gebhart/patrepeval huggingface dataset:
Tufa-forming biofilms of German karstwater streams: microorganisms, exopolymers, hydrochemistry and calcification (2010)

Abstract To understand mechanisms of tufa biofilm calcification, selected karstwater stream stromatolites in Germany have been investigated with regard to their hydrochemistry, biofilm community, exopolymers, physicochemical microgradients, calcification pattern and lamination. In stream waters, CO 2 degassing drives the increase in calcite saturation to maximum values of approximately 10-fold, independent from the initial Ca 2+ /alkalinity ratio. For the cyanobacteria of tufa biofilms, a culture-independent molecular approach showed that microscopy of resin-embedded biofilm thin sections underestimated the actual diversity of cyanobacteria, i.e. the six cyanobacteria morphotypes were opposed to nine different lineages of the 16S rDNA phylogeny. The same morphotype may even represent two genetically distant cyanobacteria and the closest relatives of tufa biofilm cyanobacteria may be from quite different habitats. Diatom diversity was even higher in the biofilm at the studied exemplar site than that of the cyanobacteria, i.e. 13 diatom species opposed to 9 cyanobacterial lineages. The non-phototrophic prokaryotic biofilm community is clearly different from the soil-derived community of the stream waters, and largely composed of flavobacteria, firmicutes, proteobacteria and actinobacteria. The exopolymeric biofilm matrix can be divided into three structural domains by fluorescence lectin-binding analysis. Seasonal and spatial variability of these structural EPS domains is low in the investigated streams. As indicated by microsensor data, biofilm photosynthesis is the driving mechanism in tufa stromatolite formation. However, photosynthesis-induced biofilm calcification accounts for only 10–20% of the total Ca 2+ loss in the streams, and occurs in parallel to inorganic precipitation driven by CO 2 -degassing within the water column and on biofilm-free surfaces. Annual stromatolite laminae reflect seasonal changes in temperature and light supply. The stable carbon isotope composition of the laminae is not affected by photosynthesis-induced microgradients, but mirrors that of the bulk water body only reflecting climate fluctuations. Tufa stromatolites with their cyanobacterial–photosynthesis-related calcification fabrics form an analogue to porostromate cyanobacterial stromatolites in fossil settings high in CaCO 3 mineral supersaturation but comparatively low in dissolved inorganic carbon. Here, the sum-effect of heterotrophic exopolymer-degradation and secondary Ca 2+ -release rather decreases calcite saturation, contrary to settings high in dissolved inorganic carbon such as soda lakes.
A column generation algorithm for disrupted airline schedules (2007)

We consider the recovery of an airline schedule after an unforeseen event, called {\\em disruption}, that makes the planned schedule unfeasible. In particular we consider the aircraft recovery problem for a heterogeneous fleet of aircrafts, made of regular and reserve planes, where the aircrafts' maintenances are planned in an optimal way in order to satisfy the operational regulations. We propose a column generation scheme, where the pricing problem is modeled as a commodity flow problem on a dedicated network, one for each plane of the fleet. We present a dynamic programming algorithm to build the underlying networks and a dynamic programming algorithm for resource constrained elementary shortest paths to solve the pricing problem. We provide some computational results on real world instances.
Prediction of the resonant frequency of piezoelectric tube scanners through three-dimensional finite element modeling of a tube assembly (2008)

In this paper, we study the resonant behavior of a piezoelectric tube scanner used in scanning probe microscopes. In particular, we use a finite element model to allow the inclusion of boundary effects, i.e., nonrigid bonding layers and elastic tip holder, on the dynamic response of the scanner. We show that although existing analytical models provide a good estimation of the axial resonant frequency, their predictions of the first bending resonance may have up to a 100% error. In addition, a simple procedure is proposed that combines some precalculated factors to predict the lowest resonant frequency for a wide range of typical scanner dimensions. An experiment is carried out to illustrate the procedure and validate the prediction.
1α-Hydroxycholecalciferol for the Treatment of the Downer Cow Syndrome (1992)

