bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Optically Enriched Spirocyclic Benzofuran‐2‐ones by Bifunctional Thiourea‐Base Catalyzed Double‐Michael Addition of Benzofuran‐2‐ones to Dienones
Authors: Li Xin , Yang Chen , Jin Jia‐Lu , Xue Xiao‐Song , Cheng Jin‐Pei 
Published: February 2013

AbstractA highly enantioselective catalytic double‐Michael addition reaction of substituted benzofuran‐2‐ones with divinyl ketones promoted by readily accessible tertiary amine–thiourea Cinchona alkaloids has been developed. A number of optically enriched spirocyclic benzofuran‐2‐ones were prepared in very good yields (up to 99 %), diastereoselectivities (up to 19:1 d.r.), and very good enantioselectivities (up to 92 % ee). Density functional theory (DFT) calculations were performed to investigate the origin of stereoselectivity.
Northwestern Argentina: A Center of Genetic Diversity of Lemon Verbena (Aloysia citriodoraPaláu, Verbenaceae)
Authors: Di Leo Lira Paola , van Baren Catalina M. , López Simon , Molina Ana , Heit Cecilia , Viturro Carmen , de Lampasona Marina P. , Catalán Cesar A. , Bandoni Arnaldo 
Published: February 2013

AbstractThe aerial parts of lemon verbena (Aloysia citriodora Paláu) are worldwide used due to their medicinal and aromatic properties. The essential‐oil and acteoside contents have been proposed as the main quality markers for their pharmacological and organoleptic features. The northwestern region of Argentina has been repeatedly proposed as the place of origin for this species. For this reason, the essential‐oil yields and chemical compositions of leaves of 25 populations of lemon verbena from both wild collections and experimental crops from this region were studied. Plants from six different collections were subsequently grown on the same experimental parcel located at Cerrillos, Salta province, during more than seven years. In addition, the acteoside contents determined in all the samples collected in 2010 showed significant variations (from 0.5 to 4.0%). Large differences were observed in the essential‐oil composition and yields, which ranged from 0.4 to 2.1% (v/w). Nevertheless, most of the samples complied with the European Pharmacopoeia specifications. A remarkable chemical diversity with at least four clearly defined chemotypes was detected in this region. Therefore, it would be urgent to encourage actions to protect these genotypes of lemon verbena in the northwestern Argentina.
Chemical Composition and Antimicrobial and Allelopathic Activity of Tunisian Conyza sumatrensis (Retz.) E.Walker Essential Oils
Authors: Mabrouk Samia , Salah Karima Bel Hadj , Elaissi Ameur , Jlaiel Lobna , Jannet Hichem Ben , Aouni Mahjoub , Harzallah‐Skhiri Fethia 
Published: February 2013

AbstractConyza sumatrensis (Retz.) E.Walker (Asteraceae) is a spontaneous annual herb, fairly widespread throughout Tunisia, which has rarely been studied or valued in any sector. Essential oils were obtained by hydrodistillation of different parts (flower heads, leaves, stems, and roots) of C. sumatrensis plants, which were collected in autumn (November 2007) at the flowering stage in the area of Monastir, Tunisia. In total, 98 compounds, representing 88.1–99.3% of the oil composition, were identified by GC‐FID and GC/MS analyses. The root essential oil was distinguished by its high content in acetylenes (matricaria ester, 4; 74.3%), while those from flower heads and leaves were dominated by oxygenated sesquiterpenes (61.1 and 50.3%, resp.). The oils of C. sumatrensis from Tunisia belonged to a matricaria ester/caryophyllene oxide chemotype. All the oils were evaluated for antibacterial, antifungal, and allelopathic activities. The results indicate that the leaf oil exhibited significant in vitro antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, and Proteus mirabilis and that the C. sumatrensis oils isolated from the aerial parts presented high mycelia‐growth inhibition of Candida albicans and the filamentous fungi tested. Moreover, the essential oils of the different plant parts inhibited the shoot and root growth of Raphanus sativus (radish) seedlings. Indeed, the inhibition of the hypocotyl growth varied from 28.6 to 90.1% and that of the radicle from 42.3 to 96.2%.
Chemical Diversity among the Essential Oils of Wild Populations of Stachys lavandulifoliaVahl (Lamiaceae) from Iran
Authors: Aghaei Yaqub , Hossein Mirjalili Mohammad , Nazeri Vahideh 
Published: February 2013

