gebhart/patrepeval huggingface dataset:
Phytochrome Control of the Expression of Two Nuclear Genes Encoding Chloroplast Proteins in Lemna gibba L. G-3 (1983)

Hybridization probes for two nuclear-coded chloroplast proteins of Lemna gibba L. G-3 have been constructed in order to investigate phytochrome regulation of specific sequences. The first probe is a cDNA clone encoding the small subunit of ribulose 1,5-bisphosphate carboxylase. This probe was isolated from a set of Lemna cDNA clones in the bacterial plasmid pBR322. The second probe is a subclone of a genomic clone encoding the light-harvesting chlorophyll a/b-protein. This clone was isolated from a set of genomic clones constructed in the lambda vector Charon 4 with L. gibba DNA fragments generated by partial EcoR1 digestion. The identity of these clones was confirmed by in vitro translation of RNA which hybridized to the cloned DNA. Plants grown under continuous white light contain high concentrations of both RNA sequences; however, when these plants are put into darkness the concentration of these RNAs decreases rapidly relative to the total amount of RNA. Plants grown in the dark with intermittent red light (2 minutes/8 hours) and put into complete darkness for 8 days also contain lower concentrations of the sequences in the total RNA. One minute of red light after this dark period results in a rapid increase in the levels of RNA hybridizing to the probes. The effect of red light can be reversed by far-red light. These experiments demonstrate that phytochrome action can rapidly influence either the rates of transcription or the rates of degradation of these mRNAs.
Dimerization of the Human Receptors for Prostacyclin and Thromboxane Facilitates Thromboxane Receptor-mediated cAMP Generation (2004)

Prostacyclin (PGI(2)) and thromboxane (TxA(2)) are biological opposites; PGI(2), a vasodilator and inhibitor of platelet aggregation, limits the deleterious actions of TxA(2), a vasoconstrictor and platelet activator. The molecular mechanisms involved in the counterregulation of PGI(2)/TxA(2) signaling are unclear. We examined the interaction of the receptors for PGI(2) (IP) and TxA(2) (TPalpha). IP-induced cAMP and TP-induced inositol phosphate generation were unaltered when the receptors were co-expressed in HEK 293 cells (IP/TPalpha-HEK). TP-cAMP generation, in response to TP agonists or a TP-dependent isoprostane, iPE(2)III, was evident in IP/TPalpha-HEK and in aortic smooth muscle cells, but not in cells expressing either receptor alone, or in IP-deficient aortic smooth muscle cells. Augmentation of TP-induced cAMP generation, with the IP agonist cicaprost, was ablated in IP-deficient cells and was independent of direct IP signaling. IP/TPalpha heterodimers were formed constitutively when the receptors were co-expressed, with no overt changes in ligand binding to the individual receptor sites. However, despite inefficient binding of iPE(2)III to either the IP or TPalpha, expressed alone or in combination, robust cAMP generation was evident in IP/TPalpha-HEK, suggesting the formation of an alternative receptor site. Thus, IP/TPalpha dimerization was coincident with TP-cAMP generation, promoting a "PGI(2)-like" cellular response to TP activation. This represents a previously unknown mechanism by which IP may limit the cellular effects of TP.
Regulation of T‐Cell Activation; Differences among T‐Cell Subsets (1989)

Four regulatory phenomena appear to regulate differentially the activation of TH1, TH2, and CTL clones. First, IFN-gamma selectively inhibits proliferation of TH2 but not TH1 cells; lymphokine production by TH2 cells is not affected by IFN-gamma. In addition, when fresh OVA-specific HTL clones are derived in the presence of rIL-2 TH2 cells are preferentially obtained, whereas TH1 cells predominate if cloning is performed in rIL-2 plus rIFN-gamma. These results suggest that the presence of IFN-gamma during the course of an immune response would result in the preferential expansion of HTL of the TH1 phenotype. Proliferation of CTL clones is not influenced by IFN-gamma. Second, different APC populations appear to differentially activate TH1 and TH2 clones. Purified splenic B cells stimulate optimal proliferation of TH2 but not TH1 cells, whereas macrophage/dendritic cells appear to stimulate optimal proliferation of TH1 but not TH2 cells. Since both APC types stimulate lymphokine production by each of the HTL subsets, these results suggest the existence of TH1- and TH2-specific cofactors for growth. Third, high doses of immobilized anti-CD3 mAb inhibit IL-2-dependent proliferation of TH1 but not TH2 clones. Since this effect appears to require calcium, this observation suggests that TCR-mediated signalling events might differ between the two HTL subsets. Indeed, little or no increase in [Ca++]i can be detected in TH2 clones stimulated with Con-A, while such an increase is easily discernible in TH1 cells. Although high concentrations of immobilized anti-CD3 mAb inhibit IL-2-dependent proliferation of CTL clones, proliferation of these cells in response to immobilized anti-CD3 alone reaches a plateau. Since activation with anti-CD3 is thought to mimic antigenic stimulation, these results suggest that antigen concentration may play a role in determining which predominant T-cell types proliferate in a particular immunological situation. Fourth, pretreatment of TH1 cells, but not TH2 cells or CTL, with IL-2 results in decreased lymphokine production and proliferation in response to subsequent stimulation via the TCR. This antigen-responsive state appears to involve a defect in calcium-dependent signalling, providing additional evidence for different signalling mechanisms in TH1 and TH2 clones.(ABSTRACT TRUNCATED AT 400 WORDS)
Energetic analysis of an antigen/antibody interface: Alanine scanning mutagenesis and double mutant cycles on the hyhel‐10/lysozyme interaction (1999)

