bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitonuclear match: Optimizing fitness and fertility over generations drives ageing within generations
Authors: Lane Nick 
Published: September 2011

AbstractMany conserved eukaryotic traits, including apoptosis, two sexes, speciation and ageing, can be causally linked to a bioenergetic requirement for mitochondrial genes. Mitochondrial genes encode proteins involved in cell respiration, which interact closely with proteins encoded by nuclear genes. Functional respiration requires the coadaptation of mitochondrial and nuclear genes, despite divergent tempi and modes of evolution. Free‐radical signals emerge directly from the biophysics of mosaic respiratory chains encoded by two genomes prone to mismatch, with apoptosis being the default penalty for compromised respiration. Selection for genomic matching is facilitated by two sexes, and optimizes fitness, adaptability and fertility in youth. Mismatches cause infertility, low fitness, hybrid breakdown, and potentially speciation. The dynamics of selection for mitonuclear function optimize fitness over generations, but the same selective processes also operate within generations, driving ageing and age‐related diseases. This coherent view of eukaryotic energetics offers striking insights into infertility and age‐related diseases.
Relevance of magnetic resonance imaging-detected pelvic sidewall lymph node involvement in rectal cancer
Authors:   MERCURY Study Group, Brown G 
Published: September 2011

Abstract

Background
The significance of magnetic resonance imaging (MRI)-suspected pelvic sidewall (PSW) lymph node involvement in rectal cancer is uncertain.

Methods
Magnetic resonance images were reviewed retrospectively by specialist gastrointestinal radiologists for the presence of suspicious PSW nodes. Scans and outcome data were from patients with biopsy-proven rectal cancer and a minimum of 5 years' follow-up in the Magnetic Resonance Imaging and Rectal Cancer European Equivalence Study. Overall disease-free survival (DFS) was analysed using the Kaplan–Meier product-limit method and stratified according to preoperative therapy. Binary logistic regression was used to match patients for propensity of clinical and staging characteristics, and further survival analysis was carried out to determine associations between suspicious PSW nodes on MRI and survival outcomes.

Results
Of 325 patients, 38 (11·7 per cent) had MRI-identified suspicious PSW nodes on baseline scans. Such nodes were associated with poor outcomes. Five-year DFS was 42 and 70·7 per cent respectively for patients with, and without suspicious PSW nodes (P &lt; 0·001). Among patients undergoing primary surgery, MRI-suspected PSW node involvement was associated with worse 5-year DFS (31 versus 76·3 per cent; P = 0·001), but the presence of suspicious nodes had no impact on survival among patients who received preoperative therapy. After propensity matching for clinical and tumour characteristics, the presence of suspicious PSW nodes on MRI was not an independent prognostic variable.

Conclusion
Patients with suspicious PSW nodes on MRI had significantly worse DFS that appeared improved with the use of preoperative therapy. These nodes were associated with adverse features of the primary tumour and were not an independent prognostic factor.
Novel Allene Oxide Synthase Products Formed via Favorskii‐Type Rearrangement: Mechanistic Implications for 12‐Oxo‐10,15‐phytodienoic Acid Biosynthesis
Authors: Grechkin Alexander N. , Lantsova Natalia V. , Toporkova Yana Y. , Gorina Svetlana S. , Mukhitova Faina K. , Khairutdinov Boulat I. 
Published: September 2011