Seventeen Holstein cows that showed clinical and biochemical symptoms (hypocalcemia and hypophosphatemia) of parturient hypocalcemia within 48 h postcalving and did not respond to Ca therapy were divided into two groups. Eight cows received a second intravenous Ca infusion 24 h after the first one. This treatment increased plasma Ca concentration but had no significant effect on phosphatemia, and the cows remained unable to rise and stand during 48 h following this second Ca infusion. The 9 other cows received 1 alpha-hydroxycholecalciferol (1 microgram/kg of BW, half the dose intravenously, the other half intramuscularly). 1 alpha-Hydroxycholecalciferol induced a significant increase in plasma P concentration and recovery of all the 9 cows within 12 h after this treatment.
Nonlinear liquid crystals in periodic structures (2001)

We report optical and photoresponsive behavior of nonlinear liquid crystals in two-dimensional (2D) periodic structure. 2D structure made of photoresist and titania is constructed by interference photolithography using grating mask. Then azobenzene-doped nematic liquid crystal is infiltrated into these arrays, and photoresponsive behavior of the azobenzene-doped liquid crystal in the periodic structure is investigated. In particular, we show that the diffraction from these liquid crystal infiltrated grating structures can be optically modulated by an Ar<SUP>+</SUP> laser at 488 nm.
Simulation of bow-tie THz antenna using hybrid finite element method and spectral ray tracing technique (2009)

In this paper, we propose a hybrid method that uses commercially available Finite Element Method (FEM) software and our in-house developed Spectral Ray Tracing (SRT) algorithm. The method is used for calculating the radiation patterns of complex lens antenna such as a bow-tie antenna backed by silicon lens. A traveling-wave terahertz photomixer integrated with a coplanar stripline (CPS) waveguide is used to generate the radiation that couples to the antenna. We employ HFSS, a FEM solver, to model THz propagation along the CPS line and planar bow-tie. Once the near-field distribution is found, the SRT method is then applied to find the radiation patterns and gain of the bow-tie antenna backed by a silicon hyper-hemispherical lens. The results are compared with full FEM simulation of the antenna-lens structure.
Hohlraum symmetry measurements with surrogate solid targets (invited) (1999)

Time-resolved radiographic imaging of low density, solid spherical surrogate targets has been used to provide a time-dependent measurement of drive pressure symmetry in cylindrical hohlraums on both the Nova and Omega lasers. The experiments replace the usual capsule at the center of a gold hohlraum with a sphere of SiO2 foam (ρ=0.3 g/cm3). The laser generates an x-ray drive inside the hohlraum which does not produce perfectly symmetric drive pressure on a spherical target, giving rise to a distorted shock traveling radially inward. The rarefaction behind the shock generated in this sphere produces a rapid rise in x-ray transmission which is easily detectable experimentally by radiography. The position of this feature may be determined to within a few microns in our experimental setup using a gated x-ray pinhole camera. Time-dependent control of drive symmetry in a hohlraum requires the ability to adjust the laser power as a function of both time and position along the hohlraum axis. We have implemented this control on the Omega laser by delaying sets of beams (“beam staggering”) and on the Nova laser (“beam phasing”) by delivering two independent pulse shapes on inner and outer halves of the Nova beams. The improvement in P2 pressure symmetry with this control as measured with the foam ball technique was found to be as much as a factor of 3, compared with deliberately mistuned drives. On the National Ignition Facility (NIF), we expect to use this technique as part of the effort to tune drive symmetry to achieve higher gain. We present results from these experiments from both facilities and comparisons with LASNEX simulations. In addition, we discuss the application of the foam ball technique to NIF targets.
New Ultrarapid Method for the Separation of Milk Proteins by Capillary Electrophoresis (1998)

A new method for the separation of major milk proteins has been investigated by capillary electrophoresis. The method is based on the micellar electrokinetic chromatography principle, which is a combination of classical capillary zone electrophoresis and hydrophobic interaction chromatography, resulting in the use of surfactant included in the electrophoretic media. These proteins are separated successfully after complete denaturation with sodium dodecyl sulfate and dl-dithiothreitol. The separation of αs-, β-, and κ-caseins is discriminating but needs improvement with αs1- and αs2-caseins. Separation of major whey proteins, α-lactalbumin and β-lactoglobulin, is also perfectly achieved, and migration times are different from those of the caseins. This capillary electrophoresis technique, combined with the appropriate protocol for sample preparation, gives a separation of each protein in ≤90 s. Keywords: Capillary electrophoresis; critical micellar concentration; denaturation; milk proteins; purification efficiency
A Device for <italic>in situ</italic> Embedding of Monolayer Cultures in Lowicryl K4M (1993)

