bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of Osmotic Dehydration of Seedless Guava (Psidium guajava L.) in Sucrose Solution using Response Surface Methodology
Authors: Ganjloo Ali , Rahman Russly A. , Bakar Jamilah , Osman Azizah , Bimakr Mandana 
Published: March 2014

Abstract
In this study, osmotic dehydration of seedless guava was studied through response surface methodology. Seedless guava cubes were dehydrated in sucrose solution at different concentration (30–50% w/w), temperature (30–50°C) and immersion time (15–240 min) with respect to weight reduction, solid gain and water loss. A Box–Behnken design was used to determine the optimum processing conditions that yield maximum weight reduction, water loss and minimum solid gain. The models developed for all responses were significant (p<0.05). The response surface plots were constructed to show the interaction of process variables. Optimum process conditions were found to be sucrose concentration of 33.79% w/w, temperature of 30.00°C and immersion time of 240 min through desirability function method. At these optimum points, weight reduction, solid gain and water loss were found to be 0.189 (gg−1), 0.050 (gg−1) and 0.237 (gg−1), respectively.
Zethrene and expanded zethrenes with tunable ground states and physical properties
Authors: Sun Zhe , Wu Jishan 
Published: March 2014

Abstract
Zethrene and its related molecules have attracted much attention from the perspectives of both synthetic chemistry and materials science. One characteristic feature of these molecules is the existence of two distinct resonance structures, a closed-shell quinoidal form and an open-shell biradical form, which will lead to a significant biradical contribution to the ground-state electronic configuration. As a result, zethrene-based molecules exhibit unique optical, electronic, and magnetic properties, which open the door for a diversity of applications in the field of electronics, nonlinear optics, and spintronics.
Cu(I)/Cu(III) catalytic cycle involved in Ullmann-type cross-coupling reactions
Authors: Ribas Xavi , Güell Imma 
Published: March 2014

Abstract
Copper-catalyzed cross-coupling reactions for C–heteroatom bond formation have attracted numerous research groups in the past 15 years aiming at finding more efficient methodologies under milder conditions. The use of auxiliary ligands has tremendously improved Ullmann-type couplings although a general methodology for different heteroatom-nucleophiles is still lacking. Mechanistic insights are seen as a clue for designing new effective, broad-scope and general methodologies. In this review we describe the widely discussed mechanistic options for this reaction and the use of model compounds to unravel key mechanistic aspects for copper-catalyzed C–heteroatom transformations. Stable aryl-Cu(III) species in model systems are shown to be reliable active catalysts in the coupling of a broad nucleophile scope such as phenols, amides, sulfides, selenides, phosphites, halides and also activated methylene susbtrates for carbon–carbon couplings.
Chemoenzymatic synthesis of functional amylosic materials
Authors: Kadokawa Jun-ichi 
Published: March 2014

AbstractIn this article, a review of the chemoenzymatic synthesis of functional amylosic materials by means of a-glucan phosphorylase-catalyzed enzymatic polymerization is presented. The first topic of this review deals with the synthesis of amylose-grafted heteropolysaccharides composed of abundant polysaccharide main chains, such as chitin/chitosan, cellulose, alginate, xanthan gum, and carboxymethyl cellulose. The synthesis was achieved by combining the a-glucan phosphorylase-catalyzed enzymatic polymerization forming amylose with the appropriate chemical reaction (chemoenzymatic method). The second topic is the construction of amylosic supramolecular materials such as hydrogels and films by means of the vine-twining polymerization approach, which is a method for the formation of amylose-polymer inclusion complexes in the a-glucan phosphorylase-catalyzed polymerization field. In these studies, the designed graft copolymeric guest compounds were first synthesized. Then, the a-glucan phosphorylase-catalyzed enzymatic polymerization was carried out in the presence of the graft copolymers to produce the amylosic supramolecular materials through the formation of inclusion complexes.
Rhenium(I)-catalyzed reaction of terminal alkynes with imines leading to allylamine derivatives
Authors: Fukumoto Yoshiya , Daijo Masato , Chatani Naoto 
Published: March 2014

