bluuebunny/crossref_metadata_2025_split huggingface dataset:
Universal Reaction Mechanism of Boronic Acids with Diols in Aqueous Solution: Kinetics and the Basic Concept of a Conditional Formation Constant
Authors: Furikado Yuki , Nagahata Tomomi , Okamoto Takuya , Sugaya Tomoaki , Iwatsuki Satoshi , Inamo Masahiko , Takagi Hideo D. , Odani Akira , Ishihara Koji 
Published: August 2014

AbstractTo establish a detailed reaction mechanism for the condensation between a boronic acid, RB(OH)2, and a diol, H2L, in aqueous solution, the acid dissociation constants (${K{{{\rm BL}\hfill \atop {\rm a}\hfill}}}$) of boronic acid diol esters (HBLs) were determined based on the well‐established concept of conditional formation constants of metal complexes. The pKa values of HBLs were 2.30, 2.77, and 2.00 for the reaction systems, 2,4‐difluorophenylboronic acid and chromotropic acid, 3‐nitrophenylboronic acid and alizarin red S, and phenylboronic acid and alizarin red S, respectively. A general and precise reaction mechanism of RB(OH)2 with H2L in aqueous solution, which can serve as a universal reaction mechanism for RB(OH)2 and H2L, was proposed on the basis of (a) the relative kinetic reactivities of the RB(OH)2 and its conjugate base, that is, the boronate ion, toward H2L, and (b) the determined pKa values of HBLs. The use of the conditional formation constant, K′, based on the main reaction: RB(OH)2+H2L ${{\mathop \leftrightarrow \limits ^{K{_{1}}}_{}}}$ RB(L)(OH)−+H3O+ instead of the binding constant has been proposed for the general reaction of uncomplexed boronic acid species (B′) with uncomplexed diol species (L′) to form boronic acid diol complex species (esters, BL′) in aqueous solution at pH 5–11: B′+L′ ${{\mathop \leftrightarrow \limits ^{K{^\prime}}_{}}}$ BL′. The proposed reaction mechanism explains perfectly the formation of boronic acid diol ester in aqueous solution.
Assessments of Semilocal Density Functionals and Corrections for Carbon Dioxide Adsorption on Metal–Organic Frameworks
Authors: Ji Hyunjun , Park Joonho , Cho Moses , Jung Yousung 
Published: August 2014

AbstractThe significant amount of attention that has been directed toward metal–organic frameworks (MOFs) for a wide spectrum of applications can be attributed to their variety and tunability, which are precisely the aspects that computational modeling can offer by systematically exploring the chemical space. In this minireview, we describe density functional theory calculations for gas adsorption on MOFs, mainly focusing on the interaction of CO2 with MOF‐74. The generalized gradient approximation (GGA) level of density functional studies seems suited to treat MOFs, owing to the balance between its practical applicability and its useful accuracy, although this method is not without deficiencies such as the lack of nonlocal correlations and self‐interactions. We review and analyze the effects of correction schemes to the GGA to amend the latter weaknesses, and the choice of exchange correlation functionals to treat MOFs for gas capture and separation. We also discuss a few topical questions that are currently missing in the present literature and that require further investigations.
Photocatalytic oxidation of cytostatic drugs by microwave‐treated N‐doped TiO2 under visible light
Authors: Lin Hank Hui‐Hsiang , Lin Angela Yu‐Chen , Hung Chia‐Lin 
Published: August 2014

