bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intramolecular Domino Electrophilic and Thermal Cyclization of peri‐Ethynylene Naphthalene Oligomers
Authors: Huang Xiaobo , Zeng Lintao , Zeng Zebing , Wu Jishan 
Published: December 2011

AbstractThe intramolecular electrophilic or thermal cyclization of arylene ethynylene precursors recently became a powerful method for the synthesis of new polycyclic aromatic hydrocarbons (PAHs). In this work, we investigated in detail the synthesis and intramolecular cyclization reaction of a series of peri‐ethynylene naphthalene oligomers in which the ethynylene units are fixed in close proximity within the naphthalene framework. The high reactivity of these precursors led to simultaneous thermal cyclization reactions, even during their syntheses. Electrophilic cyclizations with iodine were also undertaken. Several new PAHs containing five‐membered rings, for example, indeno[2,1‐a]phenalene, acenaphtho[1,2‐a]pyrene, and benzo‐ or naphtho‐annulated fluoranthene derivatives, were synthesized and their structures were unambiguously determined by X‐ray crystallographic analysis. Plausible mechanisms were proposed and it was demonstrated that oligomers most probably underwent intramolecular domino cyclization via either radical or cationic intermediates. The photophysical and electrochemical properties of these new PAHs were investigated and some of them displayed amphoteric redox behavior, due to the existence of five‐membered rings.
Stable N‐Heterocyclic Carbene (NHC)–Palladium(0) Complexes as Active Catalysts for Olefin Cyclopropanation Reactions with Ethyl Diazoacetate
Authors: Martín Carmen , Molina Francisco , Alvarez Eleuterio , Belderrain Tomás R. 
Published: December 2011

AbstractThe Pd0 complexes [(NHC)PdLn] (NHC=N‐heterocyclic carbene ligand; L=styrene for n=2 or PR3 for n=1) efficiently catalyse olefin cyclopropanation by using ethyl diazoacetate (EDA) as the carbene source with activities that improve on previously described catalytic systems based on this metal. Mechanistic studies have shown that all of these catalyst precursors deliver the same catalytic species in solution, that is, [(IPr)Pd(sty)], a 14e− unsaturated intermediate that further reacts with EDA to afford [(IPr)Pd(CHCO2Et)(sty)], from which the cyclopropane is formed.
Fully developed mixed convection of a binary fluid in a vertical porous channel
Authors: Alloui Z. , Vasseur P. 
Published: December 2011

AbstractThis paper reports an analytical and numerical study of mixed convection heat and mass transfer of a binary fluid in a vertical parallel plate channel filled with a porous medium. The thermal conditions applied on the walls of the system are uniform heat fluxes. Both the cases of double‐diffusion and Soret‐induced convection are considered. The governing equations for the porous medium rely on Darcy's model. The governing parameters for the problem are the Rayleigh number, Ra, Peclet number, Pe, Lewis number, Le, buoyancy ratio, φ, aspect ratio of the channel $A = L'/H'$ and the constant a (a = 0 for double diffusive convection and a = 1 for Soret induced convection). The resulting problem, in the limit of fully developed mixed convection, is solved analytically in closed form. A numerical solution of the full governing equations is demonstrated to be in good agreement with the analytical model. The temperature and velocity fields and the Nusselt and Sherwood numbers are obtained in terms of the governing parameters. The possible existence of reversed flows in the channel is discussed. © 2011 Canadian Society for Chemical Engineering
The isolation of poly(3‐hydroxybutyrate) from recombinant Escherichia coli XL1‐blue using the digestion method
Authors: Peng Yu‐Chiang , Lo Chi‐Wei , Wu Ho‐Shing 
Published: December 2011

AbstractThis study examines the isolation of poly(3‐hydroxybutyrate) (PHB) from recombinant Escherichia coli XL1‐blue pBHB2 OLD‐2 harbouring the PHB biosynthesis gene. Six types of commercial surfactants (Emal 10P, Emal AD‐25, Emal S PASTE, Neopelex S‐S, Triton X‐100 and cetyl trimethyl ammonium bromide (CTAB)) were screened for PHB isolation by solubilising non‐polymer cellular material (NPCM) in the cell. Emal 10P, Emal AD‐25, Emal S PASTE and Triton X‐100 are suitable surfactants for PHB isolation. Factors such as the reaction temperature, reaction time, ratio of NPCM/surfactant and pH were investigated to achieve optimum conditions. For 80% of the PHB content in dry cells, the purity and recovery of the obtained PHB was 98% and 99% when 0.67 of NPCM/Emal S PASTE was used at 70°C for 30 min. The cost of the used surfactant is below 0.5 USD/kg (PHB). The pretreatment and multistage digestion method must be combined when the PHB content is lower than 80%. © 2011 Canadian Society for Chemical Engineering
MicroRNA‐200b reverses chemoresistance of docetaxel‐resistant human lung adenocarcinoma cells by targeting E2F3
Authors: Feng Bing , Wang Rui , Song Hai‐Zhu , Chen Long‐Bang 
Published: December 2011