Abstract
The rhenium-catalyzed reaction of terminal alkynes with imines gives N-alkylideneallylamine derivatives. A diphenylmethyl group as the substituent on the imine nitrogen gave the best result. Deuterium labeling experiments revealed that the regioselective addition of both the hydrogen and the N-alkylideneaminoalkyl group to the terminal alkynes also proceeded stereoselectively. While alkynes bearing primary and secondary alkyl-, vinyl-, and aryl groups were applicable to the catalytic reaction, tertiary alkyl- and silyl-substituted alkynes gave propargylamines. The C–C bond-forming step via the nucleophilic attack of the alkynyl β-carbon on the imine carbon leading to the formation of a vinylidene rhenium species appears to be involved in the catalytic cycle.
A database of water transitions from experiment and theory (IUPAC Technical Report)
Authors: Tennyson Jonathan , Bernath Peter F. , Brown Linda R. , Campargue Alain , Császár Attila G. , Daumont Ludovic , Gamache Robert R. , Hodges Joseph T. , Naumenko Olga V. , Polyansky Oleg L. , Rothman Laurence S. , Vandaele Ann Carine , Zobov Nikolai F. 
Published: March 2014

Abstract
The report and results of an IUPAC Task Group (TG) formed in 2004 on “A Database of Water Transitions from Experiment and Theory” (Project No. 2004-035-1-100) are presented. Energy levels and recommended labels involving exact and approximate quantum numbers for the main isotopologues of water in the gas phase, H2
16O, H2
18O, H2
17O, HD16O, HD18O, HD17O, D2
16O, D2
18O, and D2
17O, are determined from measured transition frequencies. The transition frequencies and energy levels are validated using first-principles nuclear motion computations and the MARVEL (measured active rotational–vibrational energy levels) approach. The extensive data including lines and levels are required for analysis and synthesis of spectra, thermochemical applications, the construction of theoretical models, and the removal of spectral contamination by ubiquitous water lines. These datasets can also be used to assess where measurements are lacking for each isotopologue and to provide accurate frequencies for many yet-to-be measured transitions. The lack of high-quality frequency calibration standards in the near infrared is identified as an issue that has hindered the determination of high-accuracy energy levels at higher frequencies. The generation of spectra using the MARVEL energy levels combined with transition intensities computed using high accuracy ab initio dipole moment surfaces are discussed. A recommendation of the TG is for further work to identify a single, suitable model to represent pressure- (and temperature-) dependent line profiles more accurately than Voigt profiles.
The complex structure of ionic liquids at an atomistic level: from “red-and-greens” to charge templates
Authors: Shimizu Karina , Bernardes Carlos E.S. , Lopes José N. Canongia 
Published: March 2014

Abstract
In this article, we discuss how the relation between interactions and structure in ionic liquids (ILs) can be probed at a molecular level using ab initio and molecular dynamics (MD) methodologies. The first part of the discussion will focus on the unique and complex properties of ILs as pure substances including the existence of an extended and flexible polar network and the possibility of a second nanosegregated subphase containing the nonpolar residues of the molecular ions that constitute some ILs. The discussion will then be extended to IL plus molecular species mixtures/solutions. In this context the concept of ILs as charge templates for the electronic make-up of the molecular species will be analyzed at length. Finally, that concept will be extended to ILs adsorbed over solid substrates.
What is “hypermobile” water?: detected in alkali halide, adenosine phosphate, and F-actin solutions by high-resolution microwave dielectric spectroscopy
Authors: Suzuki Makoto 
Published: March 2014

AbstractExperimental observation by high-resolution microwave dielectric spectroscopy of hydration properties of alkali halide ions, adenosine phosphate ions, and F-actin revealed the existence of hypermobile water (HMW) molecules around those solutes. To understand the molecular process of HMW, two theoretical approaches are reviewed here. One is based on a statistical mechanical approach to analyze the rotational freedom of water molecules around a charged particle. Another approach reports direct calculation of dielectric relaxation process of water molecules around an ion. Experimentally observed HMW molecules are theoretically explained with the significance of multi-correlations among an ion and water molecules.
Defining the transfer coefficient in electrochemistry: An assessment (IUPAC Technical Report)
Authors: Guidelli Rolando , Compton Richard G. , Feliu Juan M. , Gileadi Eliezer , Lipkowski Jacek , Schmickler Wolfgang , Trasatti Sergio 
Published: March 2014