AbstractBACKGROUND5‐Fluorouracil is one of the most commonly used cytostatic drugs worldwide. However, the toxicity and persistence of 5‐fluorouracil in the environment have recently received considerable attention. In this study, 5‐fluorouracil removal was performed by photocatalytic oxidation with microwave‐treated N‐doped TiO2 under visible light.RESULTSThe microwave‐treated N‐doped TiO2 removed 5‐fluorouracil with a higher degradation efficiency than N‐doped TiO2 synthesized with the traditional thermal treatments. The most efficient N‐doped TiO2 (N6) was synthesized using 1 M NH4OH pre‐immersion and a 3 h 180°C microwave treatment, followed by 55°C calcination for 6 h. The photocatalytic degradation of 5‐fluorouracil achieved 88.8% removal within 20 h of treatment by N6 under visible light, which is higher than that obtained by Degussa P25 TiO2 (61.5%). Higher concentrations of NH4OH and longer calcination times resulted in decreased 5‐fluorouracil degradation; the particle size of the synthesized N‐doped TiO2 increased after calcination. The surface area decreased while the pore volume and pore size increased after synthesis. Furthermore, the basicity of the sites on the synthesized N‐doped TiO2 decreased after calcination.CONCLUSIONThis study, for the first time, reported that microwave‐assisted treatment for N‐doped TiO2 synthesis effectively removed 5‐fluorouracil and cyclophosphamide compared with traditional thermal treatment. © 2014 Society of Chemical Industry
A first demonstration and analysis of the biprimary color system for reflective displays
Authors: Mukherjee Sayantika , Smith Nathan , Goulding Mark , Topping Claire , Norman Sarah , Liu Qin , Kramer Laura , Kularatne Senal , Heikenfeld Jason 
Published: August 2014

AbstractA new biprimary color system is demonstrated for single‐layer reflective displays, capturing much of the improved color performance of multilayer displays while potentially maintaining single‐layer display advantages in high resolution and faster switching. Electrophoretic pixels were operated with dual‐particle complementary‐colored dispersions such as green/magenta (G/M). Using simple interdigitated three‐electrode architecture, four colored states (KWGM) were achieved with a preliminary contrast ratio of 10 : 1. Furthermore, biprimary ink dispersions were shown to be functional in a more advanced electrokinetic pixel structure. A full‐color biprimary pixel contains three complementary subpixels (G/M, B/Y, R/C), and the requisite electrophoretic ink dispersions were also formulated and spectrally characterized in this work. Lastly, theoretical color space mapping confirms that the biprimary concept provides twice the brightness and twice the color fraction compared with the conventional RGBW subpixel approach, and that the biprimary concept can approach performance close to that of magazine print (Specifications for Web‐Offset Print).
Sharpness and noise characteristics of a half‐mirror stereoscopic display
Authors: Yamazaki Asumi , Marini‐Bettolo Cecilia , Kodera Yoshie , Badano Aldo 
Published: August 2014

AbstractStereoscopic displays are becoming popular in entertainment and industrial applications. We characterize the spatial resolution and noise properties of a stereoscopic display with a half‐mirror and passive polarizing glasses. The upper display images reflected off the mirror have slightly degraded sharpness and reduced high spatial‐frequency noise resulting in modulation transfer functions (MTFs) of 0.59 and 0.50 at the Nyquist frequency with corresponding noise power spectra (NPS) values of 4.79 × 10−6 and 5.17 × 10−6 mm2 at 10 mm−1 in the horizontal and vertical directions. These results are compared to the characteristics of the individual displays with MTF values of 0.64 and 0.53 and NPS values of 6.24 × 10−6 and 5.87 × 10−6 mm2. The polarizing glasses cause minimal reduction in sharpness and high‐frequency noise. The MTFs in the upper images observed with glasses are decreased to 0.54 and 0.47, while the NPS are decreased to 2.86 × 10−6 and 2.01 × 10−6 mm2. When both displays are turned on and using the mirror and glasses, the observed luminance for each eye is increased from the luminance of the individual displays owing to crosstalk. We find that sharpness and noise are not affected by the interaction between the displays at the particular geometry tested in this study.
iPP–sPP Stereoblocks or Blends? Studies on the Synthesis of Isotactic–Syndiotactic Polypropylene Using Single C1‐Symmetric {Ph2C‐(Flu)(3‐Me3Si‐Cp)}ZrR2 Metallocene Precatalysts
Authors: Theurkauff Gabriel , Roisnel Thierry , Waassenaar Jeroen , Carpentier Jean‐François , Kirillov Evgeny 
Published: August 2014

