bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Synthesis of Indolylquinolines, Indolylacridines, and Indolylcyclopenta[b]quinolines from the Baylis—Hillman Adducts: An in situ [1,3]‐Sigmatropic Rearrangement of an Indole Nucleus to Access Indolylacridines and Indolylcyclopenta[b]quinolines.
Authors: Ramesh Chintakunta , Lei Po‐Min , Janreddy Donala , Kavala Veerababurao , Kuo Chun‐Wei , Yao Ching‐Fa 
Published: February 2013

AbstractThe coupling of cyclic Baylis—Hillman adducts like (I), (V), and (X) with indoles is found to result in formation of α‐ or γ‐heteroarylated products depending on the nature of educts.
ChemInform Abstract: Highly Regioselective and Practical Synthesis of 1‐Acyl‐5‐hydroxypyrazolines and 1‐Acyl Pyrazoles from 1,2‐Allenic Ketones and Hydrazides.
Authors: Guo Shenghai , Wang Jiliang , Guo Dongqiang , Zhang Xinying , Fan Xuesen 
Published: February 2013

AbstractCondensation of allenic ketones (I) with hydrazides results in the formation of hydroxypyrazolines which can be easily converted into the corresponding pyrazoles by dehydration with BF3·Et2O.
ChemInform Abstract: Nitroimidazoles. Part 8. Synthesis and anti‐HIV Activity of New 4‐Nitroimidazole Derivatives Using the Suzuki Cross‐Coupling Reaction.
Authors: Al‐Soud Yaseen A. , Al‐Masoudi Najim A. , Al‐Suod Hossam H. , Pannecouque Christophe 
Published: February 2013

AbstractAmong the newly synthesized compounds, only derivative (Va) inhibits HIV‐1 and HIV‐2 replication.
ChemInform Abstract: Novel Synthesis and Antimicrobial Activity of 3‐Substituted 5‐Bromo‐7‐methyl‐1,2,4‐triazolo‐[3,4‐b]‐benzothiazoles.
Authors: Bhagat T. M. , Deshmukh S. K. , Kuberkar S. V. 
Published: February 2013

AbstractAll new compounds (VI), (VIII), (X) and (XIII) are tested for their antimicrobial activities.
ChemInform Abstract: Efficient and Rapid Synthesis of Highly Functionalized Novel Symmetric 1,4‐Dihydropyridines Using Glacial Acetic Acid as Solvent.
Authors: Thakrar Shailesh , Bavishi Abhay , Bhavsar Dhairya , Parekh Shrey , Vala Hardev , Radadiya Ashish , Parmar Manisha , Savant Mahesh , Shah Anamik 
Published: February 2013

AbstractNovel 1,4‐dihydropyridines (III) (14 examples) bearing a pyrazole moiety in 4‐position are prepared by a variation of the classical Hantzsch synthesis.
ChemInform Abstract: Iridium‐Catalyzed Oxidant‐Free Dehydrogenative C—H Bond Functionalization: Selective Preparation of N‐Arylpiperidines Through Tandem Hydrogen Transfers.
Authors: Yuan Kedong , Jiang Fan , Sahli Zeyneb , Achard Mathieu , Roisnel Thierry , Bruneau Christian 
Published: February 2013

AbstractStarting from easily accessible anilines, diols, and aldehydes, the piperidines are prepared by an atom‐economical method which is also compatible with the use of diethyl carbonate as an ecofriendly solvent.
ChemInform Abstract: A Simple Efficient Sequential One‐Pot Intermolecular Aza‐Michael Addition and Intramolecular Buchwald—Hartwig α‐Arylation of Amines: Synthesis of Functionalized Tetrahydroisoquinolines.
Authors: Reddy Alavala Gopi Krishna , Satyanarayana Gedu 
Published: February 2013

