bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethylene polymerization with long‐lifetime monopendant thienyl‐substituted group 4 metallocenes
Authors: Li Aike , Xiao Wei , Ma Haiyan , Huang Jiling
Published: May 2014

A series of group 4 metallocenes (RCp)[Cp―(bridge)―(2‐C4H3S)]MCl2 [M = Ti (C1, C2, C3, C4); M = Zr (C5, C6, C7, C8)] bearing a pendant thiophene group on a cyclopentadienyl ring have been synthesized, characterized and tested as catalyst precursors for ethylene polymerization. The molecular structures of representative titanocenes C2 and C4 were confirmed by single‐crystal X‐ray diffraction and revealed that both complexes exist in an expected coordination environment for a monomeric bent metallocene. No intramolecular coordination between the thiophene group and the titanium center could be observed in the solid state. Upon activation by methylaluminoxane (MAO), titanocenes C1, C2, C3, C4 showed moderate catalytic activities and produced high‐ or ultra‐high‐molecular‐weight polyethylene (Mv 70.5–227.1 × 104 g mol−1). Titanocene C3 is more active and long‐lived, with a lifetime of nearly 9 h at 30 °C. At elevated temperatures of 80–110 °C, zirconocenes C5, C6, C7, C8 displayed high catalytic activities (up to 27.6 × 105 g PE (mol Zr)−1 h−1), giving high‐molecular‐weight polyethylene (Mv 11.2–53.7 × 104 g mol−1). Even at 80 °C, a long lifetime of at least 2 h was observed for the C8/MAO catalyst system. Copyright © 2014 John Wiley & Sons, Ltd.
Lewis base‐catalyzed electrophilic lactonization of selenyl bromide resin and facile solid‐phase synthesis of furan‐2(5H)‐one derivatives
Authors: Jun He Rong , Chun Zhu Bing , Wang Yu Guang
Published: May 2014

A facile solid‐phase synthesis approach was developed for the rapid synthesis of multi‐substituted furan‐2(5H)‐one derivatives libraries. The synthetic strategy included the selenyl bromide resin‐induced electrophilic lactonization catalyzed by Lewis base, lithiation, nucleophilic substitution and oxidation–elimination of the selenium resins. The advantages of the new method are good yields, high purity, straightforward operations and high diversity of the products, lack of odor, and good stability of the selenium resins. Copyright © 2014 John Wiley & Sons, Ltd.
Stimulus‐Responsive Metal–Organic Frameworks
Authors: Nagarkar Sanjog S. , Desai Aamod V. , Ghosh Sujit K.
Published: May 2014

Materials that can recognize the changes in their local environment and respond by altering their inherent physical and/or chemical properties are strong candidates for future “smart” technology materials. Metal–organic frameworks (MOFs) have attracted a great deal of attention in recent years owing to their designable architecture, host–guest chemistry, and softness as porous materials. Despite this fact, studies on the tuning of the properties of MOFs by external stimuli are still rare. This review highlights the recent developments in the field of stimulus‐responsive MOFs or so‐called smart MOFs. In particular, the various stimuli used and the utility of stimulus‐responsive smart MOFs for various applications such as gas storage and separation, sensing, clean energy, catalysis, molecular motors, and biomedical applications are highlighted by using representative examples. Future directions in the developments of stimulus‐responsive smart MOFs and their applications are proposed from a personal perspective.
Simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma by UPLC‐MS/MS and its application to a pharmacokinetic study after administration of Reduning injection
Authors: Wang Yanjuan , Wen Jing , Zheng Weihua , Zhao Longshan , Fu Xiaohuan , Wang Zhenzhong , Xiong Zhili , Li Famei , Xiao Wei
Published: May 2014

A simple, specific and sensitive ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was established and validated for simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma using puerarin as an internal standard (IS). Plasma samples were pretreated by a one‐step direct protein precipitation procedure with acetonitrile after acidified using as little as 50 μL plasma. Chromatographic separation was performed on an Acquity BEH C18 column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.2 mL/min by a gradient elution, using 0.2% acetic acid–methanol as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with negative ion mode. Calibration curves showed good linearity (r > 0.995) over wide concentration ranges. The intra‐ and inter‐day precisions were <15%, and the accuracy was within ±8.0%. The validated method was successfully applied to a pharmacokinetic study of the four bioactive components in rats after intravenous administration of Reduning injection. Copyright © 2014 John Wiley & Sons, Ltd.
3D restoration microscopy improves quantification of enzyme‐labeled fluorescence‐based single‐cell phosphatase activity in plankton
Authors: Diaz‐de‐Quijano Daniel , Palacios Pilar , Horňák Karel , Felip Marisol
Published: May 2014

