bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational Design of Cyclic Nitroxides as Efficient Redox Mediators for Dye‐Sensitized Solar Cells
Authors: Gryn'ova Ganna , Barakat Jonathan M. , Blinco James P. , Bottle Steven E. , Coote Michelle L. 
Published: April 2012

AbstractCyclic nitroxide radicals represent promising alternatives to the iodine‐based redox mediator commonly used in dye‐sensitized solar cells (DSSCs). To date DSSCs with nitroxide‐based redox mediators have achieved energy conversion efficiencies of just over 5 % but efficiencies of over 15 % might be achievable, given an appropriate mediator. The efficacy of the mediator depends upon two main factors: it must reversibly undergo one‐electron oxidation and it must possess an oxidation potential in a range of 0.600–0.850 V (vs. a standard hydrogen electrode (SHE) in acetonitrile at 25 °C). Herein, we have examined the effect that structural modifications have on the value of the oxidation potential of cyclic nitroxides as well as the reversibility of the oxidation process. These included alterations to the N‐containing skeleton (pyrrolidine, piperidine, isoindoline, azaphenalene, etc.), as well as the introduction of different substituents (alkyl‐, methoxy‐, amino‐, carboxy‐, etc.) to the ring. Standard oxidation potentials were calculated using high‐level ab initio methodology that was demonstrated to be very accurate (with a mean absolute deviation from experimental values of only 16 mV). An optimal value of 1.45 for the electrostatic scaling factor for UAKS radii in acetonitrile solution was obtained. Established trends in the values of oxidation potentials were used to guide molecular design of stable nitroxides with desired , and a number of compounds were suggested for potential use as enhanced redox mediators in DSSCs.
Enantioselective Synthesis of anti‐β‐Hydroxy‐α‐Amido Esters by Asymmetric Transfer Hydrogenation in Emulsions
Authors: Seashore‐Ludlow Brinton , Villo Piret , Somfai Peter 
Published: April 2012

AbstractHerein, we present two methods for an asymmetric transfer hydrogenation through the dynamic kinetic resolution of α‐amido‐β‐ketoesters. These procedures yield the corresponding anti‐β‐hydroxy‐α‐amido esters in good yields and with good diastereo‐ and enantioselectivities. First, the scope of the reduction of α‐amido‐β‐ketoesters by using triethylammonium formate azeotrope is examined. Then, an emulsion technology with sodium formate is explored, which allows for broader substrate scope, faster reaction times, and lower catalyst loading. Furthermore, these reactions are operationally simple and can be set up in air.
Electrochemiluminescent Determination of Cancer Cells Based on Aptamers, Nanoparticles, and Magnetic Beads
Authors: Ding Caifeng , Wei Shuang , Liu Haitao 
Published: April 2012

AbstractHerein we report a polymerase chain reaction (PCR)‐free electrochemiluminescence (ECL) approach that uses ECL nanoprobes for the determination of cancer cells with high sensitivity. The ECL nanoprobe consists of gold nanoparticles (AuNPs), linker DNA, and tris(2,2′‐bipyridyl)ruthenium (TBR)‐labeled signal DNA. The linker DNA and signal DNA were modified on the surface of the AuNPs through AuS bonds. The linker DNA can partly hybridize with the aptamers of cancer cells loaded onto the magnetic beads (MB1) to construct the magnetic biocomplexes. In the presence of the cancer cells, the aptamers conjugated with the cancer cells with higher affinity. The ECL nanoprobe was released from the biocomplexes and subsequently hybridized with the capture DNA loaded onto another magnetic bead (MB2) to form the magnetic nanocomposite. The nanocomposites can be easily separated and firmly attached to an electrode on account of their excellent magnetic properties. The ECL intensity of the TBR loaded onto the nanocomposites directly reflected the amount of cancer cells. By using cell lines of Burkitt’s lymphoma (Ramos cells) as a model, the ECL response was proportional to the cell concentration in the range from 5 to 100 cells ml−1; a limit of detection as low as 5 cells ml−1 of Ramos cells could be achieved. The proposed method described here is ideal for the diagnosis of cancers due to its high sensitivity, simplicity, and low cost.
En Route to Dinitroacetylene: Nitro(trimethylsilyl)acetylene and Nitroacetylene Harnessed by Dicobalt Hexacarbonyl
Authors: Windler G. Kenneth , Zhang Mao‐Xi , Zitterbart Robert , Pagoria Philip F. , Vollhardt K. Peter C. 
Published: April 2012

