bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estrogen signalling through amphiregulin may be implicated in human hepatocellular carcinoma
Authors: Carruba Giuseppe , Miceli Vitale , Cocciadiferro Letizia , Zarcone Maurizio , Agostara Biagio , Montalto Giuseppe , Granata Orazia M. 
Published: March 2011

Abstract

Background: We investigated aromatase (Aro)-driven estrogen formation in non-tumoral and malignant liver tissues and cells, also in relation to expression of the estrogen receptors α and β (ERα and ERβ) and amphiregulin (AREG), aiming to gain insights into the potential role of estrogens in human hepatocellular carcinoma (HCC).

Materials and methods: Chromatographic and reverse transcriptase polymerase chain reaction (RT-PCR) analyses were used to assess activity and expression of the Aro enzyme and AREG as well as the expression of wild-type and variant ERs, both in vivo and in vitro.

Results: Following 24 h and 72 h incubation of liver tissues or cells with testosterone, human HCC tissues and HepG2 hepatoma cells showed elevated Aro activity (estrogen formation, respectively, of 20% and 52%–99%). By contrast, no Aro activity could be detected in non-tumoral tissues and HA22T liver cancer cells. Cirrhotic samples and Huh7 cells exhibited intermediate enzyme activity, with estrogen formation of 4% and 34%, respectively. Markedly lower or undetectable Aro mRNA levels were observed in HA22T cells and non-tumoral liver tissues compared with HepG2 cells and HCC samples. Cirrhotic specimens displayed variable transcript levels. Interestingly, no or low expression of wild-type ERα and ERβ could be observed in liver cancer cells and malignant tissues. However, ubiquitous expression of the hERα46 variant and occasional expression of the hERβ2/Cx variant were observed in cancer tissues and cells.

Conclusions: It is noteworthy that the pattern of wild-type ERα was inversely related to Aro, whilst AREG expression was consistently associated with that of Aro. This combined evidence suggests that locally elevated Aro activity may increase malignant cell proliferation also through AREG signalling.
The polysemy of the German suffix ‑er: aspects of its origin and development
Authors: Müller Peter O. 
Published: March 2011

Abstract
The nominal suffix ‑er is polysemous in contemporary German. It is not only used for the formation of terms designating persons (Maler ‘artist’) but also animals (Würger ‘shrike’), objects (Entsafter ‘juicer’) and events (Seufzer ‘sigh’). Until now, there has been little research into the way this polysemy has developed in the course of German language history. The central theme of this article is the reconstruction of its origin and development from Old High German onwards. It will be demonstrated that the various meanings of ‑er occur as a result of different strands of development, for which both language contact phenomena and semantic change have been decisive.
Polysemy and productivity in German
Authors: Scherer Carmen 
Published: March 2011

Abstract
In this paper, agent polysemy in German will be discussed in the framework of lexical semantics as outlined in Lieber (2004). I will show that Lieber’s explanation of agent polysemy works fine for German ‑er derivation as far as agent, instrument and patient nouns are concerned. It also helps us to understand differences in frequency and productivity of the different semantic groups. However, I will argue that Lieber’s framework is not yet elaborate enough to account for German event derivatives such as Hüpfer ‘hop’.
Low Quality as a Signal of High Quality
Authors: Clements Matthew T. 
Published: March 2011

Abstract
If a product has two dimensions of quality, one observable and one not, a firm can use observable quality as a signal of unobservable quality. The correlation between consumers’ valuation of high quality in each dimension is a key determinant of the feasibility of such signaling. A firm may use price alone as a signal, or price and quality together. Both signals tend to be used when the market is very uninformed, whereas price signaling alone tends to be used when the market is moderately informed. If high observable quality is inexpensive to provide, then it cannot signal high unobservable quality, and low observable quality is always an indication that unobservable quality is high.
Preclinical Models of Pediatric Solid Tumors (Neuroblastoma) and Their Use in Drug Discovery
Authors: Patterson Danielle M. , Shohet Jason M. , Kim Eugene S. 
Published: March 2011

