bluuebunny/crossref_metadata_2025_split huggingface dataset:
Red‐Emitting Rhodamines with Hydroxylated, Sulfonated, and Phosphorylated Dye Residues and Their Use in Fluorescence Nanoscopy
Authors: Kolmakov Kirill , Wurm Christian A. , Hennig René , Rapp Erdmann , Jakobs Stefan , Belov Vladimir N. , Hell Stefan W. 
Published: September 2012

AbstractFluorescent dyes emitting red light are frequently used in conventional and super‐resolution microscopy of biological samples, although the variety of the useful dyes is limited. We describe the synthesis of rhodamine‐based fluorescent dyes with absorption and emission maxima in the range of 621–637 and 644–660 nm, respectively and demonstrate their high performance in confocal and stimulated emission depletion (STED) microscopy. New dyes were prepared by means of reliable chemical transformations applied to a rhodamine scaffold with three variable positions. They feature polarity, water solubility, variable net charges, improved stabilities of N‐hydroxysuccinimidyl (NHS) esters, as well as large fluorescence quantum yields in dye solutions and antibody conjugates. The photophysical and imaging properties of dyes containing three different polar groups, namely primary phosphate, sulfonic acid (in two different positions), and hydroxyl were compared. A dye with two primary phosphate groups was explored as a valuable alternative to dyes with “classical” sulfonic acid groups. Due to the increased net charge of the phosphorylated dye (q=−4 at pH 8), it demonstrated a far better electrophoretic mobility compared with analogues with two sulfonic acid groups (q=−2). As an example, one fluorescent dye was designed to be especially convenient for practical use. It is characterized by sufficiently high chemical stability of the NHS ester, its simple isolation, handling, and solubility in aqueous buffers, as well as in organic solvents. All these features, accompanied by a zero net charge in conjugates, were accomplished by the introduction of hydrophilic groups of two types: two hydroxyl groups and one sulfonic acid residue.
Multiple States of Dimeric Aggregates Formed by (Amido–ethynyl)helicene Bidomain Compound and (Amido–ethynyl–amido)helicene Tridomain Compound
Authors: Ichinose Wataru , Shigeno Masanori , Yamaguchi Masahiko 
Published: September 2012

AbstractAn (amido–ethynyl)helicene bidomain compound and an (amido–ethynyl–amido)helicene tridomain compound were synthesized. The multidomain compounds were designed on the basis of previous findings that amido and ethynyl oligomers form dimeric aggregates with properties orthogonal to each other. Four aggregate states of multidomain compounds, namely, all‐dimer, amido‐dimer, ethynyl‐dimer, and random‐coil states, were obtained in different solvents, which were analyzed by circular dichroism (CD), UV/Vis, 1H NMR, and IR spectroscopy; vapor pressure osmometry (VPO); dynamic light scattering (DLS); and atomic force microscopy (AFM). The amido and ethynyl domains independently aggregated and disaggregated in a two‐state manner. Reversible structural changes occurred for a tridomain compound between the ethynyl‐dimer/random‐coil state and the all‐dimer/amido‐dimer state with heating and cooling. Two structural change processes with different properties were obtained using a single compound.
Application of Supramolecular Bidentate Hybrid Ligands in Asymmetric Hydroformylation
Authors: Bellini Rosalba , Reek Joost N. H. 
Published: September 2012

AbstractIn this study we report a novel class of supramolecular bidentate hybrid ligands in which the two inequivalent phosphorus units and pyridine moieties are covalently attached to a chiral scaffold and the supramolecular interactions are used as a second handle to control the coordination sphere around the transition‐metal centre. The coordination chemistry of these ligands was investigated under hydroformylation conditions by high‐pressure NMR and IR spectroscopy, revealing the formation of a single active species in which the phosphane ligand is in the axial position and the phosphoramidite adopts the equatorial position. These ligands were applied in the asymmetric Rh‐catalysed hydroformylation of styrene and para‐substituted analogues. In these hydroformylation reactions, modification of the electronic and steric properties of the zinc(II)‐templates appear to have a significant influence on the activity and selectivity of the catalysis. In particular, zinc(II)‐templates bearing more electron‐withdrawing substituents led to an increase in enantioselectivity.
Application of Dispersive Liquid–Liquid Microextraction Based on Solidification of Floating Organic Droplet Multi‐residue Method for the Simultaneous Determination of Polychlorinated Biphenyls, Organochlorine, and Pyrethroid Pesticides in Aqueous Sample
Authors: Zuo Mei , Cheng Jing , Matsadiq Guzalnur , Liu Lu , Li Man‐Liang , Zhang Miao 
Published: September 2012

