bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Palladium‐Catalyzed Synthesis of 4‐Aminophthalazin‐1(2H)‐ones by Isocyanide Insertion.
Authors: Vlaar Tjoestil , Ruijter Eelco , Znabet Anass , Janssen Elwin , de Kanter Frans J. J. , Maes Bert U. W. , Orru Romano V. A. 
Published: March 2012

AbstractThe multicomponent reaction combines isocyanides and free hydrazines in a Pd‐catalyzed process and is specific for tertiary alkyl isocyanides.
ChemInform Abstract: Divergent Outcomes of Carbene Transfer Reactions from Dirhodium‐ and Copper‐Based Catalysts Separately or in Combination.
Authors: Xu Xinfang , Hu Wen‐Hao , Zavalij Peter Y. , Doyle Michael P. 
Published: March 2012

AbstractThe reaction between vinyl diazoacetates and cinnamaldehydes can be highly selectively directed to the formation of 4,5‐dihydrooxepins or bicyclic hexanones by appropriate use of Cu‐ and Rh‐catalyst, either separately or in combination.
ChemInform Abstract: A New Cycloartane‐Type Triterpenoid from the Stigma of Zea mays L.
Authors: Qiang Yin , Ni Jing‐Man , Shi Yan‐Bin , Zhang Xiao‐Yun , Yang Xian , Li Shou‐Tang 
Published: March 2012

Abstractisolation, structure and cytotoxicity of (I)
ChemInform Abstract: Molecular Design, Synthesis and Bioactivity of Glycosyl Hydrazine and Hydrazone Derivatives: Notable Effects of the Sugar Moiety.
Authors: Cui Zining , Yang Xinling , Shi Yanxia , Uzawa Hirotaka , Cui Jingrong , Dohi Hirofumi , Nishida Yoshihiro 
Published: March 2012

AbstractThe compounds (III) are screened for their antitumor and antifungal activities.
ChemInform Abstract: Hydrogen Storage Properties of LiBH4—Li3AlH6 Composites.
Authors: Wu Xiaocheng , Wang Xinhua , Cao Guozhou , Li Shouquan , Ge Hongwei , Chen Lixin , Yan Mi 
Published: March 2012

AbstractThe title composites are prepared by ball milling of LiBH4 and Li3AlH6 in the molar ratio of 1:1 (0.1 MPa Ar, 0.5 h).
ChemInform Abstract: Fast Repair of DNA Radicals in the Earliest Stage of Carcinogenesis Suppresses Hallmarks of Cancer.
Authors: Zheng Rongliang , Jia Zhongjian , Li Ji , Huang Shuangsheng , Mu Ping , Zhang Fangxin , Wang Chunming , Yuan Chengshan 
Published: March 2012

AbstractReview: about 100 refs.
Synthesis and Spectral Properties of 4‐(2,5‐Dimethoxyphenylmethelene)‐2‐phenyl‐5‐oxazolone (DMPO)
Authors: El‐Daly Samy A. , Asiri Abdullah M. , Alamry Khalid A. , Hussein Mahmoud A. 
Published: March 2012

AbstractAn interesting flourophore, 4‐(2,5‐dimethoxyphenylmethelene)‐2‐phenyl‐5‐oxazolone (DMPO) was synthesized by mixing an equivalent molar quantity of hippuric acid and 2,5‐dimethoxybenzaldehyde in acetic anhydride in the presence of anhydrous sodium acetate. The absorption and fluorescence characteristics of 4‐(2,5‐dimethoxy‐phenylmethelene)‐2‐phenyl‐5‐oxazolone (DMPO) were investigated in different solvents. DMPO dye exhibits red shift in both absorption and emission spectra as solvent polarity increases, indicating change in the dipole moment of molecules upon excitation due to an intramolecular charge transfer interaction. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. A crystalline solid of DMPO gave strong excimer like emission at 630 nm due to the excitation of molecular aggregates. This is expected from the idealized crystal structure of the dye that belongs to the B‐type class of Steven's Classification. DMPO displayed fluorescence quenching by triethylamine via nonemissive exciplex formation.
Electrochemical Immunosensor for α‐Fetoprotein Based on Gold Nanoparticles/Graphene‐Prussian Blue
Authors: Wang Guangfeng , Zhang Ge , Huang Hao , Wang Lun 
Published: March 2012

