gebhart/patrepeval huggingface dataset:
Relationship Among Calmodulin‐, Forskolin‐, and Guanine Nucleotide‐Dependent Adenylate Cyclase Activities in Cerebellar Membranes: Studies by Limited Proteolysis (1985)

Adenylate cyclase activity in bovine cerebellar membranes is regulated by calmodulin, forskolin, and both stimulatory (Ns) and inhibitory (Ni) guanine nucleotide-binding components. The susceptibility of the enzyme to chymotrypsin proteolysis was used as a probe of structure-function relationships for these different regulatory pathways. Pretreatment of membranes with low concentrations of chymotrypsin (1-2 micrograms/ml) caused a three- to fourfold increase in basal adenylate cyclase activity and abolished the Ca2+-dependent activation of the enzyme by calmodulin. In contrast, the stimulation of the enzyme by GTP plus isoproterenol was strongly potentiated after protease treatment, an effect that mimics the synergistic activation of adenylate cyclase by Ns and calmodulin in unproteolyzed membranes. Limited proteolysis revealed low- and high-affinity components in the activation of adenylate cyclase by forskolin. The low-affinity component was readily lost on proteolysis, together with calmodulin stimulation of the enzyme. The activation via the high-affinity component was resistant to proteolysis and nonadditive with the Ns-mediated activation of the enzyme, suggesting that both effectors utilize a common pathway. The inhibitory effect of low concentrations (10(-7) M) of guanyl-5'-yl imidodiphosphate [Gpp(NH)p] on forskolin-activated adenylate cyclase was retained after limited proteolysis of the membranes, indicating that the proteolytic activation does not result from an impairment of the Ni subunit. Moreover, in the rat cerebellum, proteolysis as well as calmodulin was found to enhance strongly the inhibitory effect of Gpp(NH)p on basal adenylate cyclase activity. Our results suggest that calmodulin and Ns/Ni interact with two structurally distinct but allosterically linked domains of the enzyme. Both domains appear to be involved in the mode of action of forskolin.
Imaging magnetic vortices by magnetic force microscopy: experiments and modelling (2004)

The requirements for imaging magnetic vortices properly by magnetic force microscopy are discussed. Special attention is devoted to the influence of the tip on the sample magnetic configuration. It is shown that one can obtain a quantitative understanding of the experiments using micromagnetic simulations within a general framework for reversible tip-induced perturbations. Finally, preliminary results obtained with specially prepared 'nanowire tips' are presented.
Informative sensing : theory and applications (2012)

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.
An Investigation Into the Effect of the PCB Motion on the Dynamic Response of MEMS Devices Under Mechanical Shock Loads (2008)

We present an investigation into the effect of the motion of a printed circuit board (PCB) on the response of a microelectromechanical system (MEMS) device to shock loads. A two-degrees-of-freedom model is used to model the motion of the PCB and the microstructure, which can be a beam or a plate. The mechanical shock is represented as a single point force impacting the PCB. The effects of the fundamental natural frequency of the PCB, damping, shock pulse duration, electrostatic force, and their interactions are investigated. It is found that neglecting the PCB effect on the modeling of MEMS under shock loads can lead to erroneous predictions of the microstructure motion. Further, contradictory to what is mentioned in literature that a PCB, as a worst-case scenario, transfers the shock pulse to the microstructure without significantly altering its shape or intensity, we show that a poor design of the PCB or the MEMS package may result in severe amplification of the shock effect. This amplification can cause early pull-in instability for MEMS devices employing electrostatic forces.
Structural and mechanistic basis of neutralization by a pan-hantavirus protective antibody (2023)

Emerging rodent-borne hantaviruses cause severe diseases in humans with no approved vaccines or therapeutics. We recently isolated a monoclonal broadly neutralizing antibody (nAb) from a Puumala virus-experienced human donor. Here, we report its structure bound to its target, the Gn/Gc glycoprotein heterodimer comprising the viral fusion complex. The structure explains the broad activity of the nAb: It recognizes conserved Gc fusion loop sequences and the main chain of variable Gn sequences, thereby straddling the Gn/Gc heterodimer and locking it in its prefusion conformation. We show that the nAb's accelerated dissociation from the divergent Andes virus Gn/Gc at endosomal acidic pH limits its potency against this highly lethal virus and correct this liability by engineering an optimized variant that sets a benchmark as a candidate pan-hantavirus therapeutic.
A two-dimensional mathematical model for an acoustically soft parabolic cylinder reflector (1973)