The ELF or fluorescence‐labeled enzyme activity (FLEA) technique is a culture‐independent single‐cell tool for assessing plankton enzyme activity in close‐to‐in situ conditions. We demonstrate that single‐cell FLEA quantifications based on two‐dimensional (2D) image analysis were biased by up to one order of magnitude relative to deconvolved 3D. This was basically attributed to out‐of‐focus light, and partially to object size. Nevertheless, if sufficient cells were measured (25–40 cells), biases in individual 2D cell measurements were partially compensated, providing useful and comparable results to deconvolved 3D. We also discuss how much caution should be used when comparing the single‐cell enzyme activities of different sized bacterio‐ and/or phytoplankton populations measured on 2D images. Finally, a novel method based on deconvolved 3D images (wide field restoration microscopy; WFR) was devised to improve the discrimination of similar single‐cell enzyme activities, the comparison of enzyme activities between different size cells, the measurement of low fluorescence intensities, the quantification of less numerous species, and the combination of the FLEA technique with other single‐cell methods. These improvements in cell enzyme activity measurements will provide a more precise picture of individual species' behavior in nature, which is essential to understand their functional role and evolutionary history. © 2014 International Society for Advancement of Cytometry
Rationale and study design of the NEuroCardiac TherApy foR Heart Failure Study: NECTAR‐HF
Authors: De Ferrari Gaetano M. , Tuinenburg Anton E. , Ruble Stephen , Brugada Josep , Klein Helmut , Butter Christian , Wright David J. , Schubert Bernd , Solomon Scott , Meyer Scott , Stein Kenneth , Ramuzat Agnes , Zannad Faiez
Published: May 2014

Aims

Increased sympathetic activation and reduced parasympathetic tone are important pathophysiological contributors to the progression of heart failure, and are associated with poor outcome in patients. The aim of this study is to determine if vagal nerve stimulation (VNS) is a promising approach to modulate autonomic function and slow cardiac remodelling and the progression of heart failure.

Methods

The NECTAR‐HF (NEural Cardiac TherApy foR Heart Failure) trial is designed to evaluate whether the Boston Scientific VNS device is safe and may attenuate cardiac remodelling, improve cardiac function and increase exercise capacity, in symptomatic heart failure patients (New York Heart Association Class II–III) with left ventricular systolic dysfunction (ejection fraction ≤35%) and receiving optimal medical therapy. Patients will be randomized in a 2:1 ratio to receive standard optimal medical treatment plus VNS system in an active mode vs. optimal medical treatment plus VNS system in an inactive mode, for a 6 month period. After the 6 month control period, inactive VNS systems will be activated and all patients will receive VNS. The study is powered to detect differences in the primary efficacy endpoint of change in left ventricular end systolic diameter. Secondary endpoints include ejection fraction, left ventricular volumes, quality of life scores, functional capacity, and changes in biomarkers.

Conclusion

This Phase II, randomized clinical trial conducted with vagal stimulation for heart failure will provide important new information on the potential of this novel and promising technique.
Misinitiation of intrathymic MART‐1 transcription and biased TCR usage explain the high frequency of MART‐1‐specific T cells
Authors: Pinto Sheena , Sommermeyer Daniel , Michel Chloé , Wilde Susanne , Schendel Dolores , Uckert Wolfgang , Blankenstein Thomas , Kyewski Bruno
Published: May 2014

Immunity to tumor differentiation antigens, such as melanoma antigen recognized by T cells 1 (MART‐1), has been comprehensively studied. Intriguingly, CD8+ T cells specific for the MART‐126(27)‐35 epitope in the context of HLA‐A0201 are about 100 times more abundant compared with T cells specific for other tumor‐associated antigens. Moreover, MART‐1‐specific CD8+ T cells show a highly biased usage of the Vα‐region gene TRAV12–2. Here, we provide independent support for this notion, by showing that the combinatorial pairing of different TCRα‐ and TCRβ‐ chains derived from HLA‐A2–MART‐126–35‐specific CD8+ T‐cell clones is unusually permissive in conferring MART‐1 specificity, provided the CDR1α TRAV12–2 region is used. Whether TCR bias alone accounts for the unusual abundance of HLA‐A2–MART‐126–35‐specific CD8+ T cells has remained conjectural. Here, we provide an alternative explanation: misinitiated transcription of the MART‐1 gene resulting in truncated mRNA isoforms leads to lack of promiscuous transcription of the MART‐126–35 epitope in human medullary thymic epithelial cells and, consequently, evasion of central self‐tolerance toward this epitope. Thus, biased TCR usage and leaky central tolerance might act in an independent and additive manner to confer high frequency of MART‐126–35‐specific CD8+ T cells.
Human Y‐chromosome SNP characterization by multiplex amplified product‐length polymorphism analysis
Authors: Medina Laura Smeldy Jurado , Muzzio Marina , Schwab Marisol , Costantino María Leticia Bravi , Barreto Guillermo , Bailliet Graciela
Published: May 2014

We designed an allele‐specific amplification protocol to optimize Y‐chromosome SNP typing, which is an unavoidable step for defining the phylogenetic status of paternal lineages. It allows the simultaneous highly specific definition of up to six mutations in a single reaction by amplification fragment length polymorphism (AFLP) without the need of specialized equipment, at a considerably lower cost than that based on single‐base primer extension (SNaPshot™) technology or PCR‐RFLP systems, requiring as little as 0.5 ng DNA and compatible with the small fragments characteristic of low‐quality DNA. By designation of two primers recognizing the derived and ancestral state for each SNP, which can be differentiated by size by the addition of a noncomplementary nucleotide tail, we could define major Y clades E, F, K, R, Q, and subhaplogroups R1, R1a, R1b, R1b1b, R1b1c, J1, J2, G1, G2, I1, Q1a3, and Q1a3a1 through amplification fragments that ranged between 60 and 158bp.
MiR‐135b is a direct PAX6 target and specifies human neuroectoderm by inhibiting TGF‐β/BMP signaling
Authors: Bhinge Akshay , Poschmann Jeremie , Namboori Seema C , Tian Xianfeng , Jia Hui Loh Sharon , Traczyk Anna , Prabhakar Shyam , Stanton Lawrence W
Published: May 2014

