gebhart/patrepeval huggingface dataset:
The genome-wide screening of yeast deletion mutants to identify the genes required for tolerance to ethanol and other alcohols (2006)

A set of homozygous diploid deletion mutants of the yeast Saccharomyces cerevisiae was screened for the genes required for tolerance to aliphatic alcohols. The screen identified 137, 122 and 48 deletion mutants sensitive to ethanol, 1-propanol and 1-pentanol, respectively. A number of the genes required for ethanol tolerance were those also required for tolerance to other alcohols. Numerous mutants with defective genes encoding for vacuolar H+ -ATPase (V-ATPase) were cosensitive to these alcohols. A global screening approach of yeast deletion library mutants was useful in elucidating the mechanisms of alcohol tolerance based on different lipophilicities.
Highly efficient hydrolytic cleavage of adenosine monophosphate resulting in a binuclear cobalt(III) complex with a novel doubly bidentate .mu.4-phosphato bridge (1989)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHighly efficient hydrolytic cleavage of adenosine monophosphate resulting in a binuclear cobalt(III) complex with a novel doubly bidentate .mu.4-phosphato bridgeJik Chin and Mariusz BanaszczykCite this: J. Am. Chem. Soc. 1989, 111, 11, 4103–4105Publication Date (Print):May 1, 1989Publication History Published online1 May 2002Published inissue 1 May 1989https://pubs.acs.org/doi/10.1021/ja00193a053https://doi.org/10.1021/ja00193a053research-articleACS PublicationsRequest reuse permissionsArticle Views193Altmetric-Citations55LEARN 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
Site-directed alanine mutagenesis of Phe33, Arg35, and Arg42-Ser43-Lys44 in the human gonadotropin alpha-subunit. (1993)

Residues Phe33 and Arg35, individually, and a composite mutation of residues Arg42, Ser43, and Lys44 were changed to alanine in the human glycoprotein hormone common alpha-subunit using site-directed mutagenesis. These specific residues are highly conserved across species and have by chemical modification and synthetic peptide approaches been implicated in the binding of human chorionic gonadotropin (hCG) to leutinizing hormone (LH) receptor. In the present study we tested the hypothesis that specific alpha-subunit amino acid residues which stabilize the hormone receptor interaction for hCG have the same function in human follicle-stimulating hormone (hFSH). Wild type or mutant alpha-subunit cDNAs were coexpressed with wild type hFSH or hCG beta cDNA in sialylation defective Chinese hamster ovary cells. Recombinant hormones were tested in a radioligand receptor competition assay, using rat testis membranes as a source of FSH and LH receptors. Mutant hFSH heterodimers F33A-FSH, R35A-FSH, Arg42-Ser43-Lys44/Ala42-Ala43-Ala44- FSH all displaced 125I-hFSH in a similar fashion, indicating that these residues are not important for binding of hFSH to the rat FSH receptor. On the other hand, F33A-CG evidenced a 5-fold decrease in binding, while R35A-CG had over a 100-fold decrease in binding to the rat LH receptor when compared to the wild type recombinant hCG. These data demonstrate that a receptor-binding site on the common alpha-subunit which is very important for hCG binding to LH receptor is not important for the binding of hFSH to FSH receptor. Our interpretation of these findings is that there are fundamental structural differences in the receptor interface contacts of the common alpha-subunit, which stabilize receptor binding among members of the glycoprotein hormone family.
Physical nature of the phase transition in globular proteins (1986)

The guanidine hydrochloride-induced unfolding of human alpha-lactalbumin has been studied by isothermal calorimetry. It has been shown that a cooperative transition takes place only in the concentration interval of the denaturant between 0.3 and 2 mol X l-1. The cooperative transition coincides with the transition detected by circular dichroism in the near-ultraviolet region which reflects the destruction of the specific environment of aromatic side groups. According to scanning calorimetric investigations, the transition disappears in the acid form of the protein where circular dichroism of aromatic side groups is practically absent. At higher concentrations of guanidine hydrochloride, where destruction of the secondary structure and unfolding of the chain are observed, there is no cooperative heat absorption.
On-chip differential interference contrast microscopy using lensless digital holography (2010)