AbstractThe allene oxide synthase (AOS) pathway is widespread in plants. Its products, such as cyclopentenone 12‐oxo‐10,15‐phytodienoic acid (12‐oxo‐PDA) and related jasmonates, play important biological roles in plants. We found that 12‐oxo‐PDA in some plant tissues co‐occur with an unknown minor oxylipin 1. In vitro incubations of AOSs with α‐linolenic acid 13(S)‐hydroperoxide reliably afforded 1 along with 12‐oxo‐PDA and α‐ketol. A similar oxylipin 3 was formed during the AOS conversions of γ‐linolenic acid 9(S)‐hydroperoxide. Linoleic acid hydroperoxides formed neither products similar to 1 and 3 nor cyclopentenones. Oxylipins 1 and 3 were purified and identified as the products of Favorskii‐type rearrangement, (2′Z,4Z)‐2‐(2′‐pentenyl)‐4‐tridecene‐1,13‐dioic acid and (2′Z,4Z)‐2‐(2′‐octenyl)‐4‐decene‐1,10‐dioic acid, respectively. Detection of Favorskii products 1 and 3 demonstrates that cyclopropanones are short‐lived AOS products along with allene oxides. The observed parallels between the Favorskii product 1 and 12‐oxo‐PDA formation suggests that cyclopropanone is either a byproduct or a precursor of 12‐oxo‐PDA.
A Synthetic Mirror Image of Kalata B1 Reveals that Cyclotide Activity Is Independent of a Protein Receptor
Authors: Sando Lillian , Troeira Henriques Sónia , Foley Fiona , Simonsen Shane M. , Daly Norelle L. , Hall Kristopher N. , Gustafson Kirk R. , Aguilar Marie‐Isabel , Craik David J. 
Published: September 2011

AbstractFeaturing a circular, knotted structure and diverse bioactivities, cyclotides are a fascinating family of peptides that have inspired applications in drug design. Most likely evolved to protect plants against pests and herbivores, cyclotides also exhibit anti‐cancer, anti‐HIV, and hemolytic activities. In all of these activities, cell membranes appear to play an important role. However, the question of whether the activity of cyclotides depends on the recognition of chiral receptors or is primarily modulated by the lipid‐bilayer environment has remained unknown. To determine the importance of lipid membranes on the activity of the prototypic cyclotide, kalata B1, we synthesized its all‐D enantiomer and assessed its bioactivities. After the all‐D enantiomer had been confirmed by 1H NMR to be the structural mirror image of the native kalata B1, it was tested for anti‐HIV activity, cytotoxicity, and hemolytic properties. The all‐D peptide is active in these assays, albeit with less efficiency; this reveals that kalata B1 does not require chiral recognition to be active. The lower activity than the native peptide correlates with a lower affinity for phospholipid bilayers in model membranes. These results exclude a chiral receptor mechanism and support the idea that interaction with phospholipid membranes plays a role in the activity of kalata B1. In addition, studies with mixtures of L and D enantiomers of kalata B1 suggested that biological activity depends on peptide oligomerization at the membrane surface, which determines affinity for membranes by modulating the association–dissociation equilibrium.
Gas‐Phase Photooxidation of Alkenes by V‐Doped TiO2‐MCM‐41: Mechanistic Insights of Ethylene Photooxidation and Understanding the Structure–Activity Correlation
Authors: Bhattacharyya Kaustava , Varma Salil , Tripathi Arvind Kumar , Vinu Ajayan , Tyagi Avesh Kumar 
Published: September 2011

AbstractNanoparticles of Ti0.95V0.05O2 were found to be impregnated in the hexagonal channels of the MCM‐41 host, with a distribution of some particles on the surface, thus leading to an effective variation in the particle size as a function of loading host MCM‐41 matrix. These catalysts were subjected to the photocatalytic degradation of alkenes under the ambient conditions in which the photocatalytic activity varied as a function of the loading percentage of Ti0.95V0.05O2 in the host MCM‐41.This is explained in light of the structure–activity correlation, and the better catalytic activity can be attributed to an electronic interaction between the host and guest molecules, as established from X‐ray photoelectron spectroscopy. To understand the mechanistic aspect of the photooxidation of ethylene on the vanadium‐doped titania dispersed in the MCM‐41 matrix, extensive in situ FTIR experiments were undertaken. The intermediate species produced on bare Ti0.95V0.05O2 are different from that produced on the Ti0.95V0.05O2/MCM‐41 surface. Moreover, different intermediates were produced during ethylene oxidation under UV and visible irradiation, thus leading to different rates. The ethylene decomposition over bare Ti0.95V0.05O2 occurs by means of formation of ethoxy groups, transformed to acetaldehyde or enolates, subsequently to acetates, and then to CO2 under both UV and visible irradiation. However, in the case of Ti0.95V0.05O2/MCM‐41 catalyst with UV irradiation, the adsorbed acetaldehyde thus formed undergoes aldol condensation over the Lewis acid sites to lead to the formation of crotonaldehyde, which is subsequently oxidized to acetate and consequently to CO2. It was observed that during visible irradiation labile ethyl acetate is produced either by the Tischenko reaction or by the reaction between the labile acetic acid and the unreacted ethoxy groups. The ethyl acetate produces acetic acid monomer, which is oxidized to CO2. Furthermore, in this work the effects of particle size on the intermediate species were also studied.
Insights into the Acid–Base Properties of PtIV–Diazidodiam(m)inedihyroxido Complexes from Multinuclear NMR Spectroscopy
Authors: Ronconi Luca , Pizarro Ana M. , McQuitty Ruth J. , Sadler Peter J. 
Published: September 2011

