gebhart/patrepeval huggingface dataset:
Chemical valorization of aldaric acids: synthesis of pyrroles from di-unsaturated aldaric lactones (2017)

Chemical building blocks from biomass are gaining increasing attention for the production of high&#13;\nadded-value chemicals.[1] Aldaric acids are sugar dicarboxylic acids, produced by oxidative hydrolysis&#13;\nof biomasses, like lemon peel, apple peel, and in general pectins, with relevant potentiality to high&#13;\nvalue polyfunctional fine chemicals, pharmaceuticals, cosmetics, and polymeric materials.[2]&#13;\nAlternative oxidative processes are also known from simple hexose sugars both by chemical or&#13;\nbiochemical methods [2][3] via the corresponding aldonic and alduronic acids (Fig. a). However, the&#13;\njust recognized potentialities of aldaric acid is mainly related to simple chemical transformations&#13;\n(esterification, amidation, etc.) and this induced us to a deep analysis of the chemistry of this class of&#13;\ncompounds in new directions, focusing mainly on high value compounds of the pyrrole series. The&#13;\napproach involves the selective dehydration of galactaric acid (as representative aldaric acid) to 2,5-&#13;\ndihydroxy-muconic acid (and related keto and internal lactone forms) identifying the possible use of&#13;\nthese compounds in a Paal-Knorr reaction with amines (Fig. b). This allows us to better envisage the&#13;\nmechanistic details of previous reports of pyrrole synthesis in low yield from aldaric acid [4] and to&#13;\nobtain a large variety of 2,5-disubstituted, 2-substituted and unsubstituted N-alkyl and N-aryl pyrroles,&#13;\nuseful as intermediates for fine chemicals and as monomer for polymers.
Cellular Membrane Composition Defines Aβ-Lipid Interactions (2001)

Alzheimer's disease pathology has demonstrated amyloid plaque formation associated with plasma membranes and the presence of intracellular amyloid-beta (A beta) accumulation in specific vesicular compartments. This suggests that lipid composition in different compartments may play a role in A beta aggregation. To test this hypothesis, we have isolated cellular membranes from human brain to evaluate A beta 40/42-lipid interactions. Plasma, endosomal, lysosomal, and Golgi membranes were isolated using sucrose gradients. Electron microscopy demonstrated that A beta fibrillogenesis is accelerated in the presence of plasma and endosomal and lysosomal membranes with plasma membranes inducing an enhanced surface organization. Alternatively, interaction of A beta with Golgi membranes fails to progress to fibril formation, suggesting that A beta-Golgi head group interaction stabilizes A beta. Fluorescence spectroscopy using the environment-sensitive probes 1,6-diphenyl-1,3,5-hexatriene, laurdan, N-epsilon-dansyl-L-lysine, and merocyanine 540 demonstrated variations in the inherent lipid properties at the level of the fatty acyl chains, glycerol backbone, and head groups, respectively. Addition of A beta 40/42 to the plasma and endosomal and lysosomal membranes decreases the fluidity not only of the fatty acyl chains but also the head group space, consistent with A beta insertion into the bilayer. In contrast, the Golgi bilayer fluidity is increased by A beta 40/42 binding which appears to result from lipid head group interactions and the production of interfacial packing defects.
A realistic model for heme-containing catalases and peroxidases: the X-ray structural characterisation of a non-porphyrin iron(III) macrocyclic complex, and the mechanism of its peroxidation of aromatic substrates (1987)

