gebhart/patrepeval huggingface dataset:
Improving Performance of Mammalian Cells in Fed‐Batch Processes through “Bioreactor Evolution” (2007)

The amount of recombinant product obtained from mammalian cells grown in a bioreactor is in part limited by achievable cell densities and the ability of cells to remain viable over extended periods of time. In an attempt to generate cell lines capable of better bioreactor performance, we subjected the DG44 Chinese Hamster Ovary (CHO) host cell line and a recombinant production cell line to an iterative process whereby cells capable of surviving the harsh conditions in the bioreactor were selected. This selective process was termed "bioreactor evolution". Following the selective process, the "evolved" host cells attained a 2-fold increase in peak cell density and a 72% increase in integral cell area. Transient transfection experiments demonstrate that the evolved cells have the same transfection efficiency and the same secretory potential as the initial cells. The "evolved" host was also found to contain a large subpopulation of cells that did not require insulin for growth. From this, a new population of growth-factor-independent cells was obtained. These improvements in host properties should prove beneficial in the expression of recombinant proteins in fed-batch processes. The selective process was also applied to a recombinant production cell line. The evolved cells from this selection exhibited a 38% increase in peak cell density, a 30% increase in integral cell area, and a 36% increase in product titer. These increases were obtained without any appreciable impact on product quality, demonstrating the usefulness of this simple approach to improve the performance of recombinant cell lines.
ChemInform Abstract: Corrosion Behaviour of the Zinc‐Mild Steel Galvanic Cell in Hot Sodium Bicarbonate Solution. (1986)

Abstract Both zinc and steel spontaneously passivated in hot (65°C) oxygen‐saturated 0.0l M NaHCO 3 s‐olution with steel passivation occuring much more slowly.
Intraspecific variations in finback (B. physalus) 20-Hz doublets: An acoustic multipath interpretation. (1996)

Biologists have pointed to differences in received calls as evidence for some separation in finback populations in different locations [Watkins et al., J. Acoust. Soc. Am. 82, 1901–1912 (1987)]. More specifically, it has been concluded by Thompson et al. that the unique finback doublet interpulse intervals recorded in the Gulf of California constitute corroborating evidence for the hypothesis that ‘‘Gulf of California fin whales may be a separate population, distinct from fin whales in nearby Pacific regions’’ [Thompson et al., J. Acoust. Soc. Am. 92, 3051–3057 (1992)]. An alternative explanation is offered—that regional differences in finback doublet interpulse intervals may be accounted for by differences in acoustic propagation conditions. In this work, a broadband acoustic propagation code is combined with an empirically derived geoacoustic seafloor model for the purpose of interpreting finback doublet sequences recorded in the northern Gulf of California by Thompson et al. in 1987 [ibid.]. The result is that for ranges less than 30 km, it is possible to explain the appearance of the finback doublet in terms of multipath propagation through the water column and the seafloor. Further, the interpulse delay is demonstrated to be strongly range dependent. Scientists might consider the possibility that finbacks make use of multipath intervals to estimate distances to other finbacks, perhaps for reasons related to social behavior.
Sleep and Mammalian Hibernation: Homologous Adaptations and Homologous Processes? (1993)

Evidence from electroencephalographic, thermoregulatory and cellular neurophysiological studies suggests that sleep and hibernation may be homologous adaptations for energy conservation. However, despite the similarities between non-rapid eye movement (NREM) sleep and hibernation, the restorative function normally associated with slow wave sleep appears not to occur during hibernation, perhaps because of the low body temperature (Tb). Cellular neurophysiological studies also suggest that a bout of hibernation is not exclusively NREM sleep but is punctuated by periods of wakefulness. The entrance to hibernation involves both an inhibition of cortical activity and activation of hypothalamic regions, whereas the arousal from hibernation is primarily a hypothalamic function. Multiple neurochemical systems are affected by the arousal state change that occurs in hibernation, and a serotonergic-opiatergic interaction, in particular, may be important in regulating these events. Among regulated physiological systems affected by arousal state changes, the episodic respiration evident in hibernation shows striking similarities to the apneas observed during sleep in both humans and other mammals. Although the slight down-regulation of Tb and metabolism that accompanies the transition from wakefulness to NREM sleep may have served as a preadaptation for the evolution of hibernation among the mammals, increasing consideration must be given to the possibility that hibernation represents an arousal state distinct from any known normothermic arousal state.
A Signaling Complex of Ca 2+ -Calmodulin-Dependent Protein Kinase IV and Protein Phosphatase 2A (1998)