AbstractDinitroacetylene and other nitroacetylenes are attractive stoichiometric precursors to high energy‐density materials, but suffer from high reactivity and thermal instability. Herein, we report that nitroacetylenes can be dramatically stabilized in the form of their dicobalt hexacarbonyl complexes. In particular, we describe the syntheses and characterization of the first two transition‐metal complexes of nitroalkynes, [μ‐1‐nitro‐2‐(trimethylsilyl)ethyne‐1,2‐diyl]bis(tricarbonylcobalt)(Co—Co) and [μ‐1‐nitroethyne‐1,2‐diyl]bis(tricarbonylcobalt)(Co—Co). The chemistry of these compounds reveals their potential as reaction partners in [2+2+2] cyclotrimerizations, furnishing nitroindane, nitrotetralin, and trinitrobenzene products. The X‐ray crystal structure of 1,3,5‐trinitro‐2,4,6‐tris(trimethylsilyl)benzene presents a distorted, yet planar, aromatic ring.
Plant Extraction: Key Technology for Sustained Use of Bio‐Resources
Authors: Tegtmeier Martin 
Published: April 2012

AbstractSeit Beginn der Zivilisation gehören Pflanzen zu den wichtigsten Alltagsgegenständen für den Menschen. Schon bald werden Pflanzen nicht nur eine direkte Nahrungsquelle sondern auch Basis für die Herstellung und Bereitstellung vieler im täglichen Leben benötigter Utensilien sein. Die Verarbeitung von Pflanzen erfordert dabei immer weiter entwickelte Fertigkeiten, um wachsende Bedürfnisse zu erfüllen. Mit der Nutzung von abgetrennten Pflanzenbestandteilen, vornehmlich von ausgewählten Inhaltsstofffraktionen, wurden die Kenntnisse zur Extraktion weiterentwickelt. Das fortschreitende Wissen zur Materialkunde und zur Mechanisierung führte zur Etablierung von Extraktionsverfahren, die die kontinuierliche Herstellung von qualitativ hochwertigen Produkten gewährleisten. Diese Phase markiert auch den Ursprung der Phytotechnologie als eigenständige wissenschaftliche und technische Disziplin zur Extraktion von Pflanzen.
Health Risk Assessment for Arsenic in Water Sources of Cankiri Province of Turkey
Authors: Caylak Emrah 
Published: April 2012

AbstractTo investigate the levels of arsenic (As) in the water sources of Cankiri Province, the samples were collected from the stations of central Cankiri (n = 27) and Kursunlu town (n = 12) during 2009 and 2010. The concentrations of As were analyzed with an atomic absorption spectrophotometer, and then compared with permissible limit, 10 µg/L in drinking water, by Turkish legislation and World Health Organization (WHO). The As levels were higher than this limit (mean value 10–30 µg/L in 26 stations), whereas, they were found to be >30 µg/L in 12 sampling points. The water sources were categorized for health risk assessment such as reservoir, tap, well, and spring, and then chronic daily intake for oral and dermal exposure to As via drinking water, hazard quotient (HQ), and hazard index were calculated by using indices. The HQ values were found to be >1 in all samples of Cankiri Province. The effects of As on human health were then evaluated using carcinogenic risk (CR). CR values for As were also estimated to be >10−5 in drinking water samples of Cankiri Province and might exert potential CR for people. These assessments would point out required drinking water treatment strategy to ensure safety of consumers.
Ultrafast Photoinduced Electron Transfer at Electrodes: The General Case of a Heterogeneous Electron‐Transfer Reaction
Authors: Gundlach Lars , Willig Frank 
Published: April 2012

AbstractThe general case of a heterogeneous electron‐transfer reaction is realized by ultrafast electron transfer from a light‐absorbing molecule to a wide continuum of electronic acceptor states, realizing the so‐called wide band limit. Experimental data obtained for perylene dye/TiO2 systems confirm the predictions of fully quantum mechanical model calculations of the dynamics. The energy distribution of the injected electron shows an energy loss due to excitations of high‐energy (quantum) vibrational modes in the ionized perylene moiety. The electron‐transfer mechanism is non‐adiabatic and the reaction is ultrafast, for example, with a time constant of 9 fs for the COOH anchor‐bridge group. The underlying strong coupling of the electronic states to high‐energy vibrational modes is a characteristic feature of sensitizer molecules.
Firefly Chemiluminescence and Bioluminescence: Efficient Generation of Excited States
Authors: Pinto da Silva Luís , Esteves da Silva Joaquim C. G. 
Published: April 2012

