gebhart/patrepeval huggingface dataset:
Effects of single-residue substitutions on negative cooperativity in ligand binding to dihydrofolate reductase (1997)

The effects of six amino acid substitutions in Lactobacillus casei dihydrofolate reductase, predominantly in the coenzyme binding site, on catalysis and on the negative cooperativity between NADPH and tetrahydrofolate binding have been determined. Replacement of Leu62, His64 or Leu54 by alanine has no effect on kcat, and produces only modest changes in negative cooperativity. Alanine substitution of His77, which interacts indirectly with the coenzyme adenine ring, leads to a doubling of the negative cooperativity and a consequent doubling of kcat. Replacement of Arg43, which interacts with the coenzyme 2'-phosphate, by alanine, or of Trp21, which interacts with the coenzyme nicotinamide ring, by histidine leads to a 20-100-fold decrease in negative cooperativity. In both mutants there is a decrease in kcat; isotope effects show that product release is largely rate-limiting in R43A, whereas in W21H hydride ion transfer is rate-limiting. 1H NMR has been used to obtain information on the extent of the structural changes produced by the substitutions. This varies from very local effects in H64A to very widespread effects in W21H. These changes are used as the basis for discussion of the mechanisms of the functional effects of the various substitutions. It is suggested that residues in helix C, beta-strand 3 and the beta3-beta4 loop may be involved in the transmission of effects between the coenzyme and substrate binding sites.
Localized distributed state feedback control with communication delays (2014)

This paper introduces the notion of localizable distributed systems. These are systems for which a distributed controller exists that limits the effect of each disturbance to some local subset of the entire plant, akin to spatio-temporal dead-beat control. We characterize distributed systems for which a localizing state-feedback controller exists in terms of the feasibility of a set of linear equations. We then show that when a feasible solution exists, it can be found in a distributed way, and used for the localized synthesis and implementation of controllers that lead to the desired closed loop response. In particular, by allowing controllers to exchange both state and control actions, the information needed by a particular controller is limited to a local subset of the system's state and control inputs.
Lightweight composite cadmium electrodes (1981)

The design and fabrication of the electrodes are discussed. The electrode efficiency of different impregnations of plaques is reported. The chemical impregnation for commercial use has the lowest efficiency, and for aerospace application it has higher efficiency. The electrochemically impregnated electrode is the most efficient.
One-Step Purification, Covalent Immobilization, and Additional Stabilization of a Thermophilic Poly-His-Tagged β-Galactosidase from<i>Thermus</i>sp. Strain T2 by using Novel Heterofunctional Chelate−Epoxy Sepabeads (2002)

Using the poly-His-tagged-beta-galactosidase from Thermus sp. strain T2 overexpressed in Escherichia coli (MC1116) as a model enzyme, we have developed a strategy to purify and immobilize proteins in a single step, combining the excellent properties of epoxy groups for enzyme immobilization with the good performance of immobilized metal-chelate affinity chromatography for protein purification. The aforementioned enzyme could not be immobilized onto standard epoxy supports with good yields, and after purification and storage, it exhibited a strong trend to yield very large aggregates as shown by ultracentrifugation experiments. That preparation could not be immobilized in any support, very likely because the pores of the solid became clogged by the large aggregates. These novel epoxy-metal chelate heterofunctional supports contain a low concentration of Co(2+) chelated in IDA groups and a high density of epoxy groups. This enabled the selective adsorption of poly-His-tagged enzymes, and as this adsorption step is necessary for the covalent immobilization procedure, the selective covalent immobilization of the target enzyme could take place. This strategy allowed similar maximum loadings of the target enzyme using either pure or crude preparations of the enzyme. The enzyme derivative presented a very high activity at 70 degrees C (over 1000 IU in the hydrolysis of lactose) and very high stability and stabilization when compared to its soluble counterpart (activity remained unaltered after several days of incubation at 50 degrees C). In fact, this preparation was much more stable than when the same enzyme was immobilized onto standard epoxy Sepabeads.
Control of Cajal body number is mediated by the coilin C-terminus (2002)