Stimulation of T lymphocytes results in a rapid increase in intracellular calcium concentration ([Ca 2+ ] i ) that parallels the activation of Ca 2+ -calmodulin–dependent protein kinase IV (CaMKIV), a nuclear enzyme that can phosphorylate and activate the cyclic adenosine monophosphate (cAMP) response element–binding protein (CREB). However, inactivation of CaMKIV occurs despite the sustained increase in [Ca 2+ ] i that is required for T cell activation. A stable and stoichiometric complex of CaMKIV with protein serine-threonine phosphatase 2A (PP2A) was identified in which PP2A dephosphorylates CaMKIV and functions as a negative regulator of CaMKIV signaling. In Jurkat T cells, inhibition of PP2A activity by small t antigen enhanced activation of CREB-mediated transcription by CaMKIV. These findings reveal an intracellular signaling mechanism whereby a protein serine-threonine kinase (CaMKIV) is regulated by a tightly associated protein serine-threonine phosphatase (PP2A).
Interaction ofEscherichia coliribosomal protein S7 with 16S rRNA (1993)

The interaction between Escherichia coli ribosomal protein S7 and 16S rRNA was investigated using in vitro synthesized RNA transcripts. It was shown by nitrocellulose membrane filtration that RNA transcripts corresponding to the 3' major domain (nucleotides 926-1393) and to the lower half of this domain (nucleotides 926-986/1219-1393) bound S7 with the same affinity as 16S rRNA. A series of deletion mutants of the DNA coding for the lower half of the 3' major domain were constructed and the corresponding RNA fragments were assayed for their capacity to bind S7. A minimal domain of 108 nucleotides which can still efficiently bind S7 was thus obtained. In this domain, the 1304-1308/1329-1333 irregular helix and the 1351-1371 irregular hairpin were found to contain important determinants for S7 binding.
1,25-Dihydroxyvitamin D3-Conditioned CD11c+ Dendritic Cells are Effective Initiators of CNS Autoimmune Disease (2015)

Dendritic cells (DC) play a crucial role in regulating T cell activation. Due to their capacity to shape the immune response, tolerogenic DC have been used to treat autoimmune diseases. In this study, we examined whether 1,25 dihydroxyvitamin D3-conditioned bone marrow-derived DC (VitD-BMDC) were able to limit the development of autoimmune pathology in experimental autoimmune encephalomyelitis (EAE). We found that VitD-BMDC had lower expression of MHC class II and co-stimulatory molecules and were less effective at priming autoreactive T cells in vitro. Using our recently described BMDC-driven model of EAE, we demonstrated that VitD-BMDC had a significantly reduced ability to initiate EAE. We found that the impaired ability of VitD-BMDC to initiate EAE was not due to T cell tolerization. Instead, we discovered that the addition of 1,25(OH)2D3 to BMDC cultures resulted in a significant reduction in the proportion of CD11c+ cells. Purified CD11c+ VitD-BMDC were significantly less effective at priming T cells in vitro yet were similarly capable of initiating EAE as vehicle-treated CD11c+ BMDC. This study demonstrates that in vitro assays of DC function can be a poor predictor of in vivo behavior and that CD11c+ VitD-BMDC are highly effective initiators of an autopathogenic T cell response.
Flow of Single-Phase Fluids through Fibrous Beds (1970)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFlow of Single-Phase Fluids through Fibrous BedsC. P. Kyan, D. T. Wasan, and R. C. KintnerCite this: Ind. Eng. Chem. Fundamen. 1970, 9, 4, 596–603Publication Date (Print):November 1, 1970Publication History Published online1 May 2002Published inissue 1 November 1970https://pubs.acs.org/doi/10.1021/i160036a012https://doi.org/10.1021/i160036a012research-articleACS PublicationsRequest reuse permissionsArticle Views455Altmetric-Citations94LEARN 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 options Get e-Alerts
Finite element implementation of a two-phase model for compression molding of composites (2005)

A two-phase approach is proposed to model the rheology of polymer glass-fiber compounds such as SMC or GMT during processing. The anisotropic behavior of the composite, which is related to the microstructure of the fiber network, is reduced to the simple case of transverse isotropy. The rheology of the two media, e.g. the matrix and the fiber network, as well as their interaction follow non-linear viscous behaviors. The equations of this model are simplified to the case of the compression of SMC, giving the formulation of a shell model whose equations are written into a finite element code. Simple simulation examples thus show the strong influence of material and process parameters on the phenomenon of phase separation.
Application of macrocyclic compounds in chemical analysis (1979)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplication of macrocyclic compounds in chemical analysisI. M. KolthoffCite this: Anal. Chem. 1979, 51, 5, 1–22Publication Date (Print):April 1, 1979Publication History Published online1 May 2002Published inissue 1 April 1979https://pubs.acs.org/doi/10.1021/ac50041a001https://doi.org/10.1021/ac50041a001research-articleACS PublicationsRequest reuse permissionsArticle Views719Altmetric-Citations232LEARN 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
PMU-Based Evaluation of Transmission Bus Strength through Angle Sensitivity Metrics (2020)

