bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aza‐Crown Ether Complex Cation Ionic Liquids: Preparation and Applications in Organic Reactions
Authors: Song Yingying , Cheng Chen , Jing Huanwang 
Published: August 2014

AbstractAza‐crown ether complex cation ionic liquids (aCECILs) were devised, fabricated, and characterized by using NMR spectroscopy, MS, thermogravimetric differential thermal analysis (TG‐DTA), elemental analysis and physical properties. These new and room‐temperature ILs were utilized as catalysts in various organic reactions, such as the cycloaddition reaction of CO2 to epoxides, esterification of acetic acid and alcohols, the condensation reaction of aniline and propylene carbonate, and Friedel–Crafts alkylation of indole with aldehydes were investigated carefully. In these reactions, the ionic liquid exhibited cooperative catalytic activity between the anion and cation. In addition, the aza‐[18‐C‐6HK][HSO4]2 was the best acidic catalyst in the reactions of esterification and Friedel–Crafts alkylation under mild reaction conditions.
Enzymatic Desymmetrising Redox Reactions for the Asymmetric Synthesis of Biaryl Atropisomers
Authors: Staniland Samantha , Yuan Bo , Giménez‐Agulló Nelson , Marcelli Tommaso , Willies Simon C. , Grainger Damian M. , Turner Nicholas J. , Clayden Jonathan 
Published: August 2014

AbstractAtropisomeric biaryls carrying ortho‐hydroxymethyl and formyl groups were made enantioselectively by desymmetrisation of dialdehyde or diol substrates. The oxidation of the symmetrical diol substrates was achieved using a variant of galactose oxidase (GOase), and the reduction of the dialdehydes using a panel of ketoreductases. Either M or P enantiomers of the products could be formed, with absolute configurations assigned by time‐dependent DFT calculations of circular dichroism spectra. The differing selectivities observed with different biaryl structures offer an insight into the detailed structure of the active site of the GOase enzyme.
Structure‐Guided Design of Thiazolidine Derivatives as Mycobacterium tuberculosis Pantothenate Synthetase Inhibitors
Authors: Devi Parthiban Brindha , Samala Ganesh , Sridevi Jonnalagadda Padma , Saxena Shalini , Alvala Mallika , Salina Elena G. , Sriram Dharmarajan , Yogeeswari Perumal 
Published: August 2014

AbstractThe pantothenate biosynthetic pathway is essential for the persistent growth and virulence of Mycobacterium tuberculosis (Mtb) and one of the enzymes in the pathway, pantothenate synthetase (PS, EC: 6.3.2.1), encoded by the panC gene, has become an appropriate target for new therapeutics to treat tuberculosis. Herein, we report nanomolar thiazolidine inhibitors of Mtb PS developed by a rational inhibitor design approach. The thiazolidine compounds were discovered by using energy‐based pharmacophore modelling and subsequent in vitro screening, which resulted in compounds with a half maximal inhibitory concentration (IC50) value of (1.12±0.12) μM. These compounds were subsequently optimised by a combination of modelling and synthetic chemistry. Hit expansion of the lead by chemical synthesis led to an improved inhibitor with an IC50 value of 350 nM and an Mtb minimum inhibitory concentration (MIC) of 1.55 μM. Some of these compounds also showed good activity against dormant Mtb cells.
Position and Length of Fatty Acids Strongly Affect Receptor Selectivity Pattern of Human Pancreatic Polypeptide Analogues
Authors: Mäde Veronika , Bellmann‐Sickert Kathrin , Kaiser Anette , Meiler Jens , Beck‐Sickinger Annette G. 
Published: August 2014

AbstractPancreatic polypeptide (PP) is a satiety‐inducing gut hormone targeting predominantly the Y4 receptor within the neuropeptide Y multiligand/multireceptor family. Palmitoylated PP‐based ligands have already been reported to exert prolonged satiety‐inducing effects in animal models. Here, we suggest that other lipidation sites and different fatty acid chain lengths may affect receptor selectivity and metabolic stability. Activity tests revealed significantly enhanced potency of long fatty acid conjugates on all four Y receptors with a preference of position 22 over 30 at Y1, Y2 and Y5 receptors. Improved Y receptor selectivity was observed for two short fatty acid analogues. Moreover, [K30(E‐Prop)]hPP2−36 (15) displayed enhanced stability in blood plasma and liver homogenates. Thus, short chain lipidation of hPP at key residue 30 is a promising approach for anti‐obesity therapy because of maintained selectivity and a sixfold increased plasma half‐life.
Optoelectronic and Self‐assembly Properties of Porphyrin Derivatives with Click Chemistry Modification
Authors: Pengxia Liang , Du Zhengcai , Wang Dong , Yang Zhou , Sheng Huiyun , Liang Shuqiong , Cao Hui , He Wanli , Yang Huai 
Published: August 2014