Cajal bodies (CBs) are nuclear suborganelles implicated in the post-transcriptional maturation of small nuclear and small nucleolar RNAs. The number of CBs displayed by various cell lines and tissues varies, and factors that control CB numbers within a given cell have yet to be described. In this report, we show that specific regions within the C-terminus of coilin, the CB marker protein, are responsible for regulating the number of nuclear foci. Despite the fact that the coilin N-terminal domain is responsible for its self-oligomerization activity, truncation or mutation of predicted sites of phosphorylation in the conserved C-terminal region leads to a striking alteration in the number of nuclear bodies. Similarly, coilin constructs from various species display differential propensities to form nuclear foci when expressed in heterologous backgrounds. We mapped the domain responsible for this variability to the coilin C-terminus utilizing chimeric proteins. Furthermore, the activities responsible for regulating coilin self-association must reside in the nucleus, as constructs lacking critical nuclear localization sequences fail to form foci in the cytoplasm. Factors controlling the putative signal transduction cascade that phosphorylates coilin are also discussed. The results point to a model whereby phosphorylation of the coilin C-terminus regulates the availability of the N-terminal self-interaction domain.
Nanostructure Fabrication by Ultra-High-Resolution Environmental Scanning Electron Microscopy (2007)

Electron beam induced deposition (EBID) is a maskless nanofabrication technique capable of surpassing the resolution limits of resist-based lithography. However, EBID fabrication of functional nanostructures is limited by beam spread in bulk substrates, substrate charging, and delocalized film growth around deposits. Here, we overcome these problems by using environmental scanning electron microscopy (ESEM) to perform EBID and etching while eliminating charging artifacts at the nanoscale. Nanostructure morphology is tailored by slimming of deposits by ESEM imaging in the presence of a gaseous etch precursor and by pre-etching small features into a deposit (using a stationary or a scanned electron beam) prior to a final imaging process. The utility of this process is demonstrated by slimming of nanowires deposited by EBID, by the fabrication of gaps (between 4 and 7 nm wide) in the wires, and by the removal of thin films surrounding such nanowires. ESEM imaging provides a direct view of the slimming process, yielding process resolution that is limited by ESEM image resolution ( approximately 1 nm) and surface roughening occurring during etching.
Resonant grating filters as refractive index sensors for chemical and biological detections (2005)

A chemical and biological sensor based on a free-space waveguide resonant grating optical filter has been developed. Different from the conventional surface plasmon resonance sensors and the conventional waveguide mode sensors, which require either prism coupling or grating coupling, the proposed free-space optical sensor device does not require special separate coupling. The inherent 100% coupling efficiency at resonance can significantly boost probe efficiency. Both simulation and experimental results have demonstrated that the sensor could deliver a resolution of better than 0.001–0.0001 for refractive index sensing, which is enough for detecting various chemical and biological materials. More importantly, under an angular detection scheme, the proposed waveguide resonant grating sensor could be one order’s more sensitive than the conventional surface plasmon resonance sensor.
A broadband dual‐polarized printed dipole antenna with low cross‐polarization and high isolation for base station applications (2017)

ABSTRACT A dual‐polarized dipole antenna with low cross‐polarization and high isolation characteristics is presented. The proposed antenna is composed of three basic structures, i.e., a horizontal rectangular ground plate, four vertical plates with two rectangular patches on each of them, and a horizontal substrate with eight triangle patches. Every two vertical plates are put back‐to‐back which forms a double‐layered structure. Thus the transverse E‐field of the double‐layered structure is significantly reduced because of this symmetric treatment, which gives rise to very low cross‐polarization. Then the two double‐layered structures are orthogonally arranged, generating dual polarizations. Simulated and measured results show that the proposed antenna realizes an impedance bandwidth of 47% (VSWR < 1.5), ranging from 1.8 to 2.9 GHz. The isolation between the two orthometric ports is higher than 30 dB across the bandwidth. Furthermore, the cross‐polarization is −35 dB over the bandwidth. This antenna has the advantages of high isolation, low cross‐polarization, and wide bandwidth. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1107–1111, 2017
Sustained extracellular signal‐regulated kinase activation by 6‐hydroxydopamine: implications for Parkinson's disease (2001)