Several transcription factors (TFs) have been implicated in neuroectoderm (NE) development, and recently, the TF PAX6 was shown to be critical for human NE specification. However, microRNA networks regulating human NE development have been poorly documented. We hypothesized that microRNAs activated by PAX6 should promote NE development. Using a genomics approach, we identified PAX6 binding sites and active enhancers genome‐wide in an in vitro model of human NE development that was based on neural differentiation of human embryonic stem cells (hESC). PAX6 binding to active enhancers was found in the proximity of several microRNAs, including hsa‐miR‐135b. MiR‐135b was activated during NE development, and ectopic expression of miR‐135b in hESC promoted differentiation toward NE. MiR‐135b promotes neural conversion by targeting components of the TGF‐β and BMP signaling pathways, thereby inhibiting differentiation into alternate developmental lineages. Our results demonstrate a novel TF‐miRNA module that is activated during human neuroectoderm development and promotes the irreversible fate specification of human pluripotent cells toward the neural lineage.
STAG3‐mediated stabilization of REC8 cohesin complexes promotes chromosome synapsis during meiosis
Authors: Fukuda Tomoyuki , Fukuda Nanaho , Agostinho Ana , Hernández‐Hernández Abrahan , Kouznetsova Anna , Höög Christer
Published: May 2014

Cohesion between sister chromatids in mitotic and meiotic cells is promoted by a ring‐shaped protein structure, the cohesin complex. The cohesin core complex is composed of four subunits, including two structural maintenance of chromosome (SMC) proteins, one α‐kleisin protein, and one SA protein. Meiotic cells express both mitotic and meiosis‐specific cohesin core subunits, generating cohesin complexes with different subunit composition and possibly separate meiotic functions. Here, we have analyzed the in vivo function of STAG3, a vertebrate meiosis‐specific SA protein. Mice with a hypomorphic allele of Stag3, which display a severely reduced level of STAG3, are viable but infertile. We show that meiocytes in homozygous mutant Stag3 mice display chromosome axis compaction, aberrant synapsis, impaired recombination and developmental arrest. We find that the three different α‐kleisins present in meiotic cells show different dosage‐dependent requirements for STAG3 and that STAG3‐REC8 cohesin complexes have a critical role in supporting meiotic chromosome structure and functions.
Parametric Simulation of Low‐Temperature Heat Recovery using a Rankine Cycle to Drive Multi‐effect Distillation
Authors: Xue Jianliang , Zhao Dongfeng , Chen Jianguang , Li Shi , Liu Wei , Shen Chanchan
Published: May 2014

The Rankine cycle (RC) has been widely applied to the conversion of low‐grade heat. In this study, low‐temperature heat recovery based upon a Rankine system was proposed to drive multi‐effect distillation (MED) in a refinery. The thermal model was described, including the important parameters. The results indicated that a higher mass of steam could be produced by using a higher temperature of the low‐temperature heat source. The lower pinch‐point temperature difference could inevitably lead to higher evaporator costs. The inlet temperature of the working fluid and ambient temperature both influenced the thermodynamic efficiency of the system. The thermodynamic efficiency of the system increased markedly with increasing inlet temperature of the working fluid. As the ambient temperature increased, the thermodynamic efficiency of system was improved. The thermodynamic efficiency with ammonia/water as the working fluid was higher than that with water.
Is orthonasal olfaction an equilibrium driven process? Design and validation of a dynamic purge and trap system for the study of orthonasal wine aroma
Authors: Escudero Ana , San‐Juan Felipe , Franco‐Luesma Ernesto , Cacho Juan , Ferreira Vicente
Published: May 2014

Synthetic wine models containing aroma molecules at levels producing known orthonasal odour intensity scores were used to assess the representativity of the extracts obtained with a previously developed purge and trap Gas Chromatography‐Olfactometry (GC‐O) strategy. The study revealed that the GC‐O scores of polar odourants were very small or even null, even when these compounds were clearly perceived in the orthonasal evaluation of the synthetic wines. The different parts of the system were thoroughly evaluated and reoptimized, and although partial elution problems affecting polar odourants were detected and corrected, the underestimation of polar odourants persistently remained. A significant improvement was only achieved with a completely redesigned system in which a much larger flow of gas just flows out the sample vapours – instead of bubbling through the liquid – above the strictly non‐stirred liquid sample. The GC‐O scores obtained with this new design were much closer to the orthonasal odour intensity scores of the synthetic models and the underestimation of polar odourants was not observed. A final validation showed that the proposed system is able to provide significantly different GC‐O signals for solutions containing increasing amounts of polar odourants at perithreshold levels. All this suggests that the transfer of aroma molecules from the sample to the nose during orthonasal olfaction is mass transfer controlled rather than equilibrium driven, which has been experimentally verified using Atmospheric Pressure Chemical Ionization‐Mass Spectrometry (APCI‐MS). Copyright © 2014 John Wiley & Sons, Ltd.
A dual mortar approach for mesh tying within a variational multiscale method for incompressible flow
Authors: Ehrl A. , Popp A. , Gravemeier V. , Wall W.A.
Published: May 2014