We introduce the use of a birefringent crystal with lensless digital holography to create an on-chip differential interference contrast (DIC) microscope. Using an incoherent source with a large aperture, in-line holograms of micro-objects are created, which interact with a uniaxial crystal and an absorbing polarizer, encoding differential interference contrast information of the objects on the chip. Despite the fact that a unit fringe magnification and an incoherent source with a large aperture have been used, holographic digital processing of such holograms rapidly recovers the differential phase contrast image of the specimen over a large field-of-view of approximately 24 mm(2).
Identification of epitopes associated with hCG and the beta hCG carboxyl terminus by monoclonal antibodies produced against a synthetic peptide. (1985)

We have produced a library of monoclonal antibodies directed against a 37-amino acid synthetic polypeptide analogous to the carboxyl terminus of hCG. Five antibodies, designated FB01, FB02, FB03, FB04, and FB00, were developed and analyzed with respect to affinity and specificity for epitopes on human chorionic gonadotropin (hCG) and beta hCG by enzyme-linked immunoabsorbent and radioimmunoassays (RIA). All monoclonal antibodies demonstrated low affinity constants (approximately 10(-7) liters/mol) compared with those obtained by immunization with native beta hCG. One antibody, namely FB00, bound only to the synthetic peptide, whereas all other monoclonal antibodies recognized either free native beta hCG or both beta hCG and HCG. Antibodies produced against the synthetic peptide did not cross-react with other glycoprotein hormones such as LH, TSH, and FSH. Characterization of the monoclonal antibody-binding sites revealed the presence of at least four separate and distinct epitopes on the last 35 amino acids of beta hCG. Indeed, one epitope recognized by FB01 is located between residues 109 and 118, whereas another antigenic region recognized by FB04 appears to be present on the 109-121 portion of the molecule near or at position 118. One additional antigenic site was localized between residues 118 and 136. Finally, FB00 recognized an epitope located on the last 10 amino acids (136-145) of beta hCG. With the use of such antibodies, two- and three-site monoclonal RIA were developed and employed to detect free beta hCG and hCG in sera of patients with choriocarcinoma. These assays may be useful in the detection of beta hCG- and hCG-producing tumors and subsequent monitoring of patients in response to surgery and/or chemotherapy.
Determination of recognition nucleotides for Escherichia coli phenylalanyl-tRNA synthetase (1992)

The nucleotides in Escherichia coli tRNA(Phe) required for recognition by its cognate synthetase have been determined in vitro by measuring the kinetic parameters for aminoacylation using mutant tRNA(Phe) transcripts with purified E. coli tRNA(Phe) synthetase. The substitution of 11 nucleotides in E. coli tRNA(Phe) is shown to decrease the kcat/KM by as much as 1000-fold relative to the wild type. The most important recognition elements are the three anticodon nucleotides G34, A35, and A36. The recognition set also includes nucleotides in the variable pocket (U20 and U59), the acceptor end (A73), and the tRNA central core (G10, C25, A26, G44, and U45). Many of the recognition nucleotides are also among the residues comprising the identity set determined in vivo using an amber suppressor tRNA(Phe) [McClain, W. H., & Foss, K. (1988) J. Mol. Biol. 202, 697-709]. As could be anticipated from the very different methods used, some nucleotides in the identity set determined by the suppressor method were not among the recognition nucleotides and vice versa. The E. coli tRNA(Phe) recognition data can also be compared to the recognition sets for yeast and human tRNA(Phe) determined previously. The results indicate that the mechanism by which phenylalanyl-tRNA synthetases recognize their substrates seems to have diverged somewhat among different species. For example, nucleotide 20 in the D-loop, the anticodon nucleotides and the discriminator base 73 are important for the recognition by all three enzymes. However, recognition of the tRNA central core nucleotides is unique to E. coli FRS.(ABSTRACT TRUNCATED AT 250 WORDS)
Cells expressing an H chain Ig gene carrying a viral T cell epitope are lysed by specific cytolytic T cells (1992)

