bluuebunny/crossref_metadata_2025_split huggingface dataset:
D–π–A Dye Sensitizers Made of Polymeric Metal Complexes Containing 1,10‐Phenanthroline and Alkylfluorene or Alkoxybenzene: Synthesis, Characterization and Photovoltaic Performance for Dye‐Sensitized Solar Cells
Authors: Yu Xiaoguang , Jin Xueliang , Tang Guipeng , Zhou Jun , Zhang Wei , Peng Dahai , Hu Jiaomei , Zhong Chaofan 
Published: July 2013

AbstractFour polymeric metal complexes (P1–P4) based on 1,10‐phenanthroline metal complexes and alkylfluorene or alkoxybenzene were synthesized by the Heck coupling reaction and were developed for dye‐sensitized solar cell applications. The target dyes use alkoxybenzene or alkylfluorene as the electron donor, a C=C moiety as the π linker, and the phenanthroline derivative complex was used as the electron acceptor. Bipyridine derivatives were ancillary ligands as well as providing anchoring groups. The thermal, photophysical, electrochemical and photovoltaic properties of these copolymers were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), C–V curves and I–V curves. Dye‐sensitized solar cells with these polymeric metal complexes as dye sensitizers exhibited considerable power conversion efficiencies (PCE). The dyes containing alkoxybenzenes (P3, P4) exhibited higher PCE values than the corresponding target polymers containing alkylfluorenes (P1, P2), The dye P3 showed the maximal power conversion efficiency of 2.12 % (Jsc = 4.91 mA/cm2, Voc = 0.69 V, FF = 62.5). In addition, the four polymers possessed excellent stabilities, and their thermal decomposition temperatures all exceeded 300 °C, indicating that these polymeric metal complexes are suitable for the fabrication processes of optoelectronic devices.
A Convenient Microwave‐Assisted Propylphosphonic Anhydride (T3P®) Mediated One‐Pot Pyrazolone Synthesis
Authors: Desroses Matthieu , Jacques‐Cordonnier Marie‐Caroline , Llona‐Minguez Sabin , Jacques Sylvain , Koolmeister Tobias , Helleday Thomas , Scobie Martin 
Published: July 2013

AbstractThis paper describes a facile, efficient, and clean synthesis of various pyrazolones by employing T3P® as a catalyst and performing the reaction under microwave irradiation. This two‐step, one‐pot reaction proceeded readily and tolerated a variety of functional groups. A wide range of pyrazolone derivatives were obtained in good to excellent yields.
Investigation of BOLD fMRI resonance frequency shifts and quantitative susceptibility changes at 7 T
Authors: Bianciardi Marta , van Gelderen Peter , Duyn Jeff H. 
Published: July 2013

AbstractAlthough blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) experiments of brain activity generally rely on the magnitude of the signal, they also provide frequency information that can be derived from the phase of the signal. However, because of confounding effects of instrumental and physiological origin, BOLD related frequency information is difficult to extract and therefore rarely used. Here, we explored the use of high field (7 T) and dedicated signal processing methods to extract frequency information and use it to quantify and interpret blood oxygenation and blood volume changes. We found that optimized preprocessing improves detection of task‐evoked and spontaneous changes in phase signals and resonance frequency shifts over large areas of the cortex with sensitivity comparable to that of magnitude signals. Moreover, our results suggest the feasibility of mapping BOLD quantitative susceptibility changes in at least part of the activated area and its largest draining veins. Comparison with magnitude data suggests that the observed susceptibility changes originate from neuronal activity through induced blood volume and oxygenation changes in pial and intracortical veins. Further, from frequency shifts and susceptibility values, we estimated that, relative to baseline, the fractional oxygen saturation in large vessels increased by 0.02–0.05 during stimulation, which is consistent to previously published estimates. Together, these findings demonstrate that valuable information can be derived from fMRI imaging of BOLD frequency shifts and quantitative susceptibility changes. Hum Brain Mapp 35:2191–2205, 2014. © 2013 Wiley Periodicals, Inc.
River temperature regimes of England and Wales: spatial patterns, inter‐annual variability and climatic sensitivity
Authors: Garner Grace , Hannah David M. , Sadler Jonathan P. , Orr Harriet G. 
Published: July 2013