In acidic buffered aqueous solution the complex dichloro{meso-2,12-dimethyl-3,7,11,17-tetra-azabicyclo[11.3.1] heptadeca-1 (17),13,15-triene}iron(III) tetrafluoroborate, [Fe(meso-L′)Cl2]BF4, exhibits both catalase- and peroxidase-like activity. The predominant cation in aqueous buffered solution at pH 4.65 is the mixed species [Fe(meso-L′)(OH)(H2O)]2+. The catalase- and peroxidase-like activity is proposed to occur via a high oxidation state intermediate rather than through involvement of free hydroxyl radicals. Quantitative compliance with the algebraic forms of theoretical rate laws fails to distinguish between these possibilities. However, the kinetics of dioxygen evolution in the presence of hydroxyl radical traps leads to the elimination of the hydroxyl radical model. In addition, the peroxidase-like reactivity of substituted benzenes toward the [Fe(meso-L′)(OH)(H2O)]2+–H2O2 model system parallels that expected for an electrophilic oxidant, and not that of free OH radicals. Parallel experiments with Fenton's reagent support this view. An X-ray structural determination on the dichloro complex indicates that the macrocycle adopts a folded conformation allowing the two chloride ligands to occupy cis positions in the co-ordination sphere. This stereochemistry is proposed to be retained in aqueous solution, and may allow bidentate co-ordination of hydrogen peroxide, a structural feature that may be critical to the catalase- and peroxidase-like activity. The iron(III) complex crystallises in the orthorhombic system, a= 10.046(2), b= 13.322(2), c= 15.262(3)Å, space group Pnma, with four molecules per unit cell. Final residuals had values of 0.042 and 0.043, for R and R′, respectively, upon convergence for 1 525 observed reflections. Both the cationic, macrocyclic complex and the BF4 anion display crystallographically imposed mirror symmetry. The iron(III) ion displays an approximately octahedral geometry, with co-ordination angles ranging from 77 to 95°. An analysis of associated torsion angles suggests that the folded conformation of the macrocycle is almost strain free.
Vibration Monitoring of Power Distribution Poles (2006)

Some of the most visible and least monitored elements of our national security infrastructure are the poles and towers used for the distribution of our nation's electrical power. Issues surrounding these elements within the United States include safety such as unauthorized climbing and access, vandalism such as nut/bolt removal or destructive small arms fire, and major vandalism such as the downing of power poles and towers by the cutting of the poles with a chainsaw or torches. The Idaho National Laboratory (INL) has an ongoing research program working to develop inexpensive and sensitive sensor platforms for the monitoring and characterization of damage to the power distribution infrastructure. This presentation covers the results from the instrumentation of a variety of power poles and wires with geophone assemblies and the recording of vibration data when power poles were subjected to a variety of stimuli. Initial results indicate that, for the majority of attacks against power poles, the resulting signal can be seen not only on the targeted pole but on sensors several poles away in the distribution network and a distributed sensor system can be used to monitor remote and critical structures.
Purification and characterization of S-acyl fatty acid synthase thioester hydrolase which modifies the product specificity of fatty acid synthase in the uropygial gland of mallard. (1982)

A thioesterase present in the uropygial gland of mallard functions in conjunction with fatty acid synthase to produce short chain acids in this gland (deRenobales,
Macrocyclic Design Strategies for Small, Stable Parallel β-Sheet Scaffolds (2009)

Pairs of short peptide strands can be induced to adopt an antiparallel beta-sheet secondary structure in aqueous solution via a macrocyclic constraint, as illustrated by many natural and designed peptides. We show that an analogous strategy is successful for creation of small units of parallel beta-sheet secondary structure in aqueous solution. Cyclization in this case requires nonpeptide segments for N-to-N and C-to-C interstrand linkage. Surprisingly, we find that only one of these segments needs to be preorganized.
Acute toxicity of nanoplastics on Daphnia and Gammarus neonates: Effects of surface charge, heteroaggregation, and water properties (2022)

