bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association of Hippocampal Atrophy With Cerebrospinal Fluid Antibodies Against the NR2 Subtype of the N‐Methyl‐D‐Aspartate Receptor in Patients With Systemic Lupus Erythematosus and Patients With Primary Sjögren's Syndrome
Authors: Lauvsnes Maria B. , Beyer Mona K. , Kvaløy Jan Terje , Greve Ole J. , Appenzeller Simone , Kvivik Ingeborg , Harboe Erna , Tjensvoll Anne B. , Gøransson Lasse G. , Omdal Roald 
Published: August 2014

ObjectiveCognitive dysfunction is common in both systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS). Antibodies against the NR2 subtype of the N‐methyl‐D‐aspartate receptor (anti‐NR2 antibodies) cause hippocampal atrophy and cognitive impairment in mice and have been associated with memory impairment in both patients with SLE and patients with primary SS. In addition, a reduced volume of hippocampal gray matter has been demonstrated in both SLE and primary SS. This study was undertaken to investigate whether there is a connection between the presence of anti‐NR2 antibodies and hippocampal atrophy in human diseases.MethodsFifty patients with SLE and 50 patients with primary SS underwent clinical examination and cerebral magnetic resonance imaging. Anti‐NR2 antibodies in cerebrospinal fluid (CSF) were measured, and hippocampal gray matter volumes were compared between patients who were positive for and those who were negative for anti‐NR2 antibodies.ResultsPatients with anti‐NR2 antibodies in CSF had less hippocampal gray matter than patients without these antibodies. No other differences regarding gray matter volumes in other parts of the brain were identified.ConclusionThe present findings indicate that anti‐NR2 antibodies in patients with SLE and primary SS cause neuronal death manifested as reduced hippocampal gray matter, as has been previously demonstrated in mice with autoimmune disease.
Thermally Stable 3,6‐Dinitropyrazolo[4,3‐c]pyrazole‐based Energetic Materials
Authors: Zhang Jiaheng , Parrish Damon A. , Shreeve Jean'ne M. 
Published: August 2014

Abstract3,6‐Dinitropyrazolo[4,3‐c]pyrazole was prepared using an efficient modified process. With selected cations, ten nitrogen‐rich energetic salts and three metal salts were synthesized in high yield based on the 3,6‐dinitropyrazolo[4,3‐c]pyrazolate anion. These compounds were fully characterized by IR and multinuclear NMR spectroscopies, as well as elemental analyses. The structures of the neutral compounds 4 and its salt 16 were confirmed by single‐crystal X‐ray diffraction showing extensive hydrogen‐bonding interactions. The neutral pyrazole precursor and its salts are remarkably thermally stable. Based on the calculated heats of formation and measured densities, detonation pressures (22.5–35.4 GPa) and velocities (7948–9005 m s−1) were determined, and they compare favorably with those of TNT and RDX. Their impact and friction sensitivities range from 12 to >40 J and 80 to 360 N, respectively. These properties make them competitive as insensitive and thermally stable high‐energy density materials.
Peptide Conjugates of a Nonsteroidal Anti‐Inflammatory Drug as Supramolecular Gelators: Synthesis, Characterization, and Biological Studies
Authors: Roy Rajdip , Deb Jolly , Jana Siddhartha Sankar , Dastidar Parthasarathi 
Published: August 2014