AbstractFirefly luciferase catalyzes a light‐emitting reaction in which an excited‐state product is formed. Both experimental and theoretical methodologies are used to study this system, and the reactions catalyzed by luciferase are relatively well characterized. However, the mechanism by which an excited‐state product is formed is still unknown. This Minireview deals with the current understanding of firefly bioluminescence and chemiluminescence. Thermal decomposition of simple 1,2‐dioxetanes is also discussed, due to their role in formation of the excited‐state bioluminophore.
Mitigating Product Hazards via User Warnings Alone: When/Why “Warnings‐Only” Approaches Are Likely to Fail
Authors: Lenorovitz David R. , Karnes Edward W. , Leonard S. David 
Published: April 2012

AbstractSome products may involve hazards in their use. Manufacturers are obligated to evaluate such hazards and to abate them according to a hierarchy of hazard control approaches, namely, 1) to design them out, 2) to shield users from their effects, or 3) to adequately warn users of their danger(s). Warnings are last in this hierarchy because they provide a lesser guarantee of success. Additionally, warnings developed for this purpose may be inadequate because of a variety of factors, including the warning's clarity/understandability, its high cost of compliance, the need for responses beyond the users' capabilities, the need for unavailable or difficult‐to‐use protective equipment, or asking users to perform actions contrary to previously learned or innately reactive behaviors. This article describes problems with three types of vehicles that contained known hazards—where the manufacturer relied solely on product warnings to mitigate that hazard, and, in turn, provided warnings that were inadequate for one or more of these reasons. © 2012 Wiley Periodicals, Inc.
Interfering with Fos expression in rat perirhinal cortex impairs recognition memory
Authors: Seoane Ana , Tinsley Christopher J. , Brown Malcolm W. 
Published: April 2012

AbstractPrevious work has shown that immunohistochemical imaging of Fos protein is a reliable marker for changes in activity related to recognition memory in the perirhinal (PRH) cortex of the medial temporal lobe; however, whether PRH Fos expression is necessary for recognition memory had not been established. To investigate this potential requirement, antisense Fos oligodeoxynucleotide (ODN) was infused locally into PRH cortex to interfere with Fos production. As in previous studies, differential Fos expression produced by viewing novel or familiar visual stimuli was measured by immunohistochemistry: antisense Fos ODN infusion into PRH cortex disrupted the normal pattern of differential Fos expression in PRH cortex. The effect of antisense Fos ODN infusion into PRH cortex was therefore sought on recognition memory. Infusion before or immediately after acquisition impaired recognition memory for objects when the memory delay was 3 or 24 h, but not when the delay was 20 min, or when the ODN was infused before retrieval after a 24‐h delay. The findings indicate a role for Fos in consolidation processes underlying long‐term recognition memory for objects and establish that interfering with its expression impairs recognition memory. Antisense Fos ODN infusion also impaired object‐in‐place recognition memory. The results demonstrate that Fos is necessary for neuronal mechanisms in PRH cortex essential to recognition memory. © 2012 Wiley Periodicals, Inc.
Delineation of saltwater intrusion zones using the time domain electromagnetic method: the Nabeul–Hammamet coastal aquifer case study (NE Tunisia)
Authors: Trabelsi Fatma , Mammou Abdallah Ben , Tarhouni Jamila , Piga Carlo , Ranieri Gaetano 
Published: April 2012