AbstractBACKGROUND:MicroRNAs (miRNAs) have been identified as important posttranscriptional regulators involved in various biological and pathological processes of cells, but their association with tumor chemoresistance has not been fully understood.METHODS:We detected miRNA‐200b (miR‐200b) expression in different lung adenocarcinoma cell lines and then focused on its roles in regulation of docetaxel chemoresistance. We also identified E2F3 as a novel target of miR‐200b.RESULTS:Based on miRNA microarray data, miR‐200b was identified as the most down‐regulated miRNA in docetaxel‐resistant SPC‐A1/DTX cells compared with parental SPC‐A1 cells. Ectopic miR‐200b expression reversed docetaxel chemoresistance of lung adenocarcinoma cells through cell proliferation inhibition, apoptosis enhancement, and G2/M cell cycle arrest. In a nude mouse xenograft model, up‐regulation of miR‐200b significantly enhanced response of SPC‐A1/DTX cells to docetaxel. Luciferase reporters containing the 3′ untranslated region sequence of E2F3 messenger RNA were used to demonstrate that miR‐200b could directly target E2F3. Small interfering RNA–mediated E2F3 knockdown revealed similar effects as that of ectopic miR‐200b expression. Decreased miR‐200b expression was also detected in tumor tissues sampled from lung adenocarcinoma patients treated with docetaxel‐based chemotherapy and was proved to be correlated with high expression of E2F3, decreased sensitivity to docetaxel, and poor prognosis.CONCLUSIONS:Our results suggest that down‐regulation of miR‐200b could lead to E2F3 overexpression and in turn contribute to chemoresistance of lung adenocarcinoma cells to docetaxel. Cancer 2011. © 2011 American Cancer Society.
Prospective assessment of outcomes in 411 patients treated with hyperbaric oxygen for chronic radiation tissue injury
Authors: Hampson Neil B. , Holm James R. , Wreford‐Brown Claude E. , Feldmeier John 
Published: December 2011

AbstractBACKGROUND:Although hyperbaric oxygen is used to treat chronic radiation tissue injury, clinical evidence supporting its efficacy has been limited to date. The authors report prospectively collected patient outcomes from a single center's large experience using hyperbaric oxygen to treat chronic radiation injury.METHODS:Since 2002, patient outcomes at the conclusion of a course of hyperbaric oxygen treatment for chronic radiation tissue injury at Virginia Mason Medical Center in Seattle have been graded by a board‐certified hyperbaric physician and prospectively recorded. From 2002 to 2010, a total of 525 patients received treatment for 1 of 6 forms of radionecrosis analyzed. After excluding 114 patients for incomplete records or treatment courses or for previous receipt of hyperbaric oxygen therapy, records of 411 patients were retrospectively reviewed in 2010, and outcomes were regraded by a second board‐certified physician. A positive clinical response was defined as an outcome graded as either “resolved” (90%‐100% improved) or “significantly improved” (50%‐89% improved).RESULTS:A positive outcome from hyperbaric treatment occurred in 94% of patients with osteoradionecrosis of the jaw (n = 43), 76% of patients with cutaneous radionecrosis that caused open wounds (n = 58), 82% of patients with laryngeal radionecrosis (n = 27), 89% of patients with radiation cystitis (n = 44), 63% of patients with gastrointestinal radionecrosis (n = 73), and 100% of patients who were treated in conjunction with oral surgery in a previously irradiated jaw (n = 166).CONCLUSIONS:The outcomes of 411 patients collected prospectively over 8 years strongly supported the efficacy of hyperbaric oxygen treatment for the 6 conditions evaluated. The response rates previously reported in numerous small series were supported by the responses achieved in this large, single‐center experience. Cancer 2012. © 2011 American Cancer Society.
Improved survival for BRCA2‐associated serous ovarian cancer compared with both BRCA‐negative and BRCA1‐associated serous ovarian cancer
Authors: Hyman David M. , Zhou Qin , Iasonos Alexia , Grisham Rachel N. , Arnold Angela G. , Phillips Mary F. , Bhatia Jasmine , Levine Douglas A. , Aghajanian Carol , Offit Kenneth , Barakat Richard R. , Spriggs David R. , Kauff Noah D. 
Published: December 2011

