bluuebunny/crossref_metadata_2025_split huggingface dataset:
Female “dispersal” in hamadryas baboons: Transfer among social units in a multilevel society
Authors: Swedell Larissa , Saunders Julian , Schreier Amy , Davis Brittany , Tesfaye Teklu , Pines Mathew 
Published: April 2011

AbstractUnlike most cercopithecines, hamadryas baboons (Papio hamadryas hamadryas) are characterized by female‐biased dispersal. To clarify this pattern within the context of their hierarchical social system (comprising one‐male units, clans, bands, and troops), we report here 7 years of data on female transfers among social units in wild hamadryas baboons in Ethiopia. Female tenure in one‐male units (OMUs) ranged from 1 to 2,556 days (N= 208) and survival analysis revealed a median tenure length of 1,217 days (40 months). Changes in OMU membership consisted almost exclusively of takeovers by males, not voluntary transfer. Of 130 takeovers, 67% occurred within the band and 33% across bands, and, of the 22 takeovers for which we have clan membership data, 77% occurred within, not between, clans. These results reinforce the notion that hamadryas female dispersal is not analogous to sex‐biased dispersal in other taxa, because (1) at least in Ethiopian populations, females do not disperse voluntarily but are transferred, often forcibly, by males; (2) only dispersal between bands will promote gene flow, whereas females are most often rearrangedwithinbands; (3) hamadryas females undergo social dispersal but not usually locational dispersal; and (4) while male hamadryas are far more philopatric than females, they have been observed to disperse. It thus appears that the ancestral baboon pattern of female philopatry and male dispersal has evolved into a system in which neither sex is motivated to disperse, but females are forcibly transferred by males, leading to female‐mediated gene flow, and males more rarely disperse to find females. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
An LC‐ESI‐MS method for the quantitative analysis of bile acids composition in fecal materials
Authors: Cai Xiaohan , Liu Yiding , Zhou Xiang , Navaneethan Udayakumar , Shen Bo , Guo Baochuan 
Published: April 2011

ABSTRACTIn this work, a liquid chromatography coupled with electrospray ionization mass spectrometry (LC‐ESI‐MS) method was developed and validated for quantification of bile acids in fecal materials. Co‐eluting matrix impurities in fecal materials have been shown to greatly suppress the ionization of analytes in mass spectrometry, which is known as the matrix effect. To correct large quantitative errors caused by the matrix effect, we developed a scheme that combined the standard addition method with internal standard (SA‐IS). The fecal sample pretreatment involved a single step of extraction with ethanol. Bile acids were separated using a Luna C18 column (150 mm, 2 mm i.d., 5 µm) with gradient elution. The deprotonated analytes were detected in selective ion monitoring mode. Our results showed that, by using this method, the accuracy of quantification was significantly improved in comparison to the conventional internal standard method. The linearity, sensitivity, accuracy and precision of the method were within the range of 0.05–5 µmol/L. This SA‐IS method was successfully applied to the analysis of bile acids in the samples collected from patients diagnosed with inflammatory bowel disease. Copyright © 2011 John Wiley & Sons, Ltd.
Squaric Acid Monoamide Mannosides as Ligands for the Bacterial Lectin FimH: Covalent Inhibition or Not?
Authors: Grabosch Carsten , Hartmann Mirja , Schmidt‐Lassen Jörn , Lindhorst Thisbe K. 
Published: April 2011

AbstractBacteria use long proteinaceous appendages, called fimbriae or pili, to adhere to the surfaces of their host cells. Widely distributed among the Enterobacteriacae are type 1 fimbriae that mediate mannose‐specific bacterial adhesion through the lectin FimH, located at the fimbrial tips. It is possible to design synthetic mannosides such that they show high affinity for FimH and can thus inhibit mannose‐specific bacterial adhesion in a competitive manner. It has been found that mannosidic squaric acid monoamides serve especially well as inhibitors of type 1 fimbriae‐mediated bacterial adhesion, but it has remained unclear whether this effect is due to specific inhibition of the bacterial lectin FimH or to unspecific bioconjugation between the lectin's carbohydrate binding site and a squaric acid monoamide. A bioconjugation reaction would result in a covalently crosslinked squaric acid diamide. Here it is shown that covalent inhibition of FimH by mannosidic squaric acid derivatives is very unlikely and that compounds of this type serve rather as excellent specific candidates for low‐molecular‐weight inhibitors of bacterial adhesion. This has been verified by testing the properties of glycosidic squaric acid monoamides in diamide formation, by two different adhesion assays with a series of selected control compounds, and by molecular docking studies that further support the results obtained in the bioassays.
The First Total Synthesis of Ganglioside GalNAc‐GD1a, a Target Molecule for Autoantibodies in Guillain–Barré Syndrome
Authors: Fujikawa Kohki , Nakashima Shinya , Konishi Miku , Fuse Tomoaki , Komura Naoko , Ando Takayuki , Ando Hiromune , Yuki Nobuhiro , Ishida Hideharu , Kiso Makoto 
Published: April 2011