AbstractA series of functionalized porphyrin molecules containing electron‐rich alkynes, synthesized by means of the Sonogashira coupling reaction were further modified by reacting the ethynyl groups with click reagent through a formal [2+2] click reaction. The photophysical and electrochemical properties of the porphyrin derivatives were studied by UV/Vis spectroscopy and cyclic voltammetry. We show that the optoelectronic properties are affected by the click reagent groups and central metal ions. The functionalized porphyrin molecules show strong charge‐transfer (CT) bands in the visible region (near‐IR region) and potent redox activities. Through a phase‐exchange self‐assembly method, the highly organized morphologies were observed by scanning electron microscopy (SEM). The functionalized porphyrin molecules represent an interesting set of candidates for optoelectronic device components. The effect of the metal ions or click reagent groups on the self‐assembly properties were also studied by the UV/Vis spectroscopic titration experiments.
Optimization of rhabdomyosarcoma disseminated disease assessment by flow cytometry
Authors: Almazán‐Moga Ana , Roma Josep , Molist Carla , Vidal Isaac , Jubierre Luz , Soriano Aroa , Segura Miguel Francisco , Llort Anna , Sánchez de Toledo Josep , Gallego Soledad 
Published: August 2014

AbstractRhabdomyosarcoma (RMS) is the most common type of soft tissue sarcoma in children. Circulating tumor cells in peripheral blood or disseminated to bone marrow, a concept commonly referred to as minimal residual disease (MRD), are thought to be key to the prediction of metastasis and treatment efficacy. To date, two MRD markers, MYOD and MYOGENIN, have been tested; however, MRD detection continues to be challenging mainly owing to the closeness of the detection limit and the discordance of both markers in some samples. Therefore, the addition of a third marker could be useful for more accurate MRD assessment. The PAX3 gene is expressed during embryo development in all myogenic precursor cells in the dermomyotome. As RMS cells are thought to originate from these muscle precursor cells, they are expected to be positive for PAX3. In this study, PAX3 expression was characterized in cancer cell lines and tumors, showing wide expression in RMS. Detection sensitivities by quantitative polymerase chain reaction (qPCR) of the previously proposed markers, MYOD and MYOGENIN, were similar to that of PAX3, thereby indicating the feasibility of its detection. Interestingly, the flow cytometry experiments supported the usefulness of this technique in the quantification of MRD in RMS using PAX3 as a marker. These results indicate that flow cytometry, albeit in some cases slightly less sensitive, can be considered a good approach for MRD assessment in RMS and more consistent than qPCR, especially owing to its greater specificity. Furthermore, fluorescence‐activated cell sorting permits the recovery of cells, thereby providing material for further characterization of circulating or disseminated cancer cells. © 2014 International Society for Advancement of Cytometry
The effect of call libraries and acoustic filters on the identification of bat echolocation
Authors: Clement Matthew J. , Murray Kevin L. , Solick Donald I. , Gruver Jeffrey C. 
Published: August 2014

AbstractQuantitative methods for species identification are commonly used in acoustic surveys for animals. While various identification models have been studied extensively, there has been little study of methods for selecting calls prior to modeling or methods for validating results after modeling. We obtained two call libraries with a combined 1556 pulse sequences from 11 North American bat species. We used four acoustic filters to automatically select and quantify bat calls from the combined library. For each filter, we trained a species identification model (a quadratic discriminant function analysis) and compared the classification ability of the models. In a separate analysis, we trained a classification model using just one call library. We then compared a conventional model assessment that used the training library against an alternative approach that used the second library. We found that filters differed in the share of known pulse sequences that were selected (68 to 96%), the share of non‐bat noises that were excluded (37 to 100%), their measurement of various pulse parameters, and their overall correct classification rate (41% to 85%). Although the top two filters did not differ significantly in overall correct classification rate (85% and 83%), rates differed significantly for some bat species. In our assessment of call libraries, overall correct classification rates were significantly lower (15% to 23% lower) when tested on the second call library instead of the training library. Well‐designed filters obviated the need for subjective and time‐consuming manual selection of pulses. Accordingly, researchers should carefully design and test filters and include adequate descriptions in publications. Our results also indicate that it may not be possible to extend inferences about model accuracy beyond the training library. If so, the accuracy of acoustic‐only surveys may be lower than commonly reported, which could affect ecological understanding or management decisions based on acoustic surveys.
A Planar‐Chiral Phosphino(alkenyl)ferrocene for Suzuki–Miyaura C–C Coupling Reactions
Authors: Schaarschmidt Dieter , Grumbt Martin , Hildebrandt Alexander , Lang Heinrich 
Published: August 2014