A devised technique for observation of monolayer cultures by flat-embedding with Lowicryl K4M was presented. Cells were cultured on a plastic-sheet and embedded after fixation and dehydration. A beam capsule filled with Lowicryl resin was placed upside down on its cap where a small piece of plastic-sheet with cells was introduced and the cap tightened. The polymerization of Lowicryl resin was carried out by ultraviolet light irradiation at −30°C. After polymerization, only the plastic-sheet could be easily removed leaving all the cells in the Lowicryl resin. Using this technique combined with immunogold staining, the localization of actin and vimentin in the in situ embedded fibroblasts was demonstrated in the present report.
Nonlinear characterization of GeSbS chalcogenide glass waveguides (2016)

GeSbS ridge waveguides have recently been demonstrated as a promising mid - infrared platform for integrated waveguide - based chemical sensing and photodetection. To date, their nonlinear optical properties remain relatively unexplored. In this paper, we characterize the nonlinear optical properties of GeSbS glasses, and show negligible nonlinear losses at 1.55 μm. Using self - phase modulation experiments, we characterize a waveguide nonlinear parameter of 7 W-1/m and nonlinear refractive index of 3.71 × 10-18 m2/W. GeSbS waveguides are used to generate supercontinuum from 1280 nm to 2120 nm at the -30 dB level. The spectrum expands along the red shifted side of the spectrum faster than on the blue shifted side, facilitated by cascaded stimulated Raman scattering arising from the large Raman gain of chalcogenides. Fourier transform infrared spectroscopic measurements show that these glasses are optically transparent up to 25 μm, making them useful for short - wave to long - wave infrared applications in both linear and nonlinear optics.
Cell surface molecules of human melanoma. Immunohistochemical analysis of the gp57, GD3, and mel-CSPG antigenic systems. (1989)

The rapidly expanding list of monoclonal antibodies (MAbs) to human cell surface antigens provides reagents to probe the biology of malignant melanoma and to develop new diagnostic and therapeutic approaches to this disease. The criteria used to select MAb-defined antigens as targets for passive immunotherapy or immunolocalization of melanoma include: 1) consistent antigen expression in melanomas, 2) restricted antigen distribution in normal tissues and nonmelanocytic tumors, and 3) cytotoxic activity of the MAb or MAb conjugates. The present study examined the tissue distribution of three prototype melanoma cell surface antigens, the Mr 57,000 glycoprotein (gp57) recognized by MAb A42, the GD3 ganglioside, and the mel-CSPG chondroitin sulfate proteoglycan. The avidin-biotin immunoperoxidase method was used to examine a large panel of normal tissues and over 150 malignant tumors. It was found that A42 has a highly restricted distribution in normal tissues and is expressed in subsets of melanomas and nonmelanocytic tumors. It was also found that GD3 and mel-CSPG are more widely distributed in normal tissues and among tumors than was thought previously. These immunohistochemical patterns provide an essential data base to evaluate the ongoing clinical trials employing MAbs to GD3 and mel-CSPG for the therapy and immunolocalization of melanomas, and they identify gp57 as a potential marker for subsets of normal and transformed melanocytic cells.
Access to Constrained Fluoropseudopeptides via Ring-Closing Metathesis of Fluoroalkenes (2016)

Bis-alkene substrates, containing one fluoroalkene and linked by an amide moiety, have been designed and synthesized to be subjected to ring-closing metathesis reactions. The substitution of fluoroalkene by a phenyl group enhanced the reactivity, and the resulting fluorinated lactams were obtained in high yields except when a hindered alkyl group was present in the molecule. The cycles were then subjected to ring opening in order to develop a new route to constrained fluoropseudopeptides bearing a fluoroalkene as a peptide bond mimic.
An Intramolecular Quinhydrone of the [2](1,4)Naphthaleno[2]paracyclophane Series (1977)

Studies on the transmission of donor-acceptor interactions are facilitated by the quinhydrone (1) and some of its derivatives which have now been synthesized as model compounds. These compounds have less pronounced CT bands than quinhydrones of the naphthalenophane series.
Physical characteristics of scattered radiation in diagnostic radiology: Monte Carlo simulation studies (1985)