AbstractThe time domain electromagnetic method (TDEM) is applied to monitor, to delineate and to map the saltwater intrusion zones in the Mediterranean Plio‐Quaternary aquifer. Forty‐two TDEM soundings were carried out in the coastal plain of Nabeul–Hammamet region (NE Tunisia). TDEM resistivity data were correlated with the existing borehole logging data to assign them to a particular lithology and to provide information about the position of the freshwater–seawater transition zone. The geoelectric sections showing the vertical configuration of seawater intrusion, with the brackish‐salty‐saturated zones, have a resistivity ranging from ~0.1 to 5 Ω⋅m and are detected at a depth lower than 1.5 m. The salinized zones are located at Nabeul (Sidi Moussa, Sidi El Mahrsi, Al Gasba and Mrazgua) and at Hammamet (Touristic zone of Hammamet north and south, Baraket Essahel) and reached a distance of 4 km from the coastline, indicating a severe state for the aquifer in these zones. These TDEM results are confirmed by the increase of chloride concentration content in the analysed water samples of monitoring wells. Moreover, in the northeastern part, the presence of a saltwater front located far from the coast and along the NW–SE major surface fault can be explained by two hypothesis: (i) this fault seems to provide a conduit for seawater to move readily towards the water wells and (ii) the clay and gypsum infiltration of marine Messinian deposits through the fault plane leads to low resistivities. Finally, it comes out from this study that TDEM survey has successfully depicted salinized zones of this coastal aquifer. Copyright © 2012 John Wiley & Sons, Ltd.
Discrete wavelet‐based trend identification in hydrologic time series
Authors: Sang Yan‐Fang , Wang Zhonggen , Liu Changming 
Published: April 2012

AbstractTrend identification is a substantial issue in hydrologic series analysis, but it is also a difficult task in practice due to the confusing concept of trend and disadvantages of methods. In this article, an improved definition of trend was given as follows: ‘a trend is the deterministic component in the analysed data and corresponds to the biggest temporal scale on the condition of giving the concerned temporal scale’. It emphasizes the intrinsic and deterministic properties of trend, can clearly distinguish trend from periodicities and points out the prerequisite of the concerned temporal scale only by giving which the trend has its specific meaning. Correspondingly, the discrete wavelet‐based method for trend identification was improved. Differing from those methods used presently, the improved method is to identify trend by comparing the energy difference between hydrologic data and noise, and it can simultaneously separate periodicities and noise. Furthermore, the improved method can quantitatively estimate the statistical significance of the identified trend by using proper confidence interval. Analyses of both synthetic and observed series indicated the identical power of the improved method as the Mann–Kendall test in assessing the statistical significance of the trend in hydrologic data, and by using the former, the identified trend can adaptively reflect the nonlinear and nonstationary variability of hydrologic data. Besides, the results also showed the influences of three key factors (wavelet choice, decomposition level choice and noise content) on discrete wavelet‐based trend identification; hence, they should be carefully considered in practice. Copyright © 2012 John Wiley & Sons, Ltd.
Characteristics of canopy interception loss in Moso bamboo forests of Japan
Authors: Shinohara Yoshinori , Komatsu Hikaru , Kuramoto Kohei , Otsuki Kyoichi 
Published: April 2012

AbstractIn recent years, Moso bamboo (Phyllostachys pubescens) forests have rapidly expanded in Japan by replacing surrounding coniferous and/or broadleaved forests. To evaluate the change in water yield from forested areas because of this replacement, it is necessary to examine evapotranspiration for Moso bamboo forests. However, canopy interception loss, one of the major components of evapotranspiration in forested areas, has been observed in only two Moso bamboo forests in Japan with relatively high stem density (~7000 stems/ha). There are, in fact, many Moso bamboo forests with much lower stem density. Thus, we made precipitation (Pr), throughfall (Tf) and stemflow (Sf) observations for 1 year in a Moso bamboo forest with stem density of 3611 stems/ha and quantified canopy interception loss (Ic). Pr and Ic for the experimental period were 1636 and 166 mm, respectively, and Ic/Pr was 10%. The value was approximately the same as values for the other two Moso bamboo forests and lower than values for coniferous and broadleaved forests. On the other hand, Tf/Pr and Sf/Pr for our forest (86% and 4%, respectively) were approximately 10% of Pr larger and smaller than values for the other two Moso bamboo forests. These results suggest that the difference in stem density greatly affects precipitation partitioning (i.e. Tf/Pr and Sf/Pr) but does not greatly change Ic/Pr. Copyright © 2012 John Wiley & Sons, Ltd.
Quantifying watershed surface depression storage: determination and application in a hydrologic model
Authors: Amoah Joseph K. O. , Amatya Devendra M. , Nnaji Soronnadi 
Published: April 2012

