bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excited‐State Proton Transfer in Bifunctional Compounds
Authors: Bardez Elisabeth 
Published: November 2013

AbstractWhen the acidic and basic groups of an amphoteric compound become stronger on excitation, excited‐state proton transfers (ESPT) are driven by the photoinduced synergy between the two functions. This is exemplified here by 7‐ and 8‐hydroxyquinolines (7‐ and 8‐HQ), whatever the initially excited form. For instance, the ‐OH group of the 7‐hydroxyquinolinium form undergoes photoinduced deprotonation even in 8M HClO4! This reveals its outstanding photoacidity, confirmed by the value of the deprotonation rate constant k1 at infinite dilution, 5.5 × 1010 s−1. The decrease of k1 on increasing the ionic strength pointed out the key number of 4 water molecules as proton acceptors. In neutral medium, a very efficient photoinduced tautomerization is observed. For 7‐HQ in water, a mechanism consisting of three competitive paths was established: A proton translocation via a bridge of water molecules within less than 10 ps for the cis‐isomer, and two stepwise competitive reactions for the trans‐isomer. Concerning the weakly fluorescent 8‐HQ, the photoinduced tautomerization occurs even in organic media. In most solvents, an intrinsic ESPT takes place within intramolecularly H‐bonded molecules, but preferential solvation by residual water of the solvent may lead to open structures where ESPT is impaired. In alkanes, a biprotonic ESPT is expected to occur within very stable dimers (Kdim= 7.0 × 107). In all cases, the coupling between proton transfers and an intramolecular electron transfer leads to the ketonic structure of the tautomer. This might be a general feature in phototautomerization reactions.
Theoretical Studies of the Grotthuss Mechanism in Biological Proton Wires
Authors: Pomès Régis 
Published: November 2013

AbstractThe structural, dynamic, and thermodynamic properties of proton wires are examined. Detailed molecular aspects of both hop and turn steps of the Grotthuss mechanism for proton conduction along single‐file chains of water molecules in model nonpolar pores and in the gramicidin A channel are reviewed, and new simulation results are presented. The Grotthuss mechanism is discussed and analyzed in terms of hydrogen‐bonded network structure and connectivity, and the properties of proton wires are contrasted to those of bulk water. General considerations regarding the biological relevance of such studies are proposed.
Highly aligned porous Ti scaffold coated with bone morphogenetic protein‐loaded silica/chitosan hybrid for enhanced bone regeneration
Authors: Jung Hyun‐Do , Yook Se‐Won , Han Cheol‐Min , Jang Tae‐Sik , Kim Hyoun‐Ee , Koh Young‐Hag , Estrin Yuri 
Published: November 2013

AbstractPorous Ti has been widely investigated for orthopedic and dental applications on account of their ability to promote implant fixation via bone ingrowth into pores. In this study, highly aligned porous Ti scaffolds coated with a bone morphogenetic protein (BMP)‐loaded silica/chitosan hybrid were produced, and their bone regeneration ability was evaluated by in vivo animal experiments. Reverse freeze casting allowed for the creation of highly aligned pores, resulting in a high compressive strength of 254 ± 21 MPa of the scaffolds at a porosity level of ∼51 vol %. In addition, a BMP‐loaded silica/chitosan hybrid coating layer with a thickness of ∼1 μm was uniformly deposited on the porous Ti scaffold, which enabled the sustained release of the BMP over a prolonged period of time up to 26 days. The cumulative amount of the BMP released was ∼4 μg, which was much higher than that released from the specimen without a hybrid coating layer. In addition, the bone regeneration ability of the porous Ti scaffold with a BMP‐loaded silica/chitosan coating layer was examined by in vivo animal testing using a rabbit calvarial defect model and compared with those of the as‐produced porous Ti scaffold and porous Ti scaffold with a silica/chitosan coating layer. After 4 weeks of healing, the specimen coated with a BMP‐loaded silica/chitosan hybrid showed a much higher bone regeneration volume (∼36%) than the as‐produced specimen (∼15%) (p < 0.005) and even the specimen coated with a silica/chitosan hybrid (∼25%) (p < 0.05). © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 913–921, 2014.
99mTc‐Doxycycline hyclate: a new radiolabeled antibiotic for bacterial infection imaging
Authors: İlem‐Özdemir Derya , Asikoglu Makbule , Ozkilic Hayal , Yilmaz Ferda , Hosgor‐Limoncu Mine , Ayhan Semin 
Published: November 2013