AbstractNeuroblastoma is the most common pediatric abdominal solid tumor. This aggressive embryonal malignancy of neural crest origin has a peak age of onset of 22 months, and accounts for ∼11% of all pediatric cancers and 15% of all pediatric cancer deaths. With current treatment protocols, including high‐dose chemotherapy with autologous stem cell transplantation, radiation, and surgery, ∼80% of high‐risk patients go into remission, although the majority relapse and succumb to therapy‐resistant tumors. Long‐term survival rates (>5 years) are <50%. Mouse models of neuroblastoma provide clinically relevant tools for studying the growth and metastasis of this aggressive malignancy, and for testing the efficacy of potentially novel therapeutics in vivo. This unit describes an orthotopic murine model of neuroblastoma using cultured human cells that closely mimics the clinical condition in terms of the bulky intra‐abdominal tumors and other aspects of metastatic disease. Also described are methods for in vivo imaging and monitoring of tumor growth, and procedures for necropsy and tumor preservation for pathological analysis. Curr. Protoc. Pharmacol. 52:14.17.1‐14.17.18. © 2011 by John Wiley & Sons, Inc.
Effect of Recrystallization on Tensile Behavior, Texture, and Anisotropy of Ti‐3Al‐2.5 V Cold Pilgered Tubes
Authors: Bayona‐Carrillo Nicolás , Bozzolo Nathalie , Fundenberger Jean‐Jacques , Thomas Bertrand , Camelin Patrick , Lenarduzzi Emmanuel , Wagner Francis 
Published: March 2011

AbstractThe recrystallized volume fraction of Ti 3Al 2.5 V seamless tubes is measured using electron BackScatter diffraction (EBSD) after annealing under various conditions. Standard tensile tests and contractile strain ratio (CSR) measurements are carried out in order to analyze the effect of recrystallization on the tensile behavior and the anisotropy of the tubes. The tensile tests show anomalous yield‐point phenomena, which become stronger when the recrystallized fraction is increased. CSR value changes through recrystallization, from 0.8 in the cold worked stress relieved (CWSR) state to 1.1 in the fully recrystallized structure. Orientation distribution functions (ODFs) calculated from X‐ray data reveal a decay in the intensity of the crystallographic texture as recrystallization advances. This can explain the tendency toward isotropy when complete recrystallization is achieved.
Molding Micropatterns of Elasticity on PEG‐Based Hydrogels to Control Cell Adhesion and Migration
Authors: Diez Mar , Schulte Vera A. , Stefanoni Filippo , Natale Carlo F. , Mollica Francesco , Cesa Claudia M. , Chen Jingyu , Möller Martin , Netti Paolo A. , Ventre Maurizio , Lensen Marga C. 
Published: March 2011

AbstractWe present an innovative and simple, soft UV lithographic method “FIll‐Molding In Capillaries” (FIMIC) that combines soft lithography with capillary force driven filling of micro‐channels to create smooth hydrogel substrates with a 2D micro‐pattern on the surface. The lithographic procedure involves the molding of a polymer; in our case a bulk PEG‐based hydrogel, via UV‐curing from a microfabricated silicon master. The grooves of the created regular line pattern are consequently filled with a second hydrogel by capillary action. As a result, a smooth surface is obtained with a well‐defined pattern design of the two different polymers on its surface. The FIMIC method is very versatile; the only prerequisite is that the second material is liquid before curing in order to enable the filling process. In this specific case we present the proof of principle of this method by applying two hydrogels which differ in their crosslinking density and therefore in their elasticity. Preliminary cell culture studies on the fabricated elasticity patterned hydrogels indicate the preferred adhesion of the cells to the stiffer regions of the substrates, which implies that the novel substrates are a very useful platform for systematic cell migration studies, e.g. more fundamental investigation of the concept of “durotaxis”.
The Control of Shrinkage and Thermal Instability in SU‐8 Photoresists for Holographic Lithography
Authors: Denning Robert G. , Blanford Christopher F. , Urban Henning , Bharaj Harpal , Sharp David N. , Turberfield Andrew J. 
Published: March 2011

AbstractThe negative‐tone epoxy photoresist, SU‐8, expands ≈1% by volume after postexposure baking. However, if the maximum optical fluence is comparable to that at the insolubility threshold, as in a holographic exposure, the developed resist shrinks (≈35% by volume) due to the removal of light oligomers not incorporated into the polymeric network. IR spectroscopy shows that, at this level of exposure, only 15% of the epoxy groups in the insoluble polymer have reacted; consequently microstructural elements soften and collapse at >100 °C. When the light oligomers are removed, the sensitivity of the resist is unchanged, provided that 5% (w/w) of a high‐molecular‐weight reactive plasticizer (glycidoxy‐terminated polyethylene glycol) is added, but it shrinks less on development and, when used as a photonic crystal template, shows improved uniformity with less cracking and buckling. Reinforcing the polymer network by reaction with the polyfunctional amine (bis‐N,N′‐(3‐aminopropyl)ethylenediamine) increases the extent of cross‐linking and the thermal stability, allowing inverse replicas of photonic crystal templates to be fabricated from both Al:ZnO and Zr3N4 using atomic layer deposition at temperatures up to 200 °C.
Permeation through CO2selective glassy polymeric membranes in the presence of hydrogen sulfide
Authors: Scholes Colin A. , Stevens Geoff W. , Kentish Sandra E. 
Published: March 2011