Abstract Alanine scanning mutagenesis of the HyHEL‐10 paratope of the HyHEL‐10/HEWL complexdemonstrates that the energetically important side chains (hot spots) of both partners are in contact.A plot of ΔΔ G HyHEL‐10_mutant vs.ΔΔ G hewl_mutant for the five of six interacting side‐chain hydrogen bonds is linear (Slope = 1).Only 3 of the 13 residues in the HEWL epitope contribute &gt;4 kcal/mol to the free energy of formation of the complexwhen replaced by alanine, but 6 of the 12 HyHEL‐10 paratope amino acids do.Double mutant cycle analysis of the single crystallographically identified salt bridge, D32 H /K97, shows that there is a significant energetic penalty when either partner is replaced with a neutral side‐chain amino acid, but the D32 H N/K97M complex is as stable as the WT.The role of the disproportionately high number of Tyr residues in the CDR was evaluated by comparing theΔΔ G values of the Tyr Phe vs. the corresponding Tyr Ala mutations.The nonpolar contacts in the light chain contribue only about one‐half of the totalΔΔ G observed for the Tyr Ala mutation, while they are significantly more important in the heavy chain.Replacement of the N31 L /K96 hydrogen bond with a salt bridge, N31D L /K96, destabilizes the complex by 1.4 kcal/mol. The free energy of interaction,ΔΔ G int , obtained from double mutant cycle analysis showed that ΔΔ G int for any complex for which the HEWL residue probed is a major immunodeterminant is very close to the loss of free energy observed for the HyHEL‐10 single mutant.Error propagation analysis of double mutant cycles shows that data of atypically high precision are required to use this method meaningfully, except where large ΔΔ G values are analyzed.
Economic aspects and policy issues in groundwater development (1981)

Technical, economic and social aspects of groundwater development policy are discussed. The various groundwater system components and categories of agricultural demands are analysed. Opportunities exist for obtaining benefits from conjunctive use with surface water. These are stressed as well as the economic aspects of wells and well-field design and the need to consider drainage before soil problems become insurmountable. Groundwater development is usually very profitable, and it is therefore likely to be monopolized by a few farmers or overexploited by the majority. Public control to obtain an equitable regime is desirable, but institutional barriers are enormous. The pros and cons of public and private sector development are discussed. Once they are developed, aquifers need overall management to maximize economic yield and to safeguard water quality. Operating experiences from several countries are quoted, and the role of mathematical models to gain improved insight is briefly considered. An analytical framework for research into key topics is presented.
Amino Acids and Ammonium Regulate Mouse Embryo Development in Culture1 (1993)

The regulation of 1-cell mouse embryo development in culture by amino acids was investigated. When the 20 amino acids in Eagle's medium were present, blastocyst formation at 72 h (9%; p < 0.01), and blastocyst cell number (66; p < 0.05) and hatching (45%; p < 0.05) after 96 h of culture were significantly increased, compared to control embryos grown in the absence of amino acids (0%, 60, and 23%, respectively). The beneficial effect of Eagle's amino acids was attributed primarily to the non-essential group. In the presence of non-essential amino acids, blastocyst formation (54%; p < 0.001) and cell number after 72 h of culture (33; p < 0.05), and blastocyst cell number (69; p < 0.01) and hatching (68%; p < 0.01) after 96 h of culture were all significantly greater than for embryos cultured with all amino acids (9%, 26, 66, and 45%, respectively). In the absence of glutamine, essential amino acids significantly reduced blastocyst cell number after 96 h (53; p < 0.05). Continual culture in the presence of amino acids reduced the cleavage rate after around 72 h of in vitro culture; this decrease was not observed in the absence of amino acids. Transfer of embryos to fresh medium after 48-72 h of culture resulted in increases in the percentage of blastocysts formed and in blastocyst cell numbers. These data are consistent with the build-up of an inhibitory compound in the medium, possibly ammonium, an end-product of amino acid metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
VLSI Implementation of a Reconfigurable Mixed-Signal Finite Impulse Response Filter (2007)