Radiolabeled antibiotics are promising radiopharmaceuticals for the precise diagnosis and detection of infectious lesions. Doxycycline Hyclate (DOX) was chosen to investigate new 99mTc‐labeled antibacterial agent. Ready to use freeze dry kits were formulated with optimum labeling conditions. Human serum stability, sterility, and pyrogenicity of kits were estimated, and gamma scintigraphy, in vivo biodistribution, and histopathological studies with bacterial infected rats were performed.DOX were successfully labeled by 99mTc with high radiochemical purity, and the labeled compound was stable in human serum. Kits were sterile, pyrogen‐free, and stable up to 6 months.Static images depicted rapid distribution throughout the body and high uptake in bacterial infected thigh muscle. The uptake ratios of radiopharmaceuticals in infected thigh muscle were found above 2 up to 5 h.Five hours after injection, the rats were sacrificed, and biodistribution was determined. Samples of bacterial infected muscle, healthy muscle, blood, liver, spleen, lung, kidney, stomach, intestine, urine and heart were weighed, and the radioactivity was measured by using a gamma counter. The %ID/g of 99mTc‐DOX was found 0.23 ± 0.06 for infected thigh muscle.According to the imaging, biodistribution, and histopathological studies, the promising characteristics of 99mTc‐DOX make the new radiopharmaceutical valuable to examine for future studies. Copyright © 2013 John Wiley & Sons, Ltd.
Simultaneous Polymerization‐Induced Self‐Assembly (PISA) and Guest Molecule Encapsulation
Authors: Karagoz Bunyamin , Boyer Cyrille , Davis Thomas P. 
Published: November 2013

Nanoparticles with various morphologies such as micelles, worm‐like/rod‐like and spherical vesicles are made using a polymerization‐induced self‐assembly (PISA) approach via a one‐pot RAFT dispersion polymerization. On polymerization/self‐assembly, we report a concurrent highly efficient loading of guest molecules within the nanoparticle structures. Different nanoparticle morphologies, such as spherical micelles, worm‐like, rod‐like, and spherical vesicles, are achieved by gradually increasing the number‐average degree of polymerization (DPn) of the PST block via increasing polymerization times (in a poor solvent) as determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. In parallel, a guest molecule (Nile Red) is encapsulated during the polymerization without disturbing the morphology or the polymerization kinetics.
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Nature of molecular network in thermal shrinkage behavior of oriented high‐density polyethylene
Authors: Fu Lianlian , Jiang Zhiyong , Enderle Hans‐Friedrich , Lilge Dieter , Li Xiuhong , Funari Sérgio S. , Men Yongfeng 
Published: November 2013

ABSTRACTShrinkage and structural evolution of oriented high‐density polyethylene on heating were investigated by a combination of thermomechanical analysis (TMA) and synchrotron small angle X‐ray scattering (SAXS) techniques. Under varying load conditions, TMA study was performed to record the continuous length changes as a function of temperature. The value of shrinkage without any load could be evaluated by a linear extrapolation method, which eliminated the influence of the required tension by traditional TMA approach. In addition, the apparent modulus of network was used to describe the nature of entangled molecular network in detail during the shrinkage process. Importantly, it was found that the apparent modulus decreased gradually with increasing temperature. Furthermore, the SAXS data provided a direct evidence for the variation trend of shrinkage stress obtained by the tensile testing stage, and the results confirmed that the shrinkage force mainly originates from interfibrillar networks. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 368–376
Tandem mass spectrometry for the study of glyoxal‐derived advanced glycation end‐products (AGEs) in peptides
Authors: Lopez‐Clavijo Andrea F. , Duque‐Daza Carlos A. , O'Connor Peter B. 
Published: November 2013