AbstractThe electrochemical immunosensor for α‐fetoprotein (AFP) was fabricated based on the platform of gold nanoparticles (GNP)/graphene (Gr)‐prussian blue (PB). By electrodeposition, GNP were modified on the surface of the prepared Gr‐PB. The anti‐AFP‐1,1′‐ferrocenedicarboxylic acid (FcDA) as label was directly immobilized on the platform of GNP/Gr‐PB. And after the immunoreactions, the formed complex inhibited the electron transfer and decreased the catalytic current of FcDA toward the reduction of H2O2. And in the range of 10–3200 pg·mL−1, the decreased current is linear with the concentration of AFP, with a detection limit of 3 pg·mL−1. The developed immunoassay method showed good precision, high sensitivity, acceptable stability and reproducibility, and could be used for the detection of real samples with consistent results in comparison with those obtained by the enzyme linked immunosorbent assay (ELISA) method.
Feuerwerk im Chemieunterricht
Authors: Kometz Andreas , Urbanger Michael , Fraterman Thorsten 
Published: March 2012

AbstractDer kürzlich von uns vorgestellte Kontext „Chemie und Urlaub“ [1] nutzt die Erfahrungen der Schülerinnen und Schüler in der Ferienzeit, um einen interessanten und motivierenden Wiedereinstieg in den Chemieunterricht zu ermöglichen. Das Thema Feuerwerk als Teil dieses Kontextes bietet viele Möglichkeiten, Basiskonzepte der Chemie zu erarbeiten und Bildungs‐ und Erziehungsaufgaben wie Umwelterziehung und Sicherheitserziehung umzusetzen. Das Letztgenannte ist ein wesentlicher Schwerpunkt der Unterrichtseinheit „Feuerwerk“, da sich dieses Thema besonders gut dazu eignet, einen bewussten und verantwortungsvollen Umgang mit gefährlichen chemischen Stoffen zu fördern. Fehlendes Sicherheitsbewusstsein, Falschinformationen und der Reiz, etwas Verbotenes zu tun, führen bei selbst gemachten Feuerwerkskörpern immer wieder zu schweren Unfällen. Durch kontextualisierten Umgang mit diesem Thema lernen die Schulkinder auf nicht belehrende, sondern einsichtsfördernde Art, ein Verantwortungsbewusstsein für den Umgang mit Chemikalien aufzubauen.
Control of MCAK degradation and removal from centromeres
Authors: Ganguly Anutosh , Bhattacharya Rajat , Cabral Fernando 
Published: March 2012

AbstractMitotic centromere associated kinesin (MCAK) is a kinesin related protein with the ability to stimulate microtubule depolymerization. It is found at spindle poles, where it may be involved in poleward microtubule flux, and at kinetochores and centromeres where it plays a role in correcting chromosome alignment errors. Its microtubule depolymerase activity and recruitment to centromeres is regulated by phosphorylation, but little is known about how MCAK is maintained at appropriate levels. We previously reported that MCAK accumulates during the cell cycle and is then degraded during mitosis. Using proteomic analysis, we have now identified a new phosphorylation site on MCAK that is responsible for its degradation. Mutation of the site to prevent phosphorylation prolonged the stability of the protein beyond the metaphase to anaphase transition and into the subsequent cell cycle whereas a phosphomimetic mutation accelerated degradation. Unexpectedly, the mutation that prevented phosphorylation also inhibited the removal of MCAK from centromeres causing it to remain attached throughout the cell cycle. Even low expression of phosphorylation‐resistant MCAK delayed mitosis and interfered with cell division. Mitotic defects were also observed by overexpressing a green fluorescent protein‐tagged version of wild‐type MCAK that similarly escaped degradation and accumulated to toxic levels, but did not remain associated with kinetochores during interphase. The results demonstrate that degradation is an important mechanism for controlling the activity of MCAK. © 2012 Wiley Periodicals, Inc
An Efficient Synthesis of Quinoxalinone Derivatives as Potent Inhibitors of Aldose Reductase
Authors: Yang Yanchun , Zhang Shuzhen , Wu Bobin , Ma Mingming , Chen Xin , Qin Xiangyu , He Minlan , Hussain Saghir , Jing Chaojun , Ma Bing , Zhu Changjin 
Published: March 2012