AbstractIdentification of the most sensitive hydrological regions to a changing climate is essential to target adaptive management strategies. This study presents a quantitative assessment of spatial patterns, inter‐annual variability and climatic sensitivity of the shape (form) and magnitude (size) of annual river/stream water temperature regimes across England and Wales. Classification of long‐term average (1989–2006) annual river (air) temperature regime dynamics at 88 (38) stations within England and Wales identified spatially differentiable regions. Emergent river temperature regions were used to structure detailed hydroclimatological analyses of a subset of 38 paired river and air temperature stations. The shape and magnitude of air and water temperature regimes were classified for individual station‐years; and a sensitivity index (SI, based on conditional probability) was used to quantify the strength of associations between river and air temperature regimes. The nature and strength of air–river temperature regime links differed between regions. River basin properties considered to be static over the timescale of the study were used to infer modification of air–river temperature links by basin hydrological processes. The strongest links were observed in regions where groundwater contributions to runoff (estimated by basin permeability) were smallest and water exposure time to the atmosphere (estimated by basin area) was greatest. These findings provide a new large‐scale perspective on the hydroclimatological controls driving river thermal dynamics and, thus, yield a scientific basis for informed management and regulatory decisions concerning river temperature within England and Wales. © 2013 The Authors. Hydrological Processes published by John Wiley & Sons, Ltd.
Angiotensin converting enzyme 2: A new important player in the regulation of glycemia
Authors: Chhabra Kavaljit H. , Chodavarapu Harshita , Lazartigues Eric 
Published: July 2013

AbstractIn spite of the novel antidiabetic drugs available on the market, type 2 diabetes mellitus (T2DM) affects nearly 25 million people in the USA and causes about 5% of all deaths globally each year. Given the rate and proportion by which T2DM is affecting human beings, it is indispensable to identify new therapeutic targets that can control the disease. Recent preclinical and clinical studies suggest that attenuating the activity of the renin–angiotensin system (RAS) could improve glycemia in diabetic patients. Angiotensin‐converting enzyme 2 (ACE2) counteracts RAS overactivity by degrading angiotensin‐II (Ang‐II), a vasoconstrictor, to Ang‐(1–7) which is a vasodilator. A decrease in ACE2 and an increase in A disintegrin and metalloproteinase (ADAM17)‐mediated shedding activity have been observed with the progression of T2DM, suggesting the importance of this mechanism in the disease. Indeed, restoration of ACE2 improves glycemia in db/db and Ang‐II‐infused mice. The beneficial effects of ACE2 can be attributed to reduced oxidative stress and ADAM17 expression in the islets of Langerhans in addition to the improvement of blood flow to the β‐cells. The advantage of ACE2 over other RAS blockers is that ACE2 not only counteracts the negative effects of Ang‐II but also increases Ang‐(1–7)/Mas receptor (MasR) [a receptor through which Ang‐(1–7) produces its actions] signaling in the cells. Increased Ang‐(1–7)/MasR signaling has been reported to improve insulin sensitivity and glycemia in diabetic animals. Altogether, ACE2/Ang‐(1–7)/MasR axis of the RAS appears to be protective in T2DM and strategies to restore ACE2 levels in the disease seem to be a promising therapy for Ang‐II‐mediated T2DM. © 2013 IUBMB Life, 65(9):731–738, 2013
Fighting an old war with a new weapon—silencing transposons by Piwi‐interacting RNA
Authors: Guo Manhong , Wu Yuliang 
Published: July 2013

AbstractDiscovered six decades ago, transposons are known to selfishly multiply within and between chromosomes. Although they may play a creative role in building new functional parts of the genome, transposons usually cause insertional mutagenesis and/or turn nearby genes on or off. To maintain genome integrity, cells use a variety of strategies to defend against the proliferation of transposons. A class of small noncoding RNA, discovered seven years ago and called piRNA, is a new player in the war to silence transposons. piRNA is made via two biogenesis pathways: the primary processing pathway and the ping‐pong amplification loop. These pathways are critically involved in transposon RNA degradation, DNA methylation, and histone modification machinery that represses transposons. In this review, we briefly introduce transposon‐caused genomic instability and summarize our current understanding of the piRNA pathway, focusing on its key function in transposon silencing. © 2013 IUBMB Life, 65(9):739–747, 2013
Targeting RAS/RAF/MEK/ERK signaling in metastatic melanoma
Authors: Wang Ao‐Xue , Qi Xiao‐Yi 
Published: July 2013