RATIONALEThe post‐translational modification known as glycation affects the physiological properties of peptides and proteins. Glycation is particularly important during hyperglycaemia where α‐dicarbonyl compounds are generated. These compounds react with proteins to generate α‐dicarbonyl‐derived glycation products, which are correlated with diabetic complications such as nephropathy, retinopathy, and neuropathy, among others. One of these α‐dicarbonyl compounds is ethanedial, also known as glyoxal. Thereby, glyoxal binding to protein/peptides is studied by electron capture dissociation (ECD) and collisionally activated dissociation (CAD).METHODSAcetylated and non‐acetylated undecapeptides containing one lysine and one arginine susceptible of glycation were reacted with glyoxal under pseudo‐physiological and MeOH/H2O (50:50) conditions. Two types of glyoxal‐derived AGEs were fragmented by ECD and CAD using 12 Tesla Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS).RESULTSReaction with glyoxal under different reaction conditions showed the addition of C2O and C2H2O2, which corresponded to a net increase on the peptide mass of 39.9949 Da and 58.0055 Da, respectively. The binding site was assigned within an error <1 ppm, using ECD and CAD. The results indicated that both types of glyoxal‐derived AGEs are formed at the side chain of arginine located in position 3.CONCLUSIONSTypes and binding sites of glyoxal‐derived AGEs were investigated in peptides containing one arginine‐one lysine using FTICRMS. Two net mass additions to the mass of the peptide were assigned as C2O and C2H2O2, which were located at the arginine side chain. In addition, these mass additions (C2O and C2H2O2) observed in the peptides were unaffected by different reaction conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Compound‐specific δ13C and δ15N analysis of amino acids: a rapid, chloroformate‐based method for ecological studies
Authors: Walsh Robert G. , He Shaoneng , Yarnes Christopher T. 
Published: November 2013

RATIONALECompound‐specific stable isotope analysis of amino acids has proven informative to many ecological systems, but only a handful of analytical methods are routinely employed. We evaluated a simple, rapid procedure in which biological samples undergo short‐duration acid hydrolysis and the resulting amino acids are derivatized with methyl chloroformate for gas chromatography/combustion/isotope‐ratio mass spectrometry (GC/C/IRMS).METHODSAmino acid derivatives were separated on a polar gas chromatography column, combusted, and δ13C and δ15N values were measured. Tests of reproducibility and accuracy were conducted for amino acid reference mixtures and biological samples. A brief case study of turtles was used to assess whether isotopic data were consistent with a priori ecological expectations.RESULTSThe methyl chloroformate based reaction successfully converted 15 amino acids from acid hydrolysates of biological materials into separable derivatives. The δ13C and δ15N values had high average measurement precision (σ <1 ‰). Reference materials were measured accurately, with good agreement between EA/IRMS and GC/C/IRMS determinations. Analysis of turtle blood samples yielded data consistent with their trophic ecology.CONCLUSIONSThis derivatization method is a rapid means of determining carbon and nitrogen isotopic ratios of amino acids present in the biological materials often sampled for ecological studies. While amino acids with charged or polar side chains do not have uniformly high recoveries, the average precision of measurements is comparable with that of other, more established methods. Batches of samples may be prepared from many raw materials in less than a day, representing a significant reduction in preparation time over prevailing methods. Copyright © 2013 John Wiley & Sons, Ltd.
Electrospray ionization mass spectrometry probing of binding affinity of berbamine, a flexible cyclic alkaloid from traditional Chinese medicine, with G‐quadruplex DNA
Authors: Tan Wei , Zhou Jiang , Yuan Gu 
Published: November 2013

