bluuebunny/crossref_metadata_2025_split huggingface dataset:
The CD4+ T‐cell epitope‐binding register is a critical parameter when generating functional HLA‐DR tetramers with promiscuous peptides
Authors: Cecconi Virginia , Moro Monica , Del Mare Sara , Sidney John , Bachi Angela , Longhi Renato , Sette Alessandro , Protti Maria Pia , Dellabona Paolo , Casorati Giulia 
Published: March 2010

AbstractDetection of CD4+ T cells specific for tumor‐associated antigens is critical to investigate the spontaneous tumor immunosurveillance and to monitor immunotherapy protocols in patients. We investigated the ability of HLA‐DR*1101 multimers to detect CD4+ T cells specific for three highly promiscuous MAGE‐A3 derived peptides: MAGE‐A3191–205 (p39), MAGE‐A3281–295 (p57) and MAGE‐A3286–300 (p58). Tetramers stained specific CD4+ T cells only when loaded with p39, although all peptides activated the specific T cells when presented by plastic‐bound HLA‐DR*1101 monomers. This suggested that tetramer staining ability was determined by the mode rather than the affinity of peptide binding to HLA‐DR*1101. We hypothesized that peptides should bear a single P1 anchor residue to bind all arms of the multimer in a homogeneous register to generate peptide‐HLA‐DR conformers with maximal avidity. Bioinformatics analysis indicated that p39 contained one putative P1 anchor residue, whereas the other two peptides contained multiple ones. Designing p57 and p58 analogues containing a single anchor residue generated HLA‐DR*1101 tetramers that stained specific CD4+ T cells. Producing HLA‐DR*1101 monomers linked with the optimized MAGE‐A3 analogues, but not with the original epitopes, further improved tetramer efficiency. Optimization of CD4+ T‐cell epitope‐binding registers is thus critical to generate functional HLA‐DR tetramers.
Successive Ligand and Metal Oxidation: Redox Reactions Involving Binuclear CuI Complexes of Chelating Guanidine Ligands
Authors: Emeljanenko Dimitri , Peters Anastasia , Wagner Norbert , Beck Johannes , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: March 2010

AbstractNew binuclear complexes of three‐coordinate CuI have been synthesized with the ligand 1,2,4,5‐tetrakis(tetramethylguanidino)benzene (ttmgb). Subsequent oxidation of the ligand unit was achieved by reaction with Br2 or I2. Reaction with Br2 leads to oxidation of both the ligand and the copper ions and formation of a bicationic dinuclear CuII complex. On the other hand, oxidation with I2 leads only to oxidation of the ligand during the first step. A metastable coordination polymer of ladder‐type structure results, in which the coordination number of the CuI ions increases to four. Electrical measurements show that this polymer is semiconductive with a band gap of around 1 eV. The electronic structure of the polymer was further studied by X‐ray photoelectron spectroscopy (XPS), Raman and Vis/NIR spectroscopy. It decomposes (with oxidation of the copper ions) in an exothermal reaction at temperatures around 230 °C. Oxidation of the copper ions and decomposition of the polymer can also be achieved by reaction of the polymer with phenanthroline.
Preparation and Conformation Analysis of N‐(Ferrocenoyl)dipeptide Esters and Their 1′‐Acetyl Derivatives
Authors: Lapić Jasmina , Djaković Senka , Kodrin Ivan , Mihalić Zlatko , Cetina Mario , Rapić Vladimir 
Published: March 2010

AbstractFerrocene‐containing dipeptides X‐Fn‐CO‐AA‐AA‐OMe(3/4, X = H, AA = Gly/Ala; 5/6, X = Ac, AA = Gly/Ala, Fn = ferrocene‐1,1′‐diyl) were prepared in 51–67 % yields from the starting appropriate ferrocenecarboxylic acid and dipeptide ester by the HOBt/EDC protocol. Conformation analysis of these bioconjugates was performed by spectroscopic methods (IR, 1H and 13C NMR, CD) and by X‐ray crystal structure analysis, as well as by molecular modelling (DFT). Crystallographic analysis showed that self‐assembly processes prevailed in compound 5, and almost exclusively hydrogen‐bonded species were also detected in all the compounds studied in the solid state by IR spectroscopy (KBr). Spectroscopic studies of conjugates 3–6 undertaken in solution in nonpolar solvents demonstrated formation of intra‐ and interchain weak to medium hydrogen bonds spanning NHAA2 with 1‐FcCO, 1′‐FcCO and/or NAA1 (Fc = ferrocenyl). The same experiments revealed that NHAA1 is not involved in hydrogen bonds. The interchain hydrogen bond in conjugate 6 caused a (P)‐helical arrangement of the ferrocene moiety exhibiting a positive Cotton effect at 495 nm (246 deg M–1cm–1). All of the experimental findings were corroborated by DFT calculations, which furthermore showed conformation preferences in respect to the natural amino acid side chain of conjugates 3–6.
New 5‐Alkoxypyrimidine Derivatives from β‐Alkoxy β‐Keto Enamides and Ammonium Salts
Authors: Lechel Tilman , Reissig Hans‐Ulrich 
Published: March 2010