AbstractThe first synthesis of ganglioside GalNAc‐GD1a, featuring efficient glycan assembly and a cyclic glucosyl ceramide as a versatile unit for ganglioside synthesis is described. Although ganglioside GalNAc‐GD1a was first found as a brain ganglioside, IgG autoantibodies to GalNAc‐GD1a were subsequently found to be closely related to a human peripheral‐nerve disorder, Guillain–Barré syndrome, which is the commonest cause of acute flaccid paralysis worldwide. In this study, the characteristic hexasaccharide part carrying two sialic acid residues was synthesized efficiently by use of a readily accessible GM2‐core unit as a common unit. The potentially difficult coupling of the oligosaccharide and ceramide moieties was carried out by using a cyclic glucosyl ceramide as a coupling partner for the hexasaccharide part, thereby successfully providing the framework of the target compound. Global deprotection delivered the homogenous ganglioside GalNAc‐GD1a. An enzyme‐linked immunosorbent assay showed that sera from patients with Guillain–Barré syndrome reacted both with natural and with synthetic GalNAc‐GD1a.
Transglutaminase‐Mediated Synthesis of a DNA–(Enzyme)n Probe for Highly Sensitive DNA Detection
Authors: Kitaoka Momoko , Tsuruda Yukito , Tanaka Yukari , Goto Masahiro , Mitsumori Masayuki , Hayashi Kounosuke , Hiraishi Yoshiyuki , Miyawaki Katsuyuki , Noji Sumihare , Kamiya Noriho 
Published: April 2011

AbstractA new synthetic strategy for DNA–enzyme conjugates with a novel architecture was explored using a natural cross‐linking catalyst, microbial transglutaminase (MTG). A glutamine‐donor substrate peptide of MTG was introduced at the 5‐position on the pyrimidine of deoxyuridine triphosphate to prepare a DNA strand with multiple glutamine‐donor sites by polymerase chain reaction (PCR). A substrate peptide that contained an MTG‐reactive lysine residue was fused to the N terminus of a thermostable alkaline phoshatase from Pyrococcus furiosus (PfuAP) by genetic engineering. By combining enzymatically the substrate moieties of MTG introduced to the DNA template and the recombinant enzyme, a DNA–(enzyme)n conjugate with 1:n stoichiometry was successfully obtained. The enzyme/DNA ratio of the conjugate increased as the benzyloxycarbonyl‐L‐glutaminylglycine (Z‐QG) moiety increased in the DNA template. The potential utility of the new conjugate decorated with signaling enzymes was validated in a dot blot hybridization assay. The DNA–(enzyme)n probe could clearly detect 104 copies of the target nucleic acid with the complementary sequence under harsh hybridization conditions, thereby enabling a simple detection procedure without cumbersome bound/free processes associated with a conventional hapten–antibody reaction‐based DNA‐detection system.
Revisiting the Lipase from Pseudomonas aeruginosa: Directed Evolution of Substrate Acceptance and Enantioselectivity Using Iterative Saturation Mutagenesis
Authors: Prasad Shreenath , Bocola Marco , Reetz Manfred T. 
Published: April 2011

AbstractThe most thoroughly studied enzyme in directed evolution is the lipase from Pseudomonas aeruginosa (PAL) as a catalyst in the hydrolytic kinetic resolution of 2‐methyldecanoic acid p‐nitrophenyl ester. Seminal studies utilized epPCR, saturation mutagenesis and DNA shuffling or combinations thereof. With current emphasis on efficacy in laboratory evolution, however, we recently applied our previously developed method, iterative saturation mutagenesis (ISM), to the same catalytic system, discovering that this approach is much more efficient than the original strategies. Herein, we consider PAL once more, this time testing ISM as a means to broaden the substrate scope of this lipase by studying bulky substrates of the type 2‐phenylalkanoic acid esters as substrates that are not accepted by the WT. Highly active and enantioselective (E up to 436) mutants were evolved, a process that required only small mutant libraries and thus a minimum of screening effort. A theoretical investigation using molecular dynamics simulations and docking experiments revealed the source of enhanced activity and stereoselectivity.
Invariant Oxidation State of Copper but not of Ruthenium in Complexes with Noninnocent N‐(2‐Methyl‐5,8‐dioxo‐5,8‐dihydroquinolin‐7‐yl)acetamide: A Combined Structural, Electrochemical and Spectroelectrochemical Investigation
Authors: Paretzki Alexa , Das Hari Sankar , Weisser Fritz , Scherer Thomas , Bubrin Denis , Fiedler Jan , Nycz Jacek E. , Sarkar Biprajit 
Published: April 2011