AbstractThe transfer coefficientαis a quantity that is commonly employed in the kinetic investigation of electrode processes. In the 3rdedition of the IUPAC Green Book, the cathodic transfer coefficientαcis defined as –(RT/nF)(dlnkc/dE), wherekcis the electroreduction rate constant,Eis the applied potential, andR, T, andFhave their usual significance. This definition is equivalent to the other, -(RT/nF)(dln|jc|/dE), wherejcis the cathodic current density corrected for any changes in the reactant concentration at the electrode surface with respect to its bulk value. The anodic transfer coefficientαais defined similarly, by simply replacingjcwith the anodic current densityjaand the minus sign with the plus sign. It is shown that this definition applies only to an electrode reaction that consists of a single elementary step involving the simultaneous uptake ofnelectrons from the electrode in the case ofαc, or their release to the electrode in the case ofαa. However, an elementary step involving the simultaneous release or uptake of more than one electron is regarded as highly improbable in view of the absolute rate theory of electron transfer of Marcus; the hardly satisfiable requirements for the occurrence of such an event are examined. Moreover, the majority of electrode reactions do not consist of a single elementary step; rather, they are multistep, multi-electron processes. The uncritical application of the above definitions ofαcandαahas led researchers to provide unwarranted mechanistic interpretations of electrode reactions. In fact, the only directly measurable experimental quantity isdln|j|/dE, which can be made dimensionless upon multiplication byRT/F, yielding (RT/F)(dln|j|/dE). One common source of misinterpretation consists in setting this experimental quantity equal toαn, according to the above definition of the transfer coefficient, and in trying to estimatenfromαn, upon ascribing an arbitrary value toα, often close to 0.5. The resultingnvalue is then identified with the number of electrons involved in a hypothetical rate-determining step or with that involved in the overall electrode reaction. A few examples of these unwarranted mechanistic interpretations are reported. In view of the above considerations, it is proposed to define the cathodic and anodic transfer coefficients by the quantitiesαc= –(RT/F)(dln|jc|/dE) andαa= (RT/F)(dlnja/dE), which are independent of any mechanistic consideration.
Enantioselective palladium(0)-catalyzed C–H arylation strategy for chiral heterocycles
Authors: Saget Tanguy , Cramer Nicolai 
Published: March 2014

Abstract
Transition-metal-catalyzed C–H functionalizations have emerged as complementary and powerful tools to access molecular complexity from widely available starting materials. Herein, we present a strategy for asymmetric intramolecular Pd(0)-catalyzed C–H functionalizations. The outlined reactivity is based on the cooperative effect between a chiral phosphorous ligand and a carboxylate base acting as a relay of chirality during the enantio-discriminating concerted metalation deprotonation step. This approach allows the enantioselective construction of a range of important semi-saturated chiral nitrogen-containing heterocycles such as indolines, tetrahydroquinolines, and dibenzazepinones.
Nickel-catalyzed oxidative cross-coupling of arylboronic acids with olefins
Authors: Liu Dong , Liu Chao , Lei Aiwen 
Published: March 2014

Abstract
A novel and efficient nickel-catalyzed oxidative cross-coupling of arylboronic acids with olefins to synthesize 1,2-diarylalkenes has been developed. By employing Ni(acac)2 as the catalyst, TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) as the oxidant, a variety of arylboronic acids and styrene derivatives could be cross-coupled efficiently to afford the corresponding 1,2-diarylalkenes in moderate-to-good yields. Notably, high E-selectivity of 1,2-diarylalkenes was obtained with the aid of a high temperature of 120°C. Moreover, boric acid esters also proved to be efficient coupling partners. Initial mechanistic studies suggest that this reaction proceeds through a radical pathway.
Transition-metal clusters as catalysts for chemoselective transesterification of alcohols in the presence of amines
Authors: Mashima Kazushi , Hayashi Yukiko , Agura Kazushi , Ohshima Takashi 
Published: March 2014