AbstractDispersive liquid–liquid microextraction based on solidification of floating organic droplet (DLLME‐SFO) technique was successfully applied for simultaneous assay of eight polychlorinated biphenyls, two organochlorine, and four pyrethroid pesticides multi‐residue in aqueous samples by using GC‐electron capture detection. The effects of various parameters such as kind of extractant and dispersant and volume of them, extraction time, effect of salt addition, and pH were optimized. As a result, 5.0 µL 1‐dodecanol was chosen as extraction solvent, 600 µL methanol were used as dispersive solvent without salt addition, pH was adjusted to 7. Under the optimized conditions, the limits of detection (LOD) were ranged from 1.4 to 8.3 ng L−1. Satisfactory linear range was observed from 5.0 to 2000 ng L−1 with correlation coefficient better than 0.9909. Good precisions were also acquired with RSD better than 13.6% for all target analytes. The enrichment factors of the method were ranged from 786 to 1427. The method can be successfully applied to simultaneous separation and determination of three class residues in real water samples and good recoveries were obtained ranging from 76 to 130, 73 to 129, and 78 to 130% for tap water, lake water, and industrial waste water, respectively.
Distribution and Contamination Assessment of Heavy Metals in Water and Soils from the College Town in the Pearl River Delta, China
Authors: Xiao Rong , Bai Junhong , Gao Haifeng , Wang Junjing , Huang Laibin , Liu Peipei 
Published: September 2012

AbstractThe accumulation of heavy metals such as Cu, Zn, Pb, Cd, Cr, and Ni in water and soils in a new‐built college town was investigated to demonstrate the effects of city construction on wetland ecosystem. Three sampling sites were chosen in wetland park (A), constructed wetland (B), and construction site (C), respectively. The results showed that the construction site C presented the highest accumulation levels of all six studied metals along soil profiles and hence had the highest eco‐toxicity to environment. Sites A and B showed similar accumulation levels, whereas their concentrations were significantly lower than those at site C though seriously high Cd were also found in soils from both sites A and B and dangerous concentration of Pb in water was observed at site A based on several standards or background concentration values. However, when compared with other regions in Pearl River Delta, this college town could be counted as “clean island” which may be benefit from its isolate location away from urban center and the effective management to avoid pollution.
Relation between Enzyme Activity of Sediments and Lake Eutrophication in Grass‐Type Lakes in North China
Authors: Zhang Yu , Cui Baoshan , Wang Shengrui , Chu Zhaosheng , Fan Xiaoyun , Hua Yanyan , Lan Yan 
Published: September 2012

AbstractIn order to discover the biochemistry mechanism of sediments in eutrophic grass‐type lakes, this study selected four grass‐type lakes in north China to explore the relation between enzyme activities of sediments and lake eutrophication condition. By applying the assessment method of organic nitrogen (ON) and total phosphorus (TP), the nutrition of lake sediments were assessed. As the results show, Hengshui (HS) Lake and Baiyangdian (BY) Lake, suffering severe pollution, have much higher urease activity in comparison with Nansi (NS) Lake and Dongping (DP) Lake. In addition, there is significant positive correlation between the urease activity and the contents of total nitrogen (TN) and organic matter (OM) of sediments (r = 0.805, p < 0.01; r = 0.840, p < 0.01). It's the same case between alkaline phosphatase (APA) activity and TP content (r = 0.876, p < 0.01). The activities of both cellulase and protease in HS Lake and BY Lake are weaker than those of NS Lake and DP Lake. The changes in the activities of polyphenol oxidase and peroxidase tend to be similar and their distributions are closely related to the degree of pollution and disruption caused by human activities. The enzymatic activity of lake sediments can serve as an indicator that reflects how serious lake eutrophication is.
Changes in Water Birds Habitat Suitability Following Wetland Restoration in the Yellow River Delta, China
Authors: Hua Yanyan , Cui Baoshan , He Wenjie 
Published: September 2012

