

Two angiographic observations of significant rectal vascularization by branches originating from the median sacral artery (MSA) are reported. In the first case, the MSA provided a complete superior rectal trunk, with left and right branches, while in the second, the MSA only contributed superior rectal branches to the right side of the rectum, the left side being supplied by left internal iliac branches. The angiographic appearance, developmental anatomy, and clinical significance of these variants are discussed. Clin. Anat. 27:900–905, 2014. © 2014 Wiley Periodicals, Inc.
An Examination of Disclosure of Nonsuicidal Self‐injury among University Students
Authors: Armiento Jenna S. , Hamza Chloe A. , Willoughby Teena
Published: February 2014

Despite the widespread prevalence of nonsuicidal self‐injury (NSSI) among community‐based samples, little is known about which self‐injurers disclose their NSSI or the factors that promote disclosure among self‐injurers. To address this gap in the literature, we examined whether disclosers could be differentiated from nondisclosers on the basis of NSSI characteristics (e.g. frequency of NSSI and severity of NSSI), NSSI motivations (e.g. interpersonal and intrapersonal motivations) and psychosocial factors (e.g. suicidal ideation and self‐esteem). Participants consisted of a large sample of 268 self‐injuring undergraduate students (Mage = 19.07 years, 70.3% women) at a Canadian university. Results indicated that 57% of self‐injurers had never disclosed their NSSI to anyone. Self‐injurers were most likely to disclose to peers and romantic partners. Logistic regression analyses revealed that pain during NSSI, severity of NSSI, interpersonal motivations for engaging in NSSI, higher suicidal ideation and higher friendship quality were all associated with a greater likelihood of NSSI disclosure. Our findings suggest that individuals with severe NSSI and suicidal ideation may be more likely to disclose. Moreover, our findings underscore the importance of equipping friends and romantic partners with effective responses to NSSI disclosures to promote more formal help‐seeking behaviours among self‐injurers. Copyright © 2014 John Wiley & Sons, Ltd.
PPAR agonists stimulate adipogenesis at the expense of osteoblast differentiation while inhibiting osteoclast formation and activity
Authors: Patel Jessal J. , Butters Oliver R. , Arnett Timothy R.
Published: February 2014

Drugs used in the treatment of type 2 diabetes and cardiovascular disease, specifically peroxisome proliferator‐activated receptor (PPAR) agonists, have been reported to affect bone cell function and fracture risk. In this study, we assessed the direct effects of PPAR‐γ agonists (rosiglitazone and troglitazone), used in the treatment of diabetes, and a PPAR‐α agonist (fenofibrate), used to treat hyperlipidaemia, on the function of primary osteoblasts and osteoclasts. Formation of ‘trabecular’ bone structures by rat calvarial osteoblasts was reduced by up to 85% in cultures treated with rosiglitazone and by 45% in troglitazone‐treated or fenofibrate‐treated cultures; at the same time, lipid droplet formation was increased by 40–70%. The expression of key osteogenic markers was similarly downregulated in cultures treated with PPAR agonists, whereas adipogenesis markers were upregulated. Formation of osteoclasts in cultures derived from mouse marrow diminished with fenofibrate treatment, whereas both glitazones reduced resorptive activity without affecting osteoclast number. Metformin, although not a PPAR agonist, is also commonly used in the treatment of type 2 diabetes. Here, metformin was found to have no effect on bone cell function. Taken together, these data suggest that PPAR‐γ agonists may enhance bone loss via increased adipogenesis at the expense of osteoblast formation. In contrast, PPAR‐α agonists may prevent bone loss. Given that the prevalence of diabetes and cardiovascular disease is expected to rise significantly, greater attention may need to be paid to the effects of PPAR agonists on bone homeostasis. Copyright © 2014 John Wiley & Sons, Ltd.
RevErbα Preferentially Deforms DNA by Induced Fit
Authors: Chung Ying‐Hua , van der Vaart Arjan
Published: February 2014

Using free‐energy simulations, we have shown that RevErbα‐induced DNA deformation preferentially occurs by induced fit rather than by conformational selection, even though the DNA is only slightly distorted in the complex. Our study shows that information on the sequence of binding events is needed to establish whether conformational selection or induced fit is operative, and that the presence of multiple apo‐state structures might not be enough to distinguish between these binding models.
The Development of Antimicrobial α‐AApeptides that Suppress Proinflammatory Immune Responses
Authors: Padhee Shruti , Smith Christina , Wu Haifan , Li Yaqiong , Manoj Namitha , Qiao Qiao , Khan Zoya , Cao Chuanhai , Yin Hang , Cai Jianfeng
Published: February 2014