AbstractMinor components present in feed gas streams can have a significant influence on the separation performance of polymeric membranes. Hydrogen sulfide is present in many of the processes where CO2 capture is possible and can therefore undergo competitive sorption with CO2 for transport through the membrane, as well as influence the membrane morphology inducing plasticization. This study investigates the change in CO2 permeability and CO2/N2 selectivity of two glassy polymeric membranes; polysulfone and 6FDA‐TMPDA, when 500 ppm H2S is present in the gas mixture. The outcomes of this study reveal that H2S in trace amounts has a strong influence on the separation performance of both membranes. For both membranes, a plasticization partial pressure ∼0.5–0.6 kPa H2S is observed. H2S competitive sorption is also observed and is modeled by competitive dual‐sorption theory. Results suggest that mixed gas permeation influences the amount of each gas immobilized within the Langmuir voids in addition to the expected competitive sorption effects. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Measurement of intraocular and intracranial pressure: Is there a relationship?
Authors: Kirk Tyler , Jones Keith , Miller Spencer , Corbett James 
Published: March 2011

AbstractObjective:To study whether noninvasive, intraocular pressure (IOP) measurements significantly correlate with standard intracranial pressure (ICP) measurements.Methods:This prospective, blinded study enrolled 46 patients who were undergoing medically indicated lumbar puncture (LP). IOP was measured by applanation tonometry immediately prior to measuring LP opening pressure. One patient was excluded due to unsuccessful ICP measurement.Results:In the 45 patients to successfully undergo IOP and ICP measurement, there was no significant relationship between ICP and average IOP for both eyes (r = −0.005). There was no significant relationship between ICP and IOP in either eye, when studied individually(r = 0.03 ocular dexter [OD], r = −0.05 ocular sinister [OS]). There was no significant relationship between ICP and IOP when the eye best correlated to the patient's ICP was chosen (r = −0.01).Interpretation:No significant relationship between ICP and IOP was observed. Noninvasive IOP measurements do not predict ICP.ANN NEUROL 2011;
Radical‐Transfer Hydroamination of Olefins with N‐Aminated Dihydropyridines
Authors: Chou Chih‐Ming , Guin Joyram , Mück‐Lichtenfeld Christian , Grimme Stefan , Studer Armido 
Published: March 2011

AbstractAn efficient synthesis of N‐phthalimidyl, benzamidyl, acetamidyl, carbamoyl, and ureayl derivatives of dihydropyridines and the application of these reagents as precursors for N‐centered radicals are presented. These aminated dihydropyridines could be used in radical‐transfer hydroamination reactions of various electron‐rich as well as nonactivated olefins in the presence of thiols as polarity‐reversal catalysts. These reactions worked without the aid of any transition metal. Steric and electronic effects exerted by the N‐substitutents of the N‐centered radicals are discussed. In contrast to most metal‐catalyzed processes, the radical hydroamination delivered the opposite regioisomer with excellent anti‐Markovnikov selectivity. Hydroamination products were obtained as protected amines that are readily isolated.
Near‐infrared laser delivery of nanoparticles to developing embryos: A study of efficacy and viability
Authors: Umanzor‐Alvarez Jose , Wade Emily C. , Gifford Aliya , Nontapot Kankowan , Cruz‐Reese Ariana , Gotoh Tetsuya , Sible Jill C. , Khodaparast Giti A. 
Published: March 2011

AbstractTargeted delivery of materials to individual cells remains a challenge in nanoscience and nanomedicine. Near infrared (NIR) laser injection may be a promising alternative to manual injection (where the micropipet diameter limits targeting to small cells) or other laser techniques (such as picosecond green and UV lasers, which can be damaging to cells). However, the efficiency with which NIR pulses can deliver nanoparticles and any adverse effects on living cells needs thorough testing. Toward this end, we have determined the efficacy and toxicity of delivering quantum dots (QDs) into cells of Xenopus laevis embryos by NIR laser injection. Because this model system provides not only living cells but also a developing organism, we were able to assess relatively long‐term effects of NIR pulses on embryonic development (through the tadpole stage). We developed parameters for NIR pulses that did not affect embryonic viability or morphology and delivered QDs as effectively as manual injection. Higher intensities of NIR pulses caused permanent damage to the targeted cells, and thus NIR pulses may also prove useful for ablation of specific cells within tissues.
Differentiation‐inducing ability of sophorolipids of oleic and linoleic acids using a glioma cell line
Authors: Joshi‐Navare Kasturi , Shiras Anjali , Prabhune Asmita 
Published: March 2011