AbstractIt has been 10 years since the 2002 implementation of a wetland restoration project in the Yellow River Delta, China. The project mainly aimed to improve natural habitat for rare birds by modifying hydrological processes. Integrated multi‐criteria evaluation methods and cartographic modeling based on long‐term field monitoring and surveying were used to determine habitat suitability for the critical bird species that belong to five orders in the study area. Results showed that the habitat suitability index (E) increased in the first 6 years but declined recently as vegetation coverage increased. Future wetland restoration efforts should consider the influence of vegetation coverage on the development of potential habitats. The results of this study will be of value in further restoration designs in the Yellow River Delta and other similar wetlands.
Systematic Structure–Activity Study on Potential Chaperone Lead Compounds for Acid α‐Glucosidase
Authors: Bruckmann Chiara , Repo Heidi , Kuokkanen Elina , Xhaard Henri , Heikinheimo Pirkko 
Published: September 2012

AbstractAcid α‐glucosidase (GAA) is a lysosomal enzyme and a pharmacological target for Pompe disease, an inherited lysosomal storage disorder (LSD). An emerging treatment for LSDs is the use of pharmacological chaperones, small molecules that enhance total cellular activity of the target lysosomal protein. We have systematically studied thirteen inhibitors, which provide good lead compounds for the development of GAA chaperones. We have verified binding on GAA at low and neutral pH, mapping the range of pH during transport to lysosomes. These ligands inhibit GAA competitively and reversibly, and a few of the compounds show higher molecular stabilisation capacity than would be expected from their binding affinity. These molecules also increase lysosomal localisation of GAA variants in cells. In order to understand the specific molecular mechanism of the interactions, we docked the compounds to a homology model of the human GAA. Three factors contribute to the tightness of binding. Firstly, well‐positioned hydroxy groups are essential to orient the ligand and make the binding specific. Secondly, the open nature of the GAA active site allows both large and small ligands to bind. The third and most important binding determinant is the positive charge on the ligand, which is neutralised by Asp 518 or Asp 616 on GAA. Our study creates a firm basis for the design of drugs to treat Pompe disease, as it provides a comparable study of the ligand properties. Our analysis suggests a useful drug design framework for specific pharmacological chaperones for human GAA.
The combination of alisertib, an investigational Aurora kinase A inhibitor, and docetaxel promotes cell death and reduces tumor growth in preclinical cell models of upper gastrointestinal adenocarcinomas
Authors: Sehdev Vikas , Katsha Ahmed , Ecsedy Jeffrey , Zaika Alexander , Belkhiri Abbes , El‐Rifai Wael 
Published: September 2012

AbstractBACKGROUND:Upper gastrointestinal adenocarcinomas (UGCs) respond poorly to current chemotherapeutic regimes. The authors and others have previously reported frequent Aurora kinase A (AURKA) gene amplification and mRNA and protein overexpression in UGCs. The objective of the current study was to determine the therapeutic potential of alisertib (MLN8237) alone and in combination with docetaxel in UGCs.METHODS:After treatment with alisertib and/or docetaxel, clonogenic cell survival, cell cycle analyses, Western blot analyses, and tumor xenograft growth assays were carried out to measure cell survival, cell cycle progression, apoptotic protein expression, and tumor xenograft volumes, respectively.RESULTS:By using the AGS, FLO‐1, and OE33 UGC cell lines, which have constitutive AURKA overexpression and variable tumor protein 53 (p53) status, significantly enhanced inhibition of cancer cell survival was observed with alisertib and docetaxel treatment in combination (P < .001), compared with single‐agent treatments. Cell cycle analyses, after 48 hours of treatment with alisertib, produced a significant increase in the percentage of polyploidy in UGC cells (P < .01) that was further enhanced by docetaxel (P < .001). In addition, an increase in the percentage of cells in sub‐G1‐phase observed with alisertib (P < .01) was significantly enhanced with the combination treatment (P < .001). Western blot analysis demonstrated higher induction of cleaved caspase 3 protein expression with the combined treatment compared with single‐agent treatments. In addition, FLO‐1 and OE33 cell xenograft models demonstrated enhanced antitumor activity for the alisertib and docetaxel combination compared with single‐agent treatments (P < .001).CONCLUSIONS:The current study demonstrated that alisertib combined with docetaxel can mediate a better therapeutic outcome in UGC cell lines. Cancer 2013. © 2012 American Cancer Society.
Chemotherapy use and patient treatment preferences in advanced colorectal cancer
Authors: Zafar S. Yousuf , Malin Jennifer L. , Grambow Steven C. , Abbott David H. , Kolimaga Jane T. , Zullig Leah L. , Weeks Jane C. , Ayanian John Z. , Kahn Katherine L. , Ganz Patricia A. , Catalano Paul J. , West Dee W. , Provenzale Dawn ,   for the Cancer Care Outcomes Research & Surveillance (CanCORS) Consortium
Published: September 2012