Abstract
Acylation is one of the most abundant organic transformations of alcohols (esterification) and amines (amidation). Because of the greater nucleophilicity of the amino group compared to the hydroxyl group and the stability of amides compared to esters, N-acylation occurs predominantly in organic synthetic reactions. We reported that the μ-oxo-tetranuclear zinc cluster Zn4(OCOCF3)6O efficiently catalyzes highly chemoselective acylation of hydroxyl groups in the presence of primary and secondary alkyl amino groups to afford the corresponding esters in high yields. Not only zinc carboxylate complexes but also various carboxylate complexes of first-row late transition metals, such as Mn, Fe, Co, and Cu, become catalysts for such the hydroxy group-selective acylation in the presence of amines. Among these carboxylate compounds, we found that the combination of an octanuclear cobalt carboxylate cluster [Co4(OCOR)6O]2 (R = CF3, CH3, and
t
Bu) with nitrogen-containing ligands such as 2,2′-bipyridine show sufficient catalytic activity toward O-selective transesterification. Notably, an alkoxide-bridged dinuclear complex, Co2(OCO
t
Bu)2(bpy)2(μ2-OCH2-C6H4-4-CH3)2, was successfully isolated as a key intermediate that proceeds with Michaelis–Menten behavior through an ordered ternary complex mechanism similar to dinuclear metallo-enzymes, suggesting that the formation of alkoxides, followed by coordination of the ester, is responsible for the unique O-selective acylation.
The effect of acceptor-substituted alkynes in gold-catalyzed intermolecular reactions
Authors: Shin Seunghoon 
Published: March 2014

Abstract
Alkynes substituted with electron-withdrawing groups participated in various intermolecular reactions with olefin substrates, including [4 + 2] annulation of propiolic acids, intermolecular metathesis-type reaction and carboalkoxylation involving allylethers.
Research on absolute gravity variations in geodynamic laboratory in Książ in the period of 2007- 2011
Authors: Kaczorowski Marek , Olszak Tomasz , Walo Janusz , Barlik Marcin 
Published: March 2014

ABSTRACT
In 2006 a gravimetric pavilion was installed inside the Geodynamic Laboratory (LG) in Książ. The pavilion was equipped with two pillars intended to serve relative and absolute gravimetric measurements. Installation of measurement platform for absolute gravity measurements inside gravimetric pavilion of LG made it possible to perform four sessions of absolute gravity measurements: two of them in 2007 (June 10-12 and Nov. 21-22), one in 2008 (Apr. 21-22) and one in 2011 (June 19-21). In 2007 the absolute measurements were performed using two FG5 ballistic gravimeters. In April 2007 the measurements were performed by Dr Makinen from Geodetic Institute of Finnish Academy of Science with application of FG5 No. 221 absolute gravimeter. In June 2007 and in the years 2008 and 2011 such gravimetric measurements were performed by the team from Department of Geodesy and Astronomical Geodesy of Warsaw University of Technology using FG5 No. 230 absolute gravimeter. Elaboration of observation sessions from both gravimeters was performed in the Department of Higher Geodesy following the procedures used in constituting of uniform gravimetric system of geodynamic polygons reference. This constituting of gravimetric system comprised inter alia application of identical models of lithospheric tides (global model by Wenzel, 1997) and ocean tides (Schwiderski, 1980) (reduction of absolute measurements with tidal signals). Observations performed during summer of 2007, autumn of 2007, and spring of 2008 and 2011 indicated existence of small changes of absolute gravity of the order of 1 Gal. Maxima of accelerations appear in the spring period, and minima in the autumn period. This effect is connected with the influence of global hydrological factors the annual amplitude of which is ca 1,5 Gal and achieve extreme values in the spring-autumn interval. Very small value of observed amplitude of gravity changes in the period of extreme variability suggests that the observed gravity changes in LG are caused only by global phenomenon. This proves high degree of „independence” of gravimetric measurement base in LG from the local environmental factors such as ground water level variations, ground humidity, impact of snow cover, etc. At this moment the instrumental environment of absolute measurements obtains particular value, especially in the case of the tiltmeters and relative the gravimeter Lacoste& Romberg (LR-648). The relative gravity measurements as performed simultaneously with absolute gravity measurements enable us to determine the local tidal ephemeredes which makes it possible to replace the global tidal modal with ocean tidal model with the more realistic, locally determined tidal parameters (the local tidal ephemeredes).
Low-threshold monopolar motor mapping for resection of lesions in motor eloquent areas in children and adolescents
Authors: Schucht Philippe , Seidel Kathleen , Murek Michael , Stieglitz Lennart Henning , Urwyler Natalie , Wiest Roland , Steinlin Maja , Leibundgut Kurt , Raabe Andreas , Beck Jürgen 
Published: March 2014

Object
Resection of lesions close to the primary motor cortex (M1) and the corticospinal tract (CST) is generally regarded as high-risk surgery due to reported rates of postoperative severe deficits of up to 50%. The authors' objective was to determine the feasibility and safety of low-threshold motor mapping and its efficacy for increasing the extent of lesion resection in the proximity of M1 and the CST in children and adolescents.