AbstractThe RAS/RAF/MEK/ERK pathway has been reported to be activated in over 80% of all cutaneous melanomas, making it the focus of many scientific studies in the melanoma field. Discoveries of mutations and aberrant expression of components in this cascade, in particular, BRAF and NRAS render a deeper understanding of the mechanisms responsible for oncogenesis and provide new therapeutic strategies for this deadly disease. This review starts with a comprehensive discussion on the role of this pathway in initiation and progress of melanoma. Mechanistically, mutated BRAF and NRAS exert most of the oncogenic effects through the activation of the MAPK pathway, which both drive the uncontrolled growth of melanoma cells and regulate the cell survival. In a subsequent section, clinical efficacy of targeted small‐molecule inhibitors is highlighted. BRAF‐targeted therapies (e.g., vemurafenib, dabrafenib) have showed impressive results in systemic therapy for melanoma harboring activating BRAF V600E mutations. MEK inhibitors show limited activity in phase I trials, and inhibitors directly targeting mutated NRAS, to date, have not been realized. Furthermore, the emerging mechanisms underlying both intrinsic and acquired drug resistance as well as approaches to prevent or abrogate the onset of therapeutic escape are addressed. Finally, the promising vistas and major challenges involving small‐molecule inhibitors targeting this MAPK pathway in melanoma therapy are briefly discussed. It can be envisaged that disseminated melanoma is no longer such a bleak prognosis in future given the research and development of new signal transduction inhibitors based on our evolving understanding of melanoma genetics and intracellular signaling. © 2013 IUBMB Life, 65(9):748–758, 2013
LED‐activated methylene blue‐loaded Pluronic‐nanogold hybrids for in vitro photodynamic therapy
Authors: Simon Timea , Boca‐Farcau Sanda , Gabudean Ana‐Maria , Baldeck Patrice , Astilean Simion 
Published: July 2013

AbstractIn this work we introduce a new class of multifunctional photodynamic agents based on the coupling of photosensitizer molecules with noble metal nanoparticles, which can be efficiently activated under low light intensity. The favourable modification of the photophysical properties of methylene blue (MB) in MB‐loaded Pluronic‐nanogold hybrids (Au‐PF127‐MB) increases the probability of singlet oxygen generation, which in turn allows the use of a light emitting diode (LED) irradiation source instead of commonly used, more invasive lasers. In this regard, Au‐PF127‐MB treated human lung carcinoma cells (HTB 177) were irradiated at different light doses, using a 660 nm LED source, the results indicating a dose dependent therapeutic effect, decreasing the cell viability down to 13%. Owing to their effectiveness, biocompatibility and integrated imaging and therapeutic functionalities, Au‐PF127‐MB could represent an important development in the field of biophotonic applications. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pigeon responding in fixed‐interval and response‐initiated fixed‐interval schedules
Authors: Fox Adam E. , Kyonka Elizabeth G. E. 
Published: July 2013

AbstractIn fixed‐interval (FI) and response‐initiated fixed‐interval (RIFI) schedules of reinforcement, a response is required after an interval has elapsed for delivery of reinforcement. In RIFI schedules, a response is required to initiate each interval as well. The objective of this experiment was a systematic comparison of performance in the two schedule types over a range of interval durations. Four pigeons were exposed to FI and RIFI schedules of 15, 30, 60, 120 and 240 s. Interfood intervals were longer and more variable in RIFI than corresponding FI schedules. In addition, response rates early in the RIFI schedules were higher than in corresponding FI schedules. However, the distribution of first‐response latencies, mean breakpoints, and normalized response gradients suggest that temporal discrimination was equivalent in the two schedules.
Dark spots on Mercury: A distinctive low‐reflectance material and its relation to hollows
Authors: Xiao Zhiyong , Strom Robert G. , Blewett David T. , Byrne Paul K. , Solomon Sean C. , Murchie Scott L. , Sprague Ann L. , Domingue Deborah L. , Helbert Jörn 
Published: July 2013