AbstractPlatinum(IV) am(m)ine complexes are of interest as potential anticancer pro‐drugs, but there are few reports of their acid–base properties. We have studied the acid–base properties of three photoactivatable anticancer platinum(IV)‐diazidodiam(m)ine complexes (cis,trans,cis‐[PtIV(N3)2(OH)2(NH3)2], trans,trans,trans‐[PtIV(N3)2(OH)2(NH3)2], and cis,trans‐[PtIV(N3)2(OH)2(en)]) using multinuclear NMR methods and potentiometry. In particular, the combination of both direct and indirect techniques for the detection of 15N signals has allowed changes of the chemical shifts to be followed over the pH range 1–11; complementary 14N NMR studies have been also carried out. A distinct pKa value of approximately 3.4 was determined for all the investigated complexes, involving protonation/deprotonation reactions of one of the axial hydroxido groups, whereas a second pH‐dependent change for the three complexes at approximately pH 7.5 appears not to be associated with a loss of an am(m)ine or hydroxido proton from the complex. Our findings are discussed in comparison with the limited data available in the literature on related complexes.
Domino Friedel–Crafts‐Type Cyclizations of Difluoroalkenes Promoted by the α‐Cation‐Stabilizing Effect of Fluorine: An Efficient Method for Synthesizing Angular PAHs
Authors: Fuchibe Kohei , Jyono Hideharu , Fujiwara Masaki , Kudo Takao , Yokota Misaki , Ichikawa Junji 
Published: September 2011

AbstractIn order to synthesize polycyclic aromatic hydrocarbons with nonlinear arrangements (angular PAHs), acid‐promoted domino cyclizations of 1,1‐difluoroalk‐1‐enes and 1,1‐difluoroalka‐1,3‐dienes were studied. 1,1‐Difluoroalkenes, each bearing two aryl substituents, were regioselectively protonated with FSO3H⋅SbF5 to generate fluorine‐stabilized carbocations, which readily underwent domino Friedel–Crafts‐type cyclizations to give carbocycles based on 6/n/m/6 ring systems (n,m=5–7) in good to high yields. Protonation of 1,1‐difluoroalka‐1,3‐dienes took place at their electron‐rich methylene (CH2) carbon atoms in the presence of milder acids such as camphorsulfonic acid and trifluoromethanesulfonic acid. Domino cyclizations of the resulting fluorine‐stabilized allylic carbocations afford carbocycles based on 6/6/6/6 or 6/6/5/6 ring systems in high yields.
Probing Platinum Azido Complexes by 14N and 15N NMR Spectroscopy
Authors: Farrer Nicola J. , Gierth Peter , Sadler Peter J. 
Published: September 2011