AbstractIndomethacin (IND), which is a well‐known nonsteroidal anti‐inflammatory drug (NSAID), was conjugated with various naturally occurring amino acids. Most of these bioconjugates were capable of gelling pure water, a solution of NaCl (0.9 wt %), and phosphate‐buffered saline (pH 7.4), as well as a few organic solvents. The gels were characterized by table‐top and dynamic rheology, and electron microscopy. Variable‐temperature 1H NMR spectroscopy studies on a selected gel were performed to gain insights into the self‐assembly process during gel formation. Both 1D and 2D hydrogen‐bonded networks were observed in the single‐crystal structures of two of the gelators. Plausible biological applications of the hydrogelators were evaluated with the ultimate aim of drug delivery in a self‐delivery fashion. All hydrogelators were stable in phosphate‐buffered saline at pH 7.4 at 37 °C, and biocompatible in mouse macrophage RAW 264.7 cell line (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay). Two of the most biocompatible hydrogelators displayed an anti‐inflammatory response comparable to that of the parent drug IND in prostaglandin E2 assay. Release of the bioconjugates into the bulk solvent interfaced with the corresponding hydrogels indicated their plausible future application in drug delivery.
Reaction‐Based Fluorescent Probe for Detection of Endogenous Cyanide in Real Biological Samples
Authors: Long Lingliang , Wang Lin , Wu Yanjun , Gong Aihua , Da Zulin , Zhang Chi , Han Zhixiang 
Published: August 2014

AbstractHerein, two compounds (1 a and 1 b) were rationally constructed as novel reaction‐based fluorescent probes for CN− by making use of the electron‐withdrawing ability of the cyano group that was formed from the sensing reaction. Notably, this design strategy was first employed for the development of fluorescent CN− probes. The experimental details showed that probe 1 a exhibited a fluorescence turn‐on response to CN−, whereas other anions, biological thiols, and hydrogen sulfide gave almost no interference. The detection limit of probe 1 a for CN− was found to be 0.12 μM. The sensing reaction product of 1 a with CN− was characterized by NMR spectroscopy and mass spectrometry. TD‐DFT calculations demonstrated that the formed cyano group drives the intramolecular charge transfer (ICT) process from coumarin dye to the cyano group and thus the original strong ICT from the coumarin dye to the 3‐position pyridyl vinyl ketone substituent is weakened, which results in recovery of coumarin fluorescence. The practical utility of 1 a was also examined. By fabricating paper strips, probe 1 a can be used as a simple tool to detect CN− in field measurements. Moreover, probe 1 a has been successfully applied for quantitative detection of endogenous CN− from cassava root.
Reaction of a Dialumene‐Benzene Adduct with Diphenylacetylene: Formation of 3,4‐Dialuminacyclobutene and 5,6‐Dialuminabicyclo[2.1.1]hex‐2‐ene Derivatives
Authors: Agou Tomohiro , Nagata Koichi , Sasamori Takahiro , Tokitoh Norihiro 
Published: August 2014

AbstractReaction of a dialumene‐benzene adduct bearing bulky aryl substituents with diphenylacetylene was found to give a novel 5,6‐dialuminabicyclo[2.1.1]hex‐2‐ene derivative in addition to the 3,4‐dialuminacyclobutene derivative, the formal [2+2]cycloadduct of an intermediary dialumene with diphenylacetylene. The molecular structure of the newly obtained 5,6‐dialuminabicyclo[2.1.1]hex‐2‐ene has been elucidated by X‐ray crystallographic analysis.
Robust Adaptive Fuzzy Control of Nonlinear Systems with Unknown and Time‐Varying Saturation
Authors: Lai Guanyu , Liu Zhi , Zhang Yun , Chen Xin , Philip Chen Chun Lung 
Published: August 2014

AbstractIn this paper, a robust adaptive fuzzy control approach is proposed for a class of nonlinear systems in strict‐feedback form with the unknown time‐varying saturation input. To deal with the time‐varying saturation problem, a novel controller separation approach is proposed in the literature to separate the desired control signal from the practical constrained control input. Furthermore, an optimized adaptation method is applied to the dynamic surface control design to reduce the number of adaptive parameters. By utilizing the Lyapunov synthesis, the fuzzy logic system technique and the Nussbaum function technique, an adaptive fuzzy control algorithm is constructed to guarantee that all the signals in the closed‐loop control system remain semiglobally uniformly ultimately bounded, and the tracking error is driven to an adjustable neighborhood of the origin. Finally, some numerical examples are provided to validate the effectiveness of the proposed control scheme in the literature.
Branched porphyrins as functional scaffolds for multisite bioconjugation
Authors: Engelen Mireille , Lombardi Angela , Vitale Rosa , Lista Liliana , Maglio Ornella , Pavone Vincenzo , Nastri Flavia 
Published: August 2014