A mathematical model is developed for a perfectly soft (zero impedance) parabolic cylinder reflector driven by a line source coincident with its focal line. The parabolic cylinder is assumed to be infinite in length but of finite aperture. The model enables one to quickly ascertain the major features of the acoustic field when given only the acoustic size of the aperture and focal length. The model is based upon the following two assumptions: (1) there exists a definite shadow zone behind the reflector, and (2) the field “within” the reflector depends primarily on the boundary conditions on the inside surface of the reflector. By means of these assumptions the problem is reduced to solving a boundary-value problem where the radiating surface is an infinite circular cylinder. The reduced problem is then solved with the aid of the fast Fourier transform algorithm. Numerical results obtained with this model are shown to be in agreement with measurements made on two test reflectors.
Abstract 2332: Oncogenic mutant KRAS modulates EZH2 expression through MEK-ERK signaling by remodeling gene expression in NSCLC (2014)

Abstract Abstract: Background. EZH2 overexpression occurs in lung cancer and is associated with a poor outcome. The mechanisms driving EZH2 expression in lung cancer are not fully understood. In this study, we investigated whether pharmacological disruption of signaling MEK-ERK pathway would affect EZH2 expression in a panel of NSCLC cell lines with and without KRAS mutation. Moreover, we analyzed the transcriptome expression following knockdown of EZH2 expression in NSCLC cell lines with different types of KRAS mutations. Methods. NSCLC cell lines were treated with different doses of MEK inhibitor AZD6244 (0, 0.5 and 1μM) and the expressions of EZH2, MEK and MAPK were determined by Western-blots. Cell lines were transfected with gene-specific EZH2 siRNA and control siRNA. Gene expression profiling was performed using the Illumina Human HT-12 v 4.0 platform. Functional pathway analysis was conducted using the software Ingenuity Pathways Analysis. Result. We found that pharmacological disruption of signaling MEK-ERK pathways with AZD6244 decreases the expression of MAPK p44/42 and phospho-MAPK p44/42 in all NSCLC cell lines analyzed wild-type and of KRAS mutant status. However, after AZD6244 treatment, EZH2 expression in NSCLC cell lines varied according to the KRAS mutation status: strong reduction only in NSCLC cell lines harboring GtoC mutation, a partial reduction in cells with GtoS and GtoR mutation, and no change in cell lines with GtoD or GtoV mutation and with wild-type KRAS. The gene expression analysis revealed that 3,235 genes were similarly regulated for mutant KRAS GtoC, GtoD and GtoV in NSCLC following EZH2 knockdown compared with KRAS wild-type (P &amp;lt; 0.05). Functional pathways analysis showed that EZH2 knockdown modulated differentially pathways commonly activated in cancer as growth factor signaling, molecular mechanism of cancer and cellular growth, proliferation and development, between cell lines that harbor mutant KRAS GtoC, GtoD or GtoV compared with KRAS wild-type. Conclusion. Our findings suggest that oncogenic mutant KRAS GtoC, GtoS and GtoR modulate EZH2 expression through MEK-ERK signaling contributing to changes of the expression of genes frequently altered in cancer (Grant support: 5 R01 CA155196 and P50CA70907) Citation Format: Erick M. Riquelme, Li Shen, Jing Wang, Carmen Behrens, John D. Minna, Ignacio I. Wistuba. Oncogenic mutant KRAS modulates EZH2 expression through MEK-ERK signaling by remodeling gene expression in NSCLC. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2332. doi:10.1158/1538-7445.AM2014-2332
ChemInform Abstract: Isodicyclopentadienes and Related Molecules. Part 41. Stereochemical Course of Diels‐Alder Cycloadditions to Hydroxymethyl‐Substituted Plane‐Nonsymmetric Cyclopentadienes. (1989)

Abstract To further clarify the divergent stereochemical dependence of the Diels‐Alder reaction on different diene substituents, the reactions of hydroxymethyl‐substituted dienes (II) and (VI) are studied.
Treatment of Myocardial Infarction in a Community Hospital Coronary Care Unit (1978)