AbstractOrbital images acquired by the MErcury, Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft reveal a distinctive low‐reflectance material on the surface of Mercury. Such material occurs in small, isolated, and thin surficial units. We term these features “dark spots.” Dark spots have the lowest average reflectance yet documented on the planet. In every case observed at sufficiently high resolution, dark spots feature hollows at their centers. Not all hollows, however, are surrounded by a dark spot. Dark spots have been found on low‐reflectance smooth plains, intercrater plains, heavily cratered terrain, and impact craters at almost all longitudes on Mercury, but they have not been documented on high‐reflectance smooth plains material. Dark spots are one of the youngest endogenic features on Mercury, and some postdate craters with distinctive rays. Sulfides may be the phase responsible for the low albedo of dark spot material. We propose that dark spots form during the initial stages of hollow formation, perhaps in a manner similar to intense outgassing events that feature exit velocities in excess of 100 m/s. Such outgassing could contemporaneously produce a depression that constitutes an embryonic hollow. Under this scenario, dark spot material is subsequently removed or modified by regolith gardening or other surface processes on time scales shorter than the lifetime of the central hollow.
Thermokarst and export of sediment and organic carbon in the Sheldrake River watershed, Nunavik, Canada
Authors: Jolivel Maxime , Allard Michel 
Published: July 2013

AbstractA spatiotemporal computation of permafrost decay covering the period from 1957 to 2009 and validated by field investigations was made over a 76 km2river catchment straddling the tree line, in the discontinuous permafrost zone, east of Hudson Bay, in order to estimate the amounts of sediments and organic carbon released by thermokarst. Lithalsas and palsas are the dominant permafrost landforms, whereas thermokarst ponds, landslides, active layer failures, and gullies are the main features of permafrost degradation. Results show that 21% of the existing permafrost in 1957 had disappeared in 2009, resulting in a 96% growth of the thermokarst pond cover and a 46 to 217% increase of the number of active erosion landforms. An increase of stream connectivity related with the degradation of permafrost potentially allowed for an increase of sediments and carbon delivery to the main stream by a factor of 1.6. Volume of active landslides and gullies also increased by 12 to 38%, enhancing sediment and organic matter yields. Significant differences in permafrost degradation and in sediment and carbon inputs were observed along an east–west transect, from sites located at the head of the watershed near the tree line to sites located downstream close to the Hudson Bay coast. Thermokarst ponds in the forest tundra area released 2.3 times more sediments and dissolved organic carbon per unit of area in the fluvial system than in the shrub tundra area. Despite these yields by thermokarst, the Sheldrake River catchment currently does not seem to be yielding proportionally more sediments and carbon than a permafrost‐free river catchment.
Serial computed tomographic and positron emission tomographic properties of injection material used for vocal fold augmentation
Authors: Kwon Tack‐Kyun , Lee Ji‐Eun , Cha Won Jae , Song Chang Myeon , Sung Myung‐Whun , Kim Kwang Hyun 
Published: July 2013

Objectives/HypothesisThis study aimed to demonstrate the radiological properties of hyaluronic acid (HA) and calcium hydroxylapatite (CAHA) on serial computed tomography (CT) and positron emission tomography (PET) scan.Study DesignRetrospective Case Series.MethodRetrospective chart and imaging analysis of patients who underwent HA or CAHA injection laryngoplasty.ResultTotal of 243 patients who underwent more than one CT of PET after last injection laryngoplasty were included. Sixty‐eight patients received HA injection and 175 patients received CAHA injection. In all cases HA showed hypo‐density in CT and no abnormal uptake on PET. CAHA showed bright calcific density on CT scan and high uptake on PET but had disappeared with time in 18 months if injected less than 0.85 mL in amount.ConclusionThese findings support previous clinical studies on CAHA longevity and provide proper radiological interpretation on injection materials in the vocal folds.Level of EvidenceIV (Case series) Laryngoscope, 123:2491–2496, 2013
High‐Solids‐Content Hybrid Acrylic/CeO2 Latexes with Encapsulated Morphology Assessed by 3D‐TEM
Authors: Aguirre Miren , Paulis Maria , Leiza Jose Ramon , Guraya Teresa , Iturrondobeitia Maider , Okariz Ana , Ibarretxe Julen 
Published: July 2013

