gebhart/patrepeval huggingface dataset:
HDAC3 overexpression and colon cancer cell proliferation and differentiation (2007)

An immunohistochemical analysis of human colorectal adenocarcinomas showed that cancer cells express widely varying levels of HDAC3. The SW480 colon cancer cell line was found to express high levels of HDAC3 compared to other colon cancer cell lines. p21 was poorly induced in SW480 cells relative to the lower HDAC3-expressing HT-29 cells. RNAi-induced reduction of HDAC3 in SW480 cells increased their constitutive, butyrate-, TSA-, and TNF-alpha-induced expression of p21, but did not cause all the gene expression changes induced upon general histone deacetylase (HDAC) inhibition. SW480 cells with lower HDAC3 expression appeared to be poised for gene expression responses with increased histone H4-K12 acetylation, but not K5, K8, or K16 acetylation. Even though p21 was readily activated in HT29 cells, HDAC3 siRNA nonetheless stimulated p21 expression in these cells to a greater degree than HDAC1 and HDAC2 siRNA. SW480 cells with lower HDAC3 levels displayed an enhanced cell cycle arrest and growth inhibition by butyrate, but without changes in apoptosis or sensitivity to chemotherapeutic agents. As reported for other colon cancer cell lines, butyrate induced the rapid downregulation of the secretory cell differentiation markers mucin 2 and intestinal trefoil factor in SW480 cells. Interestingly, selective HDAC3 inhibition was sufficient to downregulate these genes. Our data support a central role for HDAC3 in regulating the cell proliferation and differentiation of colon cancer cells and suggest a potential mechanism by which colon cancers may become resistant to luminal butyrate.
Interfacial instabilities affect microfluidic extraction of small molecules from non-Newtonian fluids (2007)

As part of a project to develop an integrated microfluidic biosensor for the detection of small molecules in saliva, practical issues of extraction of analytes from non-Newtonian samples using an H-filter were explored. The H-filter can be used to rapidly and efficiently extract small molecules from a complex sample into a simpler buffer. The location of the interface between the sample and buffer streams is a critical parameter in the function of the H-filter, so fluorescence microscopy was employed to monitor the interface position; this revealed apparently anomalous fluorophore diffusion from the samples into the buffer solutions. Using confocal microscopy to understand the three-dimensional distribution of the fluorophore, it was found that the interface between the non-Newtonian sample and Newtonian buffer was both curved and unstable. The core of the non-Newtonian sample extended into the Newtonian buffer and its position was unstable, producing a fluorescence intensity profile that gave rise to the apparently anomalously fast fluorophore transport. These instabilities resulted from the pairing of rheologically dissimilar fluid streams and were flowrate dependent. We conclude that use of non-Newtonian fluids, such as saliva, in the H-filter necessitates pretreatment to reduce viscoelasticity. The interfacial variation in position, stability and shape caused by the non-Newtonian samples has substantial implications for the use of biological samples for quantitative analysis and analyte extraction in concurrent flow extraction devices.
CuxCo3−xO4 (0 ≤x < 1) nanoparticles for oxygen evolution in high performance alkaline exchange membrane water electrolysers (2011)

Cu incorporated Co3O4 (CuxCo3−xO4, 0 ≤ x < 1) nanoparticles were prepared using a thermal decomposition method. Properties of the CuxCo3−xO4, such as morphology, particle sizes, crystallite structure and cation distribution, were characterized with SEM, TEM, XRD and EDX. The CuxCo3−xO4 particles, with various x values, were found to be cubic spinel nanoparticles, with average size of 20–30 nm. Incorporation of Cu in the spinel lattice of Co3O4 shifted the Co3+/Co4+ redox peak as well as the onset point for OER to more negative potentials, which may be related to inversion of Cu2+ into the octahedral sites. Amongst all samples studied, Cu0.7Co2.3O4 was the most active for OER. The CuxCo3−xO4 electrodes exhibited satisfying stability during repetitive cyclic voltammetry. A membrane electrode assembly, using 3 mg cm−2 Cu0.7Co2.3O4 on the anode, demonstrated, in an alkaline membrane water electrolyser, a high current density performance of 1 A cm−2 at a voltage of 1.8 V in 1 mol dm−3 KOH at 25 °C.
Structural basis of instability of the nucleosome containing a testis-specific histone variant, human H3T (2010)

