bluuebunny/crossref_metadata_2025_split huggingface dataset:
EPR Characterisation of the Ferrous Nitrosyl Complex Formed within the Oxygenase Domain of NO Synthase
Authors: Santolini Jérôme , Maréchal Amandine , Boussac Alain , Dorlet Pierre 
Published: August 2013

AbstractNitric oxide is produced in mammals by a class of enzymes called NO synthases (NOSs). It plays a central role in cellular signalling but also has deleterious effects, as it leads to the production of reactive oxygen and nitrogen species. NO forms a relatively stable adduct with ferrous haem proteins, which, in the case of NOS, is also a key catalytic intermediate. Despite extensive studies on the ferrous nitrosyl complex of other haem proteins (in particular myoglobin), little characterisation has been performed in the case of NOS. We report here a temperature‐dependent EPR study of the ferrous nitrosyl complex of the inducible mammalian NOS and the bacterial NOS‐like protein from Bacillus subtilis. The results show that the overall behaviours are similar to those observed for other haem proteins, but with distinct ratios between axial and rhombic forms in the case of the two NOS proteins. The distal environment appears to control the existence of the axial form and the evolution of the rhombic form.
Effect of Visible‐Light Exposure and Electrolyte Oxygen Content on the Capacitance of Sulfur‐Doped Carbon
Authors: Singh Kavindra , Seredych Mykola , Rodriguez Castellon Enrique , Bandosz Teresa J. 
Published: August 2013

AbstractA high‐density and low‐surface‐area sulfur‐doped carbon material is tested as a supercapacitor in acidic and neutral media. The electrolytes that are used are either oxygenated or are exposed to atmospheric oxygen. The electrochemical capacitance is measured both in dark conditions and under simulated solar irradiation. The capacitance values are calculated after the first and the 20th cycles. After cycling, a significant increase in the capacitance is observed in both electrolytes, which is accompanied by clear oxidation of the carbon surface. Oxygen in the system and visible‐light irradiation considerably increases the performance. The enhancement in the capacitance is linked to the carbon texture and chemistry. Reduced sulfur that is incorporated into the carbon matrix promotes photogeneration of electrons and holes, and the latter have a positive effect on oxygen reduction reactions as the holes contribute to the oxidation of water and the formation of radicals. These processes lead to the oxidation of the carbon surface and the formation of pores in which charge can be stored. Changes in the chemistry of sulfur lead to a clear pseudocapacitive contribution, increasing the capacitance in the acidic medium.
Orthogonal Functionalisation of Upconverting NaYF4 Nanocrystals
Authors: Voliani Valerio , González‐Béjar María , Herranz‐Pérez Vicente , Duran‐Moreno Maria , Signore Giovanni , Garcia‐Verdugo Jose M. , Pérez‐Prieto Julia 
Published: August 2013

AbstractA simple and straightforward method for the orthogonal functionalisation of upconverting NaYF4 nanocrystals (UCNCs)—doped withYb3+ and Er3+—based on N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide/N‐hydroxysuccinimide (EDC/NHS) selective reactions between two dyes and two different reactive groups present at the periphery of the upconverting nanocrystals is reported. Organic‐soluble UCNCs of 10 and 50 nm in size are encapsulated efficiently in a 1:1 mixture of two commercial 3000 Da poly(ethylene glycol) derivatives with two different reactive groups (amino and carboxylic groups). The water‐dispersible UCNCs are non‐cytotoxic, stable in the physiological environment, and present free amine and carboxylic reactive groups on their periphery, allowing rapid, selective, and modular covalent conjugation to payloads through EDC/NHS reactions. PEG‐encapsulated UCNCs with and without covalent conjugation to payloads are characterised in vitro through spectroscopic, dynamic light scattering, and electron microscopy measurements. Living cell analyses coupled with TEM measurements confirm the uptake and low cytotoxicity of the coated UCNCs. They are linked covalently to two different dyes, internalised by living cells, and analysed by confocal microscopy. The related colocalisation measurements prove the reactivity of both amines and carboxylic acids on the periphery of the nanocrystals. This approach demonstrates that it is possible to produce water‐dispersible and cyto‐compatible dual‐functional UCNCs.
Custom‐Fit Ruthenium(II) Metallopeptides: A New Twist to DNA Binding With Coordination Compounds
Authors: Gamba Ilaria , Salvadó Iria , Rama Gustavo , Bertazzon Miriam , Sánchez Mateo I. , Sánchez‐Pedregal Víctor M. , Martínez‐Costas José , Brissos Rosa F. , Gamez Patrick , Mascareñas José L. , Vázquez López Miguel , Vázquez M. Eugenio 
Published: August 2013