AbstractThe compounds [(dppf)Cu(L)](BF4) (1[BF4]) [dppf = 1,1′‐bis(diphenylphosphanylferrocene), L = N‐(2‐methyl‐5,8‐dioxo‐5,8‐dihydroquinolin‐7‐yl)acetamide] and [(acac)2Ru(L)] (2) (acac = acetylacetonato) were prepared from the reactions of [Cu(dppf)(CH3CN)2](BF4) or [Ru(acac)2(CH3CN)2], respectively with L. Structural characterization of 1[BF4] shows a distorted tetrahedral coordinated copper center. Both complexes show one‐electron reversible oxidation as well as reduction processes in their cyclic voltammogram. The first oxidation process of 1[BF4] leads to absorptions at around 900 nm in the UV/Vis/NIR spectrum and results in an EPR silent species up to 110 K thus indicating a dppf‐centered oxidation. The reduction processes of 1[BF4] show features in the UV/Vis/NIR, IR as well as EPR spectrum that are compatible with L‐centered redox processes. In contrast to this, the ruthenium complex 2 shows metal‐centered spin in both the one‐electron oxidized as well as reduced forms. These results show that the copper center does not participate in the redox processes in 1[BF4] whereas the ruthenium center participates strongly in the electron‐transfer processes in 2. Results obtained from electrochemistry as well as from UV/Vis/NIR, IR, and EPR spectroelectrochemistry are invoked to show the noninnocent nature of L in these complexes as well as the more relative importance of metal–L covalency in 2 as compared to 1[BF4].
Identification of a Δ4‐desaturase from the microalga Ostreococcus lucimarinus
Authors: Ahmann Katharina , Heilmann Mareike , Feussner Ivo 
Published: April 2011

AbstractVery long chain PUFA (VLCPUFA) like DHA are essential and health‐beneficial components of the human diet. Due to a shortfall in VLCPUFA supply, research is ongoing to establish VLCPUFA production in heterologous systems like for example oilseed plants. For this purpose it is crucial to identify the required enzymes from primary producers of VLCPUFA. Here, we describe a cDNA from the microalga Ostreococcus lucimarinus coding for a Δ4‐fatty acid desaturase. It exhibits a cytochrome b5 domain fused to its amino terminus and three histidine boxes that are typically found in front‐end desaturases. Heterologous expression of the partly codon‐optimized version of the cDNA in yeast revealed that the encoded protein catalyzes the desaturation of (n‐3)‐ as well as (n‐6)‐substrates with a preference for VLCPUFA. In yeast it localized at the endoplasmic reticulum (ER) membrane and analysis of the product distribution into different lipid classes suggested that the enzyme most likely acts in a lipid‐dependent manner.Practical applications: The identified Δ4‐desaturase may be useful for the production of DHA in transgenic oleaginous organisms like annual oilseed crops.
Direct Arylation of Pyrrole Derivatives in Ionic Liquids
Authors: Vakuliuk Olena , Gryko Daniel T. 
Published: April 2011

AbstractAn efficient methodology for the direct arylation of pyrrole derivatives has been developed. The reaction proceeds smoothly with a wide range of structurally diverse aryliodides. Derivatives bearing an N,N‐dimethylamino group at the 1‐position and an aryl substituent at the 2‐position were prepared for the first time. This protocol is more environmentally friendly than those previously reported because it is free of transition metals and utilizes ionic liquids rather than volatile organic solvents.
Total Synthesis of Lavendamycin by a [2+2+2] Cycloaddition
Authors: Nissen Felix , Detert Heiner 
Published: April 2011