AbstractMetal azido complexes are of general interest due to their high energetic properties, and platinum azido complexes in particular because of their potential as photoactivatable anticancer prodrugs. However, azido ligands are difficult to probe by NMR spectroscopy due to the quadrupolar nature of 14N and the lack of scalar 1H coupling to enhance the sensitivity of the less abundant 15N by using polarisation transfer. In this work, we report 14N and 15N NMR spectroscopic studies of cis,trans,cis‐[Pt(N3)2(OH)2(NH3)] (1) and trans,trans,trans‐[Pt(N3)2(OH)2(X)(Y)], where X=Y=NH3 (2); X=NH3, Y=py (3) (py=pyridine); X=Y=py (4); and selected PtII precursors. These studies provide the first 15N NMR data for azido groups in coordination complexes. We discuss one‐ and three‐bond J(15N,195Pt) couplings for azido and am(m)ine ligands. The 14Nα (coordinated azido nitrogen) signal in the PtIV azido complexes is extremely broad (W1/2≈2124 Hz for 4) in comparison to other metal azido complexes, attributable to a highly asymmetrical electric field gradient at the 14Nα atom. Through the use of anti‐ringing pulse sequences, the 14N NMR spectra, which show resolution of the broad 14Nα peak, were obtained rapidly (e.g., 1.5 h for 10 mM 4). The linewidths of the 14Nα signals correlate with the viscosity of the solvent. For 15N‐enriched samples, it is possible to detect azido 15N resonances directly, which will allow photoreactions to be followed by 1D 15N NMR spectroscopy. The T1 relaxation times for 3 and 4 were in the range 5.7–120 s for 15N, and 0.9–11.3 ms for 14N. Analysis of the 1J(15N,195Pt) coupling constants suggests that an azido ligand has a moderately strong trans influence in octahedral PtIV complexes, within the series 2‐pic<py<NH3<Cl−<N3−<NO2−<SCN− (2‐pic=2‐methylpyridine). In addition, an axial Cl− appears to weaken an equatorial PtIVNH3 bond to a greater extent than an axial OH− ligand.
Evaluation of Carcinogenic Risk Due to Accidental Ingestion of PAHs in Contaminated Soils
Authors: Gitipour Saeid , Mohebi Mina , Taheri Ehsan 
Published: September 2011

AbstractPolycyclic aromatic hydrocarbons (PAHs) are types of hazardous contaminants, which their ingestion could cause severe consequences on human health. Leakages from storage tanks, underground pipelines, and evaporation ponds are the main sources of soil and groundwater contaminations at the Tehran Oil Refinery area (TOR site), located in south of Tehran, Iran. In this study, soil samples were collected from different locations at and adjacent to a polluted stream in the south of the refinery. The samples were analyzed for two hazardous PAH compounds, namely benzo[a]anthracene and acenaphthene. The clean up levels due to the accidental ingestion of contaminated soils at the site were also investigated in accordance to the U.S.EPA guidelines. Comparing the soil analysis results indicated that the benzo[a]anthracene concentrations in the samples varied from 53 to 299 mg/kg, which were higher than the clean up level of 1.17 mg/kg. Thus, soil remediation is required for this contaminant. The acenaphthene analysis results denoted that the average concentration of this contaminant was below the clean up level of 116.67 mg/kg, indicating that no treatment for this contaminant is necessary at the TOR site. Also, because the slope of the ground extends to the south of the stream, which stimulates the migration of the contaminants in this direction due to advection and dispersion mechanisms, the average of benzo[a]anthracene concentrations in south samples was higher than north samples (i.e., Cavg(S) = 160 ppm, Cavg(N) = 113 ppm). Various treatment techniques such as thermal desorption, soil vapor extraction (SVE), and solidification/stabilization (S/S) were investigated for this site. Due to moderate to high plasticity and relatively low permeability of the soil and low volatility of benzo[a]anthracene, however S/S method is recommended as a practical approach for the remediation of the soil at the site.
Bioremediation of Tannery Effluents Using a Consortium of Blue–Green Algal Species
Authors: Shashirekha Viswanaathan , Sridharan Melatheru Ramanujam , Swamy Mahadeswara 
Published: September 2011