The epitope corresponding to amino acid residues 147-161 of the nucleoprotein (NP) of influenza A virus is recognized by CTL in association with H-2Kd class I Ag. Herein, we engineered an Ig molecule carrying this CTL epitope by replacing the diversity gene segment of the H chain V region of an anti-arsonate antibody with an oligonucleotide that encodes the CTL epitope. The chimeric H chain gene was expressed either alone or together with the parental L chain in the nonsecreting BALB/c myeloma B cell line, SP2/0. The Ig produced by cells transfected with both the chimeric H chain and parental L chains genes expressed the NP epitope but lost the original arsonate binding activity. In addition, SP2/0 cells expressing the chimeric H chain either alone or together with the parental L chain were lysed by class I restricted NP-epitope specific CTL. By contrast, SP2/0 cells pulsed with soluble chimeric Ig molecules were not lysed by the specific CTL. These observations indicate that: 1) this particular CTL epitope can be expressed on Ig molecules without altering the H and L chain pairing; 2) this CTL epitope can be generated from this chimeric Ig in which it is surrounded by flanking regions distinct from those of the viral NP; and 3) the generation of this CTL epitope from the Ig molecule requires the endogenous pathway as do viral proteins.
Exploiting limited feedback in tomorrow's wireless communication networks (2008)

Recent research has demonstrated that by utilizing channel state information at the transmitter, the physical layer can be optimized to provide higher link capacity and throughput, more efficiently share the channel with multiple users, increase range by exploiting diversity due to spatial and frequency selectivity, and simplify multi-user receivers through known interference cancellation. Unfortunately, acquiring channel state information at the transmitter is difficult. In most systems, the only opportunity for the transmitter to learn about the channel is through a feedback control channel. Because feedback information is control overhead, the rate of the feedback channel is limited. This motivates the study of limited feedback techniques where only partial or quantized information from the receiver is conveyed back to the transmitter.
Two genes from Bacillus subtilis under the sole control of the general stress transcription factor σB (1999)

The general stress response of Bacillus subtilis is triggered by a variety of environmental and metabolic stresses which activate the sigmaB transcription factor. Among the more than 100 genes controlled by sigmaB (the csb genes), the functions identified thus far include resistance to oxidative stress, resistance to protein denaturation and resistance to osmotic stress. To understand the breadth of functions in which csb genes participate, the transcriptional organization and predicted products of two such genes previously identified in a screen for sigmaB-dependent lacZ fusions were analysed. The csb-22::Tn917lacZ and csb-34::Tn917lacZ fusions are unusual among csb genes in that their expression appears to be completely dependent upon sigmaB. By plasmid-integration experiments, fusion analyses and site-directed mutagenesis, stress-inducible, sigmaB-dependent promoters for both these fusions were identified. The csb-34 fusion marked an ORF (yxcC or csbC) which by sequence analysis lay in a monocistronic transcriptional unit. This ORF encoded a predicted 461-residue product which had high identity with Class I sugar transporters of the major facilitator superfamily. It was speculated that the csbC product could serve either a nutritional or an osmotic protection function. In contrast, the csb-22 fusion identified an ORF (ywmG or csbD) which appeared to be the second gene of a two-gene operon. This ORF encoded a predicted 62-residue product which resembled a small Escherichia coli protein of unknown function. The sigmaB. dependent promoter lay immediately upstream from csbD and appeared to be an internal promoter for the operon.
Inhibition of the inflammatory action of interleukin-1 and tumor necrosis factor (alpha) on neutrophil function by pentoxifylline (1988)

