gebhart/patrepeval huggingface dataset:
Artificial switchable catalysts (2015)

Catalysis is key to the effective and efficient transformation of readily available building blocks into high value functional molecules and materials. For many years research in this field has largely focussed on the invention of new catalysts and the optimization of their performance to achieve high conversions and/or selectivities. However, inspired by Nature, chemists are beginning to turn their attention to the development of catalysts whose activity in different chemical processes can be switched by an external stimulus. Potential applications include using the states of multiple switchable catalysts to control sequences of transformations, producing different products from a pool of building blocks according to the order and type of stimuli applied. Here we outline the state-of-art in artificial switchable catalysis, classifying systems according to the trigger used to achieve control over the catalytic activity and stereochemical or other structural outcomes of the reaction.
Human plasma kallikrein and C1 inhibitor form a complex possessing an epitope that is not detectable on the parent molecules: demonstration using a monoclonal antibody. (1985)

The inactivation of human plasma kallikrein (EC 3.4.21.8) by the inhibitor of activated complement component 1 (C1 inhibitor) induces the formation of a 1:1 stoichiometric kallikrein-C1 inhibitor complex and a proteolytically modified form of C1 inhibitor. We have produced a monoclonal antibody that recognizes the kallikrein-C1 inhibitor complex as well as modified C1 inhibitor but fails to react with virgin C1 inhibitor or native plasma kallikrein. This observation constitutes an unequivocal demonstration that the reaction between plasma kallikrein and C1 inhibitor leads to the emergence of an epitope that is undetectable on the parent enzyme and inhibitor molecules.
Chiral and structural analysis of biomolecules using mass spectrometry and ion mobility‐mass spectrometry (2009)

This report describes the strategies for gas-phase chiral and structural characterization of biomolecules using mass spectrometry (MS) and ion mobility-MS (IM-MS) techniques. Because both MS and IM-MS do not directly provide chiral selectivity, methodologies for adding a chiral selector are discussed in the context of (i) host-guest (H-G) associations, (ii) diastereomeric collision-induced dissociation (CID) methods, (iii) ion-molecule reactions, and (iv) the kinetic method. MS techniques for the analysis of proteins and protein complexes are briefly described. New advances in performing rapid 2D gas-phase separations on the basis of IM-MS are reviewed with a particular emphasis on the different forms of IM instrumentation and how they are used for chiral and/or structural biomolecular studies. This report is not intended to be a comprehensive review of the field, but rather to underscore the contemporary techniques that are commonly or increasingly being used to complement measurements performed by chiroptical methodologies.
Microtubule assembly in cytoplasmic extracts of Xenopus oocytes and eggs. (1987)

We have investigated the differences in microtubule assembly in cytoplasm from Xenopus oocytes and eggs in vitro. Extracts of activated eggs could be prepared that assembled extensive microtubule networks in vitro using Tetrahymena axonemes or mammalian centrosomes as nucleation centers. Assembly occurred predominantly from the plus-end of the microtubule with a rate constant of 2 microns.min-1.microM-1 (57 s-1.microM-1). At the in vivo tubulin concentration, this corresponds to the extraordinarily high rate of 40-50 microns.min-1. Microtubule disassembly rates in these extracts were -4.5 microns.min-1 (128 s-1) at the plus-end and -6.9 microns.min-1 (196 s-1) at the minus-end. The critical concentration for plus-end microtubule assembly was 0.4 microM. These extracts also promoted the plus-end assembly of microtubules from bovine brain tubulin, suggesting the presence of an assembly promoting factor in the egg. In contrast to activated eggs, assembly was never observed in extracts prepared from oocytes, even at tubulin concentrations as high as 20 microM. Addition of oocyte extract to egg extracts or to purified brain tubulin inhibited microtubule assembly. These results suggest that there is a plus-end-specific inhibitor of microtubule assembly in the oocyte and a plus-end-specific promoter of assembly in the eggs. These factors may serve to regulate microtubule assembly during early development in Xenopus.
SIP1, a Novel Zinc Finger/Homeodomain Repressor, Interacts with Smad Proteins and Binds to 5′-CACCT Sequences in Candidate Target Genes (1999)