AbstractPlanar‐chiral phosphinoferrocene [Fe(η5‐C5H3‐1‐PPh2‐2‐(E)‐CH=CHPh)(η5‐C5H5)] (4) was applied in the presence of palladium in Suzuki–Miyaura couplings for the synthesis of sterically congested biaryls. The catalytic activity arises from homogeneous palladium phosphine complexes, of which the potential pre‐catalyst [Pd(4)2Cl2] was characterized structurally. The catalytic system is excellently suited for the synthesis of tri‐ortho‐substituted biaryls under mild conditions (0.1 mol‐%, 50–100 °C), whereas its application towards the synthesis of tetra‐ortho‐substituted biaryls is quite limited. Comparing the performance of the reaction with 4 as catalyst and a range of substrates with differing ortho substituents suggests that transmetalation is rate determining. Complex (Sp)‐4 was used in atropselective couplings, wherein enantioenrichments of up to 36 % were achieved. The stereoselectivity depends to some extent on the steric properties of the boronic acids; however, slight changes at the aryl halides influence the enantioselectivity.
Design of a New Carbon Paste Electrode Modified with TiO2 Nanoparticles to Use in an Electrochemical Study of Codeine and Simultaneous Determination of Codeine and Acetaminophen in Human Plasma Serum Samples
Authors: Mashhadizadeh Mohammad Hossein , Rasouli Fatemeh 
Published: August 2014

AbstractA new electrochemical sensor was fabricated via TiO2 nanoparticles onto a carbon paste electrode. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studied the response of the modified electrode toward codeine. The effects of pH, modifier amount, pulse amplitude, and scan rate of potential have been examined. Using DPV, we could measure simultaneously codeine and acetaminophen in one mixture. The detection limits of 0.018 and 0.050 µmol L−1 were achieved for codeine and acetaminophen, respectively. The electrooxidation pathway, transfer coefficient, and standard rate constant, are estimated. The proposed voltammetric sensor was successfully applied to determination of codeine and acetaminophen in human plasma serum samples.
The identification of menstrual blood in forensic samples by logistic regression modeling of miRNA expression
Authors: Hanson Erin K. , Mirza Mohid , Rekab Kamel , Ballantyne Jack 
Published: August 2014

We report the identification of sensitive and specific miRNA biomarkers for menstrual blood, a tissue that might provide probative information in certain specialized instances. We incorporated these biomarkers into qPCR assays and developed a quantitative statistical model using logistic regression that permits the prediction of menstrual blood in a forensic sample with a high, and measurable, degree of accuracy. Using the developed model, we achieved 100% accuracy in determining the body fluid of interest for a set of test samples (i.e. samples not used in model development). The development, and details, of the logistic regression model are described. Testing and evaluation of the finalized logistic regression modeled assay using a small number of samples was carried out to preliminarily estimate the limit of detection (LOD), specificity in admixed samples and expression of the menstrual blood miRNA biomarkers throughout the menstrual cycle (25–28 days). The LOD was <1 ng of total RNA, the assay performed as expected with admixed samples and menstrual blood was identified only during the menses phase of the female reproductive cycle in two donors.
The Assembly Specific Force Atlas
Authors: Schaub Karlheinz , Wakula Jurij , Berg Knut , Kaiser Bastian , Bruder Ralph , Glitsch Ulrich , Ellegast Rolf‐Peter 
Published: August 2014