Herein we describe the development of a new class of antimicrobial and anti‐inflammatory peptidomimetics: cyclic lipo‐α‐AApeptides. They have potent and broad‐spectrum antibacterial activity against a range of clinically relevant pathogens, including both multidrug‐resistant Gram‐positive and Gram‐negative bacteria. Fluorescence microscopy suggests that cyclic lipo‐α‐AApeptides kill bacteria by disrupting bacterial membranes, possibly through a mechanism similar to that of cationic host‐defense peptides (HDPs). Furthermore, the cyclic lipo‐α‐AApeptide can mimic cationic host‐defense peptides by antagonizing Toll‐like receptor 4 (TLR4) signaling responses and suppressing proinflammatory cytokines such as tumor necrosis factor‐α (TNF‐α). Our results suggest that by mimicking HDPs, cyclic lipo‐α‐AApeptides could emerge as a new class of antibiotic agents that directly kill bacteria, as well as novel antiinflammatory agents that act through immunomodulation.
Molecular Interactions between Thiostrepton and the TipAS Protein from Streptomyces lividans
Authors: Myers Cullen L. , Harris Jesse , Yeung Jacky C. K. , Honek John F.
Published: February 2014

In Streptomyces lividans, the expression of several proteins is stimulated by the thiopeptide antibiotic thiostrepton. Two of these, TipAL and TipAS, autoregulate their expression after covalently binding to thiostrepton; this irreversibly sequesters the antibiotic and desensitizes the organism to its effects. In this work, additional molecular recognition interactions involved in this critical event were explored by utilizing various thiostrepton analogues and several site‐directed mutants of the TipAS antibiotic binding protein. Dissociation constants for several thiostrepton analogues ranged from 0.19 to 12.95 μM, depending on the analogue. The contributions of specific structural elements of the thiostrepton molecule to this interaction have been discerned, and an unusual covalent modification between the antibiotic and a new residue in a TipAS mutant has been detected.
One‐pot Synthesis of Ordered Mesoporous NiCeAl Oxide Catalysts and a Study of Their Performance in Methane Dry Reforming
Authors: Wang Ning , Xu Zhenxin , Deng Jie , Shen Kui , Yu Xiaopeng , Qian Weizhong , Chu Wei , Wei Fei
Published: February 2014

Ordered mesoporous NiAl and NiCeAl catalysts with different Ce/Al molar ratios were facilely synthesized by using the improved evaporation‐induced self‐assembly method. The characterization results confirmed that the ordered mesoporous structure was well sustained in the Ce‐incorporated NiAl materials (Ce/Al molar ratio<4 %). Compared with NiAl mesoporous materials, Ce‐incorporated mesoporous materials demonstrated higher specific surface areas, larger pore volumes, and more uniform pore sizes. The catalytic test conducted by using methane dry reforming revealed that compared with NiAl catalysts, all the Ce‐promoted catalysts demonstrated improved initial catalytic activity, which was due to the high dispersion and the high reduction degree of active Ni species in NiCeAl catalysts. The stable alumina framework, confinement effect of ordered mesopores, and high oxygen mobility contributed to the improved catalytic stability of NiCeAl catalysts. For comparison, the mesoporous NiCeAl catalyst (denoted as NiCeAl‐IMP) was also prepared by using the conventional impregnation method. The agglomeration of Ni particles was observed during the stability test for the Ni‐impregnated catalyst, which accelerated the rate of carbon deposition. The NiCeAl catalyst (Ce/Al molar ratio=1 %) demonstrated excellent resistance to the formation of graphitic carbon species owing to the redox property, while a large amount of graphitic carbon species was deposited over the NiAl sample, which was responsible for deactivation.
The Effect of Platinum Nanoparticle Distribution on Oxygen Electroreduction Activity and Selectivity
Authors: Fabbri Emiliana , Taylor Susan , Rabis Annett , Levecque Pieter , Conrad Olaf , Kötz Rüdiger , Schmidt Thomas J.
Published: February 2014