Activation of transforming growth factor beta receptors causes the phosphorylation and nuclear translocation of Smad proteins, which then participate in the regulation of expression of target genes. We describe a novel Smad-interacting protein, SIP1, which was identified using the yeast two-hybrid system. Although SIP1 interacts with the MH2 domain of receptor-regulated Smads in yeast and in vitro, its interaction with full-length Smads in mammalian cells requires receptor-mediated Smad activation. SIP1 is a new member of the deltaEF1/Zfh-1 family of two-handed zinc finger/homeodomain proteins. Like deltaEF1, SIP1 binds to 5'-CACCT sequences in different promoters, including the Xenopus brachyury promoter. Overexpression of either full-length SIP1 or its C-terminal zinc finger cluster, which bind to the Xbra2 promoter in vitro, prevented expression of the endogenous Xbra gene in early Xenopus embryos. Therefore, SIP1, like deltaEF1, is likely to be a transcriptional repressor, which may be involved in the regulation of at least one immediate response gene for activin-dependent signal transduction pathways. The identification of this Smad-interacting protein opens new routes to investigate the mechanisms by which transforming growth factor beta members exert their effects on expression of target genes in responsive cells and in the vertebrate embryo.
Distribution of chitin in the yeast cell wall. An ultrastructural and chemical study. (1980)

The distribution of chitin in Saccharomyces cervisiae primary septa and cell walls was studied with three methods: electron microscopy of colloidal gold particles coated either with wheat germ agglutinin or with one of two different chitinases, fluorescence microscopy with fluorescein isothiocyanate derivatives of the same markers, and enzymatic treatments of [14C]glucosamine-labeled cells. The septa were uniformly and heavily labeled with the gold-attached markers, an indication that chitin was evenly distributed throughout. To study the localization of chitin in lateral walls, alkali-extracted cell ghosts were used. Observations by electron and fluorescence microscopy suggest that lectin-binding material is uniformly distributed over the whole cell ghost wall. This material also appears to be chitin, on the basis of the analysis of the products obtained after treatment of 14C-labeled cell ghosts with lytic enzymes. The chitin of lateral walls can be specifically removed by treatment with beta-(1 leads to 6)-glucanase containing a slight amount of chitinase. During this incubation approximately 7% of the total radioactivity is solubilized, about the same amount liberated when lateral walls of cell ghosts are completely digested with snail glucanase yield primary septa. It is concluded that the remaining chitin, i.e., greater than 90% of the total, is in the septa. The facilitation of chitin removal from the cell wall by beta-(1 leads to 6)-glucanase indicates a strong association between chitin and beta-(1 leads to 6)-glucan. Covalent linkages between the two polysaccharides were not detected but cannot be excluded.
Identification of the CD4+ T cell as a major pathogenic factor in ischemic acute renal failure (2001)

Leukocytes have been implicated in the pathogenesis of ischemic acute renal failure (ARF), but the roles of the individual cell types involved are largely unknown. Recent indirect evidence suggests that T cells may play an important role in a murine model of ARF. In the current study, we found that mice deficient in T cells (nu/nu mice) are both functionally and structurally protected from postischemic renal injury. Reconstitution of nu/nu mice with wild-type T cells restored postischemic injury. We then analyzed the contribution of the individual T cell subsets to postischemic injury and found that mice deficient in CD4+ T cells, but not mice deficient in CD8+ T cells, were significantly protected from ARF. Direct evidence for a pathophysiologic role of the CD4+ T cell was obtained when reconstitution of CD4-deficient mice with wild-type CD4+ T cells restored postischemic injury. In addition, adoptive transfers of CD4+ T cells lacking either the costimulatory molecule CD28 or the ability to produce IFN-γ were inadequate to restore injury phenotype. These results demonstrate that the CD4+ T cell is an important mediator of ischemic ARF, and targeting this cell may yield novel therapies.
Existence of different subtypes of nicotinic acetylcholine receptors in the rat habenulo-interpeduncular system (1991)