Despite progress in evaluation of risk assessment, knowledge gaps largely exist understanding the toxicity of nanoplastics in aquatic systems considering nanoplastics surface properties, environmental media characteristics and species ecological traits. In this study, amidine - functionalized polystyrene nanoparticles (PS-NPLs) of 20, 40, 60 and 100 nm are considered using Geneva lake water and mineral water to investigate the behavior and effects in neonate organisms of the plankton Daphnia magna and the benthos Gammarus fossarum. Key parameters including ζ-potential, z-average diameter, conductivity, polydispersity index, pH, EC<sub>50</sub> were investigated. The results showed that the toxicity of PS-NPLs exhibited a dose-response relationship, size- and exposure condition-dependent trend. The smaller size PS-NPLs (20 and 40 nm) induced higher adverse effects than PS-NPLs of 60 and 100 nm in both water conditions and crustacean species. Moreover, PS-NPLs were found more toxic in the mineral water compared to lake water. Principal component analysis evidenced that the surface charge and aggregation behavior are the most influential toxicity of PS-NPLs factor for D. magna and Gammarus fossarum, respectively. These results highlight the relationship between PS-NPLs intrinsic properties, their transformation behavior, water properties and species-specificity in the evaluation of PS-NPLs biological effects on crustacean neonates in natural aquatic environments.
Role of a 60-megadalton plasmid and Shiga-like toxins in the pathogenesis of infection caused by enterohemorrhagic Escherichia coli O157:H7 in gnotobiotic piglets (1987)

Enterohemorrhagic Escherichia coli (EHEC) of serotype O157:H7 has two putative virulence factors: (i) a fimbrial adhesin, specified by a 60-megadalton (MDa) plasmid, and (ii) bacteriophage-specified cytotoxin(s), known as Shiga-like toxin (SLT) or verotoxin. The contribution of these factors to the pathogenesis of EHEC-induced disease in gnotobiotic piglets was examined. The bacterial strains included the following: two EHEC strains and their corresponding plasmid-cured derivatives; another EHEC isolate and its derivative which had spontaneously lost the ability to produce SLT; one E. coli K-12 transconjugatant containing a 60-MDa plasmid from an EHEC strain; two K-12 strains into which an SLT-producing phage had been transduced (one of these strains also carried a 60-MDa EHEC-derived plasmid); and the parent K-12 strain. Each strain was fed to four piglets, which were observed for diarrhea and examined for development of characteristic mucosal lesions 3 or 5 days after inoculation. All 24 piglets inoculated with the three EHEC strains and their respective derivatives (two plasmid cured and one SLT negative) showed the typical mucosal lesions of bacterial attachment: effacement of microvillous border and cell membrane dissolution culminating in destruction of surface and glandular epithelium in the cecum and colon. No such lesions were observed in 12 piglets inoculated with three strains of E. coli K-12, including the strain which carried both the 60-MDa plasmid and a phage which specified production of SLT. Moderate to severe diarrhea was observed in 16 piglets inoculated with two EHEC strains and their derivatives (one plasmid cured and one SLT negative). The third EHEC strain and its plasmid-cured derivative produced fewer typical mucosal lesions and no diarrhea. The reason for the reduced virulence of this strain was not clear. These results demonstrate that neither the 60-MDa plasmid nor the capacity to produce SLT is essential for expression of virulence by E. coli O157:H7 in gnotobiotic piglets.
Flow Patterns of Self-Sustained Oscillations in Fluidic Diverters (2022)

A fluidic oscillator is a device capable of transforming a steady input flow into an oscillatory output using solely fluid dynamic principles and without requiring any moving components. Although the basic operation principles of fluidic oscillator are known to some extent, the unsteady and turbulent nature of its internal flow remains difficult to understand. The current study aims to further clarify the complicated flow physics involved in fluidic oscillators by investigating a device based on the fluid diverter principle. Spatiotemporally resolved velocity and pressure data obtained from a large-eddy simulation of the internal flow are decomposed into the proper orthogonal modes. The finite-time Lyapunov exponents are computed on the flowfield reconstructed using the proper orthogonal modes to perform a Lagrangian analysis of the switching mechanism. It is found that four dominant modes are sufficient to describe the jet switching. Strong coherent structures are found to separate the flow going through the oscillator from secondary flows through the feedback tube. The deflection of the jet inside the device is found to depend only on the pressure difference across the control ports, whereas the change of this pressure difference is mediated by the flows in the feedback tube.
SmallSat Missions Enabled by Paired Low- Thrust Hybrid Rocket and Low-Power Long-Life Hall Thruster (2019)

