bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accumulation of Vitamin A in the Hepatic Stellate Cell of Arctic Top Predators
Authors: Senoo Haruki , Imai Katsuyuki , Mezaki Yoshihiro , Miura Mitsutaka , Morii Mayako , Fujiwara Mutsunori , Blomhoff Rune 
Published: August 2012

AbstractWe performed a systematic characterization of the hepatic vitamin A storage in mammals and birds of the Svalbard archipelago and Greenland. The liver of top predators, including polar bear, arctic fox, bearded seal, and glaucous gull, contained about 10–20 times more vitamin A than the liver of all other arctic animals studied, as well as their genetically related continental top predators. The values are also high compared to normal human and experimental animals like mouse and rat. This massive amount of hepatic vitamin A was located in large autofluorescent lipid droplets in hepatic stellate cells (HSCs; also called vitamin A‐storing cells, lipocytes, interstitial cells, fat‐storing cells, or Ito cells). The droplets made up most of the cells' cytoplasm. The development of such an efficient vitamin A‐storing mechanism in HSCs may have contributed to the survival of top predators in the extreme environment of the arctic. These animals demonstrated no signs of hypervitaminosis A. We suggest that HSCs have capacity to take‐up and store large amounts of vitamin A, which may play a pivotal role in maintenance of the food web, food chain, biodiversity, and eventually ecology of the arctic. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Trimethyl‐4‐oxo‐4,5,6,7‐tetrahydroindazole‐1‐acetic Acid: A New Lead Compound with Selective COX‐2 Inhibitory Activity
Authors: Abdel‐Rahman Hamdy M. , Ozadali Keriman 
Published: August 2012

AbstractA novel series of 3,6,6‐trimethyl‐4‐oxo‐4,5,6,7‐tetrahydroindazole‐1‐acetic acid derivatives was designed and synthesized by a new one‐step pathway. Structure elucidation of the synthesized compounds was confirmed by various spectral and elemental analyses. The prepared compounds were evaluated for their ability to inhibit cyclooxygenase‐2 (COX‐2) and cyclooxygenase‐1 (COX‐1) enzymes in vitro. Among the synthesized compounds, the 2‐(3,6,6‐trimethyl‐4‐oxo‐4,5,6,7‐tetrahydroindazol‐1‐yl)acetic acid 4 emerged as the most potent COX‐2 inhibitor (IC50 value: 150 nM) with the highest selectivity index (COX‐1/COX‐2 inhibition ratio: 570.6). Docking studies of compound 4 in the active site of COX‐2 recognized its potential binding mode to the enzyme. Based on the preliminary results, compound 4 was considered as a lead compound for further optimization.
Keratinocyte galvanotaxis in combined DC and AC electric fields supports an electromechanical transduction sensing mechanism
Authors: Hart Francis X. , Laird Mhairi , Riding Aimie , Pullar Christine E. 
Published: August 2012

AbstractSedentary keratinocytes at the edge of a skin wound migrate into the wound, guided by the generation of an endogenous electric field (EF) generated by the collapse of the transepithelial potential. The center of the wound quickly becomes more negative than the surrounding tissue and remains the cathode of the endogenous EF until the wound is completely re‐epithelialized. This endogenous guidance cue can be studied in vitro. When placed in a direct current (DC) EF of physiological strength, 100 V/m, keratinocytes migrate directionally toward the cathode in a process known as galvanotaxis. Although a number of membrane‐bound (e.g., epidermal growth factor receptor (EGFR), integrins) and cytosolic proteins (cAMP, ERK, PI3K) are known to play a role in the downstream signaling mechanisms underpinning galvanotaxis, the initial sensing mechanism for this response is not understood. To investigate the EF sensor, we studied the migration of keratinocytes in a DC EF of 100 V/m, alternating current (AC) EFs of 40 V/m at either 1.6 or 160 Hz, and combinations of DC and AC EFs. In the AC EFs alone, keratinocytes migrated randomly. The 1.6 Hz AC EF combined with the DC EF suppressed the direction of migration but had no effect on speed. In contrast, the 160 Hz AC EF combined with the DC EF did not affect the direction of migration but increased the migration speed compared to the DC EF alone. These results can be understood in terms of an electromechanical transduction model, but not an electrodiffusion/osmosis or a voltage‐gated channel model. Bioelectromagnetics 34:85–94, 2013. © 2012 Wiley Periodicals, Inc.
Review pathway analysis for peptide‐mediated electronic coupling in the super‐exchange mechanism of ET and EET
Authors: Kawatsu Tsutomu 
Published: August 2012