AbstractBACKGROUND:The objective of this study was to determine how patient preferences guide the course of palliative chemotherapy for advanced colorectal cancer.METHODS:Eligible patients with metastatic colorectal cancer (mCRC) were enrolled nationwide in a prospective, population‐based cohort study. Data were obtained through medical record abstraction and patient surveys. Logistic regression analysis was used to evaluate patient characteristics associated with visiting medical oncology and receiving chemotherapy and patient characteristics, beliefs, and preferences associated with receiving >1 line of chemotherapy and receiving combination chemotherapy.RESULTS:Among 702 patients with mCRC, 91% consulted a medical oncologist; and among those, 82% received chemotherapy. Patients ages 65 to 75 years and aged ≥75 years were less likely to visit an oncologist, as were patients who were too sick to complete their own survey. In adjusted analyses, patients aged ≥75 years who had moderate or severe comorbidity were less likely to receive chemotherapy, as were patients who were too sick to complete their own survey. Patients received chemotherapy even if they believed that chemotherapy would not extend their life (90%) or that chemotherapy would not likely help with cancer‐related problems (89%), or patients preferred treatment focusing on comfort even if it meant not living as long (90%). Older patients were less likely to receive combination first‐line therapy. Patient preferences and beliefs were not associated with receipt of >1 line of chemotherapy or combination chemotherapy.CONCLUSIONS:The majority of patients received chemotherapy even if they expressed negative or marginal preferences or beliefs regarding chemotherapy. Patient preferences and beliefs were not associated with the intensity or number of chemotherapy regimens. Cancer 2013. © 2012 American Cancer Society.
Molecular profiling of synovial joints: Use of microarray analysis to identify factors that direct the development of the knee and elbow
Authors: Pazin Dorothy E. , Gamer Laura W. , Cox Karen A. , Rosen Vicki 
Published: September 2012

AbstractBackground: Synovial joints develop from the interzone, a dense layer of mesenchymal progenitor cells that marks the site of the future joint. During the morphogenic events that follow, joints attain their distinct shape and organization. The molecular mechanisms controlling the initial specification of synovial joints has been studied, but the question of how individual joints attain the specific structure required for their unique functions remains largely unresolved. Here, we use microarray analysis to compare knee and elbow formation to identify factors involved in the development of specific joints. Results: The knee is enriched for the hindlimb patterning genes Hoxc9, Hoxc10, and Tbx4 and for Tgfbi, Rspo2, and Sfrp2, factors involved in transforming growth factor‐beta/bone morphogenetic protein (TGFβ/BMP) and Wnt signaling. Consistent with these findings, we show that TGFβ signaling directs knee morphogenesis, and is necessary for meniscus development. The tissue surrounding the elbow is highly enriched for genes involved in muscle specification and differentiation, and in splotch‐delayed muscleless mutants, elbow, but not knee morphogenesis is disrupted. Conclusions: Our results suggest there are fundamental differences in how individual joints develop after interzone formation. Our microarray analyses provides a new resource for further investigation of the pathways involved in the morphogenesis of specific synovial joints. Developmental Dynamics 241:1816–1826, 2012. © 2012 Wiley Periodicals, Inc.
The regulation of endogenous retinoic acid level through CYP26B1 is required for elevation of palatal shelves
Authors: Okano Junko , Kimura Wataru , Papaionnou Virginia E. , Miura Naoyuki , Yamada Gen , Shiota Kohei , Sakai Yasuo 
Published: September 2012