AbstractBACKGROUND:Multiple observational studies have suggested that breast cancer gene (BRCA)‐associated ovarian cancers have improved survival compared with BRCA‐negative ovarian cancers. However, most of those studies combined BRCA1 and BRCA2 patients or evaluated only BRCA1 patients. The objective of the current study was to examine whether BRCA1‐associated and BRCA2‐associated ovarian cancers were associated with different outcomes.METHODS:This was a single‐institution, retrospective analysis of patients who had a new diagnosis of histologically confirmed stage III or IV serous ovarian, fallopian tube, or primary peritoneal cancer between January 1, 1996 and February 1, 2011 and who underwent BRCA mutation testing on 1 of 2 institutional review board‐approved follow‐up studies. Patients who had been tested for BRCA mutations beyond 24 months of diagnosis were excluded from analysis to minimize selection bias from including patients who were referred for genetic testing because of long survival.RESULTS:Data from 190 patients (143 BRCA‐negative patients, 30 BRCA1‐positive patients, and 17 BRCA2‐positive patients) were analyzed. During the study period, 73 deaths were observed (60 BRCA‐negative patients, 10 BRCA1‐positive patients, 3 BRCA2‐positive patients). The median follow‐up for the remaining 117 survivors was 2.5 years. At 3 years, 69.4%, 90.7%, and 100% of BRCA‐negative patients, BRCA1‐positive patients, and BRCA2‐positive patients were alive, respectively. On univariate analysis, age, BRCA2 mutations, debulking status, and type of first‐line therapy (intravenous or intraperitoneal) were significant predictors of overall survival. On multivariate analysis, BRCA2 mutations (hazard ratio, 0.20; 95% confidence interval, 0.06‐0.65; P = .007), but not BRCA1 mutations (hazard ratio, 0.70; 95% confidence interval, 0.36‐1.38; P = .31), predicted for improved overall survival compared with BRCA‐negative patients. When carriers of BRCA2 mutations were directly compared with carriers of BRCA1 mutations, BRCA2 mutations appeared to confer improved overall survival (hazard ratio, 0.29; 95% confidence interval, 0.08‐1.05; P = .060), although this finding did not reach significance.CONCLUSIONS:The current data suggests that BRCA2 mutations confer an overall survival advantage compared with either being BRCA‐negative or having a BRCA1 mutation in high‐grade serous ovarian cancer. This finding may have important implications for clinical trial design. Cancer 2012. © 2011 American Cancer Society.
A phase 1 dose‐escalation study of ARRY‐520, a kinesin spindle protein inhibitor, in patients with advanced myeloid leukemias
Authors: Khoury Hanna Jean , Garcia‐Manero Guillermo , Borthakur Gautam , Kadia Tapan , Foudray Maria Cielo , Arellano Martha , Langston Amelia , Bethelmie‐Bryan Beverly , Rush Selena , Litwiler Kevin , Karan Sharon , Simmons Heidi , Marcus Adam I. , Ptaszynski Mieke , Kantarjian Hagop 
Published: December 2011

AbstractBACKGROUND:ARRY‐520 selectively inhibits the mitotic kinesin spindle protein (KSP), which leads to abnormal monopolar spindle formation and apoptosis.METHODS:A phase 1 trial was conducted to establish the safety and the maximum tolerated dose (MTD) of ARRY‐520 given as a 1‐hour infusion in either a single dose or on a day 1, 3, and 5 divided‐dose schedule per cycle in patients with advanced or refractory myeloid leukemias. Additional objectives were to characterize pharmacokinetics, assess preliminary clinical activity, and explore biomarkers of KSP inhibition with ARRY‐520. A total of 36 patients with acute myelogenous leukemia (n = 34) or myelodysplastic syndromes (n = 2) with a median age of 66 years (range, 21‐88 years) were enrolled: 15 in the single‐dose schedule (dose levels: 2.5, 3.75, 4.5, and 5.6 mg/m2) and 21 in the divided‐dose schedule (dose levels: 0.8, 1.2, 1.5, and 1.8 mg/m2/day).RESULTS:The MTD was 4.5 mg/m2 total dose per cycle for both dose schedules. Dose‐limiting toxicities included mucositis, exfoliative rash, hand‐foot syndrome, and hyperbilirubinemia. Grades 3 or 4 reversible drug‐related myelosuppression were observed in 33 of 36 patients. Plasma pharmacokinetic analyses revealed low clearance of ARRY‐520 (∼3 L/hour), a volume of distribution of ∼450 L, and a median terminal half‐life of >90 hours. Monopolar spindles were observed in blood mononuclear cells, through use of 4′,6‐diamidino‐2‐phenylindole nucleic acid stain and antitubulin antibodies.CONCLUSIONS:On the basis of the relative lack of clinical activity, further development of ARRY‐520 as an antileukemic agent was halted. (Clinicaltrials.gov identifier NCT00637052). Cancer 2012;3556–3564. © 2011 American Cancer Society.
Comparison between Two Anionic Reverse Micelle Interfaces: The Role of Water–Surfactant Interactions in Interfacial Properties
Authors: Quintana Silvina S. , Falcone R. Dario , Silber Juana J. , Correa N. Mariano 
Published: December 2011