AbstractA novel and facile synthesis of quinoxalinone derivatives was developed in which a wide range of 3‐chloroquinoxalin‐2(1H)‐ones as key intermediates can be generated chemo‐ and regioselectively in good yields from corresponding quinoxaline‐2,3(1H,4H)‐diones. This new protocol is arguably superior, as it allows the design and preparation of a variety of bioactive quinoxaline‐based compounds, which are particularly effective in the treatment of diabetes and its complications. Through this procedure, a new class of quinoxalinone‐based aldose reductase inhibitors were synthesized successfully. Most of the inhibitors, with an N1‐acetic acid head group and a substituted C3‐phenoxy side chain, proved to be potent and selective. Their IC50 values ranged from 11.4 to 74.8 nM. Among them, 2‐(3‐(4‐bromophenoxy)‐7‐fluoro‐2‐oxoquinoxalin‐1(2H)‐yl)acetic acid and 2‐(6‐bromo‐3‐(4‐bromophenoxy)‐2‐oxoquinoxalin‐1(2H)‐yl)acetic acid were the most active. Structure–activity relationship and molecular docking studies highlighted the importance of the ether spacer in the C3‐phenoxy side chains, and provided clear guidance on the contribution of substitutions both at the core structure and the side chain to activity.
The impact of portal vein resection on outcomes for hilar cholangiocarcinoma
Authors: de Jong Mechteld C. , Marques Hugo , Clary Bryan M. , Bauer Todd W. , Marsh J. Wallis , Ribero Dario , Majno Pietro , Hatzaras Ioannis , Walters Dustin M. , Barbas Andrew S. , Mega Raquel , Schulick Richard D. , Choti Michael A. , Geller David A. , Barroso Eduardo , Mentha Gilles , Capussotti Lorenzo , Pawlik Timothy M. 
Published: March 2012

AbstractBACKGROUND. Surgical strategy for hilar cholangiocarcinoma often includes hepatectomy, but the role of portal vein resection (PVR) remains controversial. In this study, the authors sought to identify factors associated with outcome after surgical management of hilar cholangiocarcinoma and examined the impact of PVR on survival.METHODS:Three hundred five patients who underwent curative‐intent surgery for hilar cholangiocarcinoma between 1984 and 2010 were identified from an international, multi‐institutional database. Clinicopathologic data were evaluated using univariate and multivariate analyses.RESULTS:Most patients had hilar cholangiocarcinoma with tumors classified as T3/T4 (51.1%) and Bismuth‐Corlette type II/III (60.9%). Resection involved extrahepatic bile duct resection (EHBR) alone (26.6%); or hepatectomy and EHBR without PVR (56.7%); or combined hepatectomy, EHBR, and PVR (16.7%). Negative resection (R0) margin status was higher among the patients who underwent hepatectomy plus EHBR (without PVR, 64.2%; with PVR, 66.7%) versus EHBR alone (54.3%; P < .001). The median number of lymph nodes assessed was higher among the patients who underwent hepatectomy plus EHBR (without PVR, 6 lymph nodes; with PVR, 4 lymph nodes) versus EHBR alone (2 lymph nodes; P < .001). The 90‐day mortality rate was lower for patients who underwent EHBR alone (1.2%) compared with the rate for patients who underwent hepatectomy plus EHBR (without PVR, 10.6%, with PVR, 17.6%; P < .001). The overall 5‐year survival rate was 20.2%. Factors that were associated with an adverse prognosis included lymph node metastasis (hazard ratio [HR], 1.79; P = .002) and R1 margin status (HR, 1.81; P < .001). Microscopic vascular invasion did not influence survival (HR, 1.23; P = .19). Among the patients who underwent hepatectomy plus EHBR, PVR was not associated with a worse long‐term outcome (P = .76).CONCLUSIONS:EHBR alone was associated with a greater risk of positive surgical margins and worse lymph node clearance. The current results indicated that hepatectomy should be considered the standard treatment for hilar cholangiocarcinoma, and PVR should be undertaken when necessary to extirpate all disease. Combined hepatectomy, EHBR, and PVR can offer long‐term survival in some patients with advanced hilar cholangiocarcinoma. Cancer 2012. © 2012 American Cancer Society.
Can the new American Joint Committee on Cancer staging system predict survival in rectal cancer patients treated with curative surgery following preoperative chemoradiotherapy?
Authors: Moon Sang Hui , Kim Dae Yong , Park Ji Won , Oh Jae Hwan , Chang Hee Jin , Kim Sun Young , Kim Tae Hyun , Park Hee Chul , Choi Doo Ho , Chun Ho‐Kyung , Kim Jong Hoon , Park Jin‐hong , Yu Chang Sik 
Published: March 2012