Although the toxin 6-hydroxydopamine (6-OHDA) is utilized extensively in animal models of Parkinson's disease, the underlying mechanism of its toxic effects on dopaminergic neurons is not completely understood. We examined the effects of 6-OHDA on the CNS-derived tyrosine hydroxylase expressing B65 cell line, with particular attention to the regulation of the extracellular signal-regulated protein kinases (ERK). 6-OHDA elicited a dose-dependent cytotoxicity in B65 cells. Toxic doses of 6-OHDA also elicited a biphasic pattern of ERK phosphorylation with a prominent sustained phase, a pattern that differed from that observed with hydrogen peroxide (H(2)O(2)) treatment. 6-OHDA-elicited ERK phosphorylation was blocked by PD98059, an inhibitor of the upstream mitogen activated protein kinase kinase (MEK) that phosphorylates and activates ERK. PD98059 also conferred protection against 6-OHDA cytotoxicity, but did not affect H(2)O(2) toxicity in B65 cells. These results suggest that ERK activation plays a direct mechanistic role in 6-OHDA toxicity, rather than representing a protective compensatory response, and raise the possibility that abnormal patterns of ERK activation may contribute to dopaminergic neuronal cell death.
Effect of rumination on reduction of particle size of rumen digesta by cattle (1985)

Two Hereford steers, fitted with cannulas in the oesophagus and rumen, were given four forage diets in either the chopped or ground and pelleted form. Collections from the oesophageal fistula were made of boluses regurgitated during rumination of the chopped diets. Diets were given at 95% of voluntary feed consumption at intervals of 2 h. Rumination of the chopped diets required 28-36000 chews/day compared to values of 3-10 000 chews/day for the pelleted forms. The weight of material regurgitated during rumination averaged 786 g, of which 493 g was swallowed before chewing commenced. Fractionation of particulate DM by wet sieving showed that the material retained in the mouth for chewing contained 41% more large particulate matter than did regurgitated material. Approximately 70% of large particles in the mouth were comminuted to small particles during one cycle of rumination. Comminution per chew was positively related to the amount of large particulate matter retained in the mouth for chewing and negatively to the number of chews/cycle. Rumination accounted for approximately 85% of comminution of large particles which entered the rumen. Measurements of digestion of dietary materials from nylon bags and rates of outflow of small particles and water from the rumen were used in conjunction with intake and chewing measurements to predict the rumen content of large particles.
L'Europe et le monde colonial au XVIIIe siècle (2013)

Variant les approches et les contextes, les contributions de ce volume étudient les échanges, les rapports de pouvoir et de domination, les médiations et les transformations, les interactions et les transferts culturels entre les États européens et leurs colonies dans les espaces américains et asiatiques à l'âge des Lumières. Le phénomène colonial a, par son caractère protéiforme, permis de croiser les regards dans un esprit d'interdisciplinarité stimulante et féconde comme en témoigne la nouveauté des perspectives développées ici. Autour de l'idée de représentation - définie comme production d'images et de figures aux sens culturel, identitaire, politique et esthétique du terme - sont réunies des enquêtes dont l'interrogation centrale relève souvent d'une scénographie du " colonial " comme origine, lieu et résultat des expressions verbales ou visuelles. Il s'agit d'éclairer ce que peuvent recouvrir ces représentations. Les plus nombreuses sont liées à la question de l'identité. Elles permettent une étude directe - sinon exhaustive - des rapports socio-culturels et juridico-politiques entre centre et périphérie.
Efficacy, Plasma Pharmacokinetics, and Safety of Icofungipen, an Inhibitor of <i>Candida</i> Isoleucyl-tRNA Synthetase, in Treatment of Experimental Disseminated Candidiasis in Persistently Neutropenic Rabbits (2005)