Neuronal nicotinic ACh receptors (nAChRs) are present in the rat medial habenula (MHB) and interpeduncular nucleus (IPN), two brain regions connected through the fasciculus retroflexus (FR). The goal of the present study was to compare the electrophysiological and pharmacological characteristics of nAChRs located at pre- and postsynaptic sites within the MHB-IPN system. nAChRs located on the soma of IPN neurons were studied using patch-clamp techniques and a preparation of acutely isolated neurons. Whole-cell currents evoked by Ach and nicotine showed an intense rectification at positive membrane potentials. nAChR channels were relatively nonselective for cations, had a unitary conductance of 35 pS, and were activated by several nicotinic agonists with the following rank order: cytisine greater than ACh greater than nicotine greater than dimethylphenylpiperazinium (DMPP). They were blocked by mecamylamine, hexamethonium, curare, and dihydro-beta-erythroidine (DHBE), but were insensitive to alpha-bungarotoxin and neuronal bungarotoxin. In contrast, nAChRs recorded on the soma of MHB neurons under equivalent experimental conditions exhibited different characteristics for single-channel conductance and agonist and antagonist sensitivity. The pharmacological properties of presynaptic nAChRs in the IPN were analyzed in a rat brain slice preparation. Stimulation of the FR produced a presynaptic afferent volley recorded in the rostral subnucleus of the IPN. Nicotinic agonists decreased the amplitude of the afferent volley with different efficacies: nicotine greater than cytisine greater than ACh greater than DMPP. The action of nicotine was insensitive to alpha-bungarotoxin and to neuronal bungarotoxin, but was blocked by mecamylamine, hexamethonium, curare, and DHBE, with IC50 values different from those reported for IPN postsynaptic nAChRs. This study thus demonstrates the functional diversity of nAChRs in the rat CNS.
Molecular Understanding of Organic Solar Cells: The Challenges (2009)

Our objective in this Account is 3-fold. First, we provide an overview of the optical and electronic processes that take place in a solid-state organic solar cell, which we define as a cell in which the semiconducting materials between the electrodes are organic, be them polymers, oligomers, or small molecules; this discussion is also meant to set the conceptual framework in which many of the contributions to this Special Issue on Photovoltaics can be viewed. We successively turn our attention to (i) optical absorption and exciton formation, (ii) exciton migration to the donor-acceptor interface, (iii) exciton dissociation into charge carriers, resulting in the appearance of holes in the donor and electrons in the acceptor, (iv) charge-carrier mobility, and (v) charge collection at the electrodes. For each of these processes, we also describe the theoretical challenges that need to be overcome to gain a comprehensive understanding at the molecular level. Finally, we highlight recent theoretical advances, in particular regarding the determination of the energetics and dynamics at organic-organic interfaces, and underline that the right balance needs to be found for the optimization of material parameters that often result in opposite effects on the photovoltaic performance.
Plasma reactivity to hexagonal II phase phosphatidylethanolamine is more frequently associated with lupus anticoagulant than with antiphosphatidylethanolamine antibodies. (1993)

In membranes, phosphatidylethanolamine (PE) is usually in a lamellar phase, but it can also adopt a hexagonal II phase (HexII PE), which has been demonstrated to be immunogenic in mice and has recently been used in a new clotting assay to detect lupus anticoagulant (LA). A population of 58 patients susceptible of having LA or antiphospholipid antibodies (aPLA), was screened for reactivity to HexII PE using the new clotting assay and for the presence of anti-PE antibodies (aPEA) using ELISA. The patients could be classified as follows: 26 systemic lupus erythematosus, 14 primary antiphospholipid syndromes and 18 miscellaneous non autoimmune disorders. HexII PE reactivity was detected in 22 patients. It was significantly more often associated with LA-positivity (20/29) than with LA-negativity (2/29), (p < 0.0001). However, 9 patients with LA had negative HexII PE assays. Anti-PE antibodies were detected by ELISA in only 12% of the cases. No correlation was observed between the distribution of aPEA and that of HexII PE reactivity. Interestingly, 2 LA- and aPLA-negative patients exhibited HexII PE reactivity. The absence of identity between the distribution of HexII PE reactivity and that of either LA or aPEA indicates that this new assay has its own specificity. It might detect antibodies to the immunogenic hexagonal PE and may therefore have a broader scope than that proposed initially. Although in the studied populations, no significant relationship could be found between HexII PE positivity and clinical complications (thrombosis and/or recurrent fetal losses), it might be associated with other complications of the antiphospholipid syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)
Managing distributed ups energy for effective power capping in data centers (2012)