AbstractTrivalent chromium in the form of basic chromium sulfate (BCS) is used for tanning hides/skins and is a strong pollutant of the soil and water bodies. Significant quantities of unutilized chemicals, such as sulfates, chlorides, are also discharged, contributing to high levels of total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), etc. Though many treatment techniques are being practiced, biotechnological methods are gaining importance. Biosorption is recognized as a cost‐effective technology worldwide; one potential sorbent being blue–green algae (BGA), for treating metal‐bearing effluents. This work studies the feasibility of using a species each of Spirulina, Oscillatoria, and Synechocystis, individually and as a consortium, as sorbents to remove Cr3+ from a segregated stream, viz. exhaust chrome liquor (ECL) and synthetic BCS solution. The species studied were found to be effective in removing Cr3+ considerably at varying concentrations, besides reducing sulfates, BOD, COD, etc. The results of ECL experiments were more encouraging than those for BCS solution. The kinetic data on Cr3+ sorption onto algal biomass fit well into the pseudo‐second order model. The equilibrium data were analyzed using the classic Langmuir and Freundlich isotherm models, yielding good fits. The results of the experiments indicate that algal consortia could be good alternatives to the conventional treatment methods for leather and other industrial wastewaters containing chromium.
Facile morphology‐controlled hydrothermal synthesis of flower‐like self‐organized ZnO architectures
Authors: Zhang Rongxian , Yang Xiaofei , Zhang Du , Qin Jieling , Lu Chunyu , Ding Heyi , Yan Xuehua , Tang Hua , Wang Mingsong , Zhang Qi 
Published: September 2011

AbstractFlower‐like self‐organized crystalline ZnO architectures were obtained through a facile and controlled hydrothermal process. As‐synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM), X‐ray diffraction (XRD), electron diffraction and UV‐Vis spectroscopy. XRD and electron diffraction results confirmed the obtained materials are pure wurtzite ZnO. The effects of different ratios of starting materials and solvent on the morphologies of ZnO hydrothermal products were also evaluated by SEM observations. It is suggested that the use of water, rather than ethanol as the solvent, as well as employing a precursor of Zn(Ac)2 and 2NaOH (v/v) in hydrothermal reactions are responsible for the generation of specific flower‐like self‐assembled ZnO structures. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of enterovirus infection and cow's milk‐based formula nutrition in type 1 diabetes‐associated autoimmunity
Authors: Lempainen J. , Tauriainen S. , Vaarala O. , Mäkelä M. , Honkanen H. , Marttila J. , Veijola R. , Simell O , Hyöty H. , Knip M. , Ilonen J. 
Published: September 2011

AbstractBackgroundEnteral virus infections and early introduction of cow's milk (CM)‐based formula are among the suggested triggers of type 1 diabetes (T1D)‐associated autoimmunity, although studies on their role have remained contradictory. Here, we aimed to analyse whether interactions between these factors might clarify the controversies.MaterialsThe study population comprised 107 subjects developing positivity for at least two T1D‐associated autoantibodies and 446 control subjects from the Finnish diabetes prediction and prevention cohort. Enterovirus, rotavirus, adenovirus, respiratory syncytial virus and bovine insulin‐binding antibodies were analysed from prospective serum samples at 3–24 months of age. Data on infant cow's milk exposure were available for 472 subjects: 251 subjects were exposed to cow's milk before 3 months of age and 221 subjects later in infancy.ResultsSigns of an enterovirus infection by 12 months of age were associated with the appearance of autoimmunity among children who were exposed to cow's milk before 3 months of age. Cox regression analysis revealed a combined effect of enterovirus infection and early cow's milk exposure for the development of ICA and any of the biochemically defined autoantibodies (p = 0.001), of IAA (p = 0.002), GADA (p = 0.001) and IA‐2A (p = 0.013).ConclusionsThe effect of enterovirus infection on the appearance of T1D‐associated autoimmunity seems to be modified by exposure to cow's milk in early infancy suggesting an interaction between these factors. Moreover, these results provide an explanation for the controversial findings obtained when analysing the effect of any single one of these factors on the appearance of T1D‐associated autoimmunity. Copyright © 2011 John Wiley & Sons, Ltd.
Nonenzymatic glycation of high‐density lipoprotein impairs its anti‐inflammatory effects in innate immunity
Authors: Liu Donghui , Ji Liang , Zhang Dongmei , Tong Xunliang , Pan Bing , Liu Pinli , Zhang Youyi , Huang Yining , Su Jinzi , Willard Belinda , Zheng Lemin 
Published: September 2011