AbstractBioconjugation is a rapidly expanding field because of the numerous potential applications of bioconjugate materials. We explored the usefulness of branched porphyrins as rigid scaffolds, bearing multiple sites for bioconjugation. To this end, we first selected the tetrakis(p‐[aminomethyl] phenyl) porphyrin (TAMPP) macrocycle and developed a straightforward synthetic protocol, able to provide the desired tetraphenylporphyrin, carrying four functional amino groups. The partially protection of the amino groups by tert‐butoxy‐carbonyl allowed the selective and specific decoration of the porphyrin with different peptide sequences. To explore the utility of the macrocycle as molecular scaffold for bioconjugation, we selected peptide sequences able to function as thrombin inhibitors. In particular, two peptide sequences, named CS3 and ES7, able to interact, respectively, with the thrombin catalytic site and the fibrinogen recognition exosite, were joined onto the porphyrin macrocycle, providing the multisite‐directed inhibitor CS3–TAMPP–ES7. This multisite inhibitor and its MnIII complex are able to inhibit α‐thrombin‐catalyzed hydrolysis of Tos–Gly–Pro–Arg–nitroanilide with inhibition constants in the micromolar range, as well as the hydrolysis of the natural substrate fibrinogen. The inhibitor is resistant against enzymatic degradation by thrombin and is highly selective. The MnIII complex is capable of interacting with clot‐bound thrombin and partially inhibits clot growth in the presence of fibrinogen. The results herein reported are very promising, suggesting the potential of the newly developed conjugate as new imaging agents for clot detection.
Coenzyme B12 can be produced by engineered Escherichia coli under both anaerobic and aerobic conditions
Authors: Ko Yeounjoo , Ashok Somasundar , Ainala Satish Kumar , Sankaranarayanan Mugesh , Chun Ah Yeong , Jung Gyoo Yeol , Park Sunghoon 
Published: August 2014

AbstractCoenzyme B12 (Vitamin B12) is one of the most complex biomolecules and an essential cofactor required for the catalytic activity of many enzymes. Pseudomonas denitrificans synthesizes coenzyme B12 in an oxygen‐dependent manner using a pathway encoded by more than 25 genes that are located in six different operons. Escherichia coli, a robust and suitable host for metabolic engineering was used to produce coenzyme B12. These genes were cloned into three compatible plasmids and expressed heterologously in E. coli BL21 (DE3). Real‐time PCR, SDS–PAGE analysis and bioassay showed that the recombinant E. coli expressed the coenzyme B12 synthetic genes and successfully produced coenzyme B12. However, according to the quantitative determination by inductively coupled plasma‐mass spectrometry, the amount of coenzyme B12 produced by the recombinant E. coli (0.21 ± 0.02 μg/g cdw) was approximately 13‐fold lower than that by P. denitrificans (2.75 ± 0.22 μg/g cdw). Optimization of the culture conditions to improve the production of coenzyme B12 by the recombinant E. coli was successful, and the highest titer (0.65 ± 0.03 μg/g cdw) of coenzyme B12 was obtained. Interestingly, although the synthesis of coenzyme B12 in P. denitrificans is strictly oxygen‐dependent, the recombinant E. coli could produce coenzyme B12 under anaerobic conditions.
Insecticidal Metabolites from the Rhizomes of Veratrum album against Adults of Colorado Potato Beetle, Leptinotarsa decemlineata
Authors: Aydin Tuba , Cakir Ahmet , Kazaz Cavit , Bayrak Neslihan , Bayir Yasin , Taşkesenligil Yavuz 
Published: August 2014