AbstractElectron and excitation energy transfers (ET and EET) have an important role in biological energy‐exchange processes. Proteins are an inhomogeneous and anisotropic medium for ET and EET. The protein structure influences electronic coupling, an important factor for ET and EET. The structure factor may be predicted by obtaining information about the tunneling pathways. The present paper mainly focuses on tunneling pathway analysis using the tunneling current (flux) of the electron or configuration density. The tunneling pathways for ET and singlet EET through peptides are introduced using tunneling current (flux) analysis. These tunneling pathways differ greatly between ET and singlet EET. This paper also reviews both the theoretical background and other methods for determining electronic tunneling pathways. These pathways are related to the effect of protein coordinates on the electronic coupling between the initial and final states of the ET and EET. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 100: 100–113, 2013.
Spectroscopy of the Simplest Criegee Intermediate CH2OO: Simulation of the First Bands in Its Electronic and Photoelectron Spectra
Authors: Lee Edmond P. F. , Mok Daniel K. W. , Shallcross Dudley E. , Percival Carl J. , Osborn David L. , Taatjes Craig A. , Dyke John M. 
Published: August 2012

AbstractCH2OO, the simplest Criegee intermediate, and ozone are isoelectronic. They both play very important roles in atmospheric chemistry. Whilst extensive experimental studies have been made on ozone, there were no direct gas‐phase studies on CH2OO until very recently when its photoionization spectrum was recorded and kinetics studies were made of some reactions of CH2OO with a number of molecules of atmospheric importance, using photoionization mass spectrometry to monitor CH2OO. In order to encourage more direct studies on CH2OO and other Criegee intermediates, the electronic and photoelectron spectra of CH2OO have been simulated using high level electronic structure calculations and Franck–Condon factor calculations, and the results are presented here. Adiabatic and vertical excitation energies of CH2OO were calculated with TDDFT, EOM‐CCSD, and CASSCF methods. Also, DFT, QCISD and CASSCF calculations were performed on neutral and low‐lying ionic states, with single energy calculations being carried out at higher levels to obtain more reliable ionization energies. The results show that the most intense band in the electronic spectrum of CH2OO corresponds to the${{\rm{\tilde B}}}$1A′ ←${{\rm{\tilde X}}}$1A′ absorption. It is a broad band in the region 250–450 nm showing extensive structure in vibrational modes involving O–O stretching and C‐O‐O bending. Evidence is presented to show that the electronic absorption spectrum of CH2OO has probably been recorded in earlier work, albeit at low resolution. We suggest that CH2OO was prepared in this earlier work from the reaction of CH2I with O2and that the assignment of the observed spectrum solely to CH2IOO is incorrect. The low ionization energy region of the photoelectron spectrum of CH2OO consists of two overlapping vibrationally structured bands corresponding to one‐electron ionizations from the highest two occupied molecular orbitals of the neutral molecule. In each case, the adiabatic component is the most intense and the adiabatic ionization energies of these bands are expected to be very close, at 9.971 and 9.974 eV at the highest level of theory used.
Preparation of Photocatalytic Au–Ag2Te Nanomaterials
Authors: Lin Zong‐Hong , Shih Zih‐Yu , Roy Prathik , Chang Huan‐Tsung 
Published: August 2012