Inflammatory cytokines, including interleukin-1 and tumor necrosis factor, are produced by monocytes and macrophages in response to microorganisms and microbial products such as endotoxins. The cytokines stimulate neutrophil adherence, degranulation, and superoxide production but inhibit neutrophil migration. We studied the modulation of cytokine-induced neutrophil activation by pentoxifylline and its principle metabolites. Lipopolysaccharide-stimulated mononuclear-leukocyte-conditioned medium containing inflammatory cytokines, purified human interleukin-1, or recombinant human tumor necrosis factor increased neutrophil adherence to nylon fiber, primed neutrophils for increased superoxide production in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP), increased neutrophil lysozyme release stimulated by FMLP, and decreased directed migration of neutrophils to FMLP. Pentoxifylline and its principle metabolites at or near therapeutically achievable levels were able to counteract these effects. Pentoxifylline inhibited the increase in free intracellular calcium in polymorphonuclear leukocytes stimulated by FMLP and increased binding of FMLP to neutrophils at 37 degrees C but not at 4 degrees C. By blocking the inflammatory action of interleukin-1 and tumor necrosis factor on neutrophils, pentoxifylline may diminish the tissue damage caused by neutrophils in such conditions as septic shock, adult respiratory distress syndrome, cardiopulmonary bypass lung damage, and myocardial reperfusion injury.
The Wheat VRN2 Gene Is a Flowering Repressor Down-Regulated by Vernalization (2004)

Plants with a winter growth habit flower earlier when exposed for several weeks to cold temperatures, a process called vernalization. We report here the positional cloning of the wheat vernalization gene VRN2, a dominant repressor of flowering that is down-regulated by vernalization. Loss of function of VRN2, whether by natural mutations or deletions, resulted in spring lines, which do not require vernalization to flower. Reduction of the RNA level of VRN2 by RNA interference accelerated the flowering time of transgenic winter-wheat plants by more than a month.
Vision and navigation for the Carnegie-Mellon Navlab (1988)

A distributed architecture articulated around the CODGER (communication database with geometric reasoning) knowledge database is described for a mobile robot system that includes both perception and navigation tools. Results are described for vision and navigation tests using a mobile testbed that integrates perception and navigation capabilities that are based on two types of vision algorithms: color vision for road following, and 3-D vision for obstacle detection and avoidance. The perception modules are integrated into a system that allows the vehicle to drive continuously in an actual outdoor environment. The resulting system is able to navigate continuously on roads while avoiding obstacles.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
A delay model and speculative architecture for pipelined routers (2002)

This paper introduces a router delay model that accurately models key aspects of modern routers. The model accounts for the pipelined nature of contemporary routers, the specific flow control method employed the delay of the flow control credit path, and the sharing of crossbar ports across virtual channels. Motivated by this model, we introduce a microarchitecture for a speculative virtual-channel router that significantly reduces its router latency to that of a brown hole router. Simulations using our pipelined model give results that differ considerably from the commonly assumed 'unit-latency' model which is unreasonably optimistic. Using realistic pipeline models, we compare wormhole and virtual-channel flow control. Our results show that a speculative virtual-channel router has the same per-hop router latency as a wormhole router while improving throughput by up to 40%.
The effect of pH, temperature and heating time on inulin chemical stability (2011)

Background. Inulin is a storage carbohydrate found in many plants especially in chicory root, Jerusalem artichoke and dahlia tuber. It is a prebiotic with many functional proper-ties. In earlier research concerning chemical stability of inulin, the effect of pH on rheological properties of inulin gels was mainly analysed. In these studies, the effect of time, temperature and pH on inulin chemical stability was not analysed profoundly espe-cially considering the inulin concentrations unable to form gel structure. Thus, the aim of this work was to study the effect of the above mentioned factors on inulin chemical stabil-ity in water solution. Material and methods. 5 % (w/w) inulin solutions at pH 1-12 were heated at 20, 40, 60, 80 and 100°C for 5-60 min. After the neutralisation the content of reducing sugar was analysed according to Miller’s method (1959) with 3,5-dinitrosalicylic acid. Results. The conducted studies showed that inulin chemical stability at pH 4 decreased with an increase of heating time and temperature. In a neutral and basic environment inu-lin was chemically stable regardless of heating time and temperature. Conclusions. Inulin application in food systems may be limited in acidic products espe-cially when heated above 60°C during the production process. However, in products at pH ≥ 5, the degradation of this fructan does not occur even at thermal processing. Key words: inulin, hydrolysis, temperature, pH
Gigahertz operation in flexible transistors on plastic substrates (2006)