AbstractThe total synthesis of the bacterial‐derived, pentacyclic, antitumor antibiotic lavendamycin has been achieved through a highly convergent strategy. The key step of this synthesis is a ruthenium‐catalyzed [2+2+2] cycloaddition of an electron‐deficient nitrile to an alkynyl‐ynamide to prepare the carboline scaffold. The elaborate cycloaddition substrate is obtained in few steps by an N‐ethynylation using alkynyliodonium salt chemistry and two palladium‐catalyzed cross‐coupling reactions. An efficient synthesis of a halogenated quinoline‐5,8‐dione building block starting from hydroquinone is presented.
Impact of the kind of ultraviolet light on the photocatalytic degradation kinetics of the TiO2/UV process
Authors: Cortés J.A. , Alarcón‐Herrera M.T. , Villicaña‐Méndez M. , González‐Hernández J. , Pérez‐Robles J.F. 
Published: April 2011

AbstractAdvanced oxidation processes have gained importance in the last decade because of their application in the treatment of wastewater containing toxic, recalcitrant, and/or colored compounds. The catalyst TiO2, activated with ultraviolet (UV) light, has been used for the degradation of different kinds of compounds, but its activation has been performed with different varieties of UV light without a clear reason for choosing any of the three wavelengths that can be generated with commercially available sources. This work evaluates the degradation speed of acid blue 9 dye through the activation of TiO2 with the different kinds of UV light (UV‐A, UV‐B, and UV‐C). The results indicate that the wavelength of the light used for photoactivation has an impact on the dye degradation speed; shorter wavelengths lead to faster degradation.The analysis of the possible causes affecting the degradation speed was performed by superposing the emission bands of the used UV light with the absorption bands of the dye and catalyst. It is concluded that the interaction zone between the type of UV light and the catalyst notoriously impacts the degradation kinetics. © 2011 American Institute of Chemical Engineers Environ Prog, 2011.
Erosion rates and mechanisms of knickzone retreat inferred from 10Be measured across strong climate gradients on the northern and central Andes Western Escarpment
Authors: Abbühl Luca M. , Norton Kevin P. , Jansen John D. , Schlunegger Fritz , Aldahan Ala , Possnert Göran 
Published: April 2011

ABSTRACTA steep escarpment edge, deep gorges and distinct knickzones in river profiles characterize the landscape on the Western Escarpment of the Andes between ~5°S and ~18°S (northern Peru to northern Chile). Strong north–south and east–west precipitation gradients are exploited in order to determine how climate affects denudation rates in three river basins spanning an otherwise relatively uniform geologic and geomorphologic setting. Late Miocene tectonics uplifted the Meseta/Altiplano plateau (~3000 m a.s.l.), which is underlain by a series of Tertiary volcanic‐volcanoclastic rocks. Streams on this plateau remain graded to the Late Miocene base level. Below the rim of the Meseta, streams have responded to this ramp uplift by incising deeply into fractured Mesozoic rocks via a series of steep, headward retreating knickzones that grade to the present‐day base level defined by the Pacific Ocean.It is found that the Tertiary units on the plateau function as cap‐rocks, which aid in the parallel retreat of the sharp escarpment edge and upper knickzone tips. 10Be‐derived catchment denudation rates of the Rio Piura (5°S), Rio Pisco (13°S) and Rio Lluta (18°S) average ~10 mm ky−1 on the Meseta/Altiplano, irrespective of precipitation rates; whereas, downstream of the escarpment edge, denudation rates range from 10 mm ky−1 to 250 mm ky−1 and correlate positively with precipitation rates, but show no strong correlation with hillslope angles or channel steepness. These relationships are explained by the presence of a cap‐rock and climate‐driven fluvial incision that steepens hillslopes to near‐threshold conditions.Since escarpment retreat and the precipitation pattern were established at least in the Miocene, it is speculated that the present‐day distribution of morphology and denudation rates has probably remained largely unchanged during the past several millions of years as the knickzones have propagated headward into the plateau. Copyright © 2011 John Wiley & Sons, Ltd.
Selective neck dissection as an early salvage intervention for clinically persistent nodal disease following chemoradiation
Authors: Dhiwakar Muthuswamy , Robbins K. Thomas , Vieira Francisco , Rao Krishna , Malone James 
Published: April 2011