AbstractA facile approach has been developed for the preparation of various morphologies of Au–Ag2Te nanomaterials (NMs) that exhibit strong photocatalytic activity. Te NMs (nanowires, nanopencils, and nanorice) were prepared from TeO2 in the presence of various concentrations (16, 8, and 4 M) of a reducing agent (N2H4) at different temperatures (25 and 60 °C). These three Te NMs were then used to prepare Au–Ag2Te NMs by spontaneous redox reactions with Au3+ and Ag+ ions sequentially. The Au–Ag2Te nanopencils exhibit the highest activity toward degradation of methylene blue and formation of active hydroxyl radicals on solar irradiation, mainly because they absorb light in the visible region most strongly. All three differently shaped Au–Ag2Te NMs (10 μg mL−1) provide a death rate of Escherichia coli greater than 80 % within 60 min, which is higher than that of 51 % for commercial TiO2 nanoparticles (100 μg mL−1). Under light irradiation, the Au NPs in Au–Ag2Te NMs enhance the overall photo‐oxidation ability of Ag2Te NMs through faster charge separation because of good contact between Ag2Te and Au segments. With high antibacterial activity and low toxicity toward normal cells, the Au–Ag2Te NMs hold great potential for use as efficient antibacterial agents.
Key Role of Intramolecular Metal Chelation and Hydrogen Bonding in the Cobalt‐Mediated Radical Polymerization of N‐Vinyl Amides
Authors: Debuigne Antoine , Morin Aurélie N. , Kermagoret Anthony , Piette Yasmine , Detrembleur Christophe , Jérôme Christine , Poli Rinaldo 
Published: August 2012

AbstractThis work reveals the preponderance of an intramolecular metal chelation phenomenon in a controlled radical polymerization system involving the reversible trapping of the radical chains by a cobalt complex bis(acetylacetonato)cobalt(II). The cobalt‐mediated radical polymerization (CMRP) of a series of N‐vinyl amides was considered with the aim of studying the effect of the cobalt chelation by the amide moiety of the last monomer unit of the chain. The latter reinforces the cobaltpolymer bond in the order N‐vinylpyrrolidone<N‐vinyl caprolactam<N‐methyl‐N‐vinyl acetamide, and is responsible for the optimal control of the polymerizations observed for the last two monomers. Such a double linkage between the controlling agent and the polymer, through a covalent bond and a dative bond, is unique in the field of controlled radical polymerization and represents a powerful opportunity to fine tune the equilibrium between latent and free radicals. Possible hydrogen bond formation is also taken into account in the case of N‐vinyl acetamide and N‐vinyl formamide. These results are essential for understanding the factors influencing CoC bond strength in general, and the CMRP mechanism in particular, but also for developing a powerful platform for the synthesis of new precision poly(N‐vinyl amide) materials, which are an important class of polymers that sustain numerous applications today.
Effects of gemfibrozil on lipid metabolism, steroidogenesis, and reproduction in the fathead minnow (Pimephales promelas)
Authors: Skolness Sarah Y. , Durhan Elizabeth J. , Jensen Kathleen M. , Kahl Michael D. , Makynen Elizabeth A. , Villeneuve Daniel L. , Ankley Gerald T. 
Published: August 2012