The catalytic activity and selectivity of Pt nanoparticles towards the oxygen reduction reaction (ORR) were investigated as a function of the Pt catalyst distribution. By means of the sputtering deposition technique, it was possible to fabricate Pt catalysts with different loadings that consisted of dispersed 2–3 nm particles, nanoparticle agglomerates and extended particulate layers. The transition from dispersed nanoparticles to extended layers led to a decrease in the electrochemical surface area (ECSA, m2Pt gPt−1) and to a shift of the platinum oxide reduction peak to more positive potentials, which indicates a decrease in the adsorption energy for oxygenated species. The latter finding was correlated to the observed decrease in specific activity with the increasing ECSA, that is, in the case of isolated nanoparticles, the higher adsorption energy for oxygenated species causes a reduction in the specific activity towards the ORR as larger amounts of active sites are blocked compared to extended surfaces. The presented data of specific and mass activity versus ECSA were found to follow a “master curve” obtained by comparing normalised Pt activities from different studies. The transition from dispersed Pt nanoparticles to extended layers also influences the Pt selectivity. At a decreased interparticle distance, a significant increase in the H2O2 production was observed below 0.6 V versus the reversible hydrogen electrode, which indicates the important role of a H2O2 desorption–readsorption reaction mechanism during the ORR on Pt nanoparticles.
Cu‐Based Catalyst Resulting from a Cu,Zn,Al Hydrotalcite‐Like Compound: A Microstructural, Thermoanalytical, and In Situ XAS Study
Authors: Kühl Stefanie , Tarasov Andrey , Zander Stefan , Kasatkin Igor , Behrens Malte
Published: February 2014

A Cu‐based methanol synthesis catalyst was obtained from a phase pure Cu,Zn,Al hydrotalcite‐like precursor, which was prepared by co‐precipitation. This sample was intrinsically more active than a conventionally prepared Cu/ZnO/Al2O3 catalyst. Upon thermal decomposition in air, the [(Cu0.5Zn0.17Al0.33)(OH)2(CO3)0.17]⋅mH2O precursor is transferred into a carbonate‐modified, amorphous mixed oxide. The calcined catalyst can be described as well‐dispersed “CuO” within ZnAl2O4 still containing stabilizing carbonate with a strong interaction of Cu2+ ions with the Zn–Al matrix. The reduction of this material was carefully analyzed by complementary temperature‐programmed reduction (TPR) and near‐edge X‐ray absorption fine structure (NEXAFS) measurements. The results fully describe the reduction mechanism with a kinetic model that can be used to predict the oxidation state of Cu at given reduction conditions. The reaction proceeds in two steps through a kinetically stabilized CuI intermediate. With reduction, a nanostructured catalyst evolves with metallic Cu particles dispersed in a ZnAl2O4 spinel‐like matrix. Due to the strong interaction of Cu and the oxide matrix, the small Cu particles (7 nm) of this catalyst are partially embedded leading to lower absolute activity in comparison with a catalyst comprised of less‐embedded particles. Interestingly, the exposed Cu surface area exhibits a superior intrinsic activity, which is related to a positive effect of the interface contact of Cu and its surroundings.
Molecularly Imprinted Polymers: Compromise between Flexibility and Rigidity for Improving Capture of Template Analogues
Authors: Pardo Antonelle , Mespouille Laetitia , Dubois Philippe , Blankert Bertrand , Duez Pierre
Published: February 2014

New synthetic strategies for molecularly imprinted polymers (MIPs) were developed to mimic the flexibility and mobility exhibited by receptor/enzyme binding pockets. The MIPs were prepared by bulk polymerization with quercetin as template molecule, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross‐linker, and THF as porogen. The innovative grafting of specific oligoethylene glycol units onto the imprinted cavities allowed MIPs to be obtained that exhibit extended selectivity towards template analogues. This synthetic strategy gives promising perspectives for the design of molecular recognition of molecules based on a congruent pharmacophore, which should be of interest for drug development.
Regiospecific Formation and Unusual Optical Properties of 2,5‐Bis(arylethynyl)rhodacyclopentadienes: A New Class of Luminescent Organometallics
Authors: Steffen Andreas , Ward Richard M. , Tay Meng Guan , Edkins Robert M. , Seeler Fabian , van Leeuwen Magda , Pålsson Lars‐Olof , Beeby Andrew , Batsanov Andrei S. , Howard Judith A. K. , Marder Todd B.
Published: February 2014