As the share of wind power generation increases, the power system stability may be adversely affected. Wind interconnection studies are conducted to evaluate and anticipate the interactions between the wind project and the power system. Various metrics have been developed to evaluate the system strength at the point of interconnection: short-circuit ratio, voltage stability limit, and system inertia. These metrics, unfortunately, rely on network data which may not be readily available. In this paper, a voltage phase angle based index is proposed for evaluating a transmission bus strength. The proposed metric describes the sensitivity of the change of voltage phase angle to the change of active power flow. The proposed metric requires no network information but solely rely on PMU measurements. The validity of the proposed metric is demonstrated by applying it to analyzing the system strength of the Panhandle region of the ERCOT transmission network. Through field data, it is shown that the proposed metric correctly identifies buses as strong or weak. Moreover, the metric can determine the system strength caused by varying wind power production. It is shown that the system strength decreases during high wind power generation, and vice versa.
Rhodium‐Catalyzed Asymmetric Ring Opening Reactions of Oxabicyclic Alkenes: Application of Halide Effects in the Development of a General Process. (2004)

Abstract For Abstract see ChemInform Abstract in Full Text.
Non-interactive password authentications without password tables (2002)

The authors propose a noninteractive password authentication scheme. The scheme simply discards the use of verification tables. The legitimacy of the login user can be validated easily by anyone inside the system. However, no one can masquerade as a legitimate user even though he intercepts the previous login password. The security of the scheme is equivalent to that of Shamir's signature scheme. It can withstand the attack of replaying a previously intercepted login request.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Digital safari guidebook with image retrieval (2003)

Digital Safari Guidebook will make it easy to file or search multimedia databases for educational and entertainment purposes. When a user takes a picture of an animal with a digital camera connected to the computer, similar images in the animal database will be retrieved simulating human preferences. The digital guidebook will then show information about the animal. This is a pursuit for the development of a new application with our KANSEI (feeling, impression or sensibility in Japanese) Image Retrieval technology which uses color and shape features of captured images. Our system extracts KANSEI features from each image, and sets adequate weights for combining those features. In the combining procedure, we introduce a new value called "adaptability". It judges how much of the features are extracted from the image. As a result, adaptability makes it possible to make a KANSEI model depending on each image and to calculate similarity between images.
Modeling the Effect of Product Architecture on Mass Collaborative Processes: An Agent-Based Approach (2009)

Traditional product development efforts are based on well-structured and hierarchical product development teams. The products are systematically decomposed into subsystems that are designed by dedicated teams with well-defined information flows. Recently, a new product development approach called Mass Collaborative Product Development (MCPD) has emerged. The fundamental difference between a traditional product development process and a MCPD process is that the former is based on top-down decomposition while the latter is based on evolution and self-organization. The paradigm of MCPD has resulted in highly successful products such as Wikipedia, Linux and Apache. Despite the success of various projects using MCPD, it is not well understood how the product architecture affects the evolution of products developed using such processes. To address this gap, an agent-based model to study MCPD processes is presented in this paper. Through this model, the effect of product architectures on the product evolution is studied. The model is executed for different architectures ranging from slot architecture to bus architecture and the rates of product evolution are determined. The simulation-based approach allows us to study how the degree of modularity of products affects the evolution time of products and different modules in the MCPD processes. The methodology is demonstrated using an illustrative example of mobile phones. This approach provides a simple and intuitive way to study the effects of product architecture on the MCPD processes. It is helpful in determining the best strategies for product decomposition and identifying the product architectures that are suitable for the MCPD processes.
Active control of ultrasonic hearing in frogs (2008)