AbstractA new bipyridine building block has been used for the solid‐phase synthesis of dinuclear DNA‐binding ruthenium(II) metallopeptides. Detailed spectroscopic studies suggest that these compounds bind to the DNA by insertion into the DNA minor groove. Moreover, the potential of the solid‐phase peptide synthesis approach is demonstrated by the straightforward synthesis of an octaarginine derivative that shows effective cellular internalization and cytotoxicity linked with strong DNA interaction, as evidenced by steady‐state fluorescence spectroscopy and AFM studies.
Cooperative Use of VCD and XRD for the Determination of Tetrahydrobenzoisoquinolines Absolute Configuration: A Reliable Proof of Memory of Chirality and Retention of Configuration in Enediyne Rearrangements
Authors: Mondal Shovan , Naubron Jean‐Valère , Campolo Damien , Giorgi Michel , Bertrand Michéle P. , Nechab Malek 
Published: August 2013

ABSTRACTThe absolute configurations (AC) of azaheterocylic compounds resulting from the cascade rearrangement of enediynes involving only light atoms were unambiguously assigned by the joint use of vibrational circular dichroism (VCD) and copper radiation single crystal X‐ray diffraction (XRD). These AC determinations proved that the rearrangements of enediynes proceeded with memory of chirality and retention of configuration. Chirality 25:832–839, 2013. © 2013 Wiley Periodicals, Inc.
Changes in the availability of screening mammography, 2000–2010
Authors: Elkin Elena B. , Atoria Coral L. , Leoce Nicole , Bach Peter B. , Schrag Deborah 
Published: August 2013

BACKGROUNDRates of screening mammography have plateaued, and the number of mammography facilities has declined in the past decade. The objective of this study was to assess changes over time and geographic disparities in the availability of mammography services.METHODSUsing information from the US Food and Drug Administration and the US Census, county‐level mammography capacity was defined as the number of mammography machines per 10,000 women aged ≥ 40 years. Cross‐sectional variation and longitudinal changes in capacity were examined in relation to county characteristics.RESULTSBetween 2000 and 2010, the number of mammography facilities declined 10% from 9434 to 8469, the number of mammography machines declined 10% from 13,100 to 11,762, and the median county mammography capacity decreased nearly 20% from 1.77 to 1.42 machines per 10,000 women aged ≥ 40 years. In cross‐sectional analysis, counties with greater percentages of uninsured residents, less educated residents, greater population density, and higher managed care penetration had lower mammography capacity. Conversely, counties with more hospital beds per 100,000 population had higher capacity. High initial mammography capacity, growth in both the percentage of the population aged ≥ 65 years and the percentage living in poverty, and increased managed care penetration were all associated with a decrease in mammography capacity between 2000 and 2010. Only the percentage of rural residents was associated with an increase in capacity.CONCLUSIONSGeographic variation in mammography capacity and declines in capacity over time are associated with demographic, socioeconomic, and health care market characteristics. Maldistribution of mammography resources may explain geographic disparities in breast cancer screening rates. Cancer 2013;119:3847–3853. © 2013 American Cancer Society.
Myelosuppression after frontline fludarabine, cyclophosphamide, and rituximab in patients with chronic lymphocytic leukemia
Authors: Strati Paolo , Wierda William , Burger Jan , Ferrajoli Alessandra , Tam Constantine , Lerner Susan , Keating Michael J. , O'Brien Susan 
Published: August 2013