Abstract
Fibrates are a class of pharmaceuticals that indirectly modulate cholesterol biosynthesis through effects on peroxisome proliferator-activated receptors. Gemfibrozil is a fibrate that has been detected in wastewater treatment plant influents, effluents, and drinking water. The objective of the present study was to assess the potential physiological and reproductive impacts of gemfibrozil on fathead minnows (Pimephales promelas). Fish were exposed to gemfibrozil in two different studies. The first was a short-term test with water concentrations of 0, 15, and 600 µg gemfibrozil/L, sampling after 2 or 8 d of exposure. Plasma cholesterol concentrations were significantly reduced in males exposed to 600 µg gemfibrozil/L for 8 d. In addition, expression of several hepatic genes important to lipid metabolism was altered, suggesting that gemfibrozil does affect lipid metabolism in fish. A 21-d study was conducted to investigate further the effects on lipid metabolism and steroidogenesis as well as to assess potential impacts of gemfibrozil on reproduction. Fish were exposed to water concentrations of 0, 1.5, 15, 600, and 1,500 µg gemfibrozil/L. Exposure to 1,500 µg gemfibrozil/L caused a modest, but not significant, reduction in fecundity. However, gemfibrozil had no consistent effect on plasma cholesterol, triglycerides, or sex steroids after 21 d of exposure. The present study showed no evidence for significant physiological or reproductive impacts of gemfibrozil at an environmentally relevant concentration of 1.5 µg/L. Environ. Toxicol. Chem. 2012; 31: 2615–2624. © 2012 SETAC
Pd Modified MmNi50.6Co10.2Mn5.4Al1.2 Alloy as the Catalyst of NaBH4 Electrooxidation
Authors: Cheng K. , Xu Y. , Miao R. R. , Yang F. , Yin J. L. , Wang G. L. , Cao D. X. 
Published: August 2012

AbstractA Pd‐modified hydrogen storage alloy was investigated as the anode electrocatalyst of direct borohydride fuel cell. The modification of the MmNi50.6 Co10.2 Mn5.4 Al1.2 hydrogen storage alloy with Pd was carried out by a self‐reduction reaction method. The morphology and the distribution of Pd on the surface of the alloy were observed by scanning electron microscope and energy dispersive X‐ray spectrometer. It was found that Pd particles uniformly distributed on the alloy surface and the content of Pd was 0.64 wt.%. The catalytic activity of the Pd‐modified hydrogen storage alloy for NaBH4 electrooxidation was evaluated by cyclic voltammetry and chronoamperometry measurements. Results showed that Pd modification significantly enhanced the catalytic activity of the hydrogen storage alloy. In the 1.0 mol dm–3 NaOH+ 0.1 mol dm–3 NaBH4 solution, the stabilized current density at –0.7 V was 34 and 22 mA cm–2 for the pristine and the Pd‐modified alloy, respectively. The utilization efficiency of NaBH4 on the Pd‐modified alloy catalyst reached 45%, which is higher than that on the pristine alloy (30%). The number of electrons released by BH4– electrooxidation on Pd‐modified alloy was found to be close four.
Toxicity of areca nut ingredients: Activation of CHK1/CHK2, induction of cell cycle arrest, and regulation of MMP‐9 and TIMPs production in SAS epithelial cells
Authors: Chang Mei‐Chi , Chan Chiu‐Po , Wang Wei‐Ting , Chang Bei‐En , Lee Jang‐Jaer , Tseng Shuei‐Kuen , Yeung Sin‐Yuet , Hahn Liang‐Jiunn , Jeng Jiiang‐Huei 
Published: August 2012

AbstractBackgroundThere are 600 million betel quid chewers around the world. betel quid chewing is a major risk factor of oral cancer. Why betel quid components induce oral cancer is not clear.MethodsCytotoxicity of areca nut extract and arecoline (an areca nut alkaloid) to SAS oral epithelial cell line was evaluated by trypan blue dye exclusion and MTT assays. Cell cycle distribution and apoptosis was analyzed by propidium iodide staining flow cytometry. Chk1 and chk2 activation was analyzed by Pathscan phospho‐enzyme‐linked immunosorbent assay. Metalloproteinase‐9 (MMP‐9), tissue inhibitors of metalloproteinase (TIMPs) production was measured by enzyme‐linked immunosorbent assay.ResultsAreca nut extract (800 μg/mL) and arecoline (>0.4 mmol/L) caused cell death, apoptosis, and cell cycle arrest of SAS cells. Areca nut extract and arecoline stimulated Chk1 and Chk2 phosphorylation in SAS cells. Areca nut extract stimulated cellular MMP‐9 but suppressed TIMP‐1 and TIMP‐2 production.ConclusionsAreca nut components activate Chk1/Chk2, alter cell cycle regulation/apoptosis, MMP‐9, and TIMPs production, contributing to the pathogenesis of oral carcinogenesis. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Quality of life in patients with head and neck cancer receiving targeted or multimodal therapy — Update of the EORTC QLQ‐H&N35, Phase I
Authors: Singer Susanne , Arraras Juan I. , Baumann Ingo , Boehm Andreas , Chie Wei‐Chu , Galalae Razvan , Langendijk Johannes A. , Guntinas–Lichius Orlando , Hammerlid Eva , Pinto Monica , Nicolatou–Galitis Ourania , Schmalz Claudia , Sen Mehmet , Sherman Allen C. , Spiegel Karin , Verdonck–de Leeuw Irma , Yarom Noam , Zotti Paola , Hofmeister Dirk ,   on behalf of the EORTC Quality of Life and the EORTC Head and Neck Cancer Groups
Published: August 2012