AbstractThe water/sodium bis(2‐ethylhexyl) phosphate (NaDEHP) reverse micelle (RM) system is revisited by using, for the first time, molecular probes to investigate interface properties. The solvatochromic behavior of 1‐methyl‐8‐oxyquinolinium betaine (QB) and 6‐propionyl‐2‐(N,N‐dimethyl)aminonaphthalene (PRODAN) in the water/NaDEHP/toluene system is studied, and the results are compared with those obtained in water/sodium 1,4‐bis(2‐ethylhexyl) sulfosuccinate (AOT)/toluene RM media. The results demonstrate that the micropolarity, microviscosity, interfacial water structure, molecular probe partition, and intramolecular electron‐transfer processes are dramatically altered for NaDEHP RM interfaces in comparison to the AOT systems. Because of organic nonpolar solvent penetration into the interface, NaDEHP RM media offer an interface with lower micropolarity and microviscosity than AOT media. Also, the interfacial water in the NaDEHP system shows enhanced water–water hydrogen‐bond interaction in comparison with bulk water. The AOT RM interface represents a unique environment for PRODAN to undergo dual emission.
Effect of copper (II) ion against elongation behavior of amyloid β fibrils on liposome membranes
Authors: Shimanouchi T. , Onishi R. , Kitaura N. , Umakoshi H. , Kuboi R. 
Published: December 2011

AbstractThe fibril growth behavior of amyloid β protein (Aβ) on cell membranes is relating to the progression of Alzheimer's disease. This growth behavior of Aβ fibrils is sensitively affected by the metal ions, neurotransmitters, or bioreactive substrate. The inhibitory effect of those materials was quantitatively estimated from the viewpoints of “crystal growth”. In a bulk aqueous solution, copper (II) ion showed the strong inhibitory effect on the growth of Aβ fibrils. Meanwhile, the addition of a closed‐phospholipid bilayer membrane (liposome) could reduce the above inhibitory effect of copper (II) ion. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chiral symmetry breaking in unstirred crystallization
Authors: Szurgot M. 
Published: December 2011

AbstractStatistics of nucleation of chiral forms of sodium bromate from unstirred aqueous solutions was studied. It was established that bimodal, trimodal and unimodal distributions of enantiomers are obtained in unstirred crystallization. It was also found out that probabilities of the creation of L or D crystals and racemates R, as well as the presence of D, L, and R peaks in distributions depend on crystallizer size, supersaturation and temperature. Nucleation at low supersaturations in small, closed crystallizers leads to the formation of pure enantiomers, and to bimodal distributions with D and L peaks at any temperature. At high supersaturations in large, open crystallizers the formation of racemates and unimodal distributions with racemate R peaks results. In open crystallizers at the lowest temperatures and at the highest temperatures used in crystallization from aqueous solution racemates of sodium bromate are preferentially formed, but in a wide range of intermediate‐temperatures apart from racemates, pure enantiomers are efficiently formed which leads to trimodal distributions. The spontaneous formation of pure enantiomers in crystallization from unstirred, unseeded solutions is caused by the chiral symmetry breaking phenomenon, the same as that discovered in stirred crystallization. The conservation of chiral symmetry is, in unstirred crystallization, one of the two possibilities, and the other one is the breakage of symmetry. Both of them occur in nature. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prilezhaev Dihydroxylation of Olefins in a Continuous Flow Process
Authors: van den Broek Bas A. M. W. , Becker René , Kössl Florian , Delville Mariëlle M. E. , Nieuwland Pieter J. , Koch Kaspar , Rutjes Floris P. J. T. 
Published: December 2011

AbstractEpoxidation of both terminal and non‐terminal olefins with peroxy acids is a well‐established and powerful tool in a wide variety of chemical processes. In an additional step, the epoxide can be readily converted into the corresponding trans‐diol. Batch‐wise scale‐up, however, is often troublesome because of the thermal instability and explosive character of the peroxy acids involved. This article describes the design and semi‐automated optimization of a continuous flow process and subsequent scale‐up to preparative production volumes in an intrinsically safe manner.
Phenotypic covariance structure and its divergence for acoustic mate attraction signals among four cricket species
Authors: Bertram Susan M. , Fitzsimmons Lauren P. , McAuley Emily M. , Rundle Howard D. , Gorelick Root 
Published: December 2011