BACKGROUNDThe combination of fludarabine, cyclophosphamide, and rituximab (FCR) has produced improved response rates and a prolonged survival in patients with chronic lymphocytic leukemia (CLL). However, its therapeutic power is counterbalanced by significant hematologic toxicity. Persistent and new‐onset cytopenia after the completion of FCR raise concern about disease recurrence, the development of therapy‐related myeloid malignancies (TRMM), and infections.METHODSA total of 207 patients with CLL who achieved complete response, complete response with incomplete bone marrow recovery, or nodular partial remission were analyzed after frontline FCR therapy.RESULTSThree months after the completion of therapy, 35% of patients had developed grade 2 to 4 cytopenia (according to Common Terminology Criteria for Adverse Events [version 4.0]). Factors found to be associated with cytopenia at 3 months after therapy were older age, advanced Rai stage disease, and lower baseline blood counts. Moreover, patients with cytopenia were less likely to have completed 6 courses of therapy with FCR. At 6 months and 9 months after therapy, the prevalence of grade 2 to 4 cytopenia was 24% and 12%, respectively. No differences in progression‐free survival and overall survival were noted between cytopenic and noncytopenic patients or between patients with persistent and new‐onset cytopenia. The prevalence of TRMM was 2.3% and did not differ significantly between cytopenic and noncytopenic patients or between those with persistent and new‐onset disease. Late infections were more common in patients who were cytopenic at 9 months (38%) and were mostly bacterial (67%).CONCLUSIONSCytopenia after the completion of therapy is a common complication of frontline FCR that improves over time, particularly for new‐onset cases. The presence of persistent cytopenia (lasting up to 9 months after the completion of therapy) should not raise concern about CLL recurrence of the development of TRMM, but should encourage surveillance for bacterial infections for an additional 9 months. Cancer 2013;119:3805–3811. © 2013 American Cancer Society.
Structural Characterization of Alumina‐Supported Rh Catalysts: Effects of Ceriation and Zirconiation by using Metal–Organic Precursors
Authors: Kroner Anna B. , Newton Mark A. , Tromp Moniek , Russell Andrea E. , Dent Andrew J. , Evans John 
Published: August 2013

AbstractThe effects of the addition of ceria and zirconia on the structural properties of supported rhodium catalysts (1.6 and 4 wt % Rh/γ‐Al2O3) are studied. Ceria and zirconia are deposited by using two preparation methods. Method I involves the deposition of ceria on γ‐Al2O3 from Ce(acac)3, and the rhodium metal is subsequently added, whereas method II is based on a controlled surface reaction technique, that is, the decomposition of metal–organic M(acac)x (in which M=Ce, x=3 and M=Zr, x=4) on Rh/γ‐Al2O3. The structures of the prepared catalyst materials are characterized ex situ by using N2 physisorption, transmission electron microscopy, high‐angle annular dark‐field scanning transmission election microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy (XPS), and X‐ray absorption fine structure spectroscopy (XAFS). All supported rhodium systems readily oxidize in air at room temperature. By using ceriated and zirconiated precursors, a larger rhodium‐based metallic core fraction is obtained in comparison to the undoped rhodium catalysts, suggesting that ceria and zirconia protect the rhodium particles against extensive oxidation. XPS results indicate that after the calcination and reduction treatments, a small amount of chlorine is retained on the support of all rhodium catalysts. EXAFS analysis shows significant RhCl interactions for Rh/Al2O3 and Rh/CeOx/Al2O3 (method I) catalysts. After reaction with H2/He in situ, for series of samples with 1.6 wt % Rh, the EXAFS first shell analysis affords a mean size of approximately 30 atoms. A broader spread is evident with a 4 wt % rhodium loading (ca. 30–110 atoms), with the incorporation of zirconium providing the largest particle sizes.
Synthesis of the Natural Product Building Block 5‐(3‐Bromophenyl)‐4‐hydroxy‐5‐methylhexan‐2‐one and its Chiral Characterization by Using Chiroptical Spectroscopy
Authors: De Gussem Ewoud , Cornelus Jelle , Pieters Sam , Van den Bossche Dries , Van der Eycken Johan , Herrebout Wouter , Bultinck Patrick 
Published: August 2013

AbstractThe absolute configuration of 5‐(3‐bromophenyl)‐4‐hydroxy‐5‐methylhexan‐2‐one, an intermediate in the synthesis of various natural products, is assigned by using vibrational circular dichroism (VCD), electronic circular dichroism (ECD), and optical rotatory dispersion (ORD). Experimental spectra were compared to density functional theory (DFT) calculations of the molecule with known configuration. These three techniques independently confirm that the absolute configuration is (S)‐5‐(3‐bromophenyl)‐4‐hydroxy‐5‐methylhexan‐2‐one, thus enabling us to assign the absolute configuration with high reliability. The reliability of the VCD analysis was assessed quantitatively by using the CompareVOA program. We found that, in cases in which the agreement between theory and experiment was very good, a value of 10 cm−1 for the triangular weighting function gave a more‐realistic discriminative power between enantiomers than the default value of 20 cm−1.
Generation and Dissociation of RCOOCaCl2− and other Carboxylate‐Substituted Superhalogens: CO2 Capture and Implications for Structure Analysis
Authors: Rodríguez‐Blanco Giovanny , Jobst Karl J. , Luider Theo M. , Terlouw Johan K. , Burgers Peter C. 
Published: August 2013