In the present work, the coupling of computational subdomains with non‐conforming discretizations is addressed in the context of residual‐based variational multiscale finite element methods for incompressible fluid flow. A mortar method using dual Lagrange multipliers is introduced for handling the coupling conditions at arbitrary fluid–fluid interfaces. Recently, mortar methods have been successfully applied in the field of nonlinear solid mechanics, for example, to weakly impose interface constraints for finite deformation contact. The focus of this study is on both the integration of the dual mortar approach into an existing variational multiscale finite element framework and the investigation of the resulting interplay between variational multiscale and coupling terms. We analyze the effects of either constraining only velocity or both velocity and pressure degrees of freedom at the internal interfaces using dual Lagrange multipliers. In analogy to other problem classes, we exploit the fact that the dual mortar approach allows for an efficient condensation of the additional Lagrange multiplier degrees of freedom from the global system of equations. As a result, the typical but often undesirable saddle‐point structure of this system is completely removed. The proposed method is validated numerically for various three‐dimensional examples, including a complex patient‐specific aneurysm, and its accuracy and efficiency in comparison with standard conforming discretizations is demonstrated. Copyright © 2014 John Wiley & Sons, Ltd.
Diabetes mellitus is an independent prognostic factor for major liver-related outcomes in patients with cirrhosis and chronic hepatitis C
Authors: Elkrief Laure , Chouinard Pascale , Bendersky Noelle , Hajage David , Larroque Béatrice , Babany Gérard , Kutala Blaise , Francoz Claire , Boyer Nathalie , Moreau Richard , Durand François , Marcellin Patrick , Rautou Pierre-Emmanuel , Valla Dominique
Published: May 2014

In patients with chronic hepatitis C (CHC), cirrhosis is associated with age, gender, diabetes, alcohol abuse, and coinfection with human immunodeficiency virus (HIV) or hepatitis B virus (HBV). The effect of these factors on the outcome of cirrhosis is unknown. This study in CHC patients with cirrhosis aimed to assess the influence of these factors on decompensation, liver transplantation, and death. Consecutive patients with CHC and cirrhosis hospitalized between January 1, 2006 and December 31, 2008 were followed up until death, transplantation, or study closure in March 2013. Gender, age, Model for End-Stage Liver Disease (MELD) score, diabetes, alcohol abuse, HIV, or HBV coinfection were collected at inclusion. The complications of cirrhosis, death, and liver transplantation were recorded at inclusion and during follow-up. The association between baseline factors and liver-related outcomes at inclusion and during follow-up were tested using logistic regression and Cox's model, respectively. A total of 348 patients with CHC and cirrhosis (68% men; median age: 59 years; median MELD: 10) were included. At baseline, 40% of the patients had diabetes, 29% alcohol abuse, and 6% HIV or HBV coinfection. Baseline MELD ≥10 (P < 0.001), diabetes (P = 0.027), and HBV coinfection (P = 0.001) were independently associated with transplantation-free survival. Baseline diabetes was independently associated with ascites (P = 0.05), bacterial infections (P = 0.001), and encephalopathy (P < 0.001) at inclusion. Baseline diabetes was independently associated with development of ascites (P = 0.057), renal dysfunction (P = 0.004), bacterial infections (P = 0.007), and hepatocellular carcinoma (P = 0.016) during the follow-up. Conclusion: In patients with CHC and cirrhosis, diabetes is an independent prognostic factor. Improving diabetes control may improve the outcome of cirrhosis. (Hepatology 2014;60:823–831)
An analysis of infiltration with moisture content distribution in a two‐dimensional discretized water content domain
Authors: Yu Han , Douglas Craig C.
Published: May 2014

On the basis of unsaturated Darcy's law, the Talbot–Ogden method provides a fast unconditional mass conservative algorithm to simulate groundwater infiltration in various unsaturated soil textures. Unlike advanced reservoir modelling methods that compute unsaturated flow in space, it only discretizes the moisture content domain into a suitable number of bins so that the vertical water movement is estimated piecewise in each bin. The dimensionality of the moisture content domain is extended from one dimensional to two dimensional in this study, which allows us to distinguish pore shapes within the same moisture content range. The vertical movement of water in the extended model imitates the infiltration phase in the Talbot–Ogden method. However, the difference in this extension is the directional redistribution, which represents the horizontal inter‐bin flow and causes the water content distribution to have an effect on infiltration. Using this extension, we mathematically analyse the general relationship between infiltration and the moisture content distribution associated with wetting front depths in different bins. We show that a more negatively skewed moisture content distribution can produce a longer ponding time, whereas a higher overall flux cannot be guaranteed in this situation. It is proven on the basis of the water content probability distribution independent of soil textures. To illustrate this analysis, we also present numerical examples for both fine and coarse soil textures. Copyright © 2014 John Wiley & Sons, Ltd.
Role of adjuvant surgery in initially unresectable pancreatic cancer after long‐term chemotherapy or chemoradiation therapy: survival benefit?
Authors: Opendro Singh Sapam , Satoi Sohei , Yanagimoto Hiroaki , Yamamoto Tomohisa , Toyokawa Hideyoshi , Hirooka Satoshi , Yamaki So , Inoue Kentaro , Matsui Yoichi , Kwon A‐Hon
Published: May 2014

Background

The purpose of the present study was to analyze the survival benefit and safety of adjuvant surgery in patients with initially unresectable pancreatic cancer following chemo(radio)therapy.

Methods

The 130 patients with unresectable pancreatic cancer treated during 2006 to 2013 were divided into a study group (15 patients) with planned adjuvant surgery, and a control group (115 patients with locally advanced disease) without adjuvant surgery.