AbstractBackground: In previous studies, we investigated the effects of excess retinoic acid (RA) during palatogenesis by RA administration to pregnant mice. In the present study, we deleted Cyp26b1, one of the RA‐degrading enzymes, to further study the effects of excess RA in the normal developing palate and to understand how endogenous levels of RA are regulated. Results: Excess RA, due to the absence of Cyp26b1, targets cells in the bend region of the palatal shelves and inhibits their horizontal elevation, leading to cleft palate. An organ culture of Cyp26b1−/− palatal shelves after tongue removal did not rescue the impaired elevation of the palatal shelves. The expression of Fgf10, Bmp2, and Tbx1, important molecules in palatal development, was down‐regulated. Cell proliferation was decreased in the bend region of palatal shelves. Tongue muscles were hypoplastic and/or missing in Cyp26b1−/− mice. Conclusions: We demonstrated that CYP26B1 is essential during palatogenesis. Excess RA due to the lack of Cyp26b1 suppresses the expression of key regulators of palate development in the bend region, resulting in a failure in the horizontal elevation of the palatal shelves. The regulation of RA signaling through CYP26B1 is also necessary for the development of tongue musculature and for tongue depression. Developmental Dynamics 241:1744–1756, 2012. © 2012 Wiley Periodicals, Inc.
Copper(II) Cubane Complexes Built from Electro‐ and Photosensitive β‐Aminovinyl Trifluoromethyl Ketone Ligands
Authors: Chopin Nicolas , Chastanet Guillaume , Le Guennic Boris , Médebielle Maurice , Pilet Guillaume 
Published: September 2012

AbstractA new family of [Cu4L4] cubane complexes have been synthesized by the self‐assembly of CuII salts and β‐aminovinyl trifluoromethyl ketone ligands. The resulting polynuclear architectures were especially designed to exhibit magnetic properties arising from the metallic cubane architecture as well as electro‐ or photosensitive properties arising from the ligands. The optical and electrochemical behaviours of the compounds were measured in solution to confirm that the properties of the free ligands were retained within the elaborated complexes. DFT investigations of the organic moieties were conducted with the aim of assigning the observed electronic processes to the different redox steps and absorption bands. The crystal structures of the polynuclear complexes were solved and refined by single‐crystal X‐ray diffraction analysis and correlated to variable‐temperature magnetic susceptibility data. The overall expected ferromagnetic behaviour of the [Cu4L4] complexes is weakly influenced by the ligand substitutions. Ab initio configuration interaction calculations helped us to detail the variations of the various magnetic exchange pathways.
Asymmetric Synthesis of Potent and Selective σ1 Receptor Ligands with Tetrahydro‐3‐benzazepine Scaffold
Authors: Sarkar Soumya , Schepmann Dirk , Köhler Jens , Fröhlich Roland , Wünsch Bernhard 
Published: September 2012

AbstractA new strategy for the synthesis of tetrahydro‐3‐benzazepinones 6 by reductive amination of keto acid 3 and subsequent carbonyl diimidazole (CDI) mediated cyclization was developed. Use of enantiomerically pure (R)‐1‐phenylethylamine led to the formation of diastereomeric lactams (Rα‐R)‐6d and (Rα‐S)‐6e in a 80:20 ratio. Diastereoselective alkylation of (Rα‐R)‐6d, BH3‐mediated reduction and exchange of the N‐phenylethyl substituent provided enantiomerically pure tetrahydro‐3‐benzazepines with various substituents in the 1‐, 3‐, and 4‐positions. High σ1 affinity was achieved with a benzyl, cyclohexylmethyl, or 1‐phenylethyl moiety at the N‐atom. Whereas (R)‐configuration of the N‐substituent is crucial for high σ1 affinity, the configuration of the 3‐benzazepine ring system does not influence the σ1 affinity considerably. Introduction of additional substituents in the 1‐position led to almost complete loss of σ1 affinity. Potent σ1 ligands show high selectivity against the σ2 subtype and the NMDA receptor.
Advances in automated detection of sand dunes on Mars
Authors: Bandeira Lourenço , Marques Jorge S. , Saraiva José , Pina Pedro 
Published: September 2012

ABSTRACTThis paper describes advances in an automatic approach for the detection of sand dunes of Mars, based on supervised learning techniques. A set of features (gradient histogram) is extracted from the remotely sensed images and two classifiers (Support Vector Machine and Random Forests) are trained from this data. The evaluation is conducted on 230 MOC‐NA images (spatial resolution between 1·45 and 6·80 m/pixel) leading to about 89% of correct detections. A detailed analysis of the detection results (dune/non‐dune) is performed by dune type or bulk shape, confirming high performances independently of the way the dataset is analysed. This demonstrates the robustness and adequacy of the automated approach to deal with the large variety of aeolian structures present on the surface of Mars. Copyright © 2012 John Wiley & Sons, Ltd.