The hospital mortality in 1,246 consecutive acute myocardial infarction patients treated in a large community hospital coronary care unit was 14.4%. Of the total, 52.3% showed no evidence of heart failure, 25.8% had mild to moderate failure, 9.9% had pulmonary edema, and 12% developed cardiogenic shock; the mortality in these groups was 2.2%, 7.4%, 8.9%, and 87.2%, respectively. The mortality in the 1,097 patients who did not have cardiogenic shock was 4.5%. Only one patient died as a result of primary ventricular fibrillation (0.08%). The mortality of complete heart block in the absence of cardiogenic shock (8.3%) was not significantly different from that of comparable patients who did not have complete heart block (4.3%). These results are lower than those generally reported. (<i>Arch Intern Med</i>138:210-215, 1978)
Deep Saliency Prior for Reducing Visual Distraction (2021)

Using only a model that was trained to predict where people look at images, and no additional training data, we can produce a range of powerful editing effects for reducing distraction in images. Given an image and a mask specifying the region to edit, we backpropagate through a state-of-the-art saliency model to parameterize a differentiable editing operator, such that the saliency within the masked region is reduced. We demonstrate several operators, including: a recoloring operator, which learns to apply a color transform that camouflages and blends distractors into their surroundings; a warping operator, which warps less salient image regions to cover distractors, gradually collapsing objects into themselves and effectively removing them (an effect akin to inpainting); a GAN operator, which uses a semantic prior to fully replace image regions with plausible, less salient alternatives. The resulting effects are consistent with cognitive research on the human visual system (e.g., since color mismatch is salient, the recoloring operator learns to harmonize objects' colors with their surrounding to reduce their saliency), and, importantly, are all achieved solely through the guidance of the pretrained saliency model, with no additional supervision. We present results on a variety of natural images and conduct a perceptual study to evaluate and validate the changes in viewers' eye-gaze between the original images and our edited results.
Sulfonated poly(ether ether ketone)/poly(vinylpyrrolidone) acid–base polymer blends for direct methanol fuel cell application (2005)

Abstract Acid–base polymer blends for polymer electrolyte membranes have been prepared by blending sulfonated poly(ether ether ketone) (SPEEK) with poly(vinylpyrrolidone) (PVP) to reduce methanol uptake and to decrease methanol permeability while maintaining high proton conductivity. The acid‐base interaction occurring on the sulfonic acid group and on the tertiary amide group was characterized by FTIR and DMA. As the composition of PVP lowered than 20 wt % in the blends, the acid–base interaction causes great reduction on methanol uptake and the methanol permeability; however, the proton conductivity is still high. In this work, membrane–electrode assemblies (MEAs) have been prepared for direct methanol fuel cell (DMFC) from both blend membrane and Nafion 117. DMFC single cell performance was also evaluated. Results confirmed that SPEEK (with the degree of sulfonation (DS) = 69%) blended with PVP ( M n = 1,300,000) with a ratio of 80/20 (w/w) exhibits higher open‐circuit voltages (OCV) and lower polarization loss than those of Nafion 117. These acid–base blends will be suitable for DMFC application. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 565–572, 2006
Modeling of the Acoustic Field Produced by Diagnostic Ultrasound Arrays in Plane and Diverging Wave Modes (2019)

Recent advances in ultrafast contrast imaging have facilitated innovations, such as superresolution imaging and ultrafast contrast-enhanced Doppler imaging. Combining plane and diverging wave imaging (PWI/DWI) with tissue harmonic imaging (THI) may offer improvements in image quality in applications such as 3-D THI and harmonic color flow. However, no studies have reported simulations of the nonlinear acoustic fields produced by diagnostic arrays in either plane or diverging wave mode. The aim of this study is to model three typical diagnostic arrays that are used in clinical practice and research, Verasonics L11-4v linear array, C5-2v convex array, and P4-2v phased array with the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. We have two specific objectives: first, to investigate whether there is increased bubble destruction due to the nature of the plane and diverging fields in contrast imaging; and second, to investigate the feasibility of combining PWI/DWI and THI by quantifying the second harmonic generated by these fields. We showed in linear simulations that using such arrays for ultrafast contrast imaging produced pressures that are greater in the near field and lower in the far field than those of focused beams and thus may induce more near-field bubble destruction. In nonlinear simulations, the second harmonic produced by ultrafast THI was found to be 2-16 dB lower than that of focused beams for all arrays considered when operated at the same MI. This moderate difference of the second harmonic between PWI/DWI and focused ultrasound suggests that it is feasible to combine PWI/DWI and THI.
Alternative cathodes for molten carbonate fuel cells (1996)