We present an implementation of a reconfigurable <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16-tap</i> finite impulse response filter for post-processing applications. This filter exploits the distributed arithmetic technique for signal processing and floating-gate voltage references for setting tunable analog coefficients. The filter is fabricated in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5μm</i> CMOS process, and its order can be increased at the cost of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.011mm<sup>2</sup></i> of die area and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.02mW</i> of power per tap. Measurement results for low-pass and band-pass filters at <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">50kHz</i> sampling frequency are presented.
Organoboron Compounds with an 8-Hydroxyquinolato Chelate and Its Derivatives:  Substituent Effects on Structures and Luminescence (2005)

Four new luminescent organoboron complexes have been synthesized and fully characterized. These compounds are four-coordinate boron chelated by either 8-hydroxyquinolato (q) or functionalized 8-hydroxylquinolato ligands, including BPh2(5-(1-naphthyl)-q) (1), BPh2(5-(2-benzothienyl)-q) (2), B(2-benzothienyl)2q (3), and B(2-benzothienyl)2(2-Me-q) (4). All four compounds have a tetrahedral geometry as established by X-ray diffraction analyses. In solution, compounds 1-4 have an emission maximum at 534, 565, 501, and 496 nm, respectively, at room temperature. They emit similar colors in the solid states without red shifts of the emission band due to the lack of significant intermolecular interactions in the crystal lattices. The substituent group at C5 or C2 position of the 8-hydroxyquinolato ligand has been observed to have a significant impact on the emission energy and the emission quantum efficiency of the boron complexes. Molecular orbital calculations (Gaussian 98) showed that the electronic transition of 1 and 2 is a pi-pi* transition centered on the functionalized 8-hydroxyquinolato group and the electronic transition of 3 and 4 is an interligand charge transfer from the 2-benzothienyl ligand to the hydroxyquinolato ring. A double-layer electroluminescent device using 3 as the emitter has been fabricated, which produced a broad emission band with a significant contribution of exciplex emission.
Design, Synthesis, Docking, and Biological Evaluation of Novel Diazide-Containing Isoxazole- and Pyrazole-Based Histone Deacetylase Probes (2011)

The design, synthesis, docking, and biological evaluation of novel potent HDAC3 and HDAC8 isoxazole- and pyrazole-based diazide probes suitable for binding ensemble profiling with photoaffinity labeling (BEProFL) experiments in cells is described. Both the isoxazole- and pyrazole-based probes exhibit low nanomolar inhibitory activity against HDAC3 and HDAC8, respectively. The pyrazole-based probe 3f appears to be one of the most active HDAC8 inhibitors reported in the literature with an IC(50) of 17 nM. Our docking studies suggest that unlike the isoxazole-based ligands the pyrazole-based ligands are flexible enough to occupy the second binding site of HDAC8. Probes/inhibitors 2b, 3a, 3c, and 3f exerted the antiproliferative and neuroprotective activities at micromolar concentrations through inhibition of nuclear HDACs, indicating that they are cell permeable and the presence of an azide or a diazide group does not interfere with the neuroprotection properties, or enhance cellular cytotoxicity, or affect cell permeability.
High-level expression of the endo- -N-acetylglucosaminidase F2 gene in E.coli: one step purification to homogeneity (1998)

The Endo F2gene was overexpressed in E.coli as a fusion protein joined to the maltose-binding protein. MBP-Endo F2was found in a highly enriched state as insoluble, inactive inclusion bodies. Extraction of the inclusion bodies with 20% acetic acid followed by exhaustive dialysis rendered the fusion protein active and soluble. MBP-Endo F2was digested with Factor Xaand purified on Q-Sepharose. The enzyme was homogeneous by SDS-PAGE, and appeared as a single symmetrical peak on HPLC. Analysis of the amino-terminus demonstrated conclusively that recombinant Endo F2was homogeneous and identical to the native enzyme.
Strand exchange in site-specific recombination. (1979)

The site-specific recombination system of phage lambda promotes crossovers at its attachment site (att). In this report we show that when phage are crossed in conditions where only the site-specific recombination system is active, a low frequency of crossovers can also be detected in a region that is close to but does not contain att. These crossovers require the phage int gene, the host hip gene, and the integrity of att. They are not detected if one of the parents carries a substitution of a heterologous attachment site (attB instead of attP). To explain these findings we suggest that site-specific recombination can proceed by exchange of single strands between the participating chromosomes at att and migration of the resulting junction outside of att.
R-Allyl Nickel(II) Complexes with Chelating N-Heterocyclic Carbenes: Synthesis, Structural Characterization, and Catalytic Activity (2012)