AbstractTetrahydroisoquinolines (IV) are efficiently synthesized from amines (I) via intermediate β‐aminoesters (III) which are not isolated but directly subjected to Pd‐catalyzed α‐arylation.
ChemInform Abstract: Catalysis by Lithium Perchlorate Enables Double‐Conjugate Addition of Electron‐Deficient Maleimides to 2‐Aminopyridines and 2‐Aminothiazoles.
Authors: Matviiuk Tetiana , Gorichko Marian , Kysil Andriy , Shishkina Svitlana , Shishkin Oleg , Voitenko Zoia 
Published: February 2013

AbstractLithium perchlorate is found to catalyze the conjugate addition of maleimides (II) to 2‐aminopyridines or 2‐aminothiazoles.
ChemInform Abstract: Facile Synthesis of 5‐Amino‐ and 7‐Amino‐6‐azaoxindole Derivatives.
Authors: Tzvetkov Nikolay T. , Mueller Christa E. 
Published: February 2013

AbstractThe synthesis of the title compounds, substructures of natural products and medicinal agents, starts with commercially available 2‐amino‐4‐chloropyridine (I).
ChemInform Abstract: Cyclobutene Ring‐Opening of Bicyclo[4.2.0]octa‐1,6‐dienes: Access to CF3‐Substituted 5,6,7,8‐Tetrahydro‐1,7‐naphthyridines.
Authors: Mailyan Artur K. , Peregudov Alexander S. , Dixneuf Pierre H. , Bruneau Christian , Osipov Sergey N. 
Published: February 2013

AbstractRegioselective ring opening of bicyclo[4.2.0]octadienes followed by intramolecular cyclization of resulting diketones of type (III)/(VI) allows an efficient access to biologically important tetrahydro‐1,7‐naphthyridines.
ChemInform Abstract: Ecofriendly Synthesis of Tetrahydropyrimidine Derivatives in Aqueous Medium under Ultrasonic Irradiation.
Authors: Rao Valasani Koteswara , Babu Boppudi Hari , Babu Kilaru Raveendra , Srinivasulu Doddaga , Raju Chamarthi Naga 
Published: February 2013

AbstractA simple, efficient, and ecofriendly procedure for the synthesis of tetrahydropyrimidines (III) is given.
Long telomeres in peripheral blood leukocytes are associated with an increased risk of soft tissue sarcoma
Authors: Xie Hui , Wu Xifeng , Wang Shui , Chang David , Pollock Raphael E. , Lev Dina , Gu Jian 
Published: February 2013

AbstractBACKGROUND:Human telomeres consisting of long, tandem repeats of the nucleotide sequence TTAGGG at the chromosome ends are essential for maintaining chromosomal stability. Previous epidemiologic studies have indicated that shorter telomere length in peripheral blood leukocytes (PBLs) is associated with the development of many cancers. However, the relation between PBL telomere length and the risk of soft tissue sarcoma (STS) has not been investigated.METHODS:The relative telomere length (RTL) was determined in PBLs using real‐time polymerase chain reaction in this case‐control study. The study participants included 137 patients with histologically confirmed STS (cases) who had received no prior chemotherapy or radiotherapy and 137 healthy controls who were frequency‐matched to cases on age, sex, and ethnicity.RESULTS:Patients in the case group had significantly longer RTL than controls (1.46 ± 0.42 for cases vs 1.15 ± 0.39 for controls; P < .001). By using median RTL in the controls as a cutoff level, individuals who had long telomere length were associated with a significantly increased risk of STS compared with those who had short telomere length (adjusted odds ratio, 4.71; 95% confidence interval, 2.63‐8.44). When participants were categorized further into 3 or 4 groups according to the tertile or quartile RTL values of healthy controls, a significant dose‐response relation was observed between longer RTL and increased risks of STS.CONCLUSIONS:The current results provided the first epidemiologic evidence that longer telomere length in PBLs is associated significantly with an increased risk of STS, potentially suggesting an important role for telomere maintenance in STS development. Cancer 2013. © 2013 American Cancer Society.
Water‐Soluble Phosphanes Derived from 1,3,5‐Triaza‐7‐phosphaadamantane and Their Reactivity towards Gold(I) Complexes
Authors: García‐Moreno Elena , Cerrada Elena , Bolsa M. José , Luquin Asunción , Laguna Mariano 
Published: February 2013