AbstractBACKGROUND:Although ypStage has been known as a strong prognosticator of recurrence and survival, the detailed interaction of ypT and ypN classification on a survival rate has never been evaluated.METHODS:Between October 2001 and December 2007, in total, 960 patients with locally advanced rectal cancer were enrolled retrospectively at 3 centers. Five‐year overall survival (OS) and disease‐free survival (DFS) rate were calculated for each ypTN classification.RESULTS:The ypT classification interacted with ypN classification to affect survival in most categories. Patients with ypStage 0 and I cancers showed a >90% 5‐year OS (ypStage 0, 96.5%; ypStage I, 92.9%; P = .346) and 5‐year DFS (ypStage 0, 90.2%; ypStage I, 90.7%; P = .879). Among ypStage III subgroups, large differences in 5‐year OS (ypStage IIIA, 90.1%; ypStage IIIB, 68.3%; ypStage IIIC, 40.5%; P < .001) and 5‐year DFS (ypStage IIIA, 74.8%; ypStage IIIB, 55.1%; ypStage IIIC, 12.3%; P < .001) were observed. OS and DFS in patients with ypStage IIIA disease were similar to or greater than those in patients with ypStage IIA or IIB/IIC disease. Four patient risk groups were defined: 1) low (ypT0‐isN0, ypT1N0, ypT2N0), 2) intermediate (ypT0‐2N1, ypT3N0), 3) moderately high (ypT0‐2N2, ypT3N1, ypT4N0), and 4) high risk (ypT3N2, ypT4N1‐2). Risk grouping showed a narrower range of survival rate compared with ypStage grouping.CONCLUSIONS:ypStage in rectal cancer, defined according to the 7th edition of the American Joint Committee on Cancer staging system, predicts survival for most ypNT classifications. However, patients with ypStage I rectal cancer have a similar prognosis to those with ypStage 0 cancer, and risk grouping reflects more precise survival outcomes than ypStage. Cancer 2012. © 2012 American Cancer Society.
Covalent Functionalization of Strained Graphene
Authors: Boukhvalov Danil W. , Son Young‐Woo 
Published: March 2012

AbstractAn enhancement of the chemical activity of graphene is evidenced by first‐principles modelling of the chemisorption of hydrogen, fluorine, oxygen and hydroxyl groups on strained graphene. For the case of negative strain or compression, chemisorption of the single hydrogen, fluorine or hydroxyl group is energetically more favourable than those of their pairs on different sublattices. This behaviour stabilizes the magnetism caused by the chemisorption being against its destruction by the pair formations. Initially flat, compressed graphene is shown to buckle spontaneously right after chemisorption of single adatoms. Unlike hydrogenation or fluorination, the oxidation process turns from the endothermic to exothermic for all types of the strain and depends on the direction of applied strains. Such properties will be useful in designing graphene devices utilizing functionalization as well as mechanical strains.
Morphometric and hydrologic characteristics of alligator holes in Everglades National Park, Florida from 1994 to 2007
Authors: Liu Zhongwei , Brandt Laura A. , Ogurcak Danielle E. , Mazzotti Frank J. 
Published: March 2012