Results

The study group of 15 patients had shrunken tumor, decreased tumor marker, and maintained performance status after 9 months (range 5–18 months) of chemo(radio)therapy. Thirteen patients had curative resection and two patients were not resected. The remaining controls of 115 patients did not undergo surgical resection due to poor response to chemo(radio)therapy or performance status. The median survival time in the study group was better than in the control group (36 vs. 9 months, P < 0.001). The mortality and morbidity rates in the study group were 0% and 46% respectively, in spite of concomitant organ resections in 77%.

Conclusion

Patients who had adjuvant surgery had significant improvement of survival without increase in morbidity and mortality, relative to patients with locally advanced disease. Thus, adjuvant surgery may provide the promising results in this group who responded favorably to initial chemo(radio)therapy in unresectable pancreatic cancer.
Synthesis of Asymmetric Monomethine Cyanine Dyes with Red‐Shifted Optical Properties
Authors: Soriano Eduardo , Outler Loretta , Owens Eric A. , Henary Maged
Published: May 2014

Six novel asymmetrical monomethine cyanine dyes were synthesized via the condensation reaction of 1‐butyl‐2‐(methylthio)benzo[c,d]indol‐1‐ium iodide and various 1,5‐substituted indolenine salts under basic conditions. The dyes were characterized using UV–vis spectroscopy, fluorescence, 1H NMR, 13C NMR, and mass spectrometry; furthermore, the purity of these compounds was observed using LC/ELSD/MS.
Chemical and Electrochemical Syntheses of Benzo[b](1,4)‐diazepine‐7,8‐diones
Authors: Habibi Davood , Nematollahi Davood , Pordanjani Hossein Mohammadkhani , Sadeghi Mohammad Reza
Published: May 2014

Electrochemical and chemical syntheses of benzodiazepinediones were carried out from the reaction of catechols with N,N′‐dialkylproylenediamine in aqueous solution at room temperature, using CV and controlled‐potential coulometry with K3Fe(CN)6 as an oxidant.
Synthesis and Biological Activity Studies of Some Novel Mannich Bases of Benzotriazolyl Triazoles
Authors: George Sonia , Chakraborty Raja , Parameswaran Manojkumar , Rajan Anju , Ravi Thengungal Kochupaappy
Published: May 2014

A series of substituted phenyl methyl piperazine triazolyl benzotriazoles 4a, 4b, 4c, 4d, 4e, 4f, 4g have been synthesized through the Mannich reaction of substituted phenyl triazolyl benzotriazoles 3a, 3b, 3c, 3d, 3e, 3f, 3g. The substituted phenyl triazolyl benzotriazoles were prepared from benzotriazolyl acetohydrazide, where the cyclization was facilitated through ammonium acetate and aryl aldehydes. The IR, 1H NMR, mass spectral data and elemental analysis were performed to assign the structure. All the newly synthesized compounds were screened for their antimicrobial and antioxidant activity.
Novel Rearrangement of 3‐Acylaminofuro[2,3‐b]pyridines into 3‐(oxazol‐4‐yl)pyridin‐2‐ones
Authors: Stroganova Tatyana A. , Vasilin Vladimir K. , Shestakova Polina S. , Red'kin Viktor M. , Krapivin Gennady D.
Published: May 2014

3‐Acylaminofuro[2,3‐b]pyridine derivatives have been synthesized, and their behavior under acidic and basic conditions was studied. A new base‐catalyzed rearrangement of 3‐acylaminofuro[2,3‐b]pyridine derivatives into 3‐(oxazol‐4‐yl)pyridine‐2‐ones has been founded.
Mix between Satisfaction and Attributes Destination Choice: A Segmentation Criterion to Understand the Ski Resorts Consumers
Authors: Miragaia Dina Alexandra Marques , Martins Marco Alexandre Batista
Published: May 2014

This study examined the attributes prioritized by tourists when choosing a winter sports destination and their degree of satisfaction with the services provided by Portugal's only ski resort. Two hundred tourists completed a questionnaire with factor analysis then deployed to extract the data that served as the basis for cluster analysis. Our results report discrepancies between the attributes valued by tourists when choosing winter sports destinations and their degree of satisfaction with the ski resort's services. Moreover, the combination between attributes/motivations prevailing in destination selection and the subsequent satisfaction with the services provided may generate information of relevance to evaluating organizational competitiveness. Copyright © 2014 John Wiley & Sons, Ltd.
Pretreatment with ablative fractional laser changes kinetics and biodistribution of topical 5‐aminolevulinic acid (ALA) and methyl aminolevulinate (MAL)
Authors: Haedersdal Merete , Sakamoto Fernanda H. , Farinelli William A. , Doukas Apostolos G. , Tam Joshua , Anderson R. Rox
Published: May 2014

Background and Objectives

5‐Aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) are porphyrin precursors used topically for photodynamic therapy (PDT). Previous studies have established that ablative fractional laser (AFXL) increases topical drug uptake. We evaluated kinetics and biodistribution of ALA‐ and MAL‐induced porphyrins on intact and disrupted skin due to AFXL.

Materials and Methods

Two Yorkshire swine were exposed to CO2 AFXL (10.6 µm, 1,850 µm ablation depth) and subsequent topical application of ALA and MAL cream formulations (20%, weight/weight). Porphyrin fluorescence was quantified by digital fluorescence photography (30, 90, and 180 minutes) and fluorescence microscopy at specific skin depths (180 minutes).