Vertebrates can modulate the sound levels entering their inner ears in the face of intense external sound or during their own vocalizations. Middle ear muscle contractions restrain the motion of the middle ear ossicles, attenuating the transmission of low-frequency sound and thereby protecting the hair cells in the inner ear. Here we show that the Chinese concave-eared torrent frog, Odorrana tormota, can tune its ears dynamically by closing its normally open Eustachian tubes. Contrary to the belief that the middle ear in frogs permanently communicates with the mouth, O. tormota can close this connection by contraction of the submaxillary and petrohyoid muscles, drastically reducing the air volume behind the eardrums. Mathematical modeling and laser Doppler vibrometry revealed that the reduction of this air volume increases the middle ear impedance, resulting in an up to 20 dB gain in eardrum vibration at high frequencies (10-32 kHz) and 26 dB attenuation at low frequencies (3-10 kHz). Eustachian tube closure was observed in the field during calling and swallowing. Besides a potential role in protecting the inner ear from intense low-frequency sound and high buccal air pressure during calling, this previously unrecognized vertebrate mechanism may unmask the high-frequency calls of this species from the low-frequency stream noise which dominates the environment. This mechanism also protects the thin tympanic membranes from injury during swallowing of live arthropod prey.
Water Shutoff in the North Sea: Testing a New Polymer Gel System in the Heather Field, UKCS Block 2/5 (1996)

Summary A new polymer gel system developed for high-temperature applications was successfully employed on Well H-43 of the Heather Field to isolate a high-rate water production zone. The high-temperature, organic polymer gel system has demonstrated long-term stability when mixed with seawater at temperatures as high as 350°F. Gel times can be delayed, allowing a large volume of polymer gelant to be placed. For Well H-43, 1,095 bbl of gelant were pumped through 1½-in. coiled tubing into a 15-ft layer of the Brent Group. The treatment increased oil production by 300 B/D and decreased water production by 2,290 B/D. A production log run 8 months later confirmed effective isolation, allowing the lower Brent to produce.
Clavanin Permeabilizes Target Membranes via Two Distinctly Different pH-Dependent Mechanisms (2002)

The pH dependence of the antimicrobial and membrane activity of clavanin A, a peptide antibiotic that is rich in histidines and glycines, was analyzed in growth and membrane leakage experiments. Clavanin A more effectively inhibited the growth of the test organism Lactobacillus sake when the pH of the medium was lowered. Whereas the wild-type peptide efficiently released fluorophores from unilamellar vesicles at neutral pH according to a nonspecific permeabilization mechanism, it did not permeabilize model bilayers at low pH. It was therefore suggested that this peptide uses a distinct mode of action under acidic conditions different than that used around neutral pH. However, at low pH, the membrane is still the target for clavanin A, as the peptide collapsed both vital transmembrane proton gradients and ion gradients under these conditions. Clavanin A did not act as a ionophore across phospholipid bilayers, indicating that membrane constituents other than membrane phospholipids are involved in the dissipation of transmembrane ion gradients. Membrane proteins that generate transmembrane ion gradients are suggested to be the targets for clavanin A at low pH. In addition to the histidines, the three glycine residues of clavanin A are shown to play an important role in the specific mode of interaction with these membrane targets. These residues may induce a flexible hydrophobic conformation that allows the peptide to exert different membrane activities. This study demonstrates that clavanin A is a special membrane-active peptide that has access to two markedly distinct pH-dependent modes of actions.
Modeling molecular motors (1997)

The authors present general considerations and simple models for the operation of isothermal motors at small scales, in asymmetric environments. Their work is inspired by recent observations on the behavior of molecular motors in the biological realm, where chemical energy is converted into mechanical energy. A generic Onsager-like description of the linear (close to equilibrium) regime is presented, which exhibits structural differences from the usual Carnot engines. Turning to more explicit models for a single motor, the authors show the importance of the time scales involved and of the spatial dependence of the motor's chemical activity. Considering the situation in which a large collection of such motors operates together. The authors exhibit new features among which are dynamical phase transitions formally similar to paramagnetic-ferromagnetic and liquid-vapor transitions.
Synthesis and characterisation of poly(arylene sulfide)s, 5. Model compound studies of debromination reactions which occur during the synthesis of poly(arylene sulfide)s from copper(I) 4‐bromobenzenethiolates [copper(I) 4‐bromothiophenoxides] (1987)

Abstract Debromination side‐reactions which occur during the synthesis of poly(arylene sulfide)s from copper(I) 4‐bromothiophenoxides Systematic name: Copper(I) 4‐bromobenzenethiolates. were investigated using bromobenzene as a model for the end unit in a poly(1,4‐phenylene sulfide) chain. Model reactions were conducted in quinoline, pyridine, and 10:1 (v/v) quinoline/pyridine solution in the presence and absence of copper(I) bromide, the condensation product of polymerisation. Reaction liquors were subjected to GLC and MS analysis and evidence is presented which indicates that a copper(I) initiated debromination reaction occurs yielding monophenylquinolines. A mechanism is proposed for the reaction and critically discussed. The consequences of the reaction at the macromolecular level are also described.