A histone H3 variant, H3T, is highly expressed in the testis, suggesting that it may play an important role in the chromatin reorganization required for meiosis and/or spermatogenesis. In the present study, we found that the nucleosome containing human H3T is significantly unstable both in vitro and in vivo, as compared to the conventional nucleosome containing H3.1. The crystal structure of the H3T nucleosome revealed structural differences in the H3T regions on both ends of the central alpha2 helix, as compared to those of H3.1. The H3T-specific residues (Met71 and Val111) are the source of the structural differences observed between H3T and H3.1. A mutational analysis revealed that these residues are responsible for the reduced stability of the H3T-containing nucleosome. These physical and structural properties of the H3T-containing nucleosome may provide the basis of chromatin reorganization during spermatogenesis.
DNA-templated combinatorial assembly of small molecule fragments amenable to selection/amplification cycles (2011)

The discovery of small molecule probes which selectively modulate biological pathways is a cornerstone in the development of new therapeutics. Progress in our ability to access libraries of biologically relevant small molecules in conjunction with streamlined screening technologies have also enabled a more systematic approach to chemical biology. Nevertheless, the current state of the art still requires a large infrastructure and only a small fraction of the proteome has been addressed thus far. The emergence of technologies based on nucleic acid encoding of small molecules presents a new screening paradigm. We describe a method based on DNA-templated combinatorial display of PNA-encoded drug fragments affording 62 500 combinations which can be amplified following a selection. This concept was demonstrated with a screen against a representative target, carbonic anhydrase, by iterative cycles of affinity selection, amplification of DNA template and “translation” back into selected library members. The results show a clear convergence towards combinations which, upon resynthesis as covalent adducts, proved to bind cooperatively to carbonic anhydrase.
Emerging adaptive antenna techniques for wireless ad-hoc networks (2002)

The effects of adaptive antennas on the performance of wireless ad-hoc networks are theoretically clarified. Their beam- and null-steering functionality saves transmission energy, suppresses co-channel interference, and increases the throughput of the network. An analog-based beamforming architecture is introduced as an adaptive antenna suitable for battery-operated terminal devices. In spite of its simple configuration, adaptive beamforming is successfully achieved by using an iterative perturb-gradient-update training procedure.
Diffusion in Titanium. (1991)

Recent studies on self-diffusion and impurity diffusion in c(-and fi-titanium are reviewed. The transition metal elements and phosphorus exhibit fast diffusion in oe-Ti, which are three to five orders of magnitude faster than the self-diffusion.
Influences of Preservation at Various Temperatures on Liposuction Aspirates (2007)

Aspirated fat should be transplanted as quickly as possible if it is preserved at room temperature. For adipose-derived stem cell isolation, aspirated fat can be stored or transported overnight if it is preserved at 4 degrees C without adipose-derived stem cell yield loss or changes in biological properties.
ChemInform Abstract: Shape‐Selective and Asymmetric Cyclopropanation of Alkenes Catalyzed by Rhodium Porphyrins. (1992)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Terahertz imaging with GaAs field-effect transistors (2008)

Imaging at 0.6 THz is tested with a commercial GaAs high-electron-mobility transistor (HEMT) operated at room temperature. The results allow the assessment of the potential of future antenna-fitted HEMT arrays for real-time imaging.
Bio-inspired nano-traps for uranium extraction from seawater and recovery from nuclear waste (2018)