RATIONALEClassic G‐quadruplex binders typically have a large aromatic core and interact with G‐quadruplexes through π–π stacking with the quartets. There are rather few reports on natural flexible cyclic molecule from traditional Chinese medicine which has high binding affinity with G‐quadruplex.METHODSElectrospray ionization mass spectrometry (ESI‐MS) experiments were performed to evaluate the binding affinities of a natural alkaloid, berbamine, with seven G‐quadruplexes. Furthermore, we utilized autodock4 analysis to uncover the binding mode of berbamine with the G‐quadruplex.RESULTSESI‐MS experiments showed that berbamine has the best binding affinity toward the (GGA)8 G‐quadruplex compared with the other six G‐quadruplexes. Autodock4 analysis indicated that berbamine interacted with the (GGA)8 G‐quadruplex through hydrogen bonding and van der Waals forces with a binding site at the lateral groove formed by DG8‐DA9‐DA15‐DG16.CONCLUSIONSIn this study, we discovered a novel G‐quadruplex binder, berbamine, which has high binding affinity toward the (GGA)8 G‐quadruplex. This study provided important clues regarding the probing of small molecule from traditional Chinese medicine which can target the G‐quadruplex with high affinity. Copyright © 2013 John Wiley & Sons, Ltd.
Is superoptimization viable for VM instruction sets?
Authors: Hume Tom , Watson Des 
Published: November 2013

SummaryThe technique of superoptimization attempts to ensure true optimality of a code (according to predefined criteria) through an exhaustive search of all potentially viable programs. Implementations have demonstrated that superoptimizers are capable of finding shorter programs than those hand optimized for size by experts or produced by conventional compilers. Superoptimizers have been developed for many machine architectures and used for diverse purposes including automating peephole optimization and binary translation of instruction sets. The output of superoptimizers is frequently surprising to human experts and often takes advantage of side effects or obscure characteristics of the targeted hardware. Virtual machines (VMs) are increasingly popular in implementations of programming languages, because they can provide a common platform across heterogeneous hardware architectures. This paper examines whether superoptimization could be a viable technique for VMs. A superoptimizer for the Java VM (JVM) has been developed and used to generate demonstrably size‐optimized versions of some simple mathematical functions, implemented in a Java bytecode. We have shown that these versions are shorter than both implementations shipped with the Java software development kit and those generated by the Java compiler. We also have some useful observations concerning techniques to allow larger programs to be optimized in a reasonable time by this approach. Copyright © 2013 John Wiley & Sons, Ltd.
Wide Resection of Inguinal Nerves versus Simple Section to Prevent Postoperative Pain after Prosthetic Inguinal Hernioplasty: Our Experience
Authors: Zannoni M. , Luzietti E. , Viani L. , Nisi P. , Caramatti C. , Sianesi M. 
Published: November 2013

AbstractBackgroundIn the literature, chronic groin pain (i.e. lasting >3 months) occurs in about 10 % of patients who undergo inguinal hernioplasty with prosthesis; it is characterized by a broad range of symptoms, and is relative to individual perceptions of pain. In 2–5 % of cases, the painful symptomatology is so intense that it interferes with daily activities, and can be debilitating in 0.5–6 % of cases. The best known cause of inguinodynia is neuropathy, due to implication of one or more inguinal nerves (iliohypogastric, ilioinguinal, and genitofemoral nerves) into fibroblastic processes; or from nervous stimulation caused by prosthetic material on adjacent nervous trunks. Many therapeutic strategies have been proposed to treat chronic groin pain, including intra‐operative prophylactic neurectomy.ObjectiveThe purpose of our study was to perform a comparative analysis between outcomes from wide resections of inguinal nerves versus those from simple nervous section (or minimal resection).Patients and methodsWe considered 350 patients who had undergone inguinal prosthetic hernioplasty with Trabucco’s technique between 2004 and 2010. Wide nervous resection (removal of nerve segments 3–8 cm in length) was performed in 180. The other 170 patients underwent simple section or minimal resection. All patients were checked 1 week, 1 month, and 1 year after surgery.ResultsGroup 1: At 1‐week follow‐up, 63 patients (35 %) reported no pain, 113 (63 %) reported moderate pain, and 4 (2 %) intense pain; 1 month after the procedure, 152 patients (84.4 %) reported no pain, 25 (14 %) complained of moderate pain, and 3 (1.6 %) of severe pain; 1 year after surgery, only 1 patient (0.5 %) complained of constant pain. Group 2: At 1 week follow‐up, 48 patients (28 %) reported no pain, 101 (59 %) reported moderate pain, and 21 (13 %) intense pain; 1 month after the procedure, 81 patients (47.6 %) had no pain, 72 (42.4 %) complained of moderate pain, and 17 (10 %) of severe pain; 1 year after surgery, 11 patients (6.5 %) had constant pain, and two of them were re‐admitted for surgery. The lower incidence of chronic pain after long nervous resection is statistically significant (0.5 vs. 6.5 %; p = 0.006); the incidence of moderate pain 1 month after operation is also lower (14 vs. 42.4 %; p < 0.0001); patients who underwent a long resection experienced faster resolution of pain symptomatology, during a month. Also noteworthy is the lower incidence of intense pain in the short and medium term (after 1 week, 13 vs. 2 %, p = 0.0005; after 1 month, 10 vs. 1.6 %, p = 0.0018).ConclusionsThe prophylactic wide resection of selected segments of inguinal nerves, despite the apparent paradox of greater tissue damage, appears more effective than simple section at preventing postoperative inguinodynia, given both the lower incidence and the faster resolution of painful symptomatology.
Changes in Tissue Lipid and Fatty Acid Composition of Farmed Rainbow Trout in Response to Dietary Camelina Oil as a Replacement of Fish Oil
Authors: Hixson Stefanie M. , Parrish Christopher C. , Anderson Derek M. 
Published: November 2013