Icofungipen (formerly PLD-118) is a synthetic derivative of the naturally occurring beta-amino acid cispentacin that blocks isoleucyl-tRNA synthetase, resulting in the inhibition of protein synthesis and growth of fungal cells. We investigated the efficacy, plasma pharmacokinetics, and safety of icofungipen in escalating dosages for the treatment of experimental subacute disseminated candidiasis in persistently neutropenic rabbits. Icofungipen was administered for 10 days starting 24 h after the intravenous inoculation of 10(3) Candida albicans blastoconidia. Study groups consisted of rabbits treated with icofungipen at 4 (ICO-4), 10 (ICO-10), and 25 (ICO-25) mg/kg of body weight/day in two divided dosages, rabbits treated with fluconazole at 10 mg/kg/day, rabbits treated with amphotericin B at 1 mg/kg/day, and untreated controls. Levels of icofungipen in plasma were derivatized by phthaldialdehyde and quantified by high-performance liquid chromatography with fluorescence detection. Rabbits treated with ICO-10 (P < 0.01) and ICO-25 (P < 0.001) showed significant dosage-dependent tissue clearance of C. albicans from the liver, spleen, kidney, brain, vitreous, vena cava, and lung in comparison to untreated controls. ICO-25 cleared C. albicans from all tissues and had activity comparable to that of amphotericin B versus untreated controls (P < 0.001). Pharmacokinetics of icofungipen in plasma approximated a dose-dependent relationship of the maximum concentration of drug in serum and the area under the concentration-time curve. There was no significant elevation of the levels of hepatic transaminases, alkaline phosphatase, bilirubin, urea nitrogen, or creatinine in icofungipen-treated rabbits. Icofungipen followed dose-dependent pharmacokinetics and was effective in the treatment of experimental disseminated candidiasis, including central nervous system infection, in persistently neutropenic rabbits.
The cognition‐enhancing activity of<scp>E1R</scp>, a novel positive allosteric modulator of sigma‐1 receptors (2013)

E1R is a novel 4,5-disubstituted derivative of piracetam that enhances cognition and demonstrates efficacy against scopolamine-induced cholinergic dysfunction in mice. These effects are attributed to its positive modulatory action on the sigma-1 receptor and this activity may be relevant when developing new drugs for treating cognitive symptoms related to neurodegenerative diseases.
菲籍华人、菲律宾人和外国人的经济地位和企业活动——对1990年菲律宾大公司的分析 (1996)

引言 本文旨在考察1990年菲律宾的大公司,并对国内不同种族和民族的经济地位和企业活动进行分析。受考察和比较的族群包括:(1)华裔菲律宾人,即众所周知的在企业界起主导作用的族群;(2)其他菲律宾人,主要指西班牙裔菲律宾人和当地菲律宾人;(3)主要由美国人、欧洲人和日本人构成的作为一个整体的外国企业界。鉴于一部分大公司属政府所有,它们将作为单独的类别来讨论。
Families with Attention Deficit Disordered Children and Others at Risk (1988)