Single isoselective C1‐symmetric {Ph2C‐(Flu)(3‐Me3Si‐Cp)}ZrR2 (R = Cl (1b), Me (2b)) metallo­cene precatalysts, upon activation with MAO or [PhNMe2H]+[B(C6F5)4]−/iBu3Al, produce isotactic polypropylene (PP) (up to 80% mmmm), which is more enriched with syndiotactic pentads (0.9–2.2% rrrr) than the statistical model assumes. Similar or even more syndiotactically enriched PPs (3.0–25.4% rrrr) are obtained using combinations of 1b or 2b with Cs‐symmetric syndioselective {Ph2C‐(Flu)(Cp)}ZrR2 (R = Cl (1a), Me (2a)) metallo­cenes. While NMR spectroscopy, differential scanning calorimetry (DSC), and gel per­meation chromatography (GPC) analyses do not provide explicit evidence on the nature of these polymers, temperature rising elution fractionation (TREF) unambiguously identifies them as blends of iPP and sPP polymers and not discrete iPP−b−sPP stereoblock copolymers. The formation of sPP fractions from the a priori isoselective 1b and 2b systems is attributed to a desilylation side reaction, which takes place in the precatalyst synthesis step and possibly also during the polymerization, resulting in the generation of the Me3Si‐free syndioselective catalytically active species. Activation of 2a with B(C6F5)3 and [PhNMe2H]+[B(C6F5)4]− selectively leads to the corresponding cationic complexes 3a and 4a, as confirmed by NMR spectroscopic methods and the solid‐state structure of {Ph2C‐(Flu)(Cp)}ZrMe(μ‐Me)B(C6F5)3 (3a). On the other hand, the activation of 2b with the same molecular activators is less selective, and the formation of the corresponding cationic products 3b and 4b along with unidentified impurities is monitored by NMR spectroscopy. A possible chain‐shuttling process between isoselective and syndioselective active species, mediated by Me3Al or iBu3Al, appears to be inoperative under given conditions.
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k‐t FASTER: Acceleration of functional MRI data acquisition using low rank constraints
Authors: Chiew Mark , Smith Stephen M. , Koopmans Peter J. , Graedel Nadine N. , Blumensath Thomas , Miller Karla L. 
Published: August 2014

PurposeIn functional MRI (fMRI), faster sampling of data can provide richer temporal information and increase temporal degrees of freedom. However, acceleration is generally performed on a volume‐by‐volume basis, without consideration of the intrinsic spatio‐temporal data structure. We present a novel method for accelerating fMRI data acquisition, k‐t FASTER (FMRI Accelerated in Space‐time via Truncation of Effective Rank), which exploits the low‐rank structure of fMRI data.Theory and MethodsUsing matrix completion, 4.27× retrospectively and prospectively under‐sampled data were reconstructed (coil‐independently) using an iterative nonlinear algorithm, and compared with several different reconstruction strategies. Matrix reconstruction error was evaluated; a dual regression analysis was performed to determine fidelity of recovered fMRI resting state networks (RSNs).ResultsThe retrospective sampling data showed that k‐t FASTER produced the lowest error, approximately 3–4%, and the highest quality RSNs. These results were validated in prospectively under‐sampled experiments, with k‐t FASTER producing better identification of RSNs than fully sampled acquisitions of the same duration.ConclusionWith k‐t FASTER, incoherently under‐sampled fMRI data can be robustly recovered using only rank constraints. This technique can be used to improve the speed of fMRI sampling, particularly for multivariate analyses such as temporal independent component analysis. Magn Reson Med 74:353–364, 2015. © 2014 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Hyperpolarized 13C NMR detects rapid drug‐induced changes in cardiac metabolism
Authors: Khemtong Chalermchai , Carpenter Nicholas R. , Lumata Lloyd L. , Merritt Matthew E. , Moreno Karlos X. , Kovacs Zoltan , Malloy Craig R. , Sherry A. Dean 
Published: August 2014