AbstractCamelina oil (CO) replaced 50 and 100 % of fish oil (FO) in diets for farmed rainbow trout (initial weight 44 ± 3 g fish−1). The oilseed is particularly unique due to its high lipid content (40 %) and high amount of 18:3n‐3 (α‐linolenic acid, ALA) (30 %). Replacing 100 % of fish oil with camelina oil did not negatively affect growth of rainbow trout after a 12‐week feeding trial (FO = 168 ± 32 g fish−1; CO = 184 ± 35 g fish−1). Lipid and fatty acid profiles of muscle, viscera and skin were significantly affected by the addition of CO after 12 weeks of feeding. However, final 22:6n‐3 [docosahexaenoic acid (DHA)] and 20:5n‐3 [eicosapentaenoic acid (EPA)] amounts (563 mg) in a 75 g fillet (1 serving) were enough to satisfy daily DHA and EPA requirements (250 mg) set by the World Health Organization. Other health benefits include lower SFA and higher MUFA in filets fed CO versus FO. Compound‐specific stable isotope analysis (CSIA) confirmed that the δ13C isotopic signature of DHA in CO fed trout shifted significantly compared to DHA in FO fed trout. The shift in DHA δ13C indicates mixing of a terrestrial isotopic signature compared to the isotopic signature of DHA in fish oil‐fed tissue. These results suggest that ~27 % of DHA was synthesized from the terrestrial and isotopically lighter ALA in the CO diet rather than incorporation of DHA from fish meal in the CO diet. This was the first study to use CSIA in a feeding experiment to demonstrate synthesis of DHA in fish.
Characterization and Oxidative Stability of Human Milk Fat Substitutes Enzymatically Produced from Palm Stearin
Authors: Zou Xiaoqiang , Huang Jianhua , Jin Qingzhe , Guo Zheng , Liu Yuanfa , Cheong Lingzhi , Xu Xuebing , Wang Xingguo 
Published: November 2013

AbstractProduction of human milk fat substitutes (HMFSs) from three types of palm stearin with palmitic acid (PA) of 91.3, 70.3 and 62.6 %, respectively, was scaled up to a kilogram scale. The physiochemical properties of these products including fatty acid profiles, triacylglycerol compositions, tocopherol contents, oxidative stability and melting and crystallization profiles were compared with those of HMFSs from lard, butterfat and tripalmitin and fats from infant formulas. Based on their chemical compositions, HMFSs from palm stearin with PA contents of 70.3 and 62.6 % produced by enzymatic acidolysis were found to have the highest degree of similarity to human milk fat, which indicated that these HMFSs were the most suitable for use in infant formulas. However, HMFSs from palm stearin with PA content of 91.3 % had the highest tocopherol contents. By investigation of the primary and secondary oxidation products during accelerated oxidation, the oxidative stability of HMFSs was found to be positively correlated to the contents of tocopherols, and the volatile oxidation compounds with the highest relative contents in HMFSs were aldehydes analyzed by solid‐phase microextraction‐GC–MS. All HMFSs had final melting points lower than body temperature.