The capabilities of a SmallSat-class spacecraft targeting the outer solar system and using a combined chemical and electric propulsion system are explored. The development of compact hybrid rockets has enabled high-thrust engines to be packaged tightly enough to fit on CubeSat and SmallSat spacecraft. These hybrid rockets provide 10's-100 N of thrust depending on the propellant load & >300 s of specific impulse and have been demonstrated in both ambient and vacuum environments. Advancements in low -power long-life Hall thruster technologies have provided the potential for significantly greater propellant throughputs, enabling their use as a primary propulsion element on interplanetary spacecraft. In a recent characterization test campaign, the MaSMi-DM Hall thruster demonstrated power throttling from 150 -1000 W with >1500 s of specific impulse available at >500 W and ≥40% total thrust efficiency available at >300 W; peak values of 1940 s and 53%, respectively, were observed. A notional low-mass spacecraft employing a combined hybrid rocket and low-power electric propulsion system was designed and used for mission concept analysis targeting the outer solar system. Using an imposed wet mass limit of 400 kg, mission trajectories to Saturn and Uranus were generated. Orbit capture with >40% of the launch mass was shown to be possible at either target, with mission transfer times of 7.5 years and 13.5 years for Saturn and Uranus, respectively. Significant follow-on mission activities near Saturn (e.g. to Titan & Enceladus) were also possible by carrying extra propellant mass while remaining under the total wet mass limit.
A model-based approach to wave front sensorless adaptive optics (2007)

In some adaptive optics systems the aberration is determined not using a wave front sensor but by sequential optimization of the adaptive correction element. Efficient schemes for the control of such systems are essential if they are to be effective. One of the simplest implementations of adaptive optics requires an adaptive correction element and a single photodetector. Aberration measurement is performed by the sequential application of chosen aberrations in order to maximise the detector signal. These wave front sensorless adaptive optics systems have been demonstrated in many applications, which have included confocal microscopy, intra-cavity aberration correction for lasers, fibre coupling and optical trapping. We develop appropriate mathematical models that lead to direct maximisation algorithms with good convergence properties and that permit the measurement of <i>N</i> modes with only <i>N</i> + 1 measurements. A scheme is introduced that permits the efficient measurement of large amplitude wavefront aberrations. This scheme uses an optimization metric based upon root-mean-square spot radius and an aberration expansion using polynomials suited to the representation of lateral aberrations. The geometrical optics basis means that the scheme can be extended to arbitrarily large aberrations. We also describe a general scheme for such wave front sensorless algorithms and relate various methods to this general scheme.
Improving the Capacity of Very Deep Networks with Maxout Units (2018)

Deep neural networks inherently have large representational power for approximating complex target functions. However, models based on rectified linear units can suffer reduction in representation capacity due to dead units. Moreover, approximating very deep networks trained with dropout at test time can be more inexact due to the several layers of nonlinearities. To address the aforementioned problems, we propose to learn the activation functions of hidden units for very deep networks via maxout. However, maxout units increase the model parameters, and therefore model may suffer from overfitting; we alleviate this problem by employing elastic net regularization. In this paper, we propose very deep networks with maxout units and elastic net regularization and show that the features learned are quite linearly separable. We perform extensive experiments and reach state-of-the-art results on the USPS and MNIST datasets. Particularly, we reach an error rate of 2.19% on the USPS dataset, surpassing the human performance error rate of 2.5% and all previously reported results, including those that employed training data augmentation. On the MNIST dataset, we reach an error rate of 0.36% which is competitive with the state-of-the-art results.
Diffusion bonding of Ti–6Al–4V alloy using superplastic titanium alloy insert material (1996)