Nature can efficiently recognize specific ions by exerting second-sphere interactions onto well-folded protein scaffolds. However, a considerable challenge remains to artificially manipulate such affinity, while being cost-effective in managing immense amounts of water samples. Here, we propose an effective approach to regulate uranyl capture performance by creating bio-inspired nano-traps, illustrated by constructing chelating moieties into porous frameworks, where the binding motif's coordinative interaction towards uranyl is enhanced by introducing an assistant group, reminiscent of biological systems. Representatively, the porous framework bearing 2-aminobenzamidoxime is exceptional in sequestering high uranium concentrations with sufficient capacities (530 mg g<sup>-1</sup>) and trace quantities, including uranium in real seawater (4.36 mg g<sup>-1</sup>, triple the benchmark). Using a combination of spectroscopic, crystallographic, and theory calculation studies, it is revealed that the amino substituent assists in lowering the charge on uranyl in the complex and serves as a hydrogen bond acceptor, boosting the overall uranyl affinity of amidoxime.
Construction and evaluation of a maize (<i>Zea mays</i>) chimaeric promoter with activity in kernel endosperm and embryo (2008)

Chimaeric promoters contain DNA sequences from different promoters. Chimaeric promoters are developed to increase the level of recombinant protein expression, to precisely control transgene activity or to combat homology-based gene silencing. Sets of chimaeric promoters, each containing different lengths of DNA from maize (Zea mays) 27zn (27 kDa gamma-zein) endosperm-specific promoter and the Glb1 (Globulin-1) embryo-specific promoter were created and tested in a transient expression assay of GFP (green fluorescent protein). Promoter fragments with the highest activity were combined to create the chimaeric promoter A27znGlb1. In the context of the chimaeric promoter, the selected Glb1 promoter fragment was necessary and sufficient to activate expression in embryo tissue and was functionally equivalent to the native Glb1 promoter. Similarly, the selected 27zn promoter fragment in the chimaeric promoter was necessary and sufficient to activate expression in endosperm tissue and was functionally equivalent to the native 27zn promoter. Maize transgenic plants containing the A27znGlb1 chimaeric promoter fused to GFP were produced to characterize this promoter in vivo. Quantitative reverse-transcriptase PCR was used to determine that the promoter was active in the embryo, endosperm, pericarp and immature leaf tissues. GFP activity in plants containing the chimaeric promoter was not significantly different in endosperm than the activity of GFP fused to the full-length 27zn promoter, nor was it different in embryo from the activity of GFP fused to the full-length Glb1 promoter. Transgene copy numbers were shown to be between 4 and 12 copies in different events.
Insertion loss and saturation effects in the diode correlator (1973)

The insertion loss and electronic saturation effects observed in the series-configuration diode correlator are described in terms of a simple 1st-order theory. The results of this theory are favourably compared with experiments for an 8-tap diode correlator operating in the 30–60 MHz range.
DNA Polymerases δ and ε are Required for Chromosomal Replication in <i>Saccharomyces cerevisiae</i> (1993)

Three DNA polymerases, alpha, delta, and epsilon are required for viability in Saccharomyces cerevisiae. We have investigated whether DNA polymerases epsilon and delta are required for DNA replication. Two temperature-sensitive mutations in the POL2 gene, encoding DNA polymerase epsilon, have been identified by using the plasmid shuffle technique. Alkaline sucrose gradient analysis of DNA synthesis products in the mutant strains shows that no chromosomal-size DNA is formed after shift of an asynchronous culture to the nonpermissive temperature. The only DNA synthesis observed is a reduced quantity of short DNA fragments. The DNA profiles of replication intermediates from these mutants are similar to those observed with DNA synthesized in mutants deficient in DNA polymerase alpha under the same conditions. The finding that DNA replication stops upon shift to the nonpermissive temperature in both DNA polymerase alpha- and DNA polymerase epsilon- deficient strains shows that both DNA polymerases are involved in elongation. By contrast, previous studies on pol3 mutants, deficient in DNA polymerase delta, suggested that there was considerable residual DNA synthesis at the nonpermissive temperature. We have reinvestigated the nature of DNA synthesis in pol3 mutants. We find that pol3 strains are defective in the synthesis of chromosomal-size DNA at the restrictive temperature after release from a hydroxyurea block. These results demonstrate that yeast DNA polymerase delta is also required at the replication fork.
Time-Dependent Changes in Matrix Metalloproteinase Activity and Expression During the Progression of Congestive Heart Failure (1998)