AbstractNew water‐soluble phosphanes derived from 1,3,5‐triaza‐7‐phosphaadamantane, namely, [PTA–R]Br (R = –CH2C≡CH, –CH2CONH2, –CH2COOH), are described. Coordination of these phosphanes and their previously reported counterparts (R = –CH2CN, –CH2Ph and –CH2COOMe) to gold(I) salts gives water‐soluble derivatives with chlorido, bromido or pentafluorophenyl coligands. The luminescence properties of all new compounds have been studied in the solid state and compared with the respective free PTA ligands. [PTA–CH2Ph]Br, [PTA–CH2COOMe]Br and [AuBr(PTA–CH2Ph)]Br have also been characterised by X‐ray diffraction analysis. Some of the new gold(I) compounds exhibit strong antiproliferative effects in the human ovarian carcinoma cell line A2780 and its cisplatin‐resistant variant (A2780cisR). A balanced relationship between lipophilicity and hydrophilicity is found in these derivatives, with distribution coefficients (log D7.4) that range from 0.14 to –0.40.
Synthesis of N‐Alkenylpurines by Rearrangements of the Corresponding N‐Allyl Isomers: Scopes and Limitations
Authors: Kania Jindrich , Gundersen Lise‐Lotte 
Published: February 2013

AbstractN‐9‐ and N‐7‐alkenylpurines have been synthesized by rearrangement of the corresponding N‐allyl derivatives, often in good yields and with high stereoselectivity. Base promoted and transition metal mediated rearrangements have been studied. Simple allylpurines were easily rearranged with catalytic amounts of RuClH(CO)(PPh3)3. The efficiency of base promoted rearrangement was highly dependent on the detailed structure of the starting material, but this reaction often occurred with surprisingly high Z‐selectivity.
Re‐evaluating genetic models for porphyry Mo mineralization at Questa, New Mexico: Implications for ore deposition following silicic ignimbrite eruption
Authors: Rosera Joshua M. , Coleman Drew S. , Stein Holly J. 
Published: February 2013

AbstractThe Questa porphyry Mo deposit in New Mexico provides a unique opportunity to study the relationship between pluton assembly and mineralization in a long‐lived volcanic field. Magmatism along the caldera margin initiated at ~ 25.20 Ma and continued for ~ 770 ka. During this time, the emplacement of mineralizing intrusions progressed westward and culminated in the assembly of the Questa Mo deposit between 24.76 Ma and 24.50 Ma. Molybdenite Re/Os geochronology shows that mineralization occurred in multiple pulses without thermal resetting of the chronometer. Because most of the molybdenite samples used in this study are from previous fluid inclusion studies, we treat Re/Os molybdenite as a new thermochronometer. Molybdenite Re/Os ages are integrated with zircon U/Pb ages to evaluate the cooling histories within the Mo deposit. This study suggests that individual cycles of magma emplacement and mineralization cooled rapidly. In contrast to prior genetic models for the Questa Mo deposit, these data show that the mineralizing intrusions were generated via rapid melt generation, separation, and intrusion into the shallow crust without involvement in a long‐lived magma chamber. It is proposed that the anomalously high magma flux event associated with ignimbrite eruption transferred materials (Mo, volatiles) from the upper mantle necessary for immediately subsequent mineralization. Partial melting and scavenging within a deep‐crustal hybridized zone generated Mo‐rich magma that ascended to form the Questa deposit. Moreover, this hypothesis predicts an important connection between caldera‐forming systems and porphyry‐style mineralization that could be incorporated into future exploration models.
An adaptive dynamic combined energy minimization model for few‐view computed tomography reconstruction
Authors: Feng Jun , Zhang Jian‐Zhou 
Published: February 2013