AbstractA series of highly substituted β‐alkoxy β‐keto enamides were prepared by a multi‐component reaction combining lithiated alkoxyallenes, nitriles and carboxylic acids. Apt conditions were developed for their conversion into 5‐alkoxypyrimidine derivatives. This synthesis is highly flexible with respect to the substitution pattern at C‐2 and C‐4 of the pyrimidine core. The corresponding pyrimidin‐5‐yl nonaflates allowed subsequent transformations at C‐5 by palladium‐catalyzed couplings such as Sonogashira and Suzuki reactions. The Sonogashira coupling of a pyrimidinyl alkyne with a pyridinyl nonaflate and a subsequent cyclization led to an efficient access to pyrimidinyl‐substituted furo[2,3‐c]pyridine derivatives. The C‐6 methyl group which is present in all of the prepared pyrimidines can easily be converted into formyl, carboxylic or alkynyl moieties which allow the synthesis of additional pyrimidine derivatives.
Novel Five‐ to Ten‐Membered Organoselenium Heterocycles from the Selenation of Aromatic Diols
Authors: Hua Guoxiong , Fuller Amy L. , Slawin Alexandra M. Z. , Woollins J. Derek 
Published: March 2010

AbstractReaction of Woollins' reagent ― WR, 2,4‐bis(phenyl)‐1,3‐diselenadiphosphetane 2,4‐diselenide [{PhP(Se)(μ‐Se)}2] ― with aromatic diols in refluxing toluene afforded a series of novel five‐ to ten‐membered phosphorus‐selenium heterocycles 1–10 with an O–P(Se)–O or O–P(Se)–Se–P(Se)–O or O–P(Se)–O–P(Se)–O linkage in 12–74 % isolated yields. It was found that the diphosphorus species O–P(Se)–Se–P(Se)–O rings could be readily reduced into the monophosphorus species O–P(Se)–O rings in almost quantitative yields via further reaction with another equivalent of corresponding aromatic diol. All new compounds have been characterized by IR, 1H NMR, 13C NMR, 31P NMR, 77Se NMR, mass spectrometry and elemental analysis or accurate mass measurement. Seven representative X‐ray structures are reported.
Optically Active Trialkynyl(phenyl)methane: Synthesis and Determination of Its Absolute Configuration by Vibrational Circular Dichroism (VCD) and Optical Rotatory Dispersion (ORD)
Authors: Buschhaus Boris , Convertino Vito , Rivera‐Fuentes Pablo , Alonso‐Gómez José Lorenzo , Petrovic Ana G. , Diederich François 
Published: March 2010

AbstractBoth enantiomers of an optically active trialkynyl(phenyl)methane (the key building blocks in the construction of a stable expanded cubane) have been prepared. The strategy involved the resolution of a racemic intermediate by means of HPLC on a chiral stationary phase. The absolute configuration of this intermediate was unambiguously assigned by using vibrational circular dichroism (VCD) and optical rotatory dispersion (ORD), in combination with density functional theory (DFT) calculations.
A Marriage of Convenience: Combining the Power of Isocyanide‐Based Multicomponent Reactions with the Versatility of (Hetero)norbornene Chemistry (Eur. J. Org. Chem. 10/2010)
Authors: Basso Andrea , Banfi Luca , Riva Renata 
Published: March 2010

AbstractThe cover picture shows one of the six paintings of Marriage á‐la‐mode (© National Gallery, London) created by William Hogarth in 1743–1745 and portrays a pointed skewering of upper‐class 18th century society. This moralistic warning shows the disastrous results of an ill‐considered marriage for money. However, the authors of this Microreview demonstrate that the marriage of convenience between the Ugi reaction and the norbornenyl scaffold is not to be blamed. Details are presented in the Microreview by A. Basso et al. on p. 1831 ff.
Continuous dielectrophoretic separation of particles in a spiral microchannel
Authors: Zhu Junjie , Tzeng Tzuen‐Rong J. , Xuan Xiangchun 
Published: March 2010