AbstractAims/hypothesisIn type 2 diabetes mellitus (T2DM), the abnormal protein and lipid composition of diabetic high‐density lipoprotein (HDL) could impair its anti‐inflammatory functions. Whether nonenzymatic glycation directly impaired the anti‐inflammatory effects of HDL in innate immunity remained unclear.MethodsHuman acute monocytic leukemia cell line (THP‐1) cells, mouse RAW 264.7 macrophages and primary human monocytes derived macrophages were pre‐incubated with native HDL, diabetic HDL isolated from T2DM patients or HDL glycated with different doses of d‐glucose in vitro and then challenged with lipopolysaccharide (LPS). The release of tumor necrosis factor (TNF)‐α and IL‐1β was assayed by enzyme‐linked immunosorbent assay (ELISA). Phosphorylation of Iκ‐Bα in cytoplasm and nuclear translocation of NF‐κB were detected by western blot. Glycation levels of native HDL, glycated HDL and diabetic HDL were determined using LC‐MS/MS.ResultsThe potency of diabetic HDL to inhibit the release of TNF‐α (p < 0.05) and IL‐1β (p < 0.001) was dramatically attenuated compared with that of native HDL. Similarly, glycation of HDL in vitro impaired its ability to inhibit TNF‐α and IL‐1β release in a glucose dose‐dependent manner. Moreover, apoHDL still effectively inhibited the release of TNF‐α and IL‐1β induced by LPS, but glycated apoHDL partly lost such abilities. Nonenzymatic glycation levels of glycated HDL and diabetic HDL increased 28 fold (p < 0.001) and 4 fold (p < 0.001), respectively compared with that of native HDL.ConclusionsIn this study, we observed that diabetic HDL and HDL glycated in vitro both partly lose their protective effects to inhibit cytokines release induced by LPS in macrophages, and nonenzymatic glycation of the protein components of HDL plays key roles in these impairments. Copyright © 2011 John Wiley & Sons, Ltd.
Zinc Complexes of Piperazinyl‐Derived Aminephenolate Ligands: Synthesis, Characterization and Ring–Opening Polymerization Activity
Authors: Ikpo Nduka , Saunders Lisa N. , Walsh Jillian L. , Smith Jennifer M. B. , Dawe Louise N. , Kerton Francesca M. 
Published: September 2011

AbstractA series of zinc complexes was prepared from 4,6‐disubstituted (R,R′) o‐[(4‐methyl‐1‐piperazinyl)methyl]phenols ([ONNR′,R]H) and characterized by elemental analysis, 1H and 13C{1H} NMR spectroscopy, and X‐ray crystallography. Reaction of these products with diethylzinc gave Zn[ONNtBu,tBu]2 (1) as a monometallic complex and {[μ‐ONNR′,R]ZnEt}2 [R′ = Me, R = tBu, (2); R′ = R = tBu (3); R′ = R = tAm (4)] bimetallic species that have distorted tetrahedral environments about the Zn centres. Reaction of 3 and 4 with alcohols gave {[ONNtAm,tAm]Zn(μ‐OR″)}2 [R″ = Bn (5); R″ = Et (6)] bimetallic species in which the Zn centres are bridged by benzyl alkoxide and ethoxide groups, respectively. A morpholinyl derived ligand was also synthesized and characterized (L4H), and its 1:1 stoichiometric reaction with ZnEt2 resulted in complex 7, {[μ‐ONOtBu,tBu]ZnEt}2. The reactivity of complexes 2–7 in the ring‐opening polymerization of rac‐lactide (LA) and ϵ‐caprolactone (ϵ‐CL) was studied. Reactions of carbon dioxide with cyclohexene oxide in the presence of 6 or 7/ROH (R = Bn, Et) afforded cyclohexene carbonate.