Hybrid acrylic/CeO2 latexes with solids content as high as 50 wt% and CeO2 content up to 1 wt% are synthesized by a seeded semibatch emulsion polymerization process. TEM images show that CeO2 nanoparticles are randomly located within the polymer particles. The 2D trasmission electron microscopy (TEM) images are not conclusive to elucidate if CeO2 is encapsulated in the hybrid polymer particles. A TEM tomographic analysis is presented here to assess their morphology. The study shows that the latexes synthesized present an encapsulated morphology for CeO2 nanoparticles regardless of whether these are located at the center or borders of the polymer particles.
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Palivizumab Prophylaxis during Nosocomial Outbreaks of Respiratory Syncytial Virus in a Neonatal Intensive Care Unit: Predicting Effectiveness with an Artificial Neural Network Model
Authors: Saadah Loai M. , Chedid Fares D. , Sohail Muhammad R. , Nazzal Yazied M. , Al Kaabi Mohammed R. , Rahmani Aiman Y. 
Published: July 2013

Study ObjectiveTo identify subgroups of premature infants who may benefit from palivizumab prophylaxis during nosocomial outbreaks of respiratory syncytial virus (RSV) infection.DesignRetrospective analysis using an artificial intelligence model.SettingLevel IIIB, 35‐bed, neonatal intensive care unit (NICU) at a tertiary care hospital in the United Arab Emirates.PatientsOne hundred seventy six premature infants, born at a gestational age of 22–34 weeks, and hospitalized during four RSV outbreaks that occurred between April 2005 and July 2007.Measurements and Main ResultsWe collected demographic and clinical data for each patient by using a standardized form. Input data consisted of seven categoric and continuous variables each. We trained, tested, and validated artificial neural networks for three outcomes of interest: mortality, days of supplemental oxygen, and length of NICU stay after the index case was identified. We compared variable impacts and performed reassignments with live predictions to evaluate the effect of palivizumab. Of the 176 infants, 31 (17.6%) received palivizumab during the outbreaks. All neural network configurations converged within 4 seconds in less than 400 training cycles. Infants who received palivizumab required supplemental oxygen for a shorter duration compared with controls (105.2 ± 7.2 days vs 113.2 ± 10.4 days, p=0.003). This benefit was statistically significant in male infants whose birth weight was less than 0.7 kg and who had hemodynamically significant congenital heart disease. Length of NICU stay after identification of the index case and mortality were independent of palivizumab use.ConclusionPalivizumab may be an effective intervention during nosocomial outbreaks of RSV in a subgroup of extremely low‐birth‐weight male infants with hemodynamically significant congenital heart disease.
Strontium concentrations and isotope ratios in enamel of healthy and carious teeth in southern Shaanxi, China
Authors: Li Zixia , He Maoyong , Peng Bin , Jin Zhangdong 
Published: July 2013

RATIONALEAs the trace element strontium (Sr) plays a significant role in dental health, it is important to determine the Sr concentration and isotope composition (87Sr/86Sr) of teeth and whether these values are related to caries formation, age and sex.METHODSA total of 160 permanent teeth were collected from 7‐ to 79‐year‐old people from the southern Shaanxi area of China, including 100 healthy teeth and 60 carious teeth (men and women each accounted for half of the samples). The concentration and isotope composition of Sr elements in the dental enamel of the teeth were measured using inductively coupled plasma mass spectrometry (ICP‐MS) and thermal ionization mass spectrometry (TIMS).RESULTSA significantly lower Sr concentration was found in the enamel of the carious teeth than in that of the healthy teeth for individuals of varying ages and sex. The Sr concentration in human carious teeth ranged between 79.70 µg/g and 85.80 µg/g; while the Sr concentration in healthy teeth ranged between 128 µg/g and 156.77 µg/g. Our results also demonstrated that the 87Sr/86Sr ratio did not appear to be affected by the caries formation, age or sex. The 87Sr/86Sr ratio in the enamel of the healthy and carious teeth of individuals of varying ages and genders ranged between 0.710935 and 0.711037, which falls into the range of 87Sr/86Sr ratios found in the local, naturally occurring water, soils and rocks.CONCLUSIONSSr plays a significant role in dental health, and there is a negative correlation between Sr and the occurrence of dental caries. The 87Sr/86Sr ratio of teeth reflects the 87Sr/86Sr ratio of the associated environment, and there is no significant relationship with the frequency of dental caries, age or sex. Copyright © 2013 John Wiley & Sons, Ltd.