The development of congestive heart failure (CHF) is associated with left ventricular (LV) dilation and myocardial remodeling. However, fundamental mechanisms that contribute to this remodeling process with the progression of CHF remain unclear. The matrix metalloproteinases (MMPs) have been demonstrated to play a significant role in tissue remodeling in a number of pathological processes. The present project tested the hypothesis that the LV dilation and remodeling during the progression of CHF is associated with early changes in MMP expression and zymographic activity. LV and myocyte function, collagen content, and MMP expression and zymographic activity were serially measured during the progression of CHF caused by pacing-induced supraventricular tachycardia (SVT) in pigs. After 7 days of SVT, LV end-diastolic dimension and myocyte length both increased by 15% from control values, and LV fractional shortening fell by 20%. At the level of the myocyte, percent shortening fell by 16% after 7 days of SVT, with no change in the steady-state velocity of shortening. Longer durations of SVT caused progressive LV dilation, LV pump failure, and myocyte contractile dysfunction. Specifically, 21 days of SVT resulted in a >50% increase in LV dimension, a 56% fall in LV fractional shortening, and a 33% decline in myocyte velocity of shortening. The decline in LV and myocyte function with 21 days of SVT was accompanied by signs and symptoms of CHF. Thus, SVT causes time-dependent changes in LV geometry and function and the subsequent development of CHF. LV myocardial collagen content and confluence fell by >25% after 7 days of SVT and were accompanied by an 80% increase in LV myocardial MMP zymographic activity against the substrate gelatin. After 14 days of SVT, total LV myocardial collagen content was reduced by 24%, and LV myocardial MMP zymographic activity increased by >100% from control values. Interstitial collagenase (MMP-1), stromelysin (MMP-3), and 72-kD gelatinase (MMP-2) were increased by approximately 2-fold after 7 days of SVT. LV MMP zymographic activity and abundance remained elevated with longer durations of SVT. The results of the present study demonstrated that in this model of CHF, early changes in LV myocardial MMP zymographic activity and protein levels occurred with the initiation and progression of LV dilation and dysfunction. These findings suggest that an early contributory mechanism for the initiation of LV remodeling that occurred in this model of developing CHF is enhanced expression and potentially increased activity of LV myocardial MMPs.
Planar waveguide spectrometer (1990)

An integrated optic consisting of buried diffraction gratings and a planar waveguide was developed as an internal reflectance element for broad-band spectroscopic analysis of liquids. Polystyrene or tantalum pentoxide waveguides were deposited over a pair of diffraction gratings etched into the surface of a glass slide. Multiwavelength light was focused through the substrate onto the first grating. Component wavelengths were coupled into the waveguide and spatially dispersed by the second grating after propagating through the waveguide. A silicon photodiode array detector was used to collect the spectral data. Our goal is to produce a compact, rapid spectrometer having no moving parts that can take advantage of fiber optics and fast array detectors in the visible and near-infrared regions for industrial process control. The thin planar waveguide provides enhanced sensitivity to analyze weaker absorptions in the near-infrared.
Evolutionary regional network modeling for efficient engineering optimization (2014)