PurposeThe diseased myocardium lacks metabolic flexibility and responds to stimuli differently compared with healthy hearts. Here, we report the use of hyperpolarized 13C NMR spectroscopy to detect sudden changes in cardiac metabolism in isolated, perfused rat hearts in response to adrenergic stimulation.MethodsMetabolism of hyperpolarized [1‐13C]pyruvate was investigated in perfused rat hearts. The hearts were stimulated in situ by isoproterenol shortly after the administration of hyperpolarized [1‐13C]pyruvate. The hyperpolarized 13C NMR results were corroborated with 1H NMR spectroscopy of tissue extracts.ResultsAddition of isoproterenol to hearts after equilibration of hyperpolarized [1‐13C]pyruvate into the existing lactate pool resulted in a sudden, rapid increase in hyperpolarized [1‐13C]lactate signal within seconds after exposure to drug. The hyperpolarized H13CO3− and hyperpolarized [1‐13C]alanine signals were not affected by the isoproterenol‐induced elevated cardiac workload. Separate experiments confirmed that the new hyperpolarized [1‐13C]lactate signal that arises after stimulation by isoproterenol reflects a sudden increase in total tissue lactate derived from glycogen.ConclusionThese results suggest that hyperpolarized pyruvate and 13C MRS may be useful for detecting abnormal glycogen metabolism in intact tissues. Magn Reson Med 74:312–319, 2015. © 2014 Wiley Periodicals, Inc.
Evaluation of 5‐Fluorouracil Metabolic Enzymes as Predictors of Response to Adjuvant Chemotherapy Outcomes in Patients with Stage II/III Colorectal Cancer: A Decision‐Curve Analysis
Authors: Shigeta Kohei , Ishii Yoshiyuki , Hasegawa Hirotoshi , Okabayashi Koji , Kitagawa Yuko 
Published: August 2014

AbstractBackgroundThe effectiveness of 5‐fluorouracil (5‐FU)‐based adjuvant chemotherapy is reported in patients with colorectal cancer (CRC), but the usefulness of 5‐FU metabolic enzymes as predictive biomarkers of the efficacy of this chemotherapy remains unclear.ObjectiveThis study aims to verify whether 5‐FU metabolic enzymes are predictive biomarkers in the clinical setting of adjuvant chemotherapy for stage II/III CRC.MethodsIn total, 179 patients with stage II/III CRC who were treated at our institute between 2000 and 2010 were enrolled. Messenger RNA (mRNA) expression of major 5‐FU metabolic enzymes, namely thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase (TP), orotate phosphoribosyl transferase, and β‐actin (control) was evaluated using the Danenberg Tumor Profile method. mRNA expression and other clinicopathological data were investigated with regard to CRC relapse.ResultsA total of 78 patients underwent surgery alone, while 101 underwent adjuvant chemotherapy (5‐FU plus leucovorin [LV] or tegafur plus uracil /LV) following surgery. Relapse‐free survival was longer and risk of recurrence was lower in association with high TP mRNA expression than in association with low TP mRNA expression in the adjuvant chemotherapy group (hazard ratio 0.66; 95 % confidence interval 0.47–0.92; p = 0.016), but not in the surgery alone group. mRNA expression of no other enzymes was associated with relapse in both groups. In decision‐curve analyses, the predictive efficiency of TP mRNA expression plus clinicopathological factors was slightly better than that of clinicopathological factors only.ConclusionsTP mRNA expression in tumors predicted the effects of adjuvant chemotherapy for stage II/III CRC, although the beneficial effects were marginal.
RELIGIOUS INFLUENCE ON NON-USE OF MODERN CONTRACEPTIVES AMONG WOMEN IN NIGERIA: COMPARATIVE ANALYSIS OF 1990 AND 2008 NDHS
Authors: WUSU ONIPEDE 
Published: August 2014

SummaryThe role of religion in contraceptive use is an issue of significant debate. This study employed the 1990 and 2008 Nigeria Demographic and Health Survey data to examine differences and similarities in the influence of religious affiliation on non-use of modern contraceptives in Nigeria over the last two decades. The results suggest that a significant increase has occurred in the level of awareness of modern contraceptives in Nigeria over the last two decades, but that non-use remains very high. Religion could not independently predict non-use of modern contraceptives in 1990. Women of Islam and Traditional religions were more likely to have never used or not to be using modern contraceptives compared with Catholics and Protestants in 2008 (p<0.05). This can be explained by their poorer socioeconomic status relative to Catholics and Protestants. Therefore, improving women's socioeconomic status is an imperative in the promotion of modern contraception in Nigeria. Education and employment are critical in this regard and adherents of Islam and Traditional religions require special attention.
Does the human immunodeficiency virus influence the vestibulocollic reflex pathways? A comparative study
Authors: Heinze B M , Vinck B M , Swanepoel D W 
Published: August 2014