We applied Monte Carlo methods for the simulation of x-ray scattering in water phantoms. The phantom thickness was varied from 5 to 20 cm, and the monoenergetic incident x rays were varied from 15 to 100 keV. Eight screen pairs and a total absorption system were used as x-ray receptors. We determined the angular, spectral, and spatial distributions of the scattered radiation and the scatter fractions recorded in the image plane. The dependence of these properties on the incident x-ray energy, the phantom thickness, and the energy response of the recording system was examined. The results of this study provide useful information for the development of antiscatter techniques and for the evaluation of radiographic procedures.
Solid Polymer Electrolyte Based on Oligomeric PEO Cross-Linked with Electron Beam (2010)

Abstract not Available.
Cavity enhanced quantum limited magnetometry (2014)

We present a quantum limited, high-spatial-resolution, radio-frequency magnetometer by optical readout of polarized Cesium spins at room temperature. The atomic vapours are contained in a microcell and placed inside a cavity for optical depth enhancement.
Secondary structure of a dynamic type I’<i>β</i>‐hairpin peptide (2004)

A spontaneously folding beta-hairpin peptide (Lys-Lys-Tyr-Thr-Val-Ser-Ile-Asn-Gly-Lys-Lys-Ile-Thr-Val-Ser-Ile) and related cyclic (cyclo-Gly-Lys-Tyr-Ile-Asn-Gly-Lys-Ile-Ile-Asn) and linear (Ser-Ile-Asn-Gly-Lys) controls were studied to determine the effects of various factors on secondary structure. Secondary structure was evaluated using circular dichroism (CD) and 1D and 2D (1)H nuclear magnetic resonance (NMR). The effects of chemical modifications in the peptide and various solution conditions were investigated to determine their impact on peptide structure. The beta-hairpin peptide displayed a CD minimum at 216 nm and a TOCSY i + 1 - i + 2 and i + 2 -i + 3 interaction, confirming the expected structure. Using NMR alpha-proton (H(alpha)) chemical shifts, the extents of folding of the beta-hairpin and linear control were estimated to be 51 and 25% of the cyclic control (pH 4, 37 degrees C), which was taken to be maximally folded. Substitution of iso-aspartic acid for Asn reduced the secondary structure dramatically; substitution of aspartic acid for Asn also disrupted the structure. This result suggests that deamidation in unconstrained beta-turns may have adverse effects on secondary structure. N-terminal acetylation and extreme pH conditions also reduced structure, while the addition of methanol increased structure.
Modificações do DNA por acetona triplete gerada na oxidação de 2-metilpropanal em presença de peroxidase (1982)

A incubacao de 2-metilpropanal em tampao saturado com ar causa uma reacao de oxidacao iniciada pela formacao de composto-I de peroxidase (HRP-I) e HRP-II para produzir acetona no estado excitado e acido formico. O pH otimo e ao redor de 7,0 e o kM a 40°C e 30 mM. Experimentos na presenca e na ausencia de ions metalicos sugerem que a peroxidase usa tracos de H2O2 gerado durante a. incubacao, para a formacao de HRP-I. Aparentemente em HRP-I e HRP-II o sitio de ligacao do substrato esta ocupado por especies fortemente ligadas as quais cianeto (10 mM) e azoteto (10 mM) nao podem deslocar. A nao linearidade de resposta para concentracoes superiores a 2,2 mm de peroxidase e a razao kHAsO4/kHPO4 indicam uma eficiencia de catalise relacionada com enolizacao de cetonas. As modificacoes estruturais do DNA depois do tratamento com acetona triplete gerada pelo sistema 2-metil propanal/peroxidase/O2 foram estudadas, usando-se terbio (III), acridina laranja e proflavina como sondas fluorescentes. Os resultados mostraram que os sitios do DNA contendo AT-GC e/ou GC-GC foram modificados e que regioes de fita simples foram formadas. O espectro de dicroismo circular de acridina laranja na presenca de DNA submetido ao sistema enzimatico, corrobora esses efeitos. Provavelmente tais aIteracoes estariam relacionadas com a formacao de adutos de pirimidina e/ou alteracoes na cadeia acucar-fosfato. 
Abstract
Abstract 3664: RARRES2 functions as a direct tumor suppressor by promoting beta-catenin phosphorylation and degradation independent of CMKLR1 and CMKLR1-mediated antitumor immune response in adrenocortical carcinoma (2016)