Ti–6Al–4 V alloy was diffusion bonded in a vacuum using β rich α–β titanium alloy SP-700 insert material sheet which shows larger superplastic elongation at lower temperatures with larger elongation than Ti–6Al–4 V alloy. The bonding was carried out for 0·3–3·6 ks at 973–1173 K at which temperature the insert material is reported to show superplastic deformation. Pressures of 1·9–9·5 MPa were applied to the bond interfaces during bonding. Effects of bonding temperature, pressure, and time on the soundness of bonding interface and strength were examined. The soundness and bonding strength increased with increases in bonding time, temperature, and pressure. The insert material led to good bonding at lower temperature with smaller pressure than direct bonding without insert material. TEM observation suggested that the insert material kept a microduplex structure consisting of equiaxed fine α–β grains and deformed superplastically during bonding.
Chronic Intracerebroventricular Administration of Relaxin-3 Increases Body Weight in Rats (2006)

Bolus-administered intracerebroventricular (ICV) relaxin-3 has been reported to increase feeding. In this study, to examine the role of relaxin-3 signaling in energy homeostasis, we studied the effects of chronically administered ICV relaxin-3 on body weight gain and locomotor activity in rats. Two groups of animals received vehicle or relaxin-3 at 600 pmol/head/day, delivered with Alzet osmotic minipumps. In animals receiving relaxin-3, food consumption and weight gain were statistically significantly higher than those in the vehicle group during the 14-day infusion. During the light phase on days 2 and 7 and the dark phase on days 3 and 8, there was no difference in locomotor activity between the two groups. Plasma concentrations of leptin and insulin in rats chronically injected with relaxin-3 were significantly higher than in the vehicle-injected controls. These results indicate that relaxin-3 up-regulates food intake, leading to an increase of body weight and that relaxin-3 antagonists might be candidate antiobesity agents.
Analytical model for predicting activation pressure and flow rate of pressure-compensating inline drip emitters and its use in low-pressure emitter design (2022)

Abstract Drip irrigation has the potential to help farmers increase crop production with lower on-farm water consumption than flood or sprinkler irrigation; yet, its high costs keep it out of reach for many smallholder farmers, who make up about 20 $$\%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>%</mml:mo> </mml:math> of the world’s population. Pressure-compensating (PC) drip emitters enable uniform water delivery to all crops in a field by regulating the emitter flow rate, but typically require high pumping pressures, contributing to high capital and operating costs for the pump and power system. Redesigning PC emitters for lower pressure operation could enable more energy-efficient and affordable drip systems. However, the current lack of published design theory for PC emitters hinders the development of emitters with desired hydraulic performance. To address this gap, we present an analytical, parametric model for the hydraulic behavior (i.e., the flow rate versus pressure curve) of inline PC emitters before the flow-regulating regime. We combine this model with a validated prototyping method to demonstrate its utility in the design of PC emitters with target activation pressures and flow rates, and demonstrate a sample design that achieves 38 $$\%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>%</mml:mo> </mml:math> lower activation pressure than commercial emitters with similar flow rates. The proposed model sheds light on the parametric relationships between PC emitter geometry and performance. It may inform R&amp;D efforts in the irrigation industry and lead to improved emitter designs with low operating pressures, helping reduce drip system costs and increase access to drip irrigation among smallholder farmers.
Enhancement of responsivity for a transistor terahertz detector by a Fabry-Pérot resonance-cavity (2017)

A method to enhance the responsivity of a transistor terahertz (THz) detector by introducing a Fabry-Pérot (FP) cavity was proposed. A theoretical model for the voltage responsivity of the transistor THz detector with a resonant cavity was derived and verified experimentally using a GaN high electron mobility transistor (HEMT) with the FP cavity formed between the GaN HEMT substrate and an indium tin oxide mirror. The measured detector responsivity shows 2.5 times enhancement compared to the device without the cavity and lower noise equivalent power. The performance of the GaN HEMT THz detector with a FP cavity, which has a designed quality factor of 16, is dependent on the incident angle of the THz radiation.