A series of 2,5‐bis(arylethynyl)rhodacyclopentadienes has been prepared by a rare example of regiospecific reductive coupling of 1,4‐(p‐R‐phenyl)‐1,3‐butadiynes (RH, Me, OMe, SMe, NMe2, CF3, CO2Me, CN, NO2, −CC‐(p‐C6H4NHex2), −CC(p‐C6H4CO2Oct)) at [RhX(PMe3)4] (1) (X=−CCSiMe3 (a), −CC‐(p‐C6H4NMe2) (b), −CCCC(p‐C6H4NPh2) (c) or CC{p‐C6H4‐CC(p‐C6H4‐N(C6H13)2)} (d) or Me (e)), giving the 2,5‐bis(arylethynyl) isomer exclusively. The rhodacyclopentadienes bearing a methyl ligand in the equatorial plane (compound 1 e) have been converted into their chloro analogues by reaction with HCl etherate. The rhodacycles thus obtained are stable to air and moisture in the solid state and the acceptor‐substituted compounds are even stable to air and moisture in solution. The photophysical properties of the rhodacyclopentadienes are highly unusual in that they exhibit, exclusively, fluorescence between 500–800 nm from the S1 state, with quantum yields of Φ=0.01–0.18 and short lifetimes (τ=0.45–8.20 ns). The triplet state formation (ΦISC=0.57 for 2 a) is exceptionally slow, occurring on the nanosecond timescale. This is unexpected, because the Rh atom should normally facilitate intersystem crossing within femto‐ to picoseconds, leading to phosphorescence from the T1 state. This work therefore highlights that in some transition‐metal complexes, the heavy atom can play a more subtle role in controlling the photophysical behavior than is commonly appreciated.
On the Use of Metal Purine Derivatives (M=Ir, Rh) for the Selective Labeling of Nucleosides and Nucleotides
Authors: Valencia Marta , Martín‐Ortiz Mamen , Gómez‐Gallego Mar , Ramírez de Arellano Carmen , Sierra Miguel A.
Published: February 2014

The reactions of neutral or cationic IrIII and RhIII derivatives of phenyl purine nucleobases with unsymmetrical alkynes produce new metallacycles in a predictable manner, which allows for the incorporation of either photoactive (anthracene or pyrene) or electroactive (ferrocene) labels in the nucleotide or nucleoside moiety. The reported methodology (metalation of the purine derivative and subsequent marker insertion) could be used for the postfunctionalization and unambiguous labeling of oligonucleotides.
Probing the Limits of Ligand Steric Bulk: Backbone CH Activation in a Saturated N‐Heterocyclic Carbene
Authors: Phillips Nicholas , Tirfoin Remi , Aldridge Simon
Published: February 2014

The consequences of extremely high steric loading have been probed for late transition metal complexes featuring the expanded ring N‐heterocyclic carbene 6‐Dipp. The reluctance of this ligand to form 2:1 complexes with d‐block metals (rationalised on the basis of its percentage buried volume, % Vbur, of 50.8 %) leads to CH and CN bond activation processes driven by attack at the backbone β‐CH2 unit. In the presence of IrI (or indeed H+) the net result is the formation of an allyl formamidine fragment, while AuI brings about an additional ring (re‐)closure step via nucleophilic attack at the coordinated alkene. The net transformation of 6‐Dipp in the presence of [(6‐Dipp)Au]+ represents to our knowledge the first example of backbone CH activation of a saturated N‐heterocyclic carbene, proceeding in this case via a mechanism which involves free carbene in addition to the AuI centre.
New RuII(arene) Complexes with Halogen‐Substituted Bis‐ and Tris(pyrazol‐1‐yl)borate Ligands
Authors: Orbisaglia Serena , Di Nicola Corrado , Marchetti Fabio , Pettinari Claudio , Pettinari Riccardo , Martins Luísa M. D. R. S. , Alegria Elisabete C. B. A. , Guedes da Silva M. Fátima C. , Rocha Bruno G. M. , Kuznetsov Maxim L. , Pombeiro Armando J. L. , Skelton Brian W. , Sobolev Alexandre N. , White Allan H.
Published: February 2014