AbstractCarboxylate‐substituted superhalogens of the type RCOOMX2− (M=Mg, Ca, Sr, Ba, Mn, Co, Ni, Zn; X=Cl, Br) are easily accessible in the gas phase by electrospray ionisation. Their collision‐induced dissociation (CID) characteristics have been probed by using ion‐trap and triple‐quadrupole mass analysers with particular emphasis on the behaviour of RCOOCaCl2−‐type ions. In the ion trap these appear to react readily with residual water to yield HOCaCl2− as the hydrolysis product. In the absence of water, a collision‐induced McLafferty‐type rearrangement takes over to produce HCaCl2− with the expulsion of an olefin and CO2. A brief computational analysis using the CBS‐QB3 model chemistry provides a satisfactory rationale for these observations. If complexed with MX2 (M=Mg, Ca, Sr, Ba), long‐chain unsaturated aliphatic carboxylate anions undergo various backbone cleavages upon collision. These lead to structure‐diagnostic olefin losses because the position of the double bonds remains intact. Such cleavages are absent in the bare ion RCOO−. The long‐chain ions RCOOMX2− also produce the intriguing species [CO2]MX2−.. These have been characterised by CID experiments, and theory indicates that they may be viewed as a CO2 molecule captured by the salt anion MX2−.. Finally, it is shown that the CID spectra of RCOOCaCl2− ions derived from all‐trans retinoic acid, a compound of current interest in biochemistry and medicine, show a unique structure‐diagnostic dissociation that may greatly aid its qualitative and quantitative analysis.
Can Semi‐empirical Calculations Help Solve Mass Spectrometry Problems? Protonation Sites and Proton Affinities of Amino Acids
Authors: Amorim Madeira Paulo J. , Vaz Pedro D. , Bettencourt da Silva R. J. N. , Florêncio M. Helena 
Published: August 2013

AbstractOwing to the recent development of the PM6 and PM6‐DH+ semi‐empirical methodologies, which belong to the neglect of diatomic differential overlap (NDDO) family, it was decided to carry out a study to assess whether these inexpensive and fast methodologies could be used with confidence to help solve mass spectrometry problems. As such, a report on the feasibility of using semi‐empirical calculations to identify probable protonation sites in amino acids is presented. The optimised geometries obtained by the semi‐empirical calculations were compared to several structures reported in the literature (obtained through high‐level theoretical calculations) and reasonable agreement was found. The proton affinities derived from semi‐empirical calculations were also compared with experimental data and benchmarked as well with predicted values from the literature (also obtained through high‐level theoretical calculations). Semi‐empirical calculations accurately predicted the most probable protonation site for all amino acids considered; thus leading to results comparable to those obtained by high‐level calculations at an extremely low computational cost. Regarding the proton affinity estimates, deviations from the available experimental values are greater for the semi‐empirical proton affinities than for those observed for high‐level calculations. A statistical analysis of the data, at a confidence level of 99 %, also showed that the semi‐empirical proton affinities were different from experimental values and high‐level proton affinities were equivalent to experimental values. Nevertheless, the overall correlation of the semi‐empirical data with experimental values is, at least, satisfactory. We believe therefore that this paper shows that semi‐empirical methodologies, which are fast and inexpensive, can indeed solve mass spectrometry problems, or at least, facilitate a quicker path to the solution.
Identification of molecular and physiological responses to chronic environmental challenge in an invasive species: the Pacific oyster, Crassostrea gigas
Authors: Clark Melody S. , Thorne Michael A. S. , Amaral Ana , Vieira Florbela , Batista Frederico M. , Reis João , Power Deborah M. 
Published: August 2013

AbstractUnderstanding the environmental responses of an invasive species is critical in predicting how ecosystem composition may be transformed in the future, especially under climate change. In this study, Crassostrea gigas, a species well adapted to the highly variable intertidal environment, was exposed to the chronic environmental challenges of temperature (19 and 24°C) and pH (ambient seawater and a reduction of 0.4 pH units) in an extended 3‐month laboratory‐based study. Physiological parameters were measured (condition index, shell growth, respiration, excretion rates, O:N ratios, and ability to repair shell damage) alongside molecular analyses. Temperature was by far the most important stressor, as demonstrated by reduced condition indexes and shell growth at 24°C, with relatively little effect detected for pH. Transcriptional profiling using candidate genes and SOLiD sequencing of mantle tissue revealed that classical “stress” genes, previously reported to be upregulated under acute temperature challenges, were not significantly expressed in any of the treatments, emphasizing the different response between acute and longer term chronic stress. The transcriptional profiling also elaborated on the cellular responses underpinning the physiological results, including the identification of the PI3K/AKT/mTOR pathway as a potentially novel marker for chronic environmental challenge. This study represents a first attempt to understand the energetic consequences of cumulative thermal stress on the intertidal C. gigas which could significantly impact on coastal ecosystem biodiversity and function in the future.
Energy intensity and global warming potential of corn grain ethanol production in Wisconsin (USA)
Authors: Kraatz Simone , Sinistore Julie C. , Reinemann Douglas J. 
Published: August 2013