Methods
The authors analyzed 8 consecutive pediatric patients in whom they performed 9 resections for lesions within or close (≤ 10 mm) to M1 and/or the CST. Monopolar high-frequency motor mapping with train-of-five stimuli (pulse duration 500 μsec, interstimulus interval 4.0 msec, frequency 250 Hz) was used. The motor threshold was defined as the minimal stimulation intensity that elicited motor evoked potentials (MEPs) from target muscles (amplitude > 30 μV). Resection was performed toward M1 and the CST at sites negative to 1- to 3-mA high-frequency train-of-five stimulation.

Results
The M1 was identified through high-frequency train-of-five via application of varying low intensities. The lowest motor thresholds after final resection ranged from 1 to 9 mA in 8 cases and up to 18 mA in 1 case, indicating proximity to motor neurons. Intraoperative electroencephalography documented an absence of seizures during all surgeries. Two transient neurological deficits were observed, but there were no permanent deficits. Postoperative imaging revealed complete resection in 8 patients and a very small remnant (< 0.175 cm3) in 1 patient.

Conclusions
High-frequency train-of-five with a minimal threshold of 1–3 mA is a feasible and safe procedure for resections in the proximity of the CST. Thus, low-threshold motor mapping might help to expand the area for safe resection in pediatric patients with lesions located within the precentral gyrus and close to the CST, and may be regarded as a functional navigational tool. The additional use of continuous MEP monitoring serves as a safety feedback for the functional integrity of the CST, especially because the true excitability threshold in children is unknown.
Clinical course of untreated pediatric brainstem cavernous malformations: hemorrhage risk and functional recovery
Authors: Li Da , Hao Shu-Yu , Tang Jie , Xiao Xin-Ru , Jia Gui-Jun , Wu Zhen , Zhang Li-Wei , Zhang Jun-Ting 
Published: March 2014

Object
The aim of this study was to investigate the clinical appearance of untreated pediatric brainstem cavernous malformations (CMs) and to identify the hemorrhage risks and functional outcomes.

Methods
All pediatric patients with a diagnosis of brainstem CM between 1985 and 2012 were registered. The clinical chart and radiographs were recorded, and follow-up evaluations were obtained prospectively.

Results
A total of 85 patients (69.4% male) were included with a mean age of 12.7 years. Sixty-seven patients (78.8%) had prior hemorrhage, and 6 patients (7.1%) were asymptomatic. There were 15 midbrain lesions, 53 pons lesions, and 17 medulla lesions. The mean lesion size was 1.9 cm. During a total of 401.6 patient-years of follow-up, 47 hemorrhages occurred in 37 patients, and the annual hemorrhage rate was 11.7% per patient-year. The mean hemorrhage interval was 47.8 months. The hemorrhage risk declined over time, especially after the first 2 years. Both a lesion size ≥ 2 cm (hazard ratio [HR] 2.122, p = 0.037) and the presence of perilesional edema (HR 2.192, p = 0.039) predicted future hemorrhage and were associated with a high annual hemorrhage rate. The hemorrhage-free survival at 6 months was 85.7%, and at 1, 5, 10, and 15 years was 71.5%, 49.4%, 27.5%, and 13.7%, respectively. At the most recent functional evaluation, 33 patients (38.8%) had improved, 32 (37.6%) had stabilized, and 20 (23.5%) had worsened, without any deaths. Twenty-two patients (25.9%) obtained a full recovery. Prospective hemorrhage (HR 0.191, p = 0.003) was the adverse predictor for full recovery. Full recovery primarily occurred within the first 12 months, after which the chance of full recovery decreased. The cumulative percentage of complete recovery at 6 months was 32.7%, and at 1, 3, and 5 years was 40.8%, 43.6%, and 49.2%, respectively.

Conclusions
In this study the hemorrhage rate was relatively high in pediatric brainstem CMs, although the functional outcome was acceptable. The decline in hemorrhage risk and the identified adverse predictors in this study were helpful for clinicians and patients when deciding on treatment. Referral bias and the insufficient follow-up period of the study were highlighted as limitations.