AbstractSophorolipids are biosurfactants produced by non‐pathogenic yeasts. They show structural similarity with the membrane components of mammalian cells, i.e., glycosphingolipids and gangliosides, which are involved in processes such as signaling, oncogenesis, and differentiation. Sophorolipids have been reported to induce differentiation in several leukemic cell lines, cell death via apoptosis in a human liver cancer cell line, and necrosis in a pancreatic adenocarcinoma cell line. Here we report, for the first time, the effects of precursor fatty acids and sophorolipids of oleic and linoleic acids in pure acidic and crude forms on LN‐229, a glioma cell line. In response to different sophorolipid forms, various morphological changes were observed, such as formation of long thread‐like extensions arising from the ends of the cells, cell alignment, cell elongation and bundle formation in a dose‐dependent manner. In this study we present the morphological evidence of the potential of sophorolipids as differentiation inducers.
A colorimetric assay for determination of methyl parathion using recombinant methyl parathion hydrolase
Authors: Anh Dau Hung , Cheunrungsikul Kritsananporn , Wichitwechkarn Jesdawan , Surareungchai Werasak 
Published: March 2011

AbstractA simple, rapid and sensitive colorimetric dipstick assay for the detection of the organophosphorous insecticide methyl parathion (MPT) residue in vegetables was developed. The assay was based on the hydrolysis of MPT by a recombinant methyl parathion hydrolase (recMPH), the encoding gene of which was isolated from Burkholderia cepacia, a soil bacterium indigenous to Thailand. This reaction generates protons leading to a change in pH that correlates with the amount of MPH present. Hence, the pH indicator bromothymol blue was used to monitor the MPH hydrolysis as the associated color changes can be observed by the naked eye. The recMPH was immobilized on a PVDF membrane to establish a dipstick assay format. The assays could detect MPT residues in spiked vegetable samples at the concentration of 1 mg/L without using analytical instrumentation. The test is reusable and stable for up to 3 months in the absence of any preservatives.
Gonadotropin purification from horse serum applying magnetic beads
Authors: Müller Christine , Preußer‐Kunze Andrea , Wagner Kerstin , Franzreb Matthias 
Published: March 2011

AbstractThe glycoprotein hormone equine chorionic gonadotropin (eCG) is a commercial product used in animal breeding as well as in veterinary medicine. The current state of the art for the purification of eCG from serum is pH fractionation with metaphosphoric acid, two ethanol precipitation steps as well as dialysis followed by fixed‐bed chromatography. Two simplified processes, including the use of magnetic microsorbents for the purification of eCG have been developed. The processes reduce or even omit the use of organic solvents and the required solid‐liquid separation steps, thus making them potential candidates for a first commercial application of magnetic beads in bioprocessing.
Chain length effects on helix‐hairpin distribution in short peptides with Aib‐DAla and Aib‐Aib Segments
Authors: Rajagopal Appavu , Aravinda Subrayashastry , Raghothama Srinivasarao , Shamala Narayanaswamy , Balaram Padmanabhan 
Published: March 2011

AbstractThe Aib‐DAla dipeptide segment has a tendency to form both type‐I′/III′ and type‐I/III β‐turns. The occurrence of prime turns facilitates the formation of β‐hairpin conformations, while type‐I/III turns can nucleate helix formation. The octapeptide Boc‐Leu‐Phe‐Val‐Aib‐DAla‐Leu‐Phe‐Val‐OMe (1) has been previously shown to form a β‐hairpin in the crystalline state and in solution. The effects of sequence truncation have been examined using the model peptides Boc‐Phe‐Val‐Aib‐Xxx‐Leu‐Phe‐NHMe (2, 6), Boc‐Val‐Aib‐Xxx‐Leu‐NHMe (3, 7), and Boc‐Aib‐Xxx‐NHMe (4, 8), where Xxx = DAla, Aib. For peptides with central Aib‐Aib segments, Boc‐Phe‐Val‐Aib‐Aib‐Leu‐Phe‐NHMe (6), Boc‐Val‐Aib‐Aib‐Leu‐NHMe (7), and Boc‐Aib‐Aib‐NHMe (8) helical conformations have been established by NMR studies in both hydrogen bonding (CD3OH) and non‐hydrogen bonding (CDCl3) solvents. In contrast, the corresponding hexapeptide Boc‐Phe‐Val‐Aib‐DAla‐Leu‐Phe‐Val‐NHMe (2) favors helical conformations in CDCl3 and β‐hairpin conformations in CD3OH. The β‐turn conformations (type‐I′/III) stabilized by intramolecular 4→1 hydrogen bonds are observed for the peptide Boc‐Aib‐DAla‐NHMe (4) and Boc‐Aib‐Aib‐NHMe (8) in crystals. The tetrapeptide Boc‐Val‐Aib‐Aib‐Leu‐NHMe (7) adopts an incipient 310‐helical conformation stabilized by three 4→1 hydrogen bonds. The peptide Boc‐Val‐Aib‐DAla‐Leu‐NHMe (3) adopts a novel α‐turn conformation, stabilized by three intramolecular hydrogen bonds (two 4→1 and one 5→1). The Aib‐DAla segment adopts a type‐I′ β‐turn conformation. The observation of an NOE between Val (1) NH↔HNCH3 (5) in CD3OH suggests, that the solid state conformation is maintained in methanol solutions. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 96: 744–756, 2011.
Measuring thermodynamic details of DNA hybridization using fluorescence
Authors: You Yong , Tataurov Andrey V. , Owczarzy Richard 
Published: March 2011