AbstractIncreasing demand for renewable alternative fuels, such as ethanol, is driven by decreasing availability of fossil resources and increasing attention to climate change. Life cycle assessment (LCA) is the tool used to evaluate environmental impacts, such as energy intensity (EI) and global warming potential (GWP), from ethanol production, but the application of this tool varies greatly. The goals of this study were to enumerate the life cycle EI, net energy value (NEV), and GWP of corn grain ethanol production in Wisconsin, to explore ethanol production scenarios which differ at the treatment of the whole stillage (WS) coproduct, and to evaluate the various solutions to the multifunctionality problem which arises in LCA. In Scenario 1, all suggested solutions to the multifunctionality problem are considered by transforming WS into the animal feed dried distillers grains with solubles (DDGS). Scenario 2 avoids allocation using an integrated system which recycles the WS with an anaerobic biodigester and a combined heat and power (CHP) plant to provide electricity and steam to the ethanol refinery and returns the residue to the land as fertilizer. Based on the Scenario 1 analysis, we recommend the use of the subdivision (SD) solution to the multifunctionality problem because it enables clear comparisons between different ethanol production systems, it distinguishes between the environmental impacts from ethanol production and coproduct processing and it reduces the number of assumptions in the LCA calculations. From the comparison of both scenarios, we find that recycling the WS into electricity, heat, and fertilizer is the most environmentally beneficial coproduct use because it results in a 54% lower EI and a 67% lower GWP than the processing of WS into DDGS.
Common use of high doses of antipsychotic medications in older Asian patients with schizophrenia (2001–2009)
Authors: Xiang Yu‐Tao , Li Yan , Correll Christoph U. , Ungvari Gabor S. , Chiu Helen F.K. , Lai Kelly Y. C. , Tang Quan‐Sheng , Hao Wei , Si Tian‐Mei , Wang Chuan‐Yue , Lee Edwin H. M , He Yan‐Ling , Yang Shu‐Yu , Chong Mian‐Yoon , Kua Ee‐Heok , Fujii Senta , Sim Kang , Yong Michael K.H. , Trivedi Jitendra K. , Chung Eun‐Kee , Udomratn Pichet , Chee Kok‐Yoon , Sartorius Norman , Tan Chay‐Hoon , Shinfuku Naotaka 
Published: August 2013

ObjectiveThis study aimed to examine the use of high doses of antipsychotic medications (≥600 mg/day chlorpromazine equivalent) in older Asian patients with schizophrenia and its demographic and clinical correlates.MethodInformation on hospitalized patients with schizophrenia aged ≥50 years was extracted from the database of the Research on Asian Psychotropic Prescription Patterns study (2001–2009). Data on 2203 patients in six Asian countries and territories, including China, Hong Kong, Japan, Korea, Singapore and Taiwan, were analyzed. Socio‐demographic and clinical characteristics and antipsychotic prescriptions were recorded.ResultsThe frequency for high‐dose antipsychotic medications was 36.0% overall, with 38.4% in 2001, 33.3% in 2004 and 36.0% in 2009. Multiple logistic regression analysis of the whole sample showed that compared to patients receiving low‐medium antipsychotic doses, those on high doses had a longer illness duration (odds ratio (OR): 2.0, 95% confidence interval (CI):1.2–3.3, p = 0.008), were more likely in the 50–59‐year group (OR: 0.95, 95% CI: 0.94–0.97, p < 0.001), more often had current positive (OR: 1.5, 95% CI: 1.2–1.8, p < 0.001) or negative symptoms (OR: 1.3, 95% CI: 1.03–1.6, p = 0.03), and more commonly received antipsychotic polypharmacy (OR: 5.3, 95% CI: 4.1–6.7, p < 0.001). Extrapyramidal symptoms (p = 0.25) and tardive dyskinesia (p = 0.92) were not more frequent in the high‐dose group.ConclusionsHigh doses of antipsychotic medications were used in more than one third of older Asian patients with schizophrenia. The reasons for the frequent use of high antipsychotic doses in older Asian patients warrant further investigation. Copyright © 2013 John Wiley & Sons, Ltd.