ABSTRACTAlligator (Alligator mississippiensis) holes are a key feature in the Everglades landscape providing aquatic refuge for alligators and other aquatic organisms. The morphology of the hole as well as its location in the landscape may influence its function as an aquatic refugium. Morphologic and hydrologic characteristics and dynamics of 50 alligator holes in Everglades National Park, Florida were examined based on 1‐m resolution digital images and field measurements from 1994 to 2007. Major morphometric parameters of alligator holes calculated for the study area included surface area, diameter, major axis orientation, basin depth, and circularity index. We used basin depth along with surface water modelling from the Everglades Depth Estimation Network to describe alligator hole hydroperiod and examine relationships among morphologic features, habitat, and hydrology. Alligator holes in this study were similar morphologically (pond surface area, basin depth, and sediment depth) among locations and habitats, and for the most part over time with the exception of holes in the Rocky glades. Alligator holes with greater surface area were not necessarily deeper holes. Hole hydroperiod was not correlated with surface area, and larger holes did not dry out less frequently than smaller holes. Although marsh hydroperiods varied by location and habitat, alligator hole hydroperiod did not, illustrating that across the landscape alligator holes provide aquatic refugia under a range of hydrologic conditions. Published in 2012. This article is a US Government work and is in the public domain in the USA.
Nucleophilic Attack on Coordinated Imines: The Synthesis of C‐Bonded Acetylacetonates of Palladium(II) and Mechanistic Insights
Authors: Birkle Thomas , Carbayo Arancha , Cuevas José V. , García‐Herbosa Gabriel , Muñoz Asunción 
Published: March 2012

AbstractThe reactivity of complexes [PdCl2(κ2‐NN′)] [NN′ = 2‐C5H4N‐CH=N‐Ar; Ar = 2‐MeC6H4, a; 4‐MeC6H4, b; 2‐MeOC6H4, c; 4‐MeOC6H4, d; 4‐CF3C6H4, e; 2,6‐Me2C6H3, f; 2‐iPrC6H4, g] and [Pd(κ2‐acac)(κ2‐NN′)][BF4] toward the nucleophilic reagent acetylacetonate (acac) has been explored. This reaction starts with nucleophilic attack on the cabonylic atom of the coordinated imine generating a new C–C bond and an amido complex. The next step in the reaction is proton migration leading to the protonation of the amido nitrogen, and finally replacement of this coordinated nitrogen atom with an anionic carbon atom. The final consequence of the nucleophilic attack on the coordinated imines is the formation of new complexes and the generation of new C–C and C–Pd bonds.
Synthesis of Aminophosphane Complexes: Searching the Boundary between Phosphanide and Phosphinidenoid Complex Chemistry
Authors: Duan Lili , Schnakenburg Gregor , Daniels Jörg , Streubel Rainer 
Published: March 2012

AbstractAminophosphane complexes 3a–e have been prepared by two different pathways: (1) the thermal reaction of 2H‐azaphosphirene complex 1 with primary or secondary amine derivatives at 75 °C (3a,b,d,e) or (2) the reaction of chlorophosphane complex 2 with sodium diphenylamide (3c). In the latter case, complex 3c was obtained together with the diphosphene complex 6, thus providing evidence for the transient formation of Na/X phosphinidenoid complexes 4a,b and/or the terminal phosphinidene complex 5. Preliminary deprotonation studies, carried out on complex 3a by using lithium diisopropylamide in TMEDA in the presence of 12‐crown‐4 at low temperature, yielded a mixture of the Li/NMe2 phosphinidenoid complex 7 together with the nonligated phosphane derivative 8, which could not be separated. Complexes 3a,b,d,e and 6 were characterized by NMR and IR spectroscopy, MS, and elemental analysis. The structures of complexes 3c–e and 6 were confirmed by single‐crystal X‐ray diffraction analysis.
Magnetoluminescent Agents for Dual MRI and Time‐Gated Fluorescence Imaging
Authors: Smolensky Eric D. , Zhou Yue , Pierre Valérie C. 
Published: March 2012