Results

Porphyrins gradually formed over time, differently on intact and AFXL‐disrupted skin. On intact skin (no AFXL), fluorescence photography showed that MAL initially induced higher fluorescence than ALA (t = 30 minutes MAL 21.1 vs. ALA 7.7 au, t = 90 minutes MAL 39.0 vs. ALA 26.6 (P < 0.009)) but reached similar intensities for long‐term applications (t = 180 minutes MAL 56.6 vs. ALA 52 au, P = ns). AFXL considerably enhanced porphyrin fluorescence from both photosensitizers (P < 0.05). On AFXL‐exposed skin, MAL expressed higher fluorescence than ALA for short‐term application (t = 30 minutes, AFXL–MAL 26.4 vs. AFXL–ALA 14.1 au, P < 0.001), whereas ALA over time overcame MAL and induced the highest fluorescence intensities obtained (t = 180 minutes, AFXL–MAL 98.6 vs. AFXL–ALA 112.0 au, P < 0.001). In deep skin layers, fluorescence microscopy showed higher fluorescence in hair follicle epithelium for ALA than MAL (t = 180 minutes, 1.8 mm, AFXL–MAL 35.3 vs. AFXL–ALA 46.7 au, P < 0.05).

Conclusions

AFXL changes kinetics and biodistribution of ALA and MAL. It appears that AFXL–ALA favors targeting deep structures. Lasers Surg. Med. 46:462–469, 2014. © 2014 Wiley Periodicals, Inc.
Influence of spatial resolution on the accuracy of quantitative myocardial perfusion in first pass stress perfusion CMR
Authors: Zarinabad Niloufar , Chiribiri Amedeo , Hautvast Gilion L. T. F. , Breeuwer Marcel , Nagel Eike
Published: May 2014

Purpose

High‐resolution myocardial perfusion analysis allows for preserving spatial information with excellent sensitivity for subendocardial ischemia detection. However, it suffers from low signal‐to‐noise ratio. Commonly, spatial averaging is used to increase signal‐to‐noise ratio. This bears the risk of losing information about the extent, localization and transmurality of ischemia. This study investigates spatial‐averaging effects on perfusion‐estimates accuracy.

Methods

Perfusion data were obtained from patients and healthy volunteers. Spatial averaging was performed on voxel‐based data in transmural and angular direction to reduce resolution to 50, 20, and 10% of its original value. Fit quality assessment method is used to measure the fraction of modeled information and remaining unmodeled information in the residuals.

Results

Fraction of modeled information decreased in patients as resolution reduced. This decrease was more evident for Fermi and exponential in transmural direction. Fermi and exponential showed significant difference at 50% resolution (Fermi P < 0.001, exponential P =0.0014). No significant differences were observed for autoregressive‐moving‐average model (P = 0.081). At full resolution, autoregressive‐moving‐average model has the lowest fraction of residual information (0.3). Differences were observed comparing ischemic regions perfusion‐estimates coefficient of variation at transmural and angular direction.

Conclusion

Angular averaging preserves more information compared to transmural averaging. Reducing resolution level below 50% at transmural and 20% at angular direction results in losing information about transmural perfusion differences. Maximum voxel size of 2 × 2 mm2 is necessary to avoid loss of physiological information due to spatial averaging. Magn Reson Med 73:1623–1631, 2015. © 2014 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.
Dynamic contrast‐enhanced MRI texture analysis for pretreatment prediction of clinical and pathological response to neoadjuvant chemotherapy in patients with locally advanced breast cancer
Authors: Teruel Jose R. , Heldahl Mariann G. , Goa Pål E. , Pickles Martin , Lundgren Steinar , Bathen Tone F. , Gibbs Peter
Published: May 2014

The aim of this study was to investigate the potential of texture analysis, applied to dynamic contrast‐enhanced MRI (DCE‐MRI), to predict the clinical and pathological response to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer (LABC) before NAC is started. Fifty‐eight patients with LABC were classified on the basis of their clinical response according to the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines after four cycles of NAC, and according to their pathological response after surgery. T1‐weighted DCE‐MRI with a temporal resolution of 1 min was acquired on a 3‐T Siemens Trio scanner using a dedicated four‐channel breast coil before the onset of treatment. Each lesion was segmented semi‐automatically using the 2‐min post‐contrast subtracted image. Sixteen texture features were obtained at each non‐subtracted post‐contrast time point using a gray level co‐occurrence matrix. Appropriate statistical analyses were performed and false discovery rate‐based q values were reported to correct for multiple comparisons. Statistically significant results were found at 1–3 min post‐contrast for various texture features for the prediction of both the clinical and pathological response. In particular, eight texture features were found to be statistically significant at 2 min post‐contrast, the most significant feature yielding an area under the curve (AUC) of 0.77 for response prediction for stable disease versus complete responders after four cycles of NAC. In addition, four texture features were found to be significant at the same time point, with an AUC of 0.69 for response prediction using the most significant feature for classification based on the pathological response. Our results suggest that texture analysis could provide clinicians with additional information to increase the accuracy of prediction of an individual response before NAC is started. Copyright © 2014 John Wiley & Sons, Ltd.
Gestational age‐adjusted trends and reference intervals of the Modified Myocardial Performance Index (Mod‐MPI) and its components, with its interpretation in the context of established cardiac physiological principles
Authors: Bhorat Ismail , Bagratee Jayanthilall , Reddy Tarylee
Published: May 2014

Objective

The objective of this study is to establish gestational age‐adjusted reference intervals and trends of the modified myocardial performance index (Mod‐MPI), isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and ejection time (ET) in pregnancy

Methods

A cross‐sectional study using Doppler echocardiography to determine the Mod‐MPI was performed on 419 fetuses from 20 to 38 weeks of gestation. Doppler signals of the opening and closing of the mitral and aortic valves were used as landmarks to determine the ICT, IRT, and ET. The Mod‐MPI was modeled using fractional polynomials and the exponential‐normal model.