AbstractEven in hi‐tech industries, physical workload is partly considerable and cannot be avoided because of product and process requirements. Especially in automotive, aviation, and marine industries, the assembly of the product geometry requires force exertions in ergonomically unfavorable conditions. Unfortunately, internationally accepted methods for the evaluation of those types of force exertions are rare. Besides some traditional German methods and EN 1005‐3 hardly any evaluation methods exist. Even those methods refer to force exertions in primarily upright symmetric working postures. To overcome these problems the Assembly Specific Fore Atlas was created during the recent years. From a sample of automotive workers (n = 273), a set of 54 whole‐body forces (6 main force directions while standing, sitting, kneeling; in an upward, bent, and overhead posture) and a set of 38 types of finger‐hand forces (all at maximum voluntary contractions [MVC] levels) were measured in the field. The inputs for the types of force exertions required in practice were sampled from a consortium of major European car and truck companies. In addition, evaluation methods were developed that allow “calculating” maximum recommended force limits from the measured maximum static forces (i.e., MVC) and task and user group relevant parameters. This contribution gives a short overview on the data collected and focuses on the evaluation methods that had been realized. First, qualitative results are presented from the first field tests.
Reactions of Quino‐Ketenes with C‐Nucleophiles: Syntheses of (2‐Hydroxyphenyl)methanols and 2‐Hydroxyphenyl Ketones
Authors: Gündüz Hande , Kumbaraci Volkan , Talinli Naciye 
Published: August 2014

AbstractIn this study, we have developed a new, efficient, and one‐step protocol for the synthesis of derivatives of 2,4‐dihydroxyphenyl ketones and/or 2,4‐dihydroxyphenyl/naphthalenyl methanols starting from benzodioxinones/naphthodioxinones and organolithium compounds. Reactions have been performed under thermal conditions without catalyst. This work is the first example of the preparation of these products starting from 2‐hydroxy acids.
Copper‐Catalyzed N‐Arylation of 1,1,3,3‐TetramethylguanidinePhenyl Isocyanate Adduct
Authors: Yavari Issa , Nematpour Manijeh 
Published: August 2014

AbstractThe synthesis of a novel class of 3‐[bis(dimethylamino)methylidene]‐1,1‐diarylureas via a Cu‐catalyzed multicomponent reaction of phenyl isocyanate (PhNCO), 1,1,3,3‐tetramethylguanidine, and aryl halides is described.
Two New C‐seco Limonoids from the Fruit of Melia azedarach
Authors: Jin Qinghao , Lee Chul , Woo Lee Jin , Yeon Choi Jeong , Tae Hong Jin , Kim Youngsoo , Kyeong Lee Mi , Yeon Hwang Bang 
Published: August 2014

AbstractA phytochemical investigation of the fruits of Melia azedarach led to the isolation of two new C‐seco‐nimbolinin‐type limonoids, 3α‐acetoxy‐1α,7α‐dihydroxy‐12α‐methoxynimbolinin (1) and 3α‐acetoxy‐1α,12α‐dihydroxy‐7α‐(2‐methylprop‐2‐enoyl)nimbolinin (2), together with eleven known compounds, 3–13. Their structures were elucidated on the basis of extensive spectroscopic analysis, including 1H‐ and 13C‐NMR, HMQC, HMBC, NOESY, and HR‐FAB‐MS.
Benzo[a]azulenediones and 10,10′‐Bibenzo[a]azulene
Authors: Sigrist Rolf , Hansen Hans‐Jürgen 
Published: August 2014

AbstractThe oxidation of benzo[a]azulene (4) with commercial MnO2 in dioxane/H2O leads to a number of products in low yield (Table 1). Treatment of 4 with ‘mild’ MnO2 (MnO2/C) in dioxane/5% H2O results in the formation of 10,10′‐bibenzo[a]azulene (18) in yields of up to 59% of isolated and purified material. Compound 18 exhibits atropisomerism and can be separated by HPLC on a Chiralcel column at room temperature into its stable antipodes (Fig.).
The New Belgian Act on Security Interests in Movable Property
Authors: Dirix Eric 
Published: August 2014

AbstractThe new Belgian Pledge Act of 11th July 2013 changes in a fundamental way the Belgian Civil Code as to security rights over movables. It contains a complete modernization of the legal framework regarding security rights over movables including the retention of title and the legal lien. The most important innovation is the possibility of a pledge over movable goods without dispossession of the pledger. It is expected that the new provisions will enter into force in 2015 when the new pledge register will be operational. The paper examines this reform from a comparative perspective against the background of legal harmonization in Europe.
Functional morphology of the copulatory system of box crabs with long second gonopods (Calappidae, Eubrachyura, Decapoda, Crustacea)
Authors: Ewers‐Saucedo Christine , Hayer Sarah , Brandis Dirk 
Published: August 2014