AbstractThe dried rhizomes of Veratrum album were individually extracted with CHCl3, acetone, and NH4OH/benzene to test the toxic effects against the Colorado potato beetle, Leptinotarsa decemlineata, which is an important agricultural pest. Fifteen compounds in various amounts were isolated from the extracts using column and thin‐layer chromatography. The chemical structures of 14 compounds were characterized as octacosan‐1‐ol (1), β‐sitosterol (2), stearic acid (3), diosgenin (4), resveratrol (5), wittifuran X (6), oxyresveratrol (7), β‐sitosterol 3‐O‐β‐D‐glucopyranoside (8), diosgenin 3‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐glucopyronoside (9), oxyresveratrol 3‐O‐β‐D‐glucopyranoside (10), jervine (11), pseudojervine (13), 5,6‐dihydro‐1‐hydroxyjervine (14), and saccharose (15) using UV, IR, MS, 1H‐ and 13C‐NMR, and 2D‐NMR spectroscopic methods. However, the chemical structure of 12, an oligosaccharide, has not fully been elucidated. Compounds 4, 6, 9, and 10 were isolated from V. album rhizomes for the first time in the current study. The toxic effects of three extracts (acetone, CHCl3, and NH4OH/benzene) and six metabolites, 2, 2+4, 5, 7, 8, and 11, were evaluated against the Colorado potato beetle. The assay revealed that all three extracts, and compounds 7, 8, and 11 exhibited potent toxic effects against this pest. This is the first report on the evaluation of the toxic effects of the extracts and secondary metabolites of V. album rhizomes against L. decemlineata. Based on these results, it can be concluded that the extracts can be used as natural insecticides.
Chemical Composition and Phytotoxic Effects of Essential Oils Obtained from Ailanthus altissima (Mill.)Swingle Cultivated in Tunisia
Authors: El Ayeb‐Zakhama Asma , Ben Salem Saoussen , Sakka‐Rouis Lamia , Flamini Guido , Ben Jannet Hichem , Harzallah‐Skhiri Fethia 
Published: August 2014

AbstractAilanthus altissima Mill. Swingle (Simaroubaceae), also known as tree of heaven, is used in the Chinese traditional medicine as a bitter aromatic drug for the treatment of colds and gastric diseases. In Tunisia, Ailanthus altissima is an exotic tree, which was introduced many years ago and used particularly as a street ornamental tree. Here, the essential oils of different plant parts of this tree, viz., roots, stems, leaves, flowers, and samaras (ripe fruits), were obtained by hydrodistillation. In total, 69 compounds, representing 91.0–97.2% of the whole oil composition, were identified in these oils by GC‐FID and GC/MS analyses. The root essential oil was clearly distinguishable for its high content in aldehydes (hexadecanal (1); 22.6%), while those obtained from flowers and leaves were dominated by oxygenated sesquiterpenes (74.8 and 42.1%, resp.), with caryophyllene oxide (4) as the major component (42.5 and 22.7%, resp.). The samara oil was rich in the apocarotenoid derivative hexahydrofarnesyl acetone (6; 58.0%), and the oil obtained from stems was characterized by sesquiterpene hydrocarbons (54.1%), mainly β‐caryophyllene (18.9%). Principal component and hierarchical cluster analyses separated the five essential oils into four groups, each characterized by the major oil constituents. Contact tests showed that the germination of lettuce seeds was totally inhibited by all the essential oils except of the samara oil at a dose of 1 mg/ml. The flower oil also showed a significant phytotoxic effect against lettuce germination at 0.04 and 0.4 mg/ml (−55.0±3.5 and −85.0±0.7%, resp.). Moreover, the root and shoot elongation was even more affected by the oils than germination. The inhibitory effect of the shoot and root elongation varied from −9.8 to −100% and from −38.6 to −100%, respectively. Total inhibition of the elongation (−100%) at 1 mg/ml was detected for all the oils, with the exception of the samara oil (−74.7 and −75.1% for roots and shoots, resp.).
Essential Oil from Blackcurrant Buds as Chemotaxonomy Marker and Antimicrobial Agent
Authors: Ðorđević Boban S. , Pljevljakušić Dejan S. , Šavikin Katarina P. , Stević Tatjana R. , Bigović Dubravka J. 
Published: August 2014