AbstractRecently, the potential harm of electromagnetic radiation used in computed tomography (CT) scanning has been paid much attention to. This makes the few‐view CT reconstruction become an important issue in medical imaging. In this article, an adaptive dynamic combined energy minimization model is proposed for few‐view CT reconstruction based on the compress sensing theory. The L2 energy of the image gradient and the total variation (TV) energy are combined, and the working regions of them are separated adaptively with a dynamic threshold. With the proposed model, the TV model's disadvantageous tendency of uniformly penalize the image gradient irrespective of the underlying image structures is overcome. Numerical experiments of the proposed model are performed with various insufficient data problems in fan‐beam CT and suggest that both the reconstruction speed and quality of the results are generally improved. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 44–52, 2013.
Linearity condition for orbital energies in density functional theory (III): Benchmark of total energies
Authors: Imamura Yutaka , Kobayashi Rie , Nakai Hiromi 
Published: February 2013

AbstractThis study presents a numerical assessment of total energy related physical quantities estimated using the orbital‐specific (OS) global and range‐separated hybrid functionals, designed to satisfy the linearity condition for orbital energies (LCOE). The numerical assessment demonstrates that accurate evaluation of the reaction energies, reaction barrier, and dissociation curve can be achieved via the OS hybrid functional, for systems in which self‐interaction is expected to be dominant. Therefore, the LCOE offers an accurate description of orbital energies as well as total energies for self‐interaction dominant systems. © 2013 Wiley Periodicals, Inc.
Enantioselective liquid–liquid extraction of (D, L)‐valine using metal–BINAP complex as chiral extractant
Authors: Tang Kewen , Fu Tao , Zhang Panliang 
Published: February 2013

AbstractBackgroundEnantioselective liquid–liquid extraction is a very attractive technology for the production of enantiomerically pure compounds. The objective of this research is to investigate enantioselective liquid–liquid extraction of valine (Val) enantiomers with metal–BINAP complexes as enantioselective extractants.ResultsResults show that BINAP complex with copper(I) as central ion allows the separation of Val enantiomers with the highest operational selectivity. Efficiency of the extraction depends, often strongly, on a number of process variables, including types of organic solvents, pH of the aqueous phase, concentration of host and substrate, and temperature. Extraction performance of the system can be accurately predicted by the model. By modeling and experiment, an optimal extraction condition was obtained at a pH of 8 and the host concentration of 2.0 × 10‐3 mol L‐1 with the highest enantioselective (α) of 3.65 and performance factor (pf) of 0.086.ConclusionsThe presented data indicate that Val enantiomers can be efficiently separated by enantioselective liquid–liquid extraction. The model provides a powerful tool for calculating distribution ratio, enantioselectivity, enantiomeric excess and performance factor. It can be used for optimization of the reactive extraction systems. This paper can provide some valuable fundamental data for the production of enantiomerically pure amino acid enantiomers. © 2013 Society of Chemical Industry
THE EFFECTS OF RESPONSE‐COST PUNISHMENT ON INSTRUCTIONAL CONTROL DURING A CHOICE TASK
Authors: Fox Adam E. , Pietras Cynthia J. 
Published: February 2013