Power over-subscription can reduce costs for modern data centers. However, designing the power infrastructure for a lower operating power point than the aggregated peak power of all servers requires dynamic techniques to avoid high peak power costs and, even worse, tripping circuit breakers. This work presents an architecture for distributed per-server UPSs that stores energy during low activity periods and uses this energy during power spikes. This work leverages the distributed nature of the UPS batteries and develops policies that prolong the duration of their usage. The specific approach shaves 19.4% of the peak power for modern servers, at no cost in performance, allowing the installation of 24% more servers within the same power budget. More servers amortize infrastructure costs better and, hence, reduce total cost of ownership per server by 6.3%.
Predictions of Enhanced Chemical Reactivity at Regions of Local Conformational Strain on Carbon Nanotubes:  Kinky Chemistry (1999)

Simulations that model the effects of conformational strain on the chemical reactivity of single-walled carbon nanotubes suggest a method for significantly enhancing their reactivity locally by controlled deformations. The chemisorption of hydrogen atoms is predicted to be enhanced by as much as 1.6 eV at regions of high conformational deformation, suggesting that local reactivity will be significantly enhanced. Analysis of the local electronic density of states suggests the introduction of radical p orbital character to the sites that are locally deformed, consistent with the heightened reactivity and large pyramidalization angles at these sites. Preliminary experimental data consistent with this predicted heightened reactivity is also presented.
The phenazine pyocyanin is a terminal signalling factor in the quorum sensing network of Pseudomonas aeruginosa (2006)

Certain members of the fluorescent pseudomonads produce and secrete phenazines. These heterocyclic, redox-active compounds are toxic to competing organisms, and the cause of these antibiotic effects has been the focus of intense research efforts. It is largely unknown, however, how pseudomonads themselves respond to - and survive in the presence of - these compounds. Using Pseudomonas aeruginosa DNA microarrays and quantitative RT-PCR, we demonstrate that the phenazine pyocyanin elicits the upregulation of genes/operons that function in transport [such as the resistance-nodulation-cell division (RND) efflux pump MexGHI-OpmD] and possibly in redox control (such as PA2274, a putative flavin-dependant monooxygenase), and downregulates genes involved in ferric iron acquisition. Strikingly, mexGHI-opmD and PA2274 were previously shown to be regulated by the PA14 quorum sensing network that controls the production of virulence factors (including phenazines). Through mutational analysis, we show that pyocyanin is the physiological signal for the upregulation of these quorum sensing-controlled genes during stationary phase and that the response is mediated by the transcription factor SoxR. Our results implicate phenazines as signalling molecules in both P. aeruginosa PA14 and PAO1.
A Mercury Ion Electrochemical Sensor Based on Porous Anodized Alumina Membrane Nanochannels Modified with DNA (2018)

A novel mercury ion (Hg2+) electrochemical sensor was established via chemical modification of porous anodic alumina (PAA) membrane nanochannels with DNA. PAA membrane was prepared by a two-step anodization. Amino groups were introduced to nanochannels by silanization. Special sequence DNA (along with amino group) was modified on PAA membrane nanochannels by the condensation reaction of amino and aldehyde groups. Electrochemical detector was built via sputtered Au nanoparticles on the surface of PAA nanochannels, which could be used as working electrode. The reduction potential of 0 V was applied, where the flux of Fe(CN)63− was determined by diffusion. The current response has a positive correlation with the concentration of Fe(CN)63−. After DNA immobilized, the negative charge and the steric hindrance of the nanochannels is increased, resulting in the decreasing of the flux of Fe(CN)63−. The detection current is reduced compared with pure PAA membrane nanochannels. When Hg2+ is present, a stable thymine-Hg2+-thymine structure is formed due to the specific reaction between thymine in DNA and Hg2+. In this case, the charge density and steric hindrance of the nanochannels are decreased, thereby increasing the flux of Fe(CN)63− and restoring current. The results show that the detection limit is about 0.08 pM with a good linear response (from 1 pM to 100 nM). Meanwhile, the sensor has a good selectivity. The current responses of other metal ions (Mn2+, Mg2+, Ba2+, Co2+ and Cd2+) are not obvious compared with Hg2+. Therefore, this new sensor could be applied for detecting Hg2+ in the environment.
A novel RING-H2 motif protein downregulated by axotomy: its characteristic localization at the postsynaptic density of axosomatic synapse (1995)