The combined use of GaAs wires with Ohmic contacts formed from bulk wafers, soft lithographic transfer printing techniques, and optimized device designs enables mechanically flexible transistors to be formed on low-cost plastic substrates, with individual device speeds in the gigahertz range and with high degrees of mechanical bendability. These high-speed devices incorporate materials in simple layouts that can be fabricated with modest lithographic patterning resolution and registration. This letter describes their electrical and mechanical characteristics. The results have the potential to be important to certain large-area, “macroelectronic” systems that can provide for high-speed communication and processing capabilities.
Acetate and CO2 assimilation by Methanothrix concilii (1985)

Biosynthetic pathways in Methanothrix concilii, a recently isolated aceticlastic methanogen, were studied by 13C-nuclear magnetic resonance spectroscopy. Labeling patterns of amino acids, lipids, and carbohydrates were determined. Similar to other methanogens, acetate was carboxylated to pyruvate, which was further converted to amino acids by various biosynthetic pathways. The origin of carbon atoms in glutamate, proline, and arginine clearly showed that an incomplete tricarboxylic acid cycle operating in the oxidative direction was used for their biosynthesis. Isoleucine was synthesized via citramalate, which is a typical route for methanogens. As with Methanosarcina barkeri, an extensive exchange of the label between the carboxyl group of acetate and CO2 was observed. Lipids predominantly contained diphytanyl chains, the labeling of which indicated that biosynthesis proceeded through mevalonic acid. Labeling of the C-1,6 of glucose from [2-13C]acetate is consistent with a glucogenic route for carbohydrate biosynthesis. Except for the different origins of the methyl group of methionine, the metabolic properties of Methanothrix concilii are closely related to those of Methanosarcina barkeri.
CD4 and CD8 recognition of class II and class I molecules of the major histocompatibility complex. (1991)

T cells recognize their specific antigen when associated to the class I or class II molecules of the major histocompatibility complex (MHC). The T cell receptors, the effector molecules of specific antigen recognition are selected to have low affinity for self MHC molecules. Other molecules have been shown to play a major role in stabilizing the interaction between the TCR, self MHC and antigen. This review will focus on two of these molecules, namely CD4 and CD8. In contrast to other accessory molecules, the ligands of CD4 and CD8 are the same MHC molecules which are recognized by the T cell receptor. The structural analysis of the interaction between CD8, CD4 and their respective ligands, namely class I and class II molecules of the MHC, will be treated in this review. We will also discuss the possible differences which exist in the interaction of CD4 and CD8 with their respective ligands.
Spray Drying: An Overview (2018)

Spray drying is a well-known method of particle production which comprises the transformation of a fluid material into dried particles, taking advantage of a gaseous hot drying medium, with clear advantages for the fabrication of medical devices. In fact, it is quite common the production of microspheres and microcapsules designed for drug delivery systems. This review describes the different stages of the mechanism of the spray-drying process: atomization, droplet-to-particle conversion and particle collection. In particular, this work addresses the diversity of available atomizers, the drying kinetics and the importance of the configuration of the drying chamber, and the efficiency of the collection devices. The final properties of the dried products are influenced by a variety of factors, namely the spray dryer design, the feed characteristics and the processing parameters. The impact of those variables in optimizing both the spray-drying process and the synthesis of dried particles with desirable characteristics is discussed. The scalability of this manufacturing process in obtaining dried particles in submicron-to-micron scale favors a variety of applications within the food, chemical, polymeric, pharmaceutical, biotechnology and medical industries.