AbstractDormant buds are recognized as valuable side product of the blackcurrant cultivation. Four blackcurrant varieties cultivated in Serbia, i.e., Ben Sarek, Ometa, Ben Lomond, and Ben Nevis, were evaluated for the content, chemical composition, and antimicrobial activity of their bud essential oils. The oil yields of buds harvested during two different growth periods ranged from 1.2–2.0%, and the variety Ometa had the highest yield among the tested varieties. GC‐FID and GC/MS analysis of the oils allowed the identification of eight main components, i.e., α‐pinene (1.6–5.4%), sabinene (1.9–38.4%), δ‐car‐3‐ene (13.0–50.7%), β‐phellandrene (2.9–18.0%), terpinolene (6.6–11.9%), terpinen‐4‐ol (0.9–6.6%), β‐caryophyllene (3.8–10.4%), and α‐humulene (0.2–4.1%). In addition, the similarity degree of the essential‐oil compositions of buds harvested from the upper and lower parts of the shrubs was investigated by hierarchical clustering. All essential oils originating from the same genotype were grouped in the same cluster, indicating the reliability of essential oils as chemotaxonomic markers. For more detailed chemotaxonomic investigations, the three compounds with the greatest variance were chosen, i.e., sabinene, δ‐car‐3‐ene, and β‐phellandrene, which proved to be efficient for the variety distinction. Factor analysis showed that the essential‐oil composition as chemotaxonomic marker in blackcurrants was more reliable for variety Ben Sarek than for variety Ben Nevis. Moreover, it was demonstrated that the essential oils had very strong inhibitory activity against all tested microorganisms. Fungi were more sensitive than bacteria; indeed their growth was completely inhibited at much lower concentrations. In comparison to commercial antibiotics, significantly lower concentrations of the oils were necessary for the complete inhibition of fungal growth.
Binding Pockets and Pathways for Dioxygen through the KijD3 N‐Oxygenase in Complex with Flavin Mononucleotide Cofactor and a 3‐Aminoglucose Substrate: Predictions from Molecular Dynamics Simulations
Authors: Pietra Francesco 
Published: August 2014

AbstractIn this work, two protein systems, Kij3DFMNAKMO2 and Kij3DFMNO2, made of KijD3 N‐oxygenase, flavin mononucleotide (FMN) cofactor, dTDP‐3‐amino‐2,3,6‐trideoxy‐4‐keto‐3‐methyl‐D‐glucose (AKM) substrate, and dioxygen (O2), have been assembled by adding a molecule of O2, and removing (or not) AKM, to crystal data for the Kij3DFMNAKM complex. Egress of AKM and O2 from these systems was then investigated by applying a tiny external random force, in turn, to their center of mass in the course of molecular dynamics in explicit H2O. It turned out that the wide AKM channel, even when emptied, does not constitute the main route for O2 egress. Other routes appear to be also viable, while various binding pockets (BPs) outside the active center are prone to trap O2. By reversing the reasoning, these can also be considered as routes for uptake of O2 by the protein, before or after AKM uptake, while BPs may serve as reservoirs of O2. This shows that the small molecule O2 is capable of permeating the protein by exploiting all nearby interstices that are created on thermal fluctuations of the protein, rather than having necessarily to look for farther, permanent channels.
Total Mercury in Sediments, Macrophytes, and Fish from a Shallow Steppe Lake in Eastern Austria
Authors: Jirsa Franz , Pirker Daniel , Krachler Regina , Keppler Bernhard K. 
Published: August 2014