[RuCl(arene)(μ‐Cl)]2 dimers were treated in a 1:2 molar ratio with sodium or thallium salts of bis‐ and tris(pyrazolyl)borate ligands [Na(Bp)], [Tl(Tp)], and [Tl(TpiPr, 4Br)]. Mononuclear neutral complexes [RuCl(arene)(κ2‐Bp)] (1: arene=p‐cymene (cym); 2: arene=hexamethylbenzene (hmb); 3: arene=benzene (bz)), [RuCl(arene)(κ2‐Tp)] (4: arene=cym; 6: arene=bz), and [RuCl(arene)(κ2‐TpiPr, 4Br)] (7: arene=cym, 8: arene=hmb, 9: arene=bz) have been always obtained with the exception of the ionic [Ru2(hmb)2(μ‐Cl)3][Tp] (5′), which formed independently of the ratio of reactants and reaction conditions employed. The ionic [Ru(CH3OH)(cym)(κ2‐Bp)][X] (10: X=PF6, 12: X=O3SCF3) and the neutral [Ru(O2CCF3)(cym)(κ2‐Bp)] (11) have been obtained by a metathesis reaction with corresponding silver salts. All complexes 1–12 have been characterized by analytical and spectroscopic data (IR, ESI‐MS, 1H and 13C NMR spectroscopy). The structures of the thallium and calcium derivatives of ligand Tp, [Tl(Tp)] and [Ca(dmso)6][Tp]2⋅2 DMSO, of the complexes 1, 4, 5′, 6, 11, and of the decomposition product [RuCl(cym)(HpziPr, 4Br)2][Cl] (7′) have been confirmed by using single‐crystal X‐ray diffraction. Electrochemical studies showed that 1–9 and 11 undergo a single‐electron RuII→RuIII oxidation at a potential, measured by cyclic voltammetry, which allows comparison of the electron‐donor characters of the bis‐ and tris(pyrazol‐1‐yl)borate and arene ligands, and to estimate, for the first time, the values of the Lever EL ligand parameter for Bp, Tp, and TpiPr, 4Br. Theoretical calculations at the DFT level indicated that both oxidation and reduction of the Ru complexes under study are mostly metal‐centered with some involvement of the chloride ligand in the former case, and also demonstrated that the experimental isolation of the μ3‐binuclear complex 5′ (instead of the mononuclear 5) is accounted for by the low thermodynamic stability of the latter species due to steric reasons.
Low‐LUMO Pyrene‐Fused Azaacenes
Authors: More Sandeep , Bhosale Rajesh , Mateo‐Alonso Aurelio
Published: February 2014

A series of pyrene‐fused azaacenes with four and six linearly fused rings that possess LUMO levels between −3.7 and −4.3 eV is reported. These LUMO values are remarkably lower than those typically observed for pyrene‐fused azaacenes, even for systems with sixteen linearly fused rings, and are comparable to those observed for state‐of‐the‐art n‐azaacenes.
Thiazolidinones Derived from Dynamic Systemic Resolution of Complex Reversible‐Reaction Networks
Authors: Zhang Yan , Ramström Olof
Published: February 2014

A complex dynamic system based on a network of multiple reversible reactions has been established. The network was applied to a dynamic systemic resolution protocol based on kinetically controlled lipase‐catalyzed transformations. This resulted in the formation of cyclized products, where two thiazolidinone compounds were efficiently produced from a range of potential transformations.
Vanadium substituted SBA‐15 supported bimetallic Pt, Pd catalysts for hydrogenation of toluene to methylcyclohexane
Authors: Roy Shyamal , Newalkar Bharat L. , Datta Siddhartha
Published: February 2014

Highly dispersed Pt–Pd nanoparticles are synthesised within the channels of a mesoporous V‐SBA‐15 support followed by thorough catalyst characterisation (BET surface area and CO chemisorptions techniques) and testing in the selective hydrogenation of toluene to methylcyclohexane. The hydrogenation reaction is investigated under varied conditions of temperature, pressure, hydrogen to feed ratio and WHSV, respectively. Furthermore, detailed kinetics of hydrogenation is investigated. Typically, 100% conversion of toluene into methylcyclohexane is achieved at 498 K and 20 bar pressure and no other products like, 1,2‐ and 1,3‐dimethyl cyclopentane and ethylcyclopentane were also observed due to isomerisation and cracking reactions. The activation energy of the reaction was found to be 51.22 kJ/mol. Thus, the obtained results are discussed with respect to the role of vanadium in hydrogenation reaction over SBA‐15 framework.
A Reevaluation of the Costs of Heart Failure and Its Implications for Allocation of Health Resources in the United States
Authors: Voigt Jeff , John M. Sasha , Taylor Andrew , Krucoff Mitchell , Reynolds Matthew R. , Michael Gibson C.
Published: February 2014