AbstractThe variation of the essential‐oil composition among ten wild populations of Stachys lavandulifolia Vahl (Lamiaceae), collected from different geographical regions of Iran, was assessed by GC‐FID and GC/MS analyses, and their intraspecific chemical variability was determined. Altogether, 49 compounds were identified in the oils, and a relatively high variation in their contents was found. The major compounds of the essential oils were myrcene (0.0–26.2%), limonene (0.0–24.5%), germacrene D (4.2–19.3%), bicyclogermacrene (1.6–18.0%), δ‐cadinene (6.5–16.0%), pulegone (0.0–15.1%), (Z)‐hex‐3‐enyl tiglate (0.0–15.1%), (E)‐caryophyllene (0.0–12.9), α‐zingiberene (0.2–12.2%), and spathulenol (1.6–11.1%). For the determination of the chemotypes and the chemical variability, the essential‐oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (germacrene D/bicyclogermacrene), Chemotype II (germacrene D/spathulenol), Chemotype III (limonene/δ‐cadinene), Chemotype IV (pulegone), and Chemotype V (α‐zingiberene). The high chemical variation among the populations according to their geographical and bioclimatic distribution imposes that conservation strategies of populations should be made appropriately, taking into account these factors. The in situ and ex situ conservation strategies should concern all populations representing the different chemotypes.
Hydrodeoxygenation of Phenol and Derivatives over an Ionic Liquid‐Like Copolymer Stabilized Nanocatalyst in Aqueous Media
Authors: Chen Jinzhu , Huang Jing , Chen Limin , Ma Longlong , Wang Tiejun , Zakai Uzma I. 
Published: February 2013

AbstractUsing phenolic bio‐oil as feedstock for sustainable production of alkane fuels is of great significance. Here, the hydrodeoxygenation of phenol and its derivatives has been systematically investigated in aqueous media with a dual‐functional catalyst system consisting of water‐soluble, ionic liquid‐like copolymer A‐stabilized nanocatalysts and the mineral acid H3PO4. The developed Ru/A‐H3PO4 catalyst system achieved a complete phenol conversion with cyclohexane selectivity higher than 99 %, making it by far one of the most efficient systems for phenol hydrodeoxygenation. Mercury poisoning experiments revealed that the in situ generated Ru nanoparticles are true a heterogeneous catalyst for hydrogenation. The catalytic activity of metal site for phenol hydrodeoxygenation to cyclohexane decreased with the order of Ru>Rh>Pt≫Pd. Our findings also demonstrated the delicate balance between activity and stability of ionic liquid‐like copolymer‐stabilized nanocatalysts. The research highlights an efficient catalyst system of transforming phenols into alkanes.
New Synthesis of A‐Ring Aromatic Strigolactone Analogues and Their Evaluation as Plant Hormones in Pea (Pisum sativum)
Authors: Chen Victor X. , Boyer François‐Didier , Rameau Catherine , Pillot Jean‐Paul , Vors Jean‐Pierre , Beau Jean‐Marie 
Published: February 2013

AbstractA new general access to A‐ring aromatic strigolactones, a new class of plant hormones, has been developed. The key transformations include in sequence ring‐closing metathesis, enzymatic kinetic resolution and a radical cyclization with atom transfer to install the tricyclic ABC‐ring system. The activity as plant hormones for the inhibition of shoot branching in pea of various analogues synthesized by this strategy is reported.
Group IV Organometallic Compounds Based on Dianionic “Pincer” Ligands: Synthesis, Characterization, and Catalytic Activity in Intramolecular Hydroamination Reactions
Authors: Luconi Lapo , Rossin Andrea , Motta Alessandro , Tuci Giulia , Giambastiani Giuliano 
Published: February 2013

AbstractNeutral ZrIV and HfIV diamido complexes stabilized by unsymmetrical dianionic N,C,N′ pincer ligands have been prepared through the simplest and convenient direct metal‐induced CarylH bond activation. Simple ligand modification has contributed to highlight the non‐innocent role played by the donor atom set in the control of the cyclometallation kinetics. The as‐prepared bis‐amido catalysts were found to be good candidates for the intramolecular hydroamination/cyclization of primary aminoalkenes. The ability of these compounds to promote such a catalytic transformation efficiently (by providing, in some cases, fast and complete substrate conversion at room temperature) constitutes a remarkable step forward toward catalytic systems that can operate at relatively low catalyst loading and under milder reaction conditions. Kinetic studies and substrate‐scope investigations, in conjunction with preliminary DFT calculations on the real systems, were used to elucidate the effects of the substrate substitution on the catalyst performance and to support the most reliable mechanistic path operative in the hydroamination reaction.
Solid‐State Structural Transformations and Photoreactivity of 1D‐Ladder Coordination Polymers of PbII
Authors: Kole Goutam Kumar , Peedikakkal Abdul Malik Puthan , Toh Belinda Mei Fang , Vittal Jagadese J. 
Published: February 2013