AbstractThe phenotypic variance–covariance matrix (P) describes the multivariate distribution of a population in phenotypic space, providing direct insight into the appropriateness of measured traits within the context of multicollinearity (i.e., do they describe any significant variance that is independent of other traits), and whether trait covariances restrict the combinations of phenotypes available to selection. Given the importance of P, it is therefore surprising that phenotypic covariances are seldom jointly analyzed and that the dimensionality of P has rarely been investigated in a rigorous statistical framework. Here, we used a repeated measures approach to quantify P separately for populations of four cricket species using seven acoustic signaling traits thought to enhance mate attraction. P was of full or almost full dimensionality in all four species, indicating that all traits conveyed some information that was independent of the other traits, and that phenotypic trait covariances do not constrain the combinations of signaling traits available to selection. P also differed significantly among species, although the dominant axis of phenotypic variation (p
max) was largely shared among three of the species (Acheta domesticus, Gryllus assimilis, G. texensis), but different in the fourth (G. veletis). In G. veletis and A. domesticus, but not G. assimilis and G. texensis, p
max was correlated with body size, while p
max was not correlated with residual mass (a condition measure) in any of the species. This study reveals the importance of jointly analyzing phenotypic traits.
Northern refugia and recent expansion in the North Sea: the case of the wrasse Symphodus melops (Linnaeus, 1758)
Authors: Robalo Joana I. , Castilho Rita , Francisco Sara M. , Almada Frederico , Knutsen Halvor , Jorde Per E. , Pereira Ana M. , Almada Vitor C. 
Published: December 2011

AbstractPleistocene climate changes have imposed extreme conditions to intertidal rocky marine communities, forcing many species to significant range shifts in their geographical distributions. Phylogeographic analyses based on both mitochondrial and nuclear genetic markers provide a useful approach to unravel phylogeographic patterns and processes of species after this time period, to gain general knowledge of how climatic changes affect shifts in species distributions. We analyzed these patterns on the corkwing wrasse (Symphodus melops, Labridae), a rocky shore species inhabiting North Sea waters and temperate northeastern Atlantic Ocean from Norway to Morocco including the Azores, using a fragment of the mitochondrial control region and the first intron of the nuclear S7 ribosomal protein gene. We found that S. melops shows a clear differentiation between the Atlantic and the Scandinavian populations and a sharp contrast in the genetic diversity, high in the south and low in the north. Within each of these main geographic areas there is little or no genetic differentiation. The species may have persisted throughout the last glacial maximum in the southern areas as paleotemperatures were not lower than they are today in North Scandinavia. The North Sea recolonization most likely took place during the current interglacial and is dominated by a haplotype absent from the south of the study area, but present in Plymouth and Belfast. The possibility of a glacial refugium in or near the English Channel is discussed.
Synthesis of Triazole‐Epothilones by Using Cu2O Nanoparticles to Catalyze 1,3‐Dipolar Cycloaddition
Authors: Duan Xiyan , Zhang Yan , Ding Yahui , Lin Jianping , Kong Xianglei , Zhang Quan , Dong Changming , Luo Guoan , Chen Yue 
Published: December 2011

AbstractWe report the total synthesis of a triazole‐epothilone analogue 1. The key step to generate the macrocyclic ring and the triazole ring was to apply Cu2O nanoparticles (Cu2O‐NPs) to catalyze the 1,3‐dipolar cycloaddition. The conformation of 1 and its bioactivity in MCF cancer cell lines were investigated.
A Cyclobutene‐1,2‐bis(imidazolium) Salt as Preligand for Palladium‐Catalyzed Cross‐Coupling Reactions: Properties and Applications
Authors: Rahimi Alireza , Pápai Imre , Madarász Ádám , Gjikaj Mimoza , Namyslo Jan C. , Schmidt Andreas 
Published: December 2011

AbstractSpectroscopic investigations and the results of calculations on the title bis‐imidazolium salt, its mono‐ and bis‐carbenes, and its interactions with palladium are presented. In addition, we report on the scope and limitations of metal‐catalyzed cross‐coupling reactions performed with the title bis‐imidazolium salt. The salt proved to be an efficient ligand precursor in room‐temperature Suzuki–Miyaura reactions, C–C couplings with sterically extremely hindered biaryls,selective thiophene arylations, and couplings with vinylic chlorides.