The annual cost of heart failure (HF) is estimated at $39.2 billion. This has been acknowledged to underestimate the true costs for care. The objective of this analysis is to more accurately assess these costs. Publicly available data sources were used. Cost calculations incorporated relevant factors such as Medicare hospital cost‐to‐charge ratios, reimbursement from both government and private insurance, and out‐of‐pocket expenditures. A recently published Atherosclerosis Risk in Communities (ARIC) HF scheme was used to adjust the HF classification scheme. Costs were calculated with HF as the primary diagnosis (HF in isolation, or HFI) or HF as one of the diagnoses/part of a disease milieu (HF syndrome, or HFS). Total direct costs for HF were calculated at $60.2 billion (HFI) and $115.4 billion (HFS). Indirect costs were $10.6 billion for both. Costs attributable to HF may represent a much larger burden to US health care than what is commonly referenced. These revised and increased costs have implications for policy makers.
Facing head and neck cancer deaths head on: Lessons for survival
Authors: Ringash Jolie
Published: February 2014

Despite making up only 3% of all cancers, squamous cell carcinomas of the head and neck (HNC) exemplify complex survivorship care. Characteristics of this cohort of patients include high levels of comorbidity, high baseline risk of psychosocial distress, and exposure to highly toxic treatment strategies. With survival rates of the primary cancer increasing over time, the population at risk for secondary complications (including recurrence, secondary primaries, illnesses induced by risk factors, and injuries related to treatment) is increasing. Recognition of elevated death rates of survivors, persisting up to 10 years after diagnosis, outline the importance of a dedicated approach to HNC survivorship care, whether provided within or outside the comprehensive cancer center.
Species‐specific differences in the medial prefrontal projections to the pons between rat and rabbit
Authors: Moya Maria V. , Siegel Jennifer J. , McCord Eedann D. , Kalmbach Brian E. , Dembrow Nikolai , Johnston Daniel , Chitwood Raymond A.
Published: February 2014

The medial prefrontal cortex (mPFC) of both rats and rabbits has been shown to support trace eyeblink conditioning, presumably by providing an input to the cerebellum via the pons that bridges the temporal gap between conditioning stimuli. The pons of rats and rabbits, however, shows divergence in gross anatomical organization, leaving open the question of whether the topography of prefrontal inputs to the pons is similar in rats and rabbits. To investigate this question, we injected anterograde tracer into the mPFC of rats and rabbits to visualize and map in 3D the distribution of labeled terminals in the pons. Effective mPFC injections showed labeled axons in the ipsilateral descending pyramidal tract in both species. In rats, discrete clusters of densely labeled terminals were observed primarily in the rostromedial pons. Clusters of labeled terminals were also observed contralateral to mPFC injection sites in rats, appearing as a less dense "mirror‐image" of ipsilateral labeling. In rabbits, mPFC labeled corticopontine terminals were absent in the rostral pons, and instead were restricted to the intermediate pons. The densest terminal fields were typically observed in association with the ipsilateral pyramidal tract as it descended ventromedially through the rabbit pons. No contralateral terminal labeling was observed for any injections made in the rabbit mPFC. The results suggest the possibility that mPFC inputs to the pons may be integrated with different sources of cortical inputs between rats and rabbits. The resulting implications for mPFC or pons manipulations for studies of trace eyeblink in each species are discussed. J. Comp. Neurol. 522:3052–3074, 2014. © 2014 Wiley Periodicals, Inc.
A meshless point collocation treatment of transient bioheat problems
Authors: Bourantas G. C. , Loukopoulos V. C. , Burganos V. N. , Nikiforidis G. C.
Published: February 2014

A meshless numerical method is proposed for the solution of the transient bioheat equation in two and three dimensions. The Pennes bioheat equation is extended in order to incorporate water evaporation, tissue damage, and temperature‐dependent tissue properties during tumor ablation. The conductivity of the tissue is not assumed constant but is treated as a local function to simulate local variability due to the existence of usually unclear interfacing of healthy and pathological segments. In this way, one avoids the need for accurate identification of the boundaries between pathological and healthy regions, which is a typical problem in medical practice, and sidesteps, evidently, the corresponding mathematical treatment of such boundaries, which is usually a tedious procedure with some inevitable degree of approximation. The numerical results of the new method for test applications of the bioheat transfer equation are validated against analytical predictions and predictions of other numerical methods. 3D simulations are presented that involve the modeling of tumor ablation and account for metabolic heat generation, blood perfusion, and heat ablation using realistic values for the various parameters. An evaluation of the effective medium approximation to homogenize conductivity fields for use with the bioheat equation is also provided. Copyright © 2014 John Wiley & Sons, Ltd.