AbstractBackground:This study compared vestibulocollic reflex and vestibulo-ocular reflex functioning in subjects with and without human immunodeficiency virus. It also described test results throughout progression of the disease and compared the results of human immunodeficiency virus positive subjects who were receiving antiretroviral therapies with those not receiving this treatment.Methods:Subjects comprised 53 adults with human immunodeficiency virus (mean age 38.5 ± 4.4 years) and 38 without human immunodeficiency virus (mean age 36.9 ± 8.2 years). Clinical examinations included cervical vestibular-evoked myogenic potential and bithermal caloric testing.Results:Abnormal cervical vestibular-evoked myogenic potential and caloric results were significantly higher in the human immunodeficiency virus positive group (p = 0.001), with an odds ratio of 10.2. Vestibulocollic reflex and vestibulo-ocular reflex involvement increased with progression of the disease. There were more abnormal test results in subjects receiving antiretroviral therapies (66.7 per cent) than in those not receiving antiretroviral therapies (63.6 per cent), but this difference was insignificant.Conclusion:Human immunodeficiency virus seems to influence vestibulocollic reflex pathways. Combining cervical vestibular-evoked myogenic potential and caloric testing may be useful to detect early neurological involvement in human immunodeficiency virus positive subjects.
Patterns of sexual mixing with respect to social, health and sexual characteristics among heterosexual couples in England: analyses of probability sample survey data
Authors: PRAH P. , COPAS A. J. , MERCER C. H. , NARDONE A. , JOHNSON A. M. 
Published: August 2014

SUMMARYPatterns of sexual mixing are major determinants of sexually transmitted infection (STI) transmission, in particular the extent to which high-risk populations mix with low-risk populations. However, patterns of mixing in the general population are poorly understood. We analysed data from a national probability sample survey of households, the Health Survey for England 2010. A total of 943 heterosexual couples living together, where at least one partner was aged between 16–44 years, were included. We used correlation coefficients to measure the strength of similarities between partners with respect to demographic characteristics, general health, health behaviours and sexual history. Males were on average 2 years older than their female partners, although this age difference ranged from a median of 0 years in men aged 16–24 years to a median of 2 years in men aged 35–44 years. A positive correlation between partners was found for all demographic characteristics. With respect to general health and health behaviours, a strongly positive correlation was found between men and women in reporting alcohol consumption at ⩾3 days a week and smoking. Men typically reported greater numbers of sexual partners than their female partner, although men and women with more partners were more likely to mix with each other. We have been able to elucidate the patterns of sexual mixing between men and women living together in England. Mixing based on demographic characteristics was more assortative than sexual characteristics. These data can better inform mathematical models of STI transmission.
A comprehensive view of epicotyl dormancy inViburnumfurcatum: combining field studies with laboratory studies using temperature sequences
Authors: Phartyal Shyam S. , Kondo Tetsuya , Fuji Akinori , Hidayati Siti N. , Walck Jeffrey L. 
Published: August 2014

AbstractSeeds with epicotyl dormancy reside in soil up to 15 months (or longer), being exposed to a sequence of temperatures, before seedlings completely emerge (i.e. with both roots and shoots). Heretofore, few studies have examined precise temperatures, especially in sequences, for promotion of radicle and cotyledon emergence and how they relate to environmental cues in nature.Viburnumis the best known genus to exhibit epicotyl dormancy and, as such, we investigated the JapaneseV.furcatum, hypothesizing a similar kind and level of dormancy. The underdeveloped embryos in mature seeds in October were spatulate shaped, unlike those in otherViburnumspecies, and they elongated from late June to August of the following year. Radicles emerged after embryo growth until mid-October, followed by cotyledons from mid-April to mid-May. Temperatures required for embryo growth, radicle and cotyledon emergence in the laboratory approximated closely those in the field. Embryo elongation and radicle emergence occurred at warm temperature regimes, and gibberellic acid (GA3) did not substitute for this warm temperature requirements. Following a 120-d cold stratification of seeds with an emerged radicle, shoots emerged from seeds at 10, 15, 15/5, 20/10 and 25/15°C. We identified that seeds ofV. furcatumhave deep simple epicotyl morphophysiological dormancy like the majority of otherViburnumspecies. For propagation of the species from seeds, the nearly 2-year period for seedling emergence could be shortened to 8 months: start fresh seeds at 25/15°C (60 d) and then move them through a sequence of 15/5°C (30 d) → 0°C (120 d) → 20/10°C (30 d).