AbstractHydrologic models often require correct estimates of surface macro‐depressional storage to accurately simulate rainfall–runoff processes. Traditionally, depression storage is determined through model calibration or lumped with soil storage components or on an ad hoc basis. This paper investigates a holistic approach for estimating surface depressional storage capacity (DSC) in watersheds using digital elevation models (DEMs). The methodology includes implementing a lumped DSC model to extract geometric properties of storage elements from DEMs of varying grid resolutions and employing a consistency zone criterion to quantify the representative DSC of an isolated watershed. DSC obtained using the consistency zone approach is compared to DSC estimated by “brute force” (BF) optimization method. The BF procedure estimates optimal DSC by calibrating DRAINMOD, a quasi‐process based hydrologic model, with observed streamflow under different climatic conditions. Both methods are applied to determine the DSC for relatively low‐gradient coastal plain watersheds on forested landscape with slopes less than 3%. Results show robustness of the consistency zone approach for estimating depression storage. To test the adequacy of the calculated DSC values obtained, both methods are applied in DRAINMOD to predict the daily watershed flow rates. Comparison between observed and simulated streamflow reveals a marginal difference in performance between BF optimization and consistency zone estimated DSCs during wet periods, but the latter performed relatively better in dry periods. DSC is found to be dependent on seasonal antecedent moisture conditions on surface topography. The new methodology is beneficial in situations where data on depressional storage is unavailable for calibrating models requiring this input parameter. Copyright © 2012 John Wiley & Sons, Ltd.
Parental involvement in home visiting: Interpersonal predictors and correlates
Authors: Sierau Susan , Brand Tilman , Jungmann Tanja 
Published: April 2012

AbstractParents' commitment to and usage of early intervention are key variables in understanding discrepancies in families' susceptibility to these services. Although the important role of fathers in infant development is widely recognized, early interpersonal predictors of paternal involvement in home‐visiting programs have been understudied. This article aims to fill this gap by regressing parents' postnatal involvement on prenatal partnership satisfaction and quality of the helping relationship in a sample of 124 socially and financially disadvantaged families. Paternal program engagement was predicted by partnership satisfaction whereas the perceived quality of the helping relationship best predicted maternal program engagement, with demographical characteristics controlled. Maternal program engagement also mediated the relationship between partnership satisfaction and paternal program engagement. The results are discussed against the theoretical background.
Tumor-induced osteomalacia: An important cause of adult-onset hypophosphatemic osteomalacia in China: Report of 39 cases and review of the literature
Authors: Jiang Yan , Xia Wei-bo , Xing Xiao-ping , Silva Barbara C , Li Mei , Wang Ou , Zhang Hua-bing , Li Fang , Jing Hong-li , Zhong Ding-rong , Jin Jin , Gao Peng , Zhou Lian , Qi Fang , Yu Wei , Bilezikian John P , Meng Xun-wu 
Published: April 2012

Abstract
Tumor-induced osteomalacia (TIO) is an acquired form of hypophosphatemia. Tumor resection leads to cure. We investigated the clinical characteristics of TIO, diagnostic methods, and course after tumor resection in Beijing, China, and compared them with 269 previous published reports of TIO. A total of 94 patients with adult-onset hypophosphatemic osteomalacia were seen over a 6-year period (January, 2004 to May, 2010) in Peking Union Medical College Hospital. After physical examination (PE), all patients underwent technetium-99m octreotide scintigraphy (99Tcm-OCT). Tumors were removed after localization. The results demonstrated that 46 of 94 hypophosphatemic osteomalacia patients had high uptake in 99Tcm-OCT imaging. Forty of them underwent tumor resection with the TIO diagnosis established in 37 patients. In 2 patients, the tumor was discovered on PE but not by 99Tcm-OCT. The gender distribution was equal (M/F = 19/20). Average age was 42 ± 14 years. In 35 patients (90%), the serum phosphorus concentration returned to normal in 5.5 ± 3.0 days after tumor resection. Most of the tumors (85%) were classified as phosphaturic mesenchymal tumor (PMT) or mixed connective tissue variant (PMTMCT). Recurrence of disease was suggested in 3 patients (9%). When combined with the 269 cases reported in the literature, the mean age and sex distribution were similar. The tumors were of bone (40%) and soft tissue (55%) origins, with 42% of the tumors being found in the lower extremities. In summary, TIO is an important cause of adult-onset hypophosphatemia in China. 99Tcm-OCT imaging successfully localized the tumor in the overwhelming majority of patients. Successful removal of tumors leads to cure in most cases, but recurrence should be sought by long-term follow-up. © 2012 American Society for Bone and Mineral Research.