This study presents a soft computing based optimization methodology, the evolutionary regional neural network modeling for engineering applications with sampling constraints. Engineering optimization often involves expensive experiment costs. Intelligent optimization advocates establishing a neural network model using small training samples such as orthogonal array to set up a surrogate model for the engineering system followed by an optimum search in the model to reduce optimization cost. However, scarce training samples might compromise modeling generality for a complex problem. Empirical rules suggest reliable predictions are likely restricted to the neighboring space of training samples, and interpolating designs are more reliable than extrapolating designs. To avoid imperfection of model due to small learning samples, an evolutionary regional network model is set up to confine the search of quasi-optimum using genetic algorithm. The constrained search in the regional network model provides a reliable quasi-optimum. The verification of the optimum is added to the learning samples to retrain the regional network model while the size and the distribution of reliable space will evolve intelligently during the optimization iteration using a fuzzy inference according to the prediction accuracy. An engineering case study, the optimal die gap parison programming of extrusion blow molding process for a uniform thickness, is presented to demonstrate the robustness and efficiency of the proposed methodology.
Esterifying alcohols in the chlorophylls of purple photosynthetic bacteria. New chlorophyll, bacteriochlorophyll (gg), all-trans-geranylgeranyl bacteriochlorophyllide a (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEsterifying alcohols in the chlorophylls of purple photosynthetic bacteria. New chlorophyll, bacteriochlorophyll (gg), all-trans-geranylgeranyl bacteriochlorophyllide aJ. J. Katz, H. H. Strain, A. L. Harkness, M. H. Studier, W. A. Svec, T. R. Janson, and B. T. CopeCite this: J. Am. Chem. Soc. 1972, 94, 22, 7938–7939Publication Date (Print):November 1, 1972Publication History Published online1 May 2002Published inissue 1 November 1972https://doi.org/10.1021/ja00777a054RIGHTS & PERMISSIONSArticle Views132Altmetric-Citations66LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (282 KB) Get e-Alertsclose Get e-Alerts
Attention and working memory: a dynamical model of neuronal activity in the prefrontal cortex (2003)

Cognitive behaviour requires complex context-dependent mapping between sensory stimuli and actions. The same stimulus can lead to different behaviours depending on the situation, or the same behaviour may be elicited by different cueing stimuli. Neurons in the primate prefrontal cortex show task-specific firing activity during working memory delay periods. These neurons provide a neural substrate for mapping stimulus and response in a flexible, context- or rule-dependent, fashion. We describe here an integrate-and-fire network model to explain and investigate the different types of working-memory-related neuronal activity observed. The model contains different populations (or pools) of neurons (as found neurophysiologically) in attractor networks which respond in the delay period to the stimulus object, the stimulus position ('sensory pools'), to combinations of the stimulus sensory properties (e.g. the object identity or object location) and the response ('intermediate pools'), and to the response required (left or right) ('premotor pools'). The pools are arranged hierarchically, are linked by associative synaptic connections, and have global inhibition through inhibitory interneurons to implement competition. It is shown that a biasing attentional input to define the current rule applied to the intermediate pools enables the system to select the correct response in what is a biased competition model of attention. The integrate-and-fire model not only produces realistic spiking dynamicals very similar to the neuronal data but also shows how dopamine could weaken and shorten the persistent neuronal activity in the delay period; and allows us to predict more response errors when dopamine is elevated because there is less different activity in the different pools of competing neurons, resulting in more conflict.
Older Driver Safety: A Report from the Older Drivers Project (2003)

Older driver safety is a growing public health concern for which interventions are currently being sought. Statistics show that older drivers suffer a disproportionately high rate of motor vehicle fatalities compared with other adult drivers. This disproportion is due to two factors: an increased crash rate per vehicle mile driven and an increased risk of fatality in the event of a crash. Traditionally, traffic safety efforts for the older population have focused on methods to identify unsafe drivers to enforce driving cessation, but driving cessation deprives the majority of older Americans of their primary form of transportation and has been associated with an increase in depressive symptoms. In response to these concerns, the Older Drivers Project, created by the American Medical Association in partnership with the National Highway Traffic Safety Administration, describes and advocates a more acceptable approach to traffic safety. The primary objective of this approach involves helping older drivers stay on the road safely to preserve their mobility and independence. This can be accomplished through three methods: (1) optimizing the driver, (2) optimizing the driving environment, and (3) optimizing the vehicle. In this approach, driving cessation is recommended only after the safety of the driver cannot be secured through any other means.