AbstractAn attempt has been made to design double‐stranded ladder‐like coordination polymers (CPs) of hemidirected PbII. Four CPs, [Pb(μ‐bpe)(O2C‐C6H5)2]⋅2H2O (1), [Pb2(μ‐bpe)2(μ‐O2C‐C6H5)2(O2C‐C6H5)2] (2), [Pb2(μ‐bpe)2(μ‐O2C‐p‐Tol)2(O2C‐p‐Tol)2]⋅ 1.5 H2O (3) and [Pb2(μ‐bpe)2(μ‐O2C‐m‐Tol)2(O2C‐m‐Tol)2] (4) (bpe=1,2‐bis(4′‐pyridyl)ethylene), have been synthesised and investigated for their solid‐state photoreactivity. CPs 2–4, having a parallel orientation of bpe molecules in their ladder structures and being bridged by carboxylates, were found to be photoreactive, whereas CP 1 is a linear one‐dimensional (1D) CP with guest water molecules aggregating to form a hydrogen‐bonded 1D structure. The linear strands of 1 were found to pair up upon eliminating lattice water molecules by heating, which led to the solid‐state structural transformation of photostable linear 1D CP 1 into photoreactive ladder CP 2. In the construction of the double‐stranded ladder‐like structures, the parallel alignment of CC bonds in 2–4 is dictated by the chelating and μ2‐η2:η1 bridging modes of the benzoate and toluate ligands. The role of solvents in the formation of such double‐stranded ladder‐like structures has also been investigated. A single‐crystal‐to‐single‐crystal transformation occurred when 4 was irradiated under UV light to form [Pb2(rctt‐tpcb)(μ‐O2C‐m‐Tol)2(O2C‐m‐Tol)2] (5).
Assembly of Framework‐Isomeric 4 d–4 f Heterometallic Metal–Organic Frameworks with Neutral/Anionic Micropores and Guest‐Tuned Luminescence Properties
Authors: Ma Jing‐xin , Huang Xiao‐feng , Song Xue‐qin , Liu Wei‐sheng 
Published: February 2013

AbstractFramework‐isomeric three‐dimensional (3D) Cd–Ln heterometallic metal–organic frameworks (HMOFs), {[Ln2(ODA)6Cd3(H2O)6]⋅6 H2O}n (Ln=Gd (1 a) and Tb (1 b), ODA=oxydiacetic acid) and {[Cd(H2O)6]⋅[Ln2(ODA)6Cd2]⋅H2O}n (Ln=Gd (2 a), Tb (2 b)), with neutral and anionic pores, respectively, were designed based on a lanthanide metalloligand strategy and synthesized by using a stepwise assembly and a hydrothermal method. Luminescence studies revealed that 1 b and 2 b can act as luminescent metal–organic frameworks and their light‐emitting properties can be modulated by small guest molecules and the manganese counterion, respectively.
Glycosylated Nanoscale Surfaces: Preparation and Applications in Medicine and Molecular Biology
Authors: Kennedy David C. , Grünstein Dan , Lai Chian‐Hui , Seeberger Peter H. 
Published: February 2013

AbstractCarbohydrates on cell surfaces are critical components of the extracellular landscape and contribute to cell signalling, motility, adhesion and recognition. Multivalent effects are essential to these interactions that are inherently weak. Carbohydrate‐functionalised surfaces meet an important need for studying the multivalent interactions between carbohydrates and other biomolecules. Innovations in nanomaterials are revolutionising how these carbohydrate interfaces are studied and underscore their importance in the cosmos of biochemical interactions.
Laser‐Based Generation of Nanocomposites without Matrix‐Coupling Agents for Bioactive Medical Devices
Authors: Schwenke Andreas , Wagener Philipp , Weiß André , Klimenta Klaus , Wiegel Heinz , Sajti Laszlo , Barcikowski Stephan 
Published: February 2013