Abstract Tumor suppressors and the immune system are critical players in tumor suppression. However, little is known about whether a tumor suppressor can function through both immune-dependent and immune-independent mechanisms. RARRES2 is a small secreted protein that is down-regulated in multiple human cancer types such as adrenocortical carcinoma (ACC), hepatocellular carcinoma (HCC) and melanoma. It has been shown that RARRES2 can play an indirect tumor-suppressive role by acting as a chemoattractant to recruit anti-cancer immune cells expressing its receptor CMKLR1 to sites of tumor. In this study, we show that epigenetic CpG hypermethylation of RARRES2 in vivo and in vitro in ACC causes RARRES2 down-regulation. We also found that RARRES2 can function as a direct tumor suppressor and that its tumor suppressive effect does not depend on the recruitment of CMKLR1-expressing immune cells. We show that although exogenous treatment of cultured cells with recombinant human RARRES2 protein did not show any tumor-suppressive effect, transient overexpression of RARRES2 significantly inhibited cellular invasion. Stable overexpression of RARRES2 in ACC cell line NCI-H295R led to significantly reduced cell proliferation, cell invasion, and tumorigenecity in a RARRES2 dose-dependent manner. Using xenografts of stable NCI-H295R cell lines in two immunodeficient mouse models (athymic nude mice and NSG mice), we found that in the absence of functional immune cells, stable RARRES2 overexpression can still significantly suppress tumor growth in vivo. RARRES2 overexpression promoted beta-catenin phosphorylation and degradation, reduced the phosphorylation of p38 MAP kinase and inhibited the secretion of matrix metalloprotease protein 10 (MMP10) from cancer cells in a RARRES2 dose-dependent manner. Taken into account that CMKLR1 expression is barely detectable in all the cell lines tested, our results present the first evidence that RARRES2 can function as a direct tumor suppressor independent of CMKLR1 and CMKLR1-mediated anti-tumor immune response. Citation Format: Yi Liu-Chittenden, Kelli Gaskins, Sophie Wang, Electron Kebebew. RARRES2 functions as a direct tumor suppressor by promoting beta-catenin phosphorylation and degradation independent of CMKLR1 and CMKLR1-mediated antitumor immune response in adrenocortical carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3664.
Postzygotic isolating factor in sympatric speciation in <i>Rhagoletis</i> flies: Reduced response of hybrids to parental host-fruit odors (2004)

Rhagoletis pomonella is a model for sympatric speciation (divergence without geographic isolation) by means of host-plant shifts. Many Rhagoletis species are known to use fruit odor as a key olfactory cue to distinguish among their respective host plants. Because Rhagoletis rendezvous on or near the unabscised fruit of their hosts to mate, behavioral preferences for fruit odor translate directly into premating reproductive isolation among flies. Here, we report that reciprocal F(1) hybrids between the apple and hawthorn host races of R. pomonella, as well as between the host races and an undescribed sibling species infesting Cornus florida (flowering dogwood) do not respond to host fruit volatiles in wind-tunnel assays at doses that elicit maximal directed flight in parental flies. The reduced ability of hybrids to orient to fruit volatiles could result from a conflict between neural pathways for preference and avoidance behaviors, and it suggests that hybrids might suffer a fitness disadvantage for finding fruit in nature. Therefore, host-specific mating may play a dual role as an important postzygotic as well as a premating reproductive barrier to isolate sympatric Rhagoletis flies.
Biomedical applications of chemically-modified silk fibroin (2009)

Silk proteins belong to a class of unique, high molecular weight, block copolymer-like proteins that have found widespread use in biomaterials and regenerative medicine. The useful features of these proteins, including self-assembly, robust mechanical properties, biocompatibility and biodegradability can be enhanced through a variety of chemical modifications. These modifications provide chemical handles for the attachment of growth factors, cell binding domains and other polymers to silk, expanding the range of cell and tissue engineering applications attainable. This review focuses on the chemical reactions that have been used to modify the amino acids in silk proteins, and describes their utility in biomedical applications.
Real time 3D in situ assessments for bone tissue engineering (2016)

Frontiers Events is a rapidly growing calendar management system dedicated to the scheduling of academic events. This includes announcements and invitations, participant listings and search functionality, abstract handling and publication, related events and post-event exchanges. Whether an organizer or participant, make your event a Frontiers Event!