AbstractThe present study investigated the effects of punishing responses inconsistent with rules on instructional control during a choice task. In a procedure modeled after Hackenberg and Joker (1994), 7 adults were presented with repeated choices between progressive‐ and fixed‐time schedules of reinforcement and were given instructions (rules) for how to respond to maximize earnings. Across sessions, the progressive‐time schedule step size was manipulated so that the instructions became increasingly inaccurate, and deviating from the instructions produced greater earnings. The experiment consisted of two phases, Penalty and No Penalty. During the Penalty phase, deviating from the instructions produced a money‐loss penalty (response‐cost punishment). Two participants showed persistent instructional control and therefore completed only one phase (Penalty or No Penalty), and 1 participant showed little instructional control during the Penalty phase until the punishment magnitude was increased. In all 4 participants who experienced both Penalty and No Penalty phases, punishment increased the consistency of choices with the instructions, and in 2 of these participants punishment increased the progressive‐schedule step size at which choices began to systematically deviate from the instructions. These results show that monetary penalties for breaking with rules may enhance instructional control, but that deviations from rules still occur under punishment when such deviations produce greater reinforcement than rule following.
Ultrastructure of neurosecretory granule exocytosis by crayfish sinus gland induced with ionic manipulations
Authors: David ANDREW R. , Shivers Richard R. 
Published: February 2013

AbstractNeurosecretory granule exocytosis from axon terminals in the crayfish (Orconectes virilis) sinus gland can be effected by alterations in intracellular ionic concentrations through modification of the bathing medium or by electrical stimulation. This may result in increased numbers of exocytotic profiles involving one granule (single exocytosis) or several granules (compound exocytosis), which we interpret as evidence of stimulated neurosecretion. Our results suggest that increased free intracellular Ca++ together with a decrease in intracellular K+ are prerequisite for and sufficient to elicit increased exocytosis from sinus gland terminals. Similar release, stimulated by horseradish peroxidase, indicates that local surface permeability changes are involved. A minor response to high‐K+‐Ringer, and secretion via compound exocytosis, are uncharacteristic of cells with a neural ancestry.
Incorporating endorectal MR elastography into multi‐parametric MRI for prostate cancer imaging: Initial feasibility in volunteers
Authors: Arani Arvin , Da Rosa Michael , Ramsay Elizabeth , Plewes Don B. , Haider Masoom A. , Chopra Rajiv 
Published: February 2013

PurposeTo investigate the tolerability and technical feasibility of performing endorectal MR elastography (eMRE) in human volunteers within the representative age group commonly affected by prostate cancer.Materials and MethodsEndorectal MRE was conducted on seven volunteers in a 1.5 Tesla (T) MR imager using a rigid endorectal coil. Another five volunteers were imaged on a 3T MR imager using an inflatable balloon type endorectal coil. Tolerability was accessed for vibration amplitudes of ±1–50 μm and for frequencies of 100–300 Hz.ResultsAll 12 volunteers tolerated the displacements necessary to successfully perform eMRE. Shear waves with frequencies up to 300 Hz could propagate across the entire prostate using both coil designs.ConclusionThe results of this study motivate further investigation of eMRE in prostate cancer patients to help determine if there is an added value of integrating eMRE into existing multi‐parametric prostate MRI exams. J. Magn. Reson. Imaging 2013;38:1251–1260. © 2013 Wiley Periodicals, Inc.
Serologic evidence of avian influenza virus infections among Nigerian agricultural workers
Authors: Okoye John , Eze Didacus , Krueger Whitney S. , Heil Gary L. , Friary John A. , Gray Gregory C. 
Published: February 2013