AbstractZur Ausschöpfung des Potenzials funktionaler Nanomaterialen bedarf es neuartiger Produktionsverfahren, die die Dispersion der Nanopartikel entlang der Prozesskette sicherstellen. Am Beispiel von Medizinprodukten mit antibakteriellem Schutz vor Biofilmbildung auf Basis von Silbernanopartikeln werden die Volumenintegration in Kunststoffe und die Nanopartikelsynthese durch Laserabtrag in Flüssigkeiten vorgestellt. Die antibakterielle Wirksamkeit der Nanokomposite und Verarbeitbarkeit zu Prototypen werden gezeigt.
Development of a Reactor Setup for Continuous Dehydration of Carbohydrates
Authors: Weisgerber Laurent , Palkovits Stefan , Palkovits Regina 
Published: February 2013

AbstractThe shortage of fossil energy carriers demands the use of renewable and sustainable energy resources. Biomass has the potential to fulfill these needs. The chemical transformation of cellulose, being a main part of plant biomass, allows the production of a widespread variety of chemicals. One especially promising candidate as platform molecule is 5‐hydroxymethylfurfural (5‐HMF). Until now 5‐HMF was predominantly produced in batch reactions from fructose as substrate within high boiling solvents. A working setup for producing 5‐HMF continuously out of fructose or in a coupled two‐step reaction, out of glucose, in low boiling solvents is introduced.
Evaluation of Bioavailability and Partitioning of Aluminum in Sediment Samples of Different Ecosystems by Modified Sequential Extraction Methods
Authors: Khan Sumaira , Kazi Tasneem G. , Arain Muhammad B. , Kolachi Nida F. , Baig Jameel A. , Afridi Hassan I. , Shah Abdul Q. 
Published: February 2013

AbstractSequential extraction procedures are widely used to characterize the different operational fractions with different potential toxicity of metals in environmental solid samples. The present work describes the application of different analytical approaches for sequential extraction of aluminum to evaluate its mobility, availability, and persistent chemical forms in sediment samples of different fresh water ecosystems (lake, canal, and river). The conventional BCR three‐stage sequential extraction procedure (C‐BCR) was modified at each stage, by applying ultrasonic device (U‐BCR), in order to shorten the required shaking time of 16 h for each three steps (excluding the hydrogen peroxide digestion in step 3, which was not performed with ultrasonic bath), could be completed in 40, 50, and 45 min, respectively. The aluminum in all extracts were determination by atomic absorption spectrometry using nitrous oxide – acetylene flame. The accuracy of results obtained from C‐BCR and proposed U‐BCR was verified with literature reported values of certified sediment sample (BCR 701). The overall recoveries of aluminum obtained by proposed U‐BCR were found in the range of 96.7–113% of those values obtained with C‐BCR for all fractions. Use of ultrasonic device, provided a large saving in extraction time relative to conventional shaking. It was observed that major part of Al in real sediment samples (80–83% of total Al) were bound to residual fraction. The acid soluble fraction of aluminum extracted by 0.11 mol/L CH3COOH has good correlation with aluminum content in corresponding water samples of each ecosystem.
Screening for distress in cancer patients
Authors: Grassi Luigi , Johansen Christoffer , Annunziata Maria Antonietta , Capovilla Eleonora , Costantini Anna , Gritti Paolo , Torta Riccardo , Bellani Marco ,   on behalf of the Italian Society of Psycho‐Oncology Distress Thermometer Study Group
Published: February 2013

AbstractBACKGROUND:Routine screening for distress is internationally recommended as a necessary standard for good cancer care, given its high prevalence and negative consequences on quality of life. The objective of the current study was to contribute to the Italian validation of the Distress Thermometer (DT) to determine whether the single item DT compared favorably with referent criterion measures.METHODS:In total, 1108 outpatients with cancer were recruited from 38 representative oncology centers in Italy. Each participant completed the DT and a list of 34 possible cancer‐related problems (the Problem List), the Hospital Anxiety and Depression Scale (HADS), the 18‐item Brief Symptom Inventory (BSI‐18), and a short visual analog scale to determine the understandability of the tools.RESULTS:Receiver operating characteristic analysis revealed that DT cutoff scores ≥4 and ≥5 had optimal sensitivity and specificity relative to both HADS and BSI‐18 cutoff scores for general caseness and more severe psychological distress, respectively. Patients with DT scores ≥4 (cases) were more likely to be women; to have had psychological problems in the past; to report more stressful events in the last year; and to currently have more family, emotional, and physical problems related to cancer or cancer treatment. Patients indicated that the DT was easier to fill out and to understand than the HADS, but not the BSI‐18.CONCLUSIONS:The DT was identified as a simple and effective screening instrument for detecting distress in Italian cancer patients as a first step toward more properly referring those in need to psychosocial intervention. Cancer 2013. © 2013 American Cancer Society.
Phase 2 study of preoperative image‐guided intensity‐modulated radiation therapy to reduce wound and combined modality morbidities in lower extremity soft tissue sarcoma
Authors: O'Sullivan Brian , Griffin Anthony M. , Dickie Colleen I. , Sharpe Michael B. , Chung Peter W. M. , Catton Charles N. , Ferguson Peter C. , Wunder Jay S. , Deheshi Benjamin M. , White Lawrence M. , Kandel Rita A. , Jaffray David A. , Bell Robert S. 
Published: February 2013