AbstractParticle separation is a fundamental operation in the areas of biology and physical chemistry. A variety of force fields have been used to separate particles in microfluidic devices, among which electric field may be the most popular one due to its general applicability and adaptability. So far, however, electrophoresis‐based separations have been limited primarily to batchwise processes. Dielectrophoresis (DEP)‐based separations require in‐channel micro‐electrodes or micro‐insulators to produce electric field gradients. This article introduces a novel particle separation technique in DC electrokinetic flow through a planar double‐spiral microchannel. The continuous separation arises from the cross‐stream dielectrophoretic motion of particles induced by the non‐uniform electric field inherent to curved channels. Specifically, particles are focused by DEP to one sidewall of the first spiral, and then dielectrophoretically deflected toward the other sidewall of the second spiral at a particle‐dependent rate, leading to focused particle streams along different flow paths. This DEP‐based particle separation technique is demonstrated in an asymmetric double‐spiral microchannel by continuously separating a mixture of 5/10 μm particles and 3/5 μm particles.
Pumpless dispensing of a droplet by breaking up a liquid bridge formed by electric induction
Authors: Hong Jin Seok , Lee Beom Seok , Moon Dustin , Lee Jeong–Gun , Kang In Seok 
Published: March 2010

AbstractDispensing uniform pico‐to‐nanoliter droplets has become one of essential components in various application fields from high‐throughput bio‐analysis to printing. In this study, a new method is suggested and demonstrated for dispensing a droplet on the top plate with an inverted geometry by using electric field. The process of dispensing droplets consists of two stages: (i) formation of liquid bridge by moving up the charged fluid mass using the electrostatic force between the charges on the fluid mass and the induced charges on the substrate and (ii) its break‐up by the motion of the top plate. Different from conventional electrohydrodynamic methods, electric induction enables the droplets to be dispensed on various surfaces including non‐conducting substrate. The use of capillarity with an inverted geometry removes the need of external pumps or elaborates control for constant flow feed. The droplet diameter has been characterized as a function of the nozzle‐to‐plate distance and the plate moving velocity. The robustness of the present method is shown in terms of nozzle length and applied voltage. Finally, its practical applicability is confirmed by rendering a 19 by 24 array of highly uniform droplets with only 1.8% size variation without use of any active feedback control.
Supercritical fluid extraction of lipids from the heterotrophic microalga Crypthecodinium cohnii
Authors: Couto Ricardo Miguel , Simões Pedro Calado , Reis Alberto , Da Silva Teresa Lopes , Martins Vítor Hugo , Sánchez‐Vicente Yolanda 
Published: March 2010

AbstractMicroalgae biomass can be a feasible source of ω‐3 fatty acids due to its stable and reliable composition. In the present study, the Crypthecodinium cohnii growth and docosahexaenoic acid (DHA, 22:6ω3) production in a 100 L glucose‐fed batch fermentation was evaluated. The lipid compounds were extracted by supercritical carbon dioxide (SC‐CO2) from C. cohnii CCMP 316 biomas, was and their fatty acid composition was analysed. Supercritical fluid extraction runs were performed at temperatures of 313 and 323 K and pressures of 20.0, 25.0 and 30.0 MPa. The optimum extraction conditions were found to be 30.0 MPa and 323 K. Under those conditions, almost 50% of the total oil contained in the raw material was extracted after 3 h and the DHA composition attained 72% w/w of total fatty acids. The high DHA percentage of total fatty acids obtained by SC‐CO2 suggested that this extraction method may be suitable for the production of C. cohnii value added products directed towards pharmaceutical purposes. Furthermore, the fatty acid composition of the remaining lipid fraction from the residual biomass with lower content in polyunsaturated fatty acids could be adequate for further uses as feedstock for biodiesel, contributing to the economy of the overall process suggesting an integrated biorefinery approach.
Enzymatic synthesis of short‐chain esters in n‐hexane and supercritical carbon dioxide: Effect of the acid chain length
Authors: Diaz Maria Dolores Romero , Gómez Jose M. , Díaz‐Suelto Beatriz , García‐Sanz Alicia 
Published: March 2010