Argonne National Laboratory (ANL) is developing advanced cathodes for pressurized operation of the molten carbonate fuel cell (MCFC). The present cathode, lithiated nickel oxide, tends to transport to the anode of the MCFC, where it is deposited as metallic nickel. The rate of transport increases with increasing CO{sub 2} pressure. This increase is due to an increased solubility of nickel oxide (NiO) in the molten carbonate electrolyte. An alternative cathode is lithium cobaltate (LiCoO{sub 2})-Solid solutions of LiCoO{sub 2} in LiFeO{sub 2} show promise for long-lived cathode materials. We have found that small additions of LiCoO{sub 2} to LiFeO{sub 2} markedly decrease the resistivity of the cathode material. Cells containing the LiCoO{sub 2}-LiFeO{sub 2} cathodes have stable performance for more than 2100 h of operation and display lower cobalt migration.
Peroxisome proliferator-activated receptor-γ ligands induce heme oxygenase-1 in lung fibroblasts by a PPARγ-independent, glutathione-dependent mechanism (2009)

Oxidative stress plays an important role in the pathogenesis of pulmonary fibrosis. Heme oxygenase-1 (HO-1) is a key antioxidant enzyme, and overexpression of HO-1 significantly decreases lung inflammation and fibrosis in animal models. Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a transcription factor that regulates adipogenesis, insulin sensitization, and inflammation. We report here that the PPARgamma ligands 15d-PGJ2 and 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO), which have potent antifibrotic effects in vitro, also strongly induce HO-1 expression in primary human lung fibroblasts. Pharmacological and genetic approaches are used to demonstrate that induction of HO-1 is PPARgamma independent. Upregulation of HO-1 coincides with decreased intracellular glutathione (GSH) levels and can be inhibited by N-acetyl cysteine (NAC), a thiol antioxidant and GSH precursor. Upregulation of HO-1 is not inhibited by Trolox, a non-thiol antioxidant, and does not involve the transcription factors AP-1 or Nrf2. CDDO and 15d-PGJ2 contain an alpha/beta unsaturated ketone that acts as an electrophilic center that can form covalent bonds with free reduced thiols. Rosiglitazone, a PPARgamma ligand that lacks an electrophilic center, does not induce HO-1. These data suggest that in human lung fibroblasts, 15d-PGJ2 and CDDO induce HO-1 via a GSH-dependent mechanism involving the formation of covalent bonds between 15d-PGJ2 or CDDO and GSH. Inhibiting HO-1 upregulation with NAC has only a small effect on the antifibrotic properties of 15d-PGJ2 and CDDO in vitro. These results suggest that CDDO and similar electrophilic PPARgamma ligands may have great clinical potential as antifibrotic agents, not only through direct effects on fibroblast differentiation and function, but indirectly by bolstering antioxidant defenses.
Ex vivoelectrical impedance measurements on excised hepatic tissue from human patients with metastatic colorectal cancer (2015)

Point-wise ex vivo electrical impedance spectroscopy measurements were conducted on excised hepatic tissue from human patients with metastatic colorectal cancer using a linear four-electrode impedance probe. This study of 132 measurements from 10 colorectal cancer patients, the largest to date, reports that the equivalent electrical conductivity for tumor tissue is significantly higher than normal tissue (p < 0.01), ranging from 2-5 times greater over the measured frequency range of 100 Hz-1 MHz. Difference in tissue electrical permittivity is also found to be statistically significant across most frequencies. Furthermore, the complex impedance is also reported for both normal and tumor tissue. Consistent with trends for tissue electrical conductivity, normal tissue has a significantly higher impedance than tumor tissue (p < 0.01), as well as a higher net capacitive phase shift (33° for normal liver tissue in contrast to 10° for tumor tissue).
Numerical simulation of bit-pattern dependent stimulated Raman scattering (2017)