Results

The Mod‐MPI was relatively constant from 20 to 26 weeks and thereafter steadily decreased with advancing gestational age. ICT and ET remained constant, whereas IRT decreased with advancing gestation similar to the Mod‐MPI.

Conclusion

Reference intervals of the Mod‐MPI evaluating fetal cardiac function have been established. Maturational and developmental alterations in the myocardial performance in utero resulting in better ventricular compliance is most likely responsible for the decreasing trend of the Mod‐MPI noted with advancing gestation. © 2014 John Wiley & Sons, Ltd.
Comparison of sialylated N‐glycopeptide levels in serum of pancreatic cancer patients, acute pancreatitis patients, and healthy controls
Authors: Kontro Hilkka , Joenväärä Sakari , Haglund Caj , Renkonen Risto
Published: May 2014

Serum protein glycosylation is known to be affected by pathological conditions, including cancer and inflammatory diseases. Pancreatic cancer patients would benefit from early diagnosis, as the disease is often detected in an advanced stage and has poor prognosis. Searching for changes in serum protein site‐specific glycosylation could reveal novel glycoprotein biomarkers. We used Sambucus nigra lectin affinity chromatography to enrich α‐2,6 sialylated tryptic N‐glycopeptides from albumin‐depleted sera of pancreatic cancer patients, acute pancreatitis patients, and healthy individuals, and compared their relative abundance using ultra performance LC‐MS. Relative quantitation was done using the spectrum processing software MZmine. Identification was performed on the web‐based tool GlycopeptideID, developed for in silico analysis of intact N‐glycopeptides. Seventeen high‐abundance serum proteins, mainly acute‐phase proteins, and immunoglobulins, with total 27 N‐glycosylation sites, and 62 glycoforms, were identified. Pancreatitis patient sera contained 38, and pancreatic cancer patients sera contained 13 glycoform changes with statistical significance (p < 0.05). In pancreatitis, up to tenfold changes were found in some glycoforms, and in pancreatic cancer, threefold. Analysis showed that the changes often concerned one or two, but not all, N‐glycosylation sites in a specific glycoprotein. In conclusion, the analysis shows that pancreatic cancer, and acute pancreatitis are associated with changes in concentrations of intact sialylated N‐glycopeptides derived from acute‐phase proteins, and immunoglobulins, and that changes are site specific.
Comparative proteomic analysis of early salt stress responsive proteins in roots and leaves of rice
Authors: Liu Chih‐Wei , Chang Tao‐Shan , Hsu Yu‐Kai , Wang Arthur Z. , Yen Hung‐Chen , Wu Yung‐Pei , Wang Chang‐Sheng , Lai Chien‐Chen
Published: May 2014

Growth and productivity of rice (Oryza sativaL.) are severely affected by salinity. Understanding the mechanisms that protect rice and other important cereal crops from salt stress will help in the development of salt‐stress‐tolerant strains. In this study, rice seedlings of the same genetic species with various salt tolerances were studied. We first used 2DE to resolve the expressed proteome in rice roots and leaves and then used nanospray liquid chromatography/tandem mass spectrometry to identify the differentially expressed proteins in rice seedlings after salt treatment. The 2DE assays revealed that there were 104 differentially expressed protein spots in rice roots and 59 in leaves. Then, we identified 83 proteins in rice roots and 61 proteins in rice leaves by MS analysis. Functional classification analysis revealed that the differentially expressed proteins from roots could be classified into 18 functional categories while those from leaves could be classified into 11 functional categories. The proteins from rice seedlings that most significantly contributed to a protective effect against increased salinity were cysteine synthase, adenosine triphosphate synthase, quercetin 3‐O‐methyltransferase 1, and lipoxygenase 2. Further analysis demonstrated that the primary mechanisms underlying the ability of rice seedlings to tolerate salt stress were glycolysis, purine metabolism, and photosynthesis. Thus, we suggest that differentially expressed proteins may serve as marker group for the salt tolerance of rice.
Determination of sulfoxide bond dissociation enthalpies of dibenzothiophene S‐oxide derivatives with computational methods
Authors: Zhang Miao , Welch Bradley K. , Hasanagic Medina , Fritz Adam , McCulla Ryan D.
Published: May 2014

Photodeoxygenation of dibenzothiophene S‐oxide (DBTO) has been suggested as a clean way to generate atomic oxygen in solution. Sulfoxide bond dissociation enthalpies (BDEs) are important to the quantum yield and mechanism of this photodeoxygenation. In this study, BDE of substituted DBTO molecules with various functional groups were determined using M062X/aug‐cc‐pV(T + d)Z and MP2/aug‐cc‐pV(T + d)Z levels of theory. The sulfoxide BDE was determined using an isodesmic reaction. The observed effect of substitution was that functional groups with negative σpara values (electron donating) strengthen the sulfoxide bond and that substituents with positive σpara values (electron withdrawing) weaken the sulfoxide bond. The Mulliken charge on sulfur for DBTO and the corresponding dibenzothiophene were identified as a suitable indicator of the predicted S–O BDE. Moreover, steric and hydrogen bonding interactions were found to affect sulfoxide BDE for certain functional groups when located at the 1 or 4 positions of the substituted DBTO. Copyright © 2014 John Wiley & Sons, Ltd.
Formulation and Characterizations of Nanoenergetic Compositions with Improved Safety
Authors: Wuillaume Anne , Beaucamp Arnaud , David‐Quillot Frank , Eradès Charles
Published: May 2014