AbstractEnzymatic synthesis is the preferred way to produce so‐called “natural products.” Hydrolases have been used for short‐chain ester synthesis. These esters present a pleasant flavor and they have a lot of applications in different industries. Novozym 435 from Candida antarctica (EC 3.1.1.3, triacylglycerol lipase) was used for hexyl ester synthesis in n‐hexane and supercritical carbon dioxide (SCCO2). Direct esterification provided higher yields than transesterification for the synthesis of esters. Several carboxylic acids of different chain lengths were tested for the esterification reactions: acetic, propionic, butyric, caproic and caprylic acids. The reactions were carried out at 40°C and the amount of enzyme used was 13.8 g/mol alcohol. Substrates were added at equimolar concentrations, with sufficient stirring to avoid external diffusion control. Different substrate concentrations up to 1.5 M were used. The working pressure was 14 MPa in the case of SCCO2 and atmospheric pressure in the case of organic solvent. The results in both solvents show that the reaction rate increases with the chain length of the acid, but the final yields were similar. However, some of the reactions prove to be faster in SCCO2, except for hexyl acetate and propionate synthesis, in which acetic and propionic acid presented a lower solubility in SCCO2 due to its high polarity. Moreover, an acetic acid concentration of 1.5 M brought about a strong inhibition of the enzyme activity.
A predictive model for pressure fluctuations on sloping channels using support vector machine
Authors: Guven Aytac 
Published: March 2010

AbstractIn this study, support vector machine (SVM) is proposed as a new predictive model for pressure fluctuations beneath free jump occurring on sloping channels. The proposed model reproduces the pressure fluctuation intensity C′p in terms of normalized flow and channel section characteristics. The model variables were derived from dimensional analysis. The proposed model is calibrated and validated by using a wide range of experimental data. The SVM predicted C′p with a correlation of coefficient (CC) of 0.989 and a root mean square error (RMSE) of 0.004. Also, linear and nonlinear regression analyses are applied on the same experimental data set, and the SVM model is compared to the equations obtained from these regression analyses. CC, RMSE and average absolute deviation (Di) are used in the evaluation of performance of each model. The SVM model predicted the measured pressure fluctuations better than conventional regression equations. The results of this study reveal that the proposed SVM model can be effectively used in predicting the pressure fluctuation beneath free jump. Copyright © 2010 John Wiley & Sons, Ltd.
Phenanthrene decreases neutrophil function by disrupting intracellular redox balance
Authors: Buttignol M. H. P. , Barros M. P. , Macedo R. C. , Marin D. P. , Otton R. 
Published: March 2010

AbstractThe aim of the present work was to evaluate whether the treatment of human neutrophils with phenanthrene (PHN) can alter the phagocytic and microbicidal capacity of these cells by causing a disruption in redox balance. Peripheral neutrophils from healthy subjects were treated for up to 24 h with increasing concentrations of phenanthrene. Phagocytic/microbicidal activities, antioxidant enzymes, oxidative lesions (thiobarbituric acid‐reactive substances and protein thiol and carbonyl groups) and redox signaling compounds (intracellular Ca2+, superoxide, hydrogen peroxide and nitric oxide) were monitored on neutrophils exposed to 10 µg PHN ml−1. Cell viability decreased abruptly at PHN concentrations above 10 µg ml−1 (LC50 = 20.86 ± 0.51 µg ml−1 and p‐sigmoidal slope = 19.88 ± 10.11). Phagocytic and microbicidal capacities were decreased by 60 and 82%, respectively. Substantial increases in total‐/Mn‐SOD, catalase, glutathione peroxidase and glutathione reductase activities (by 61, 15, 87, 245 and 70%, respectively) matched the oxidative injury obtained in TBARS (2.5‐fold higher) and protein thiol (54% lower). Diminished productions of superoxide by 18% and hydrogen peroxide by 29% were observed in association to exacerbated calcium (27%) and nitric oxide (63%) levels. The data indicate that phenanthrene might be associated with substantial reduction in human neutrophil functions due to severe intracellular redox imbalances. Copyright © 2010 John Wiley & Sons, Ltd.
The use of fluid boluses to safely perform extracorporeal photopheresis (ECP) in low‐weight children: A novel procedure
Authors: Schneiderman Jennifer , A. Jacobsohn David , Collins Jennifer , Thormann Kimberly , Kletzel Morris 
Published: March 2010