AbstractBackgroundThe aim of this study was to determine the efficacy of selective neck dissection (SND) performed for persistent nodal disease after chemoradiation.MethodsPatients treated with definitive chemoradiation for squamous cell carcinoma of the head and neck who subsequently underwent SND for early salvage of clinically persistent nodal disease were evaluated. The primary outcome measure was regional disease control.ResultsA total of 62 patients underwent 69 SND procedures. The median time interval between completion of chemoradiation and neck dissection was 10 weeks. There was evidence of residual tumor in 32 neck dissection specimens (46%). Forty patients (65%) remained free of disease, whereas the remaining 22 patients (35%) developed a recurrence, among which 4 were regional. Of these, 3 occurred in the contralateral neck and only 1 occurred in the targeted (ipsilateral) neck.ConclusionsSND is an effective early salvage intervention for persistent nodal disease in patients treated with chemoradiation. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Association of polymorphisms and haplotypes of the NBN gene with laryngeal cancer and multiple primary tumors of the head and neck
Authors: Ziółkowska–Suchanek Iwona , Mosor Maria , Wierzbicka Małgorzata , Fichna Marta , Rydzanicz Małgorzata , Nowak Jerzy 
Published: April 2011

AbstractBackgroundWe investigated whether genetic polymorphisms of the DNA repair gene NBN are associated with head and neck cancer risk.MethodsWe analyzed 6 polymorphisms in 175 patients with a single laryngeal tumor, 104 with multiple primary tumors but 1 malignancy (primary/second) localized in the larynx, 60 patients with multiple primary tumors localized in the head or neck, and 275 controls.ResultsAlthough frequencies of single nucleotide polymorphism alleles did not show marked differences, we found significant differences in haplotype frequencies between patients and controls. Haplotypes GGTTAA and ACCCGT were associated with an increased risk of laryngeal cancer (p < .0001, p = .002) and haplotypes GGCCAA and GCCCGT with an increased risk of multiple primary tumors (p < .0001, p = .039).ConclusionSpecific haplotypes of the NBN gene may be related to increased susceptibility to laryngeal cancer and second primary tumors localized in the head and neck. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Metastatic head and neck cutaneous squamous cell carcinoma: Defining a low‐risk patient
Authors: Ebrahimi Ardalan , Clark Jonathan R. , Lorincz Balazs B. , Milross Christopher G. , Veness Michael J. 
Published: April 2011

AbstractBackgroundThe purpose of this study was to determine whether there is a “low‐risk” subset of patients with regional metastatic head and neck cutaneous squamous cell carcinoma (SCC) suitable for treatment with surgery alone and omission of adjuvant radiotherapy.MethodsWe conducted a retrospective analysis of 168 patients with a single parotid gland or neck nodal metastasis ≤3 cm in size from cutaneous SCC treated with curative intent by surgery ± adjuvant radiotherapy.ResultsDisease‐specific survival for the 33 patients treated with surgery alone was 97% at 5 years. In the subset of 19 patients without extracapsular nodal spread (ECS), there was 1 regional recurrence which was successfully salvaged yielding a 5‐year disease‐specific survival of 100%.ConclusionIn head and neck cutaneous SCC, the subset with a single node ≤3 cm in size without ECS are at low risk of regional failure and death from cutaneous cancer. These patients may be suitable for single‐modality therapy with surgery alone. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Effects of E‐cadherin (CDH1) gene promoter polymorphisms on the risk and clinicopathologic development of oral cancer
Authors: Chien Ming‐Hsien , Chou Lin Shih‐Shen , Chung Tsung‐Te , Lin Chien‐Huang , Chou Ming‐Yung , Weng Meng‐Shih , Yang Shun‐Fa , Chen Mu‐Kuan 
Published: April 2011

AbstractBackgroundThis study investigates the association between polymorphism in the E‐cadherin/CDH1 promoter region and the risk and progression of oral cancer.MethodsGenetic polymorphisms of CDH1‐160 and ‐347 were analyzed by polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) in 347 noncancer controls and in 251 patients with oral cancer.ResultsThe statistical analysis showed that subjects with at least 1 varied GA allele of CDH1‐347 polymorphic genotypes or combinations of the CDH1‐160 CA/‐347 GGA, CDH1‐160 CC/‐347 GGA, or CDH1‐160 CC/‐347 GAGA genotypes had a significantly higher risk, whereas subjects with CDH1‐160 C/A or A/A had a significantly lower risk of developing oral cancer than those with wild‐type genotypes. Furthermore, elderly patients with the CDH1‐347 G/GA or GA/GA genotype were associated with a higher incidence in lymph node metastasis than were those with the G/G genotype.ConclusionsThese results suggest that CDH1‐347 polymorphisms are associated with increased risks of oral cancer, and may be a predictive factor for tumor lymph node metastasis. © 2011 Wiley Periodicals, Inc. Head Neck, 2012