The N-heterocyclic carbene (NHC) nickel complexes [(L)Ni(NHC)][BArF4] (ArF = 3,5-bis(trifluoromethyl)phenyl; L = allyl (1), methylallyl (2); NHC = 1-(2-picolyl)-3-methylimidazol-2-ylidene (a), 1-(2-picolyl)-3-isopropylimidazol-2-ylidene (b), 1-(2-picolyl)-3-n-butylimidazol-2-ylidene (c), 1-(2-picolyl)-3-phenylimidazol-2-ylidene (d), 1-(2-picolyl)-3-methylbenzoimidazol-2-ylidene (e), 1-(2-picolyl)-4,5-dichloro-3-methylimidazol-2-ylidene (f)) have been obtained in high yields and characterized by NMR spectroscopy. Furthermore, 1d was unambiguously characterized by single-crystal X-ray crystallography. Complexes 1a–f/2a–f have shown catalytic activity toward dimerization and hydrosilylation of styrenes. In particular, 1a proved to be the most efficient catalyst in the dimerization of styrene derivatives in the absence of cocatalyst. Also, complexes 1a,d showed high selectivity and moderate to good yields in hydrosilylation reactions.
Highly Conductive Microfiber of Graphene Oxide Templated Carbonization of Nanofibrillated Cellulose (2014)

Microfibers with conductivity of 649 ± 60 S/cm are introduced through a carbonization of well‐aligned graphene oxide (GO) – nanofibrillated cellulose (NFC) hybrid fibers. GO acts as a template for NFC carbonization, which changes the morphology of carbonized NFC from microspheres to sheets while improving the carbonization of NFC. Meanwhile, the carbonized NFC repairs the defects of reduced GO (rGO) and links rGO sheets together. The GO templated carbonization of NFC as well as the alignment of the building blocks along the fiber direction leads to excellent conductivity. Conductive microfibers are evaluated as lithium ion battery anodes, which can be applied in wearable electronics. This approach to make conductive microfibers and the low cost raw materials used in this work may be applied to other carbon based conductive structures.
The effect of acute beta‐adrenoceptor blockade on examination performance. (1985)

Simple tests of verbal reasoning and mental arithmetic, taken under mildly stressful conditions, have been shown to give a reproducible test of intellectual function within groups of normal subjects. Using these tests, in two separate examinations, a double-blind cross-over study was performed on 35 medical students to assess the effects of acute beta-adrenoceptor blockade with propranolol on intellectual function. With placebo treatment, students recorded an average total score of 231.3 marks, with average scores of 108.9 marks on the mental arithmetic paper and 122.4 marks on the verbal reasoning paper. Treatment with propranolol was associated with an improvement in total score of 9.2 +/- 3.9 marks (P less than 0.05), an improvement in mental arithmetic score of 5.6 +/- 2.3 marks (P less than 0.05) and an improvement in verbal reasoning score of 3.6 +/- 2.4 marks (NS). Eighteen out of the 35 students said that they were mildly anxious before one examination and 13 students said they were anxious before both examinations. Those students who admitted anxiety seemed to benefit the most, in terms of improved examination performance, from treatment with propranolol.
A convenient method for estimation of alkyllithium concentrations (1976)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA convenient method for estimation of alkyllithium concentrationsWilliam G. Kofron and Leona M. BaclawskiCite this: J. Org. Chem. 1976, 41, 10, 1879–1880Publication Date (Print):May 1, 1976Publication History Published online1 May 2002Published inissue 1 May 1976https://pubs.acs.org/doi/10.1021/jo00872a047https://doi.org/10.1021/jo00872a047research-articleACS PublicationsRequest reuse permissionsArticle Views7476Altmetric-Citations400LEARN 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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Release of Water Soluble Drugs from Dynamically Swelling Poly(2-Hydroxyethyl Methacrylate -Co- Methacrylic Acid) Hydrogels. (1987)

In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic underst and ing of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling release systems, can also be predicted by this model. PPA release from initially dry poly(HEMA -co- MA) gels has also been studied. The data show that the release rate is mainly controlled by the PPA loading level and quite insensitive to the methacrylic acid composition of the gels. These phenomena can be adequately explained by analyzing the transport resistances in the gels. The overall time scale of release from these gels were shown to be in the range which was suitable for oral controlled release applications. (Abstract shortened with permission of author.)