Distributed Raman amplification is an attractive way to improve the OSNR in optical transmission systems. However, this requires profound system knowledge to profit from these potential benefits. Especially in the case of co-directional pumped Raman amplifiers the evolution of the signal powers over the propagation distance is of interest in order to avoid signal distortions. Within the design process of co-directionally pumped transmission lines numerical simulations can assist to achieve optimized OSNR. Within the modelling of Raman amplification signals are often considered as continues waves to calculate the power evolution of the signals and pumps. However, this is only an approximation as the power of the transmitted signals varies over time. We present a novel approach to capture the bit-pattern dependence of Raman scattering.
Óxido nítrico exalado no diagnóstico e acompanhamento das doenças respiratórias (2000)

O presente trabalho apresenta uma sucinta revisão sobre o papel do óxido nítrico na fisiologia respiratória e na fisiopatologia de algumas pneumopatias. A perspectiva de seu uso para diagnóstico e acompanhamento de inúmeras situações clínicas é discutida.
Poly(fluorene-co-thiophene)-based ionic transition-metal complex polymers for solar energy harvesting and storage applications (2014)

This paper describes the synthesis, electrochemical and photophysical properties of two poly(fluorene-co-thiophene)-based polymers featuring pendant Ru(II) polypyridyl-based ionic transition metal complexes. These systems combine long-lived excited states of the Ru(II) chromophores and the large optical cross-sections of the conjugated backbones, potentially allowing for polymer-assisted solar radiation-harvesting and storage functions via ultrafast energy and charge transfer processes. Modified azide–alkyne “click” cycloaddition chemistry conditions are demonstrated as an effective approach to obtain quantitatively functionalized conjugated polymer–ionic transition metal complex assemblies. Introduction of variable fractions of electron-rich thiophene units into these architectures induces a bathochromic shift in the polyfluorene absorption maxima, while simultaneously stabilizing the oxidized states of the conjugated scaffolds, as determined by electrochemical and in situ spectroelectrochemical experiments. The hybrid assemblies exhibit ultrafast energy flow (700 fs to 4.8 ps) and photoinduced charge-separation (1.8–2.0 ps) between the conjugated backbone and the Ru(II) moieties. Notably, the chemical composition of the main-chain repeat unit determines the dominant pathway for decay of the conjugated backbone excited states with the fraction of electron transfer increasing from 25% to 75% upon incorporation of an additional thiophene heterocycle.
Injection-Molded Long-Fiber Thermoplastic Composites: From Process Modeling to Prediction of Mechanical Properties (2013)

This article illustrates the predictive capabilities for long-fiber thermoplastic (LFT) composites that first simulate the injection molding of LFT structures by Autodesk® Simulation Moldflow® Insight (ASMI) to accurately predict fiber orientation and length distributions in these structures. After validating fiber orientation and length predictions against the experimental data, the predicted results are used by ASMI to compute distributions of elastic properties in the molded structures. In addition, local stress-strain responses and damage accumulation under tensile loading are predicted by an elastic-plastic damage model of EMTA-NLA, a nonlinear analysis tool implemented in ABAQUS® via user-subroutines using an incremental Eshelby-Mori-Tanaka approach. Predicted stress-strain responses up to failure and damage accumulations are compared to the experimental results to validate the model.
Catalytic autothermal reforming increases fuel cell flexibility (1981)

Experimental results are presented for the autothermal reforming (ATR) of n-hexane, n-tetradecane, benzene and benzene solutions of naphthalene. The tests were run at atmospheric pressure and at moderately high reactant preheat temperatures in the 800-900 K range. Carbon formation lines were determined for paraffinic and aromatic liquids. Profiles were determined for axial bed temperature and composition. Space velocity efforts were assessed, and the locations and types of carbon were recorded. Significant reactive differences between hydrocarbons were identified. Carbon formation characteristics were hydrocarbon specific. The differing behavior of paraffinic and aromatic fuels with respect to their carbon formation may be important in explaining the narrow range of carbon-free operating conditions found in the ATR of number two fuel oil.