AbstractBackgroundThe objective of this study was to identify relevant quality of life (QOL) issues in patients with head and neck cancer receiving multimodal and/or targeted therapies.MethodsThe literature was searched for QOL issues reported after multimodal and/or targeted therapies resulting in a list of potentially relevant issues. These were discussed within a multiprofessional expert group, revised, and subsequently rated for relevance by patients and health care providers.ResultsTwenty‐seven issues were extracted that are not covered by the current version of the European Organization for Research and Treatment of Cancer (EORTC) questionnaires. Interviews (96 health care providers from 13 countries, 137 patients from 8 countries) revealed that 26 of these issues were relevant for patients with head and neck cancer.ConclusionsStudies investigating targeted and/or multimodal therapy should consider that some QOL issues specific to these treatments are not covered by the current version of the EORTC instruments. Consequently, the EORTC head and neck cancer module is currently in revision. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Circulating U2 small nuclear RNA fragments as a novel diagnostic biomarker for pancreatic and colorectal adenocarcinoma
Authors: Baraniskin Alexander , Nöpel‐Dünnebacke Stefanie , Ahrens Maike , Jensen Steffen Grann , Zöllner Hannah , Maghnouj Abdelouahid , Wos Alexandra , Mayerle Julia , Munding Johanna , Kost Dennis , Reinacher‐Schick Anke , Liffers Sven , Schroers Roland , Chromik Ansgar M. , Meyer Helmut E. , Uhl Waldemar , Klein‐Scory Susanne , Weiss Frank U. , Stephan Christian , Schwarte‐Waldhoff Irmgard , Lerch Markus M. , Tannapfel Andrea , Schmiegel Wolff , Andersen Claus Lindbjerg , Hahn Stephan A. 
Published: August 2012

AbstractImproved non‐invasive strategies for early cancer detection are urgently needed to reduce morbidity and mortality. Non‐coding RNAs, such as microRNAs and small nucleolar RNAs, have been proposed as biomarkers for non‐invasive cancer diagnosis. Analyzing serum derived from nude mice implanted with primary human pancreatic ductal adenocarcinoma (PDAC), we identified 15 diagnostic microRNA candidates. Of those miR‐1246 was selected based on its high abundance in serum of tumor carrying mice. Subsequently, we noted a cross reactivity of the established miR‐1246 assays with RNA fragments derived from U2 small nuclear RNA (RNU2‐1). Importantly, we found that the assay signal discriminating tumor from controls was derived from U2 small nuclear RNA (snRNA) fragments (RNU2‐1f) and not from miR‐1246. In addition, we observed a remarkable stability of RNU2‐1f in serum and provide experimental evidence that hsa‐miR‐1246 is likely a pseudo microRNA. In a next step,RNU2‐1fwas measured by qRT‐PCR and normalized tocel‐54in 191 serum/plasma samples from PDAC and colorectal carcinoma (CRC) patients. In comparison to 129 controls, we were able to classify samples as cancerous with a sensitivity and specificity of 97.7% [95% CI = (87.7, 99.9)] and 90.6% [95% CI = (80.7, 96.5)], respectively [area under the ROC curve 0.972]. Of note, patients with CRC were detected with our assay as early as UICC Stage II with a sensitivity of 81%. In conclusion, this is the first report showing that fragments of U2 snRNA are highly stable in serum and plasma and may serve as novel diagnostic biomarker for PDAC and CRC for future prospective screening studies.
Animal Models for Photodiagnosis and Photodynamic Therapy
Authors: D'Hallewin M. , Helle M. , Garrier J. , Bezdetnaya L. , Guillemin F. 
Published: August 2012