AbstractThe synthesis and properties of two luminescent iron oxide nanoparticles for dual imaging by MRI and time‐gated confocal microscopy are presented. These magnetoplasmonic agents consist of macrocyclic terbium complexes conjugated onto magnetite nanoparticles by a polyethylene glycol linker. Two macrocyclic terbium complexes were investigated: Tb‐DOTAm‐(Phen)3 and Tb‐DOTAm‐(acetylene)3. Both complexes display the characteristic long luminescence lifetimes of lanthanides (0.8 ms and 1.3 ms, respectively), rendering them ideal for time‐gated luminescence spectroscopy and confocal imaging – a feature currently unexplored in multimodal imaging agents. Additionally, the 5 ± 1 nm magnetite nanoparticles, with their permeable PEG coating and stable dopamide anchor, render the two constructs efficient MRI contrast agents with longitudinal (r1) and transverse (r2) relaxivities of 9.8 mM–1Fe s–1 and 98 mM–1Fe s–1 at 60 MHz and 37 °C.
High Regiocontrol in the Zinc‐Mediated Crotylation of Aldehydes and Ketones: A Straightforward and Facile Approach to Linear Homoallylic Alcohols in DMPU
Authors: Zhao Li‐Ming , Wan Li‐Jing , Jin Hai‐Shan , Zhang Shu‐Qing 
Published: March 2012

AbstractThe α‐regioselectivity of carbonyl crotylation is a long‐standing problem in the realm of C–C bond formation reactions. We demonstrate that zinc‐mediated crotylation of aldehydes and ketones can afford α‐linear homoallylic alcohols exclusively to provide a simple solution for this problem. In this context, we describe a method for the α‐regioselective crotylation of aldehydes and ketones by using an easily available starting material, such as crotyl bromide, zinc dust, and the less‐toxic solvent DMPU. The reaction has broad substrate scope and is highly efficient. Moreover, a metallo‐[3,5]‐sigmatropic rearrangement is proposed to account for the high α‐regioselectivity in the zinc‐mediated crotylation.
Sequential Suzuki/Asymmetric Aldol and Suzuki/Knoevenagel Reactions Under Aqueous Conditions
Authors: Gruttadauria Michelangelo , Bivona Lucia Anna , Lo Meo Paolo , Riela Serena , Noto Renato 
Published: March 2012

AbstractHere we describe for the first time a sequential Suzuki/asymmetric aldol reaction. Such sequential approach was achieved through the combined use of an ionic liquid supported palladium catalyst and the organocatalyst trans‐4‐(2,2‐diphenylacetoxy)proline. Suzuki and asymmetric aldol reactions were performed under aqueous conditions. The use of a palladium catalyst under basic conditions allowed also the first example of sequential Suzuki/Knoevenagel reaction. Reactions were carried out under aqueous conditions and products were isolated in good to high yields and, in the case of the Suzuki/aldol reaction, with diastereoselectivities up to 91:9 and enantioselectivities up to at least 99 %.
Basking in projected glory: The role of subjective temporal distance in future self‐appraisal
Authors: Wilson Anne E. , Buehler Roger , Lawford Heather , Schmidt Colin , Yong An Gie 
Published: March 2012

AbstractWe examined the role of subjective temporal distance in people's future self‐predictions. Consistent with temporal self‐appraisal theory, we hypothesized that people would be motivated to evaluate future selves more favorably when they felt closer in time, because subjectively close future selves have more direct implications for current identity than do subjectively distant future selves. Subjective temporal distance of a future self was manipulated, holding constant actual temporal distance. Participants predicted more favorable personal qualities (Study 1) at a future time that seemed close rather than distant. Supporting a self‐enhancement account, subjective distance effects were specific to appraisals of future self but not acquaintances (Study 2), and the link between subjective distance and future self‐appraisals was eliminated when participants satisfied their self‐image goals via a self‐affirmation exercise (Study 3). Study 4 provided evidence that subjectively close future selves influence current identity to a greater extent than do distant selves: Participants evaluated their current selves more positively when feeling close to, rather than distant from, a future success. Copyright © 2012 John Wiley & Sons, Ltd.