No abstract available for this article.
Reduction of Aldehydes with Aluminum Isopropoxide<sup>1,2</sup> (1936)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReduction of Aldehydes with Aluminum Isopropoxide1,2William G. Young, Walter H. Hartung, and Frank S. CrossleyCite this: J. Am. Chem. Soc. 1936, 58, 1, 100–102Publication Date (Print):January 1, 1936Publication History Published online1 May 2002Published inissue 1 January 1936https://pubs.acs.org/doi/10.1021/ja01292a033https://doi.org/10.1021/ja01292a033research-articleACS PublicationsRequest reuse permissionsArticle Views728Altmetric-Citations54LEARN 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
Allylic selenides in organic synthesis: new methods for the synthesis of allylic amines (1986)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAllylic selenides in organic synthesis: new methods for the synthesis of allylic aminesRegan G. Shea, Jeffrey N. Fitzner, John E. Fankhauser, Andreas Spaltenstein, Philip A. Carpino, Richard M. Peevey, Daniel V. Pratt, Bradley J. Tenge, and Paul B. HopkinsCite this: J. Org. Chem. 1986, 51, 26, 5243–5252Publication Date (Print):December 1, 1986Publication History Published online1 May 2002Published inissue 1 December 1986https://pubs.acs.org/doi/10.1021/jo00376a037https://doi.org/10.1021/jo00376a037research-articleACS PublicationsRequest reuse permissionsArticle Views2693Altmetric-Citations74LEARN 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-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Hepatitis B virus genotype A rarely circulates as an HBe-minus mutant: possible contribution of a single nucleotide in the precore region (1993)

The emergence of HBe-minus hepatitis B virus (HBV) mutants, usually through a UAG nonsense mutation at codon 28 of the precore region, helps the virus to survive the anti-HBe immune response of the host. Host and viral factors that predispose to the emergence of such mutants are not well characterized. The fact that the precore region forms a hairpin structure essential for the packaging of viral pregenomic RNA may explain the extremely high prevalence of the UAG mutation at codon 28. It converts a wobble U-G pair in the packaging signal between nucleotide 3 of codon 15 (CCU) and nucleotide 2 of codon 28 (UGG) into a U-A pair. Since genotype A of HBV has a CCC sequence at codon 15, the UAG mutation would, instead, disrupt a C-G pair present in the wild-type virus. This alteration was shown by transfection experiments to greatly compromise the packaging of pregenomic RNA. The implication of this finding was elucidated by molecular epidemiological studies. Genotype A was found to be the most prevalent genotype in the wild-type virus populations in France but was found in only 1 of the 46 isolates of HBe-minus mutants found there. These mutants were contributed chiefly by genotype D, the second most prevalent genotype in France, which is characterized by a CCU sequence at codon 15. The role of the single nucleotide at codon 15 was confirmed by the finding of the single genotype A isolate in which both wild-type and mutant viruses were present. Interestingly, nearly all of the mutants had a codon 15 sequence of CCU instead of the CCC present in the wild-type viruses. Our results suggest that genotype A of HBV rarely circulates as HBe-minus mutants, probably because of a requirement for a simultaneous sequence change at codon 15. These data, together with the virtual absence of genotype A in the Chinese samples examined, may provide some insights into the uneven prevalence of HBe-minus mutants in the world.
Effect of occlusal pressure on the histopathological changes in denture supporting tissues (1996)

Histopathological changes in the denture supporting tissues in relation to the occlusal pressure exerted through an experimental denture base were studied. An experimental denture, which prescribed the occlusal pressure by the amount of subsidence of the denture base (100, 50 and 13 microns), was constructed for the palate of the molar region of rat. Histopathological changes caused by the occlusal pressure were observed, and the intensity of the pressure was also estimated. In the 100 microns subsidence group, compression of epithelium and lamina propria mucosae, inflammatory change and bone resorption were caused by the occlusal pressure. In the 50 microns subsidence group, compression of epithelium and lamina propria mucosae and bone resorption were observed, while in the 13 microns subsidence group, no evidence of inflammatory change and bone resorption were observed. The epithelium and lamina propria mucosae recovered histopathologically depending on the gradual decrease of the occlusal pressure resulting from bone resorption, whereas no quantitative recovery of the resorbed bone tissue was observed in the 100 and 50 microns subsidence groups. From the results observed in this study, a high correlation was observed between the histopathological changes under a denture base and the intensity of the occlusal pressure, and the possibility of the existence of the threshold for bone resorption induced by occlusal pressure was suggested.