Axonal injury and its repair are common and basic neuropathological processes in the CNS, and are composed of a complex of events in a molecular term. In order to get a comprehensive understanding of these processes, we isolated several known and unknown genes which were up-or downregulated in the facial nucleus after transection of the facial nerve by a subtractive/differential screening. Among them, we focus on one downregulated gene, named Neurodap1, because this gene encodes a novel protein carrying the RING-H2 sequence motif categorized in the zinc finger family. Immunoelectron microscopic analysis revealed that the protein encoded by Neurodap1, Neurodap1, was distributed mainly on the cytoplasmic side of the membranes constituting endoplasmic reticulum and Golgi apparatus, supporting the notion of a previously postulated function of RING-H2 motif proteins, that is, involvement in the protein sorting machinery. More interestingly, Neurodap1 was also bound to the postsynaptic density (PSD) region of axosomatic synapses. This fact suggests that Neurodap1 is associated with a specific system sorting proteins to PSD. Therefore, Neurodap1, a newly identified protein as an axotomy-suppressed gene product, might play a significant role in synaptic communication and plasticity through the control of the formation of PSD for maintaining vital functions of nerve cells.
Relationship between motor proficiency, attention, impulse, and activity in children with ADHD (2004)

The aim of this study was to investigate the relationship between motor performance, attention deficit, impulsiveness, and hyperactivity in children with attention-deficit--hyperactivity disorder (ADHD). Participants were 42 school-aged children with ADHD (36 males, 6 females; mean age 8 years 2 months, SD 1 year 2 months; range 6 years to 11 years), and 42 age- and sex-matched children without ADHD (mean age 8 years 3 months, SD 1 year 1 month; range 6 years to 11 years). Motor abilities were assessed with the Bruininks-Oseretsky Test of Motor Proficiency. Attention and impulse control were measured with the Gordon Diagnostic System, and assessment of activity level was based on two Activity Level Rating Scales that were completed by parents and teachers. Analysis by t-test revealed a significant difference between children with and without ADHD in fine and gross motor skills, impulse control, and attention. Stepwise regression indicated that attention, impulse control, and parent ratings of activity level were the three best predictors of gross motor skills for children with ADHD, accounting for 55.9% of the variance. Attention and impulse control were the two best predictors of fine motor skills, accounting for 45.7% of the variance. Attention and impulse control were consistently found to be important predictors of both fine and gross motor skills in children with ADHD. However, the fact that activity level was a predictor for gross motor proficiency but not for fine motor tasks suggests that different behavioral processes are involved in fine and gross motor performance to different extents.
De lo cronístico y lo ficcional en los Naufragios de Álvar Núñez Cabeza de Vaca (2005)

Este artículo propone una síntesis de un tema muy debatido: la tipología textual de los Naufragios. Junto con algunas deducciones personales, se han expuesto las opiniones más difundidas entre los estudiosos, acerca de la difícil clasificación de la obra, y también sobre los posibles intentos e inspiraciones de su autor.
Glutathione-S-transferase P1 gene polymorphism and susceptibility to endometriosis (2005)

The results of this study suggest that GSTP1 polymorphism might modulate the risk of endometriosis with significantly decreased risk for GSTP1 val/val and marginally increased risk for GSTP1 ile/ile. Further studies on not only the disease processes but also normal distribution of the enzyme in female genital tract may provide better understanding about the role of GST types and their polymorphs in endometriosis.