AbstractApheresis procedures in small children are technically challenging and require special planning with attention to extracorporeal volume. Discontinuous procedures such as extracorporeal photopheresis (ECP) require additional consideration. Alternative methods to perform ECP have been utilized in small children that require manipulation of mononuclear cells outside the standard closed‐loop system. We present a safe and feasible alternative to the procedure for children who weigh less than 40 Kg, while maintaining a closed loop, sterile system utilizing the UVAR XTS device. A retrospective chart review was performed analyzing the use of fluid boluses (normal saline in those between 20 and 40 Kg, 5% albumin in those under 20 Kg) before ECP. Eleven patients underwent 334 ECP procedures for acute and chronic graft‐versus‐host disease (n = 9), and for prevention of graft‐versus‐host disease (n = 2). Volumes of fluid boluses were calculated based on the expected extracorporeal volume during the first draw cycle. Treatments consisted of at least three draw cycles using the 125 mL bowl. The median weight was 28.5 Kg (range 19 to 39); nine of 11 required red cell transfusions to maintain adequate hematocrit. Complications attributed to ECP included tachycardia, dizziness, nausea, and hypotension; these occurred either in combination or isolation in 31% of the procedures and resolved following additional fluid boluses. Only three (0.8%) required early photoactivation due to these complications. The median time to completion of treatment was 2 h and 58 min (range 1:30 to 5:03). ECP is well tolerated in low‐weight pediatric patients if hematocrit and hydration are carefully maintained. J. Clin. Apheresis, 2010. © 2010 Wiley‐Liss, Inc.
Oxidative damage to DNA and lipids: correlation with protein glycation in patients with type 1 diabetes
Authors: Goodarzi Mohammad Taghi , Navidi Ali Akbar , Rezaei Mohsen , Babahmadi‐Rezaei Hossein 
Published: March 2010

AbstractDiabetic hyperglycemia is associated with increased production of reactive oxygen species (ROS). ROS reacts with DNA resulting in various products, such as 8‐hydroxydeoxyguanosine (8‐OHdG), that excrete in urine owing to DNA repair processes. Urinary 8‐OHdG has been proposed as an indicator of oxidative damage to DNA. This study aimed to evaluate relationship between oxidative damage to DNA and protein glycation in patients with Type 1 diabetes. We measured urinary 8‐OHdG level in diabetic patients and healthy subjects and discussed its relationship to glycated hemoglobin (HbA1c) and glycated serum protein (GSP) levels. Furthermore plasma malondialdehyde (MDA) level monitored as an important indicator of lipid peroxidation in diabetes. We studied 32 patients with Type 1 diabetes mellitus and compared the measured factors with those of 48 age‐matched nondiabetic controls. GSP and MDA were measured bycolorimetric assay. Urinary 8‐OHdG measurement was carried out using ELISA. In this study urinary 8‐OHdG, HbA1c, plasma MDA, and GSP levels were progressively higher in diabetics than in control subjects (P<0.05). Furthermore we found significant correlation between urinary 8‐OHdG and HbA1c (P<0.05) in diabetic group. Correlation between fasting blood sugar and GSP were significant. We also found significant correlation between fasting blood sugar and MDA. This case–control study in young diabetic patients showed increased blood glucose and related metabolic disorders result in oxidative stress and oxidative damage to DNA and lipids. Furthermore oxidative damage to DNA is associated to glycemic control level, whereas lipid peroxidation level was not significantly correlated with glycemic control level. J. Clin. Lab. Anal. 24:72–76, 2010. © 2010 Wiley‐Liss, Inc.
fbl gene as a species‐specific target for Staphylococcus lugdunensis identification
Authors: Chatzigeorgiou Kalliopi‐Stavroula , Siafakas Nikolaos , Petinaki Efthymia , Zerva Loukia 
Published: March 2010

AbstractStaphylococcus lugdunensis is an unusually virulent coagulase‐negative species, associated with severe infections. The present report describes the development of a single‐step, species‐specific PCR protocol for S. lugdunensis identification. fbl gene, encoding a fibrinogen‐binding adhesin, was exploited and assessed as a suitable nucleic acid target. The gene was detected in all 17 S. lugdunensis isolates examined, while no amplification product was obtained from 98 isolates representing 11 staphylococcal and 17 nonstaphylococcal species. Forty‐seven percent of the S. lugdunensis strains produced a positive slide coagulase reaction, which is consistent with varying levels of Fbl protein expression within the species. J. Clin. Lab. Anal. 24:119–122, 2010. © 2010 Wiley‐Liss, Inc.