AbstractDuring summer 2011, samples of sediment, macrophytes, and fish tissues from the shallow, slightly alkaline Lake Neusiedl, Austria, were evaluated for their total Hg content. This is the first report of Hg levels from this lake. Sediments displayed Hg contents between 0.025 and 0.113 μg g−1 dw (dry weight), significantly correlating with the proportion of organic components pointing to a small anthropogenic impact on the lake's Hg content. Hg Levels in plants and fish were unexpectedly high: both investigated submerged plant species, Potamogeton pectinatus and Myriophyllum spicatum, showed mean values of 0.245±0.152 and 0.298±0.115 μg g−1 dw, respectively. Biomagnification was evident when comparing muscle samples of the planktivorous fish species rudd Scardinus erythrophthalmus (n=10, mean=0.084 μg g−1 ww (wet weight)) with the piscivorous perch Perca fluviatilis (n=21, mean=0.184 μg g−1 ww) or pike‐perch Sander lucioperca (n=9, mean=0.205 μg g−1 ww). Significantly lower values were found in the muscle of the piscivorous pike Esox lucius (n=25, mean=0.135 μg g−1 ww), pointing to a specific Hg metabolism of this fish, presumably under the particular physicochemical properties of the lake. Hg Concentrations in fish could pose a risk to piscivorous birds in this protected wetland system.
Ribosylhopane, a Novel Bacterial Hopanoid, as Precursor of C35 Bacteriohopanepolyols in Streptomyces coelicolor A3(2)
Authors: Liu Wenjun , Sakr Elias , Schaeffer Philippe , Talbot Helen M. , Donisi Janina , Härtner Thomas , Kannenberg Elmar , Takano Eriko , Rohmer Michel 
Published: August 2014

AbstractWild‐type Streptomyces coelicolor A3(2) produces aminobacteriohopanetriol as the only elongated C35 hopanoid. The hopanoid phenotype of two mutants bearing a deletion of genes from a previously identified hopanoid biosynthesis gene cluster provides clues to the formation of C35 bacteriohopanepolyols. orf14 encodes a putative nucleosidase; its deletion induces the accumulation of adenosylhopane as it cannot be converted into ribosylhopane. orf18 encodes a putative transaminase; its deletion results in the accumulation of adenosylhopane, ribosylhopane, and bacteriohopanetetrol. Ribosylhopane was postulated twenty years ago as a precursor for bacterial hopanoids but was never identified in a bacterium. Absence of the transaminase encoded by orf18 prevents the reductive amination of ribosylhopane into aminobacteriohopanetriol and induces its accumulation. Its reduction by an aldose‐reductase‐like enzyme produces bacteriohopanetetrol, which is normally not present in S. coelicolor.
Earth‐Abundant Oxygen Evolution Catalysts Coupled onto ZnO Nanowire Arrays for Efficient Photoelectrochemical Water Cleavage
Authors: Jiang Chaoran , Moniz Savio J. A. , Khraisheh Majeda , Tang Junwang 
Published: August 2014

AbstractZnO has long been considered as a model UV‐driven photoanode for photoelectrochemical water splitting, but its performance has been limited by fast charge‐carrier recombination, extremely poor stability in aqueous solution, and slow kinetics of water oxidation. These issues were addressed by applying a strategy of optimization and passivation of hydrothermally grown 1D ZnO nanowire arrays. The length and diameter of bare ZnO nanowires were optimized by varying the growth time and precursor concentration to achieve optimal photoelectrochemical performance. The addition of earth‐abundant cobalt phosphate (Co‐Pi) and nickel borate (Ni‐B) oxygen evolution catalysts onto ZnO nanowires resulted in substantial cathodic shifts in onset potential to as low as about 0.3 V versus the reversible hydrogen electrode (RHE) for Ni‐B/ZnO, for which a maximum photocurrent density of 1.1 mA cm−2 at 0.9 V (vs. RHE) with applied bias photon‐to‐current efficiency of 0.4 % and an unprecedented near‐unity incident photon‐to‐current efficiency at 370 nm. In addition the potential required for saturated photocurrent was dramatically reduced from 1.6 to 0.9 V versus RHE. Furthermore, the stability of these ZnO nanowires was significantly enhanced by using Ni‐B compared to Co‐Pi due to its superior chemical robustness, and it thus has additional functionality as a stable protecting layer on the ZnO surface. These remarkable enhancements in both photocatalytic activity and stability directly address the current severe limitations in the use of ZnO‐based photoelectrodes for water‐splitting applications, and can be applied to other photoanodes for efficient solar‐driven fuel synthesis.