AbstractA prerequisite for starting a clinical trial is evidence of a positive impact of the technique or drug in animals. The choice of the animal model is thus very important and should mimic as closely as possible the human situation. A variety of animal models have been validated for pharmaceutical trials. The situation in phototheranostics however is not fully clear. This is due to the very complex interplay of various elements such as vascularization, oxygenation, drug availability and biodistribution, light absorption, and scattering. The present paper will give general information on aspects of animal models that have to be considered in phototheranostics, as well as highlight some typical animal models that are useful for the investigation of light‐tissue interactions.
Stattic V, a STAT3 inhibitor, affects human spermatozoa through regulation of mitochondrial activity
Authors: Lachance Catherine , Goupil Serge , Leclerc Pierre 
Published: August 2012

AbstractWe have recently shown that many mediators of the JAK/STAT signaling pathway are present in ejaculated human spermatozoa. Among them, STAT3 is detected mainly in membranes and flagellar cytoskeletal fractions. In order to determine the importance of STAT3‐mediated signaling, sperm were incubated with Stattic V, a specific inhibitor. Effects on motility were evaluated by CASA, sperm acrosomal integrity was evaluated by FITC conjugated lectin (PSA or PNA) staining, and protein phosphotyrosine content was assessed by Western blot using a monoclonal anti‐phosphotyrosine antibody. INDO1‐AM and JC‐1 were used to measure sperm intracellular calcium and mitochondrial membrane potential, respectively, by flow cytometry, and reactive oxygen species (ROS) production was investigated by luminol‐based assay. Percentages of motility and motility parameters were significantly affected by Stattic V. This later also significantly increased intracellular Ca2+ levels, progesterone‐ and calcium ionophore (A23187)‐induced acrosome reaction. On the other hand, a significant decrease in ATP content was measured when sperm were treated with Stattic V, associated with depolarization of mitochondrial membrane and elevated ROS production. These results suggest that STAT3 is involved in sperm functions, at least through regulation of mitochondrial activity. This further emphasizes that STAT3 mediates cellular activities in a manner different than strictly the activation of gene transcription. J. Cell. Physiol. 228: 704–713, 2013. © 2012 Wiley Periodicals, Inc.
An evaluation of the spatiotemporal structure of large‐scale European drought within the HiGEM climate model
Authors: Lloyd‐Hughes Benjamin , Shaffrey Leonard C. , Vidale Pier Luigi , Arnell Nigel W. 
Published: August 2012

AbstractWe compare the characteristics of synthetic European droughts generated by the HiGEM1 coupled climate model run with present day atmospheric composition with observed drought events extracted from the CRU TS3 data set. The results demonstrate consistency in both the rate of drought occurrence and the spatiotemporal structure of the events. Estimates of the probability density functions for event area, duration and severity are shown to be similar with confidence > 90%. Encouragingly, HiGEM is shown to replicate the extreme tails of the observed distributions and thus the most damaging European drought events. The soil moisture state is shown to play an important role in drought development. Once a large‐scale drought has been initiated it is found to be 50% more likely to continue if the local soil moisture is below the 40th percentile . In response to increased concentrations of atmospheric CO2, the modelled droughts are found to increase in duration, area and severity. The drought response can be largely attributed to temperature driven changes in relative humidity. Copyright © 2012 Royal Meteorological Society