In order to improve the safety of energetic compositions, whether it has to be worked with less sensitive materials that are often less powerful or with high energetic materials crystals with improved purity and microstructure quality. A way to modify the crystal quality of an energetic material is to structure the matter on the nanoscale: the crystals size reduction should induce impurity modifications in the particles. That is one of the reasons why interest in nanoenergetic compositions that contain high energetic material (≥ 90 wt‐%) and an organic matrix (≤ 10 wt‐%) that takes part in constraining the explosive to organize itself on the nanoscale arose. The key point is to find or synthesize the matrix. In the course of this study, first ammonium perchlorate compositions structured on the nanoscale were synthesized (150 nm AP particles (80 wt‐%) dispersed in an organogel matrix (20 wt‐%)). The formulation process was based on the impregnation of porous organogels with a saturated aqueous solution of ammonium perchlorate followed by freeze drying. The overall composition had an oxygen balance equilibrated towards CO2. These AP nanocompositions show better safety behavior during combustion than there equivalent macrocompositions, while they burn more rapidly, with no degradation of their impact and thermal sensitivity properties. The formulation process of RDX nanocompositions is more complex as the solvent used is γ‐butyrolactone which can not be directly frozen dried. However, first RDX nanocompositions were formulated and characterized using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X‐ray powder diffraction, and drop weight impact. Lately compressions of these RDX compositions were performed, prior to gap‐test experiments.
U‐dual branes and mixed symmetry tensor fields
Authors: Chatzistavrakidis A. , Gautason F.F.
Published: May 2014

We review and explain the relation between U‐dual branes in string theory and mixed symmetry tensors of various degrees. In certain cases these mixed symmetry tensors can be related to diverse types of fluxes that play an important role in compactifications of string theory.
Twisted Chern‐Simons supergravity
Authors: Castellani L.
Published: May 2014

We present a noncommutative version of D = 5 Chern‐Simons supergravity, where noncommutativity is encoded in a *‐product associated to an abelian Drinfeld twist. The theory is invariant under diffeomorphisms, and under the *‐gauge supergroup SU(2,2|4), including Lorentz and N = 4 local supersymmetries.
Phenomenological studies in the matrix models
Authors: Aoki H.
Published: May 2014

Matrix models are a promising candidate for a nonperturbative formulation of the superstring theory. It is possible to study how the standard model and other phenomenological models appear from the matrix model, and estimate the probability distribution of their appearance. This article mainly addresses studies in toroidal compactifications with magnetic fluxes.
The role of water and structure on the generation of reactive oxygen species in peptide/hypericin complexes
Authors: Souza Márcia I. , Silva Emerson R. , Jaques Ygor M. , Ferreira Fabio F. , Fileti Eudes E. , Alves Wendel A.
Published: May 2014

Hybrid associates formed between peptide assemblies and fluorophores are attractive mainly because of their unique properties for biomedical applications. Recently, we demonstrated that the production of reactive oxygen species (ROS) by hypericin and their stability in excited states are enhanced upon conjugation with l,l‐diphenylalanine microtubes (FF‐MNTs). Although the detailed mechanisms responsible for improving the photophysical properties of ROS remain unclear, tentative hypotheses have suggested that the driving force is the growth of overall dipolar moments ascribed either to coupling between aligned H2O dipoles within the ordered structures or to the organization of hypericin molecules on peptide interfaces. To provide new insights on ROS activity in hypericin/FF‐MNTs hybrids and further explore the role of water in this respect, we present results obtained from investigations on the behavior of these complexes organized into different crystalline arrangements. Specifically, we monitored and compared the photophysical performance of hypericin bound to FF‐MNTs with peptides organized in both hexagonal (water‐rich) and orthorhombic (water‐free) symmetries. From a theoretical perspective, we present the results of new molecular dynamics simulations that highlight the distinct hypericin/peptide interaction at the interface of FF‐MNTs for the different symmetries. As a conclusion, we propose that although water enhances photophysical properties, the organization induced by peptide structures and the availability of a hydrophobic environment surrounding the hypericin/peptide interface are paramount to optimizing ROS generation. The findings presented here provide useful basic research insights for designing peptide/fluorophore complexes with outstanding technological potential. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Electronic structure and stability of low symmetry Ta2O5polymorphs
Authors: Kim Ja‐Yong , Magyari‐Köpe Blanka , Lee Kee‐Jeung , Kim Hyeong‐Soo , Lee Seok‐Hee , Nishi Yoshio
Published: May 2014

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The structures and electronic properties of Ta2O5 polymorphs were calculated using density‐functional theory employing the generalized gradient approximation with on‐site Coulomb corrections. Using this approach, a pseudo‐hexagonal structure was found to be a stable polymorph of Ta2O5 over δ‐ and β‐Ta2O5 and metastable relative to other recently proposed structures. Its diffraction spectrum and bandgap energy are in good agreement with experimental data. Therefore, the pseudo‐hexagonal structure might form in polycrystalline films and affect the switching process of resistive memory devices. Moreover, a neutral oxygen vacancy is found to induce an occupied defect state at 2.5 eV above the top of the valence band, in agreement with X‐ray photoelectron spectroscopy results. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)