AbstractNigeria has had multiple incursions of highly pathogenic avian influenza A (HPAI) H5N1 virus into its poultry population since 2006. This study aimed to determine if Nigerians exposed to poultry had evidence of avian influenza virus transmission to man. Between 2008 and 2010, 316 adult farmers and open market workers and 54 age‐group matched, non‐animal exposed controls were enrolled in a prospective, population‐based study of zoonotic influenza transmission in four towns in southeastern Nigeria. Questionnaire data and sera obtained at the time of enrollment were examined for evidence of previous infection with 10 avian influenza virus strains. Serologic studies on sera collected at the time of enrollment showed modest evidence of previous infection with three avian‐origin influenza viruses (H5N1, H5N2, and H11N1) and one avian‐like H9N2 influenza virus, with eight (2.4%) of animal‐exposed subjects and two (3.7%) unexposed subjects having elevated microneutralization assay antibody titer levels (ranging from 1:10 to 1:80). Statistical analyses did not identify specific risk factors associated with the elevated antibody titers observed for these zoonotic influenza viruses. These data suggested only occasional virus transmission to humans in areas thought to have been enzootic for avian influenza virus. Prospective data from this cohort will help the authors to better understand the occurrence of zoonotic infections due to avian influenza viruses in Nigeria. J. Med. Virol. 85:670–676, 2013. © 2013 Wiley Periodicals, Inc.
SIRT1 regulates the neurogenic potential of neural precursors in the adult subventricular zone and hippocampus
Authors: Saharan Sumiti , Jhaveri Dhanisha J. , Bartlett Perry F. 
Published: February 2013

AbstractWithin the two neurogenic niches of the adult mammalian brain, i.e., the subventricular zone lining the lateral ventricle and the subgranular zone of the hippocampus, there exist distinct populations of proliferating neural precursor cells that differentiate to generate new neurons. Numerous studies have suggested that epigenetic regulation by histone‐modifying proteins is important in guiding precursor differentiation during development; however, the role of these proteins in regulating neural precursor activity in the adult neurogenic niches remains poorly understood. Here we examine the role of an NAD+‐dependent histone deacetylase, SIRT1, in modulating the neurogenic potential of neural precursors in the neurogenic niches of the adult mouse brain. We show that SIRT1 is expressed by proliferating adult subventricular zone and hippocampal neural precursors, although its transcript and protein levels are dramatically reduced during neural precursor differentiation. Utilizing a lentiviral‐mediated delivery strategy, we demonstrate that abrogation of SIRT1 signaling by RNAi does not affect neural precursor numbers or their proliferation. However, SIRT1 knock down results in a significant increase in neuronal production in both the subventricular zone and the hippocampus. In contrast, enhancing SIRT1 signaling either through lentiviral‐mediated SIRT1 overexpression or through use of the SIRT1 chemical activator Resveratrol prevents adult neural precursors from differentiating into neurons. Importantly, knock down of SIRT1 in hippocampal precursors in vivo, either through RNAi or through genetic ablation, promotes their neurogenic potential. These findings highlight SIRT1 signaling as a negative regulator of neuronal differentiation of adult subventricular zone and hippocampal neural precursors. © 2013 Wiley Periodicals, Inc.
Stimulation of phenolic metabolism by silicon contributes to rice resistance to sheath blight
Authors: Zhang Guoliang , Cui Yixiang , Ding Xiuwen , Dai Qigen 
Published: February 2013

AbstractSheath blight caused by Rhizoctonia solani is a major disease of rice worldwide. Silicon (Si) can enhance rice resistance to sheath blight, but the relation with phenolic metabolism is poorly known. Two rice cultivars with different levels of resistance to R. solani (resistant Teqing and susceptible Ningjing 1) were studied to determine the effects of Si on disease intensity (rated from 0 to 9) and the involvement of phenolic compounds in disease resistance. Variation in the concentrations of phenolics (including total soluble phenolics, flavonoids, and lignin) and in the activities of defense‐related enzymes polyphenoloxidase (PPO) and phenylalanine ammonia‐lyase (PAL) in rice leaf sheaths was investigated. The results show that Si application reduced sheath‐blight disease ratings of Ningjing 1 and Teqing by 2.96 and 0.65, respectively. In uninoculated plants, Si application alone had no significant effects on the concentrations of phenolic compounds or on the activities of PPO and PAL. In inoculated plants, Si application increased phenolics concentrations and PPO and PAL activities only in the susceptible cultivar Ningjing 1. We conclude that Si‐induced enhancement of phenolic metabolism contributed to the improved resistance of rice to sheath blight in the sensitive cultivar.