AbstractModern real‐time PCR systems make it easy to monitor fluorescence while temperature is varied for hundreds of samples in parallel, permitting high‐throughput studies. We employed such system to investigate melting transitions of ordered nucleic acid structures into disordered random coils. Fluorescent dye and quencher were attached to oligonucleotides in such a way that changes of fluorescence intensity with temperature indicated progression of denaturation. When fluorescence melting data were compared with traditional ultraviolet optical experiments, commonly used dye/quencher combinations, like fluorescein and tetramethylrhodamine, showed substantial discrepancies. We have therefore screened 22 commercially available fluorophores and quenchers for their ability to reliably report annealing and melting transitions. Dependence of fluorescence on temperature and pH was also investigated. The optimal performance was observed using Texas Red or ROX dyes with Iowa Black RQ or Black Hole quenchers. These labels did not alter two‐state nature of duplex melting process and provided accurate melting temperatures, free energies, enthalpies, and entropies. We also suggest a new strategy for determination of DNA duplex thermodynamics where concentration of a dye‐labeled strand is kept constant and its complementary strand modified with a quencher is added at increasing excess. These methodological improvements will help build predictive models of nucleic acid hybridization. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 472–486, 2011.
Cage‐Shaped Borate Esters with Tris(2‐oxyphenyl)methane or ‐silane System Frameworks Bearing Multiple Tuning Factors: Geometric and Substituent Effects on Their Lewis Acid Properties
Authors: Yasuda Makoto , Nakajima Hideto , Takeda Ryosuke , Yoshioka Sachiko , Yamasaki Satoshi , Chiba Kouji , Baba Akio 
Published: March 2011

AbstractBoron complexes that contain new tridentate ligands, tris(o‐oxyaryl)methanes and ‐silanes, were prepared. These complexes had a cage‐shaped structure around a boron center and showed higher Lewis acidity and catalytic activity than open‐shaped boron compounds. The cage‐shaped ligands determined the properties of the borates by altering the geometry and were consistently bound to the metal center by chelation. The synthesized compounds were L⋅B(OC6H4)3CH, L⋅B(OC6H4)3SiMe, and its derivatives (L=THF or pyridine as an external ligand). Theoretical calculations suggested that the cage‐shaped borates had a large dihedral angle (Cipso‐O‐B‐O) compared with open‐shaped borates. The geometric effect due to the dihedral angle means that compared with open‐shaped, the cage‐shaped borates have a greater Lewis acidity. The introduction of electron‐withdrawing groups on the aryl moieties in the cage‐shaped framework increased the Lewis acidity. Substitution of a bridgehead Si for a bridgehead C decreased the Lewis acidity of the boron complexes because the large silicon atom reduces the dihedral angle of Cipso‐O‐B‐O. The ligand‐exchange rates of the para‐fluoro‐substituted compound B(OC6H3F)3CH and the ortho‐phenyl‐substituted compound B(OC6H3Ph)3CH were less than that of the unsubstituted borate B(OC6H4)3CH. The ligand‐exchange rate of B(OC6H4)3SiMe was much faster than that of B(OC6H4)3CH. A hetero Diels–Alder reaction and Mukaiyama‐type aldol reactions were more effectively catalyzed by cage‐shaped borates than by the open‐shaped borate B(OPh)3 or by the strong Lewis acid BF3⋅OEt2. The cage‐shaped borates with the bulky substituents at the ortho‐positions selectively catalyzed the reaction with less sterically hindered substrates, while the unsubstituted borate showed no selectivity.