ABSTRACTMale True Crabs use two pairs of gonopods to deliver mating products during copulation. Commonly, the second pair is shorter than the first pair, and most research to date has focused on species with short second gonopods. We investigated male and female copulatory organs in Calappula saussurei and Calappa pelii, two species of box crabs (Calappidae) with second gonopods which are longer than the first pair. Scanning electron microscopy and histological cross sectioning show that the female copulatory system is unique in several aspects: the genital duct is part concave and part simple type. The seminal receptacle is divided into two chambers, a ventral chamber of ectodermal and mesodermal origin, and a dorsal chamber of ectodermal origin. This dorsal chamber is the location of spermatophore reception during copulation. A sperm plug closes the dorsal chamber off. We propose that long second gonopods deliver male mating products directly into the dorsal chamber. To date, spermatophore reception has been associated with the mesodermal tissue of the seminal receptacle. The copulatory system of box crabs with long second gonopods shows novel deviations from this general pattern. J. Morphol. 276:77–89, 2015. © 2014 Wiley Periodicals, Inc.
Prediction of survival for patients with advanced colorectal cancer using 1H High‐resolution magic angle spinning nuclear MR spectroscopy
Authors: Pacholczyk‐Sienicka Barbara , Fabiańska Anna , Pasz‐Walczak Grażyna , Kordek Radzisław , Jankowski Stefan 
Published: August 2014

PurposeTo evaluate whether the metabolic profiles of colorectal cancer specimens can be used for prediction of survival.Materials and MethodsThe metabolic profiles of colorectal cancer tissues were determined using the high‐resolution magic angle spinning (HR MAS) nuclear magnetic resonance (NMR) technique (16.4 T). HR MAS analysis was performed for 52 tissues taken from patients classified as survivors and nonsurvivors (30). Quantitative analysis was performed for each spectrum. Receiver operating characteristic (ROC) curves were used to evaluate the potential to predict patient survival over 5.5 years.ResultsAnalysis of 1H NMR spectra led to the identification and quantitative analysis of 30 metabolites. A significant increase in the Tau/Gly and Tau/MI ratios were associated with long‐term survival (P = 0.004 and P = 0.003, respectively). ROC analysis indicated that the Tau/MI ratio had the best predictive value for survival (sensitivity 64.7% and specificity 100%). Good predictive value of survival was found for Tau/Gly ratio (sensitivity 63.6% and specificity 96.3%). Moreover, the Glu/Gln metabolic ratio with a cutoff level of 1.74 was predictive of survival with a sensitivity of 83.3% and a specificity of 85.7%.ConclusionOur results indicate that HR MAS spectroscopy is potentially useful for survival prediction in advanced colorectal cancer. J. Magn. Reson. Imaging 2015;41:1669–1674. © 2014 Wiley Periodicals, Inc.
A new frequency compensation technique for three stages OTA by differential feedback path
Authors: Hosseini Largani S. Mehdi , Shahsavari Sajjad , Biabanifard Sadegh , Jalali Ali 
Published: August 2014

AbstractA new single Miller capacitor for frequency compensation of three‐stage amplifier is proposed in this paper. In this scheme, a differential stage in which its negative and positive inputs are connected to the output and input nodes of third stage with a cascade capacitor forms the compensation block of a conventional three‐stage amplifier. Analysis shows that this configuration significantly improves the frequency domain performances of total circuit such as phase margin (PM) and gain‐bandwidth product (GBW) with just a very small amount of compensation capacitor. A three‐stage amplifier has been simulated with and without a differential feedback path in a 0.18 µm complementary metal–oxide–semiconductor (CMOS). The simulated amplifier with a 100 pF capacitive load achieved more than 9 MHz GBW and 83° PM while the compensation is less than 0.2% of load capacitor. An amplifier based on conventional nested Miller compensation can just achieve less than 0.23 MHz GBW with the same load, while using more than 100 pF as compensation capacitor. So this method shows an improvement of a factor of 40 in GBW and reduction of a factor of 550 in the size of compensation capacitor. It is a suitable strategy for ON‐CHIP compensation in comparison to other methods. Copyright © 2014 John Wiley & Sons, Ltd.