AbstractBACKGROUND:This study sought to determine if preoperative image‐guided intensity‐modulated radiotherapy (IG‐IMRT) can reduce morbidity, including wound complications, by minimizing dose to uninvolved tissues in adults with lower extremity soft tissue sarcoma.METHODS:The primary endpoint was the development of an acute wound complication (WC). IG‐IMRT was used to conform volumes to avoid normal tissues (skin flaps for wound closure, bone, or other uninvolved soft tissues). From July 2005 to June 2009, 70 adults were enrolled; 59 were evaluable for the primary endpoint. Median tumor size was 9.5 cm; 55 tumors (93%) were high‐grade and 58 (98%) were deep to fascia.RESULTS:Eighteen (30.5%) patients developed WCs. This was not statistically significantly different from the result of the National Cancer Institute of Canada SR2 trial (P = .2); however, primary closure technique was possible more often (55 of 59 patients [93.2%] versus 50 of 70 patients [71.4%]; P = .002), and secondary operations for WCs were somewhat reduced (6 of 18 patients [33%] versus 13 of 30 patients [43%]; P = .55). Moderate edema, skin, subcutaneous, and joint toxicity was present in 6 (11.1%), 1 (1.9%), 5 (9.3%), and 3 (5.6%) patients, respectively, but there were no bone fractures. Four local recurrences (6.8%, none near the flaps) occurred with median follow‐up of 49 months.CONCLUSIONS:The 30.5% incidence of WCs was numerically lower than the 43% risk derived from the National Cancer Institute of Canada SR2 trial, but did not reach statistical significance. Preoperative IG‐IMRT significantly diminished the need for tissue transfer. RT chronic morbidities and the need for subsequent secondary operations for WCs were lowered, although not significantly, whereas good limb function was maintained. Cancer 2013. © 2013 American Cancer Society.
Synchronous cancers in patients with head and neck cancer
Authors: Jain Kunal S. , Sikora Andrew G. , Baxi Shrujal S. , Morris Luc G. T. 
Published: February 2013

AbstractBACKGROUND:Second primary malignancies (SPMs) are the leading cause of death in survivors of head and neck squamous cell carcinoma (HNSCC). Synchronous SPMs are of significant clinical interest because they potentially can be identified by screening procedures at the time of diagnosis of the index cancer. Recently, human papillomavirus (HPV) has emerged as a distinct risk factor for oropharyngeal head and neck squamous cell carcinoma (HNSCC), differing from classic tobacco/alcohol‐associated HNSCC, suggesting that there also may be distinct patterns of synchronous SPMs.METHODS:The authors performed a population‐based cohort study in 64,673 patients in the National Cancer Institute Surveillance, Epidemiology, and End Results registry (1979‐2008), defining risks of synchronous SPM in patients with HNSCC who were diagnosed before and after the emergence of prevalent HPV‐associated oropharyngeal HNSCC. Excess risk was calculated using standardized incidence ratios (SIR) and excess absolute risk per 100 patients.RESULTS:Among patients with HNSCC, the SIR of synchronous SPM was 5.0, corresponding to 2.62 excess cases per 100 patients. The site with the highest excess risk of a second cancer was the head and neck (SIR, 41.4), followed by the esophagus (SIR, 21.8), and lung (SIR, 7.4). The risk of synchronous SPM changed markedly over time for patients with oropharyngeal HNSCC. In the 1970s and 1980s, oropharyngeal cancers carried the highest risk of SPM. Risk began to dramatically decline in the 1990s; and currently, oropharyngeal cancers carry the lowest risk of synchronous SPM.CONCLUSIONS:The current data are consistent with the etiologic shift of oropharyngeal HNSCC, from a primarily tobacco‐associated malignancy associated with significant field cancerization of the upper aerodigestive mucosa, to a malignancy primarily caused by oncogenic human papillomavirus. Cancer 2013. © 2013 American Cancer Society.