gebhart/patrepeval huggingface dataset:
Supported f-element complexes: surface chemistry and catalysis. Progress report, August 15, 1981-August 14, 1982 (1982)

During the past year, significant progress was made in three connected areas related to the interaction of f-element organometallic complexes with high surface area metal oxide supports. A detailed study of the reaction of Cp/sub 2/U(CH/sub 3/)/sub 2/ (Cp* = eta/sup 5/-(CH/sub 3/)/sub 5/C/sub 5/) with both partially dehydroxylated and dehydroxylated alumina, under a variety of conditions, identified four major reaction pathways which evolve methane: (1) protolysis by surface OH units; (2) hydrogen atom abstraction from a Cp* ligand; (3) hydrogen atom abstraction from another CH/sub 3/ ligand; and (4) hydrogenolysis in the presence of H/sub 2/. Closely coupled studies of the catalytic properties of the adsorbed species indicate a strong correlation between propylene hydrogenation activity and pretreatment conditions which prevent pathway (1) and promote pathways (3) and/or (4). At -63/sup 0/C, turnover frequencies (N/sub t/) as high as 1 sec/sup -1/ are observed; these values are comparable to those of the most active heterogeneous hydrogenation catalysts known. Furthermore, poisoning experiments indicate that only ca. 2% of the uranium sites are responsible for this activity. Hence, the true N/sub t/ approaches ca. 50 sec/sup -1/ at -63/sup 0/C. Solution studies of the near-infrared f-f transition spectra of a series ofmore » organouranium model compounds indicate that the observed patterns are a sensitive finger-print of actinide ligation array and oxidation state. Furthermore, we have now demonstrated that such transitions can be observed in supported organouranium complexes.« less
Chitosan-Collagen 3D Matrix Mimics Trabecular Bone and Regulates RANKL-Mediated Paracrine Cues of Differentiated Osteoblast and Mesenchymal Stem Cells for Bone Marrow Macrophage-Derived Osteoclastogenesis (2019)

Recent studies have identified the regulatory mechanism of collagen in bone ossification and resorption. Due to its excellent bio-mimicry property, collagen is used for the treatment of several bone and joint disease such as arthritis, osteoporosis, and osteopenia. In bone, the biological action of collagen is highly influenced by the interactions of other bone materials such as glycosaminoglycan and minerals. In view of the above perceptions, collagen was crosslinked with chitosan, hydroxyapatite (H), and chondroitin sulfate (Cs), to produce a natural bone-like 3D structure and to evaluate its effect on bone homeostasis using bone marrow mesenchymal stem cells, osteoblast, and bone marrow macrophages. The XRD and micro-CT data confirmed the arrangement of H crystallites in the chitosan-collagen-H-Cs (CCHCs) three-dimensional (3D)-matrix and the three-dimensional structure of the matrix. The stimulatory osteoblastogenic and exploitive osteoclastogenic activity of 3D-matrices were identified using differentiated osteoblasts and osteoclasts, respectively. Besides, osteogenic progenitor's paracrine cues for osteoclastogenesis showed that the differentiated osteoblast secreted higher levels of RANKL to support osteoclastogenesis, and the effect was downregulated by the CCHCs 3D-matrix. From that, it was hypothesized that the morphology of the CCHCs 3D-matrix resembles trabecular bone, which enhances bone growth, limits bone resorption, and could be a novel biomaterial for bone tissue engineering.
Combustion Limits and Efficiency in a Homogeneous Charge Compression Ignition Engine (2006)

Combustion phasing is characterized by CA50, the crank angle position where 50 per cent of the total heat release occurs. CA50 = ( a + b) [OI - OI 0 ] where OI is the octane index defining the fuel auto-ignition quality given by OI = (1 - K) RON + K MON = RON - KS and S is the sensitivity of the fuel, (RON - MON). K, ( a + b), and OI 0 , which is the requirement of the engine, can be estimated from in-cylinder thermodynamic parameters and engine operating conditions. If OI is much smaller or greater than OI 0 , combustion will reach, respectively, the ‘knock limit’ with unacceptably high rate pressure rise or the ‘instability limit’ with unacceptably high cyclic variation. Nineteen different gasoline-like fuels with RON &gt; 60 have been tested at many different operating conditions in a single-cylinder homogeneous charge compression ignition (HCCI) engine. This generates a data set across which the correlations between CA50 and other operating parameters such as the equivalence ratio and the inlet pressure P in are broken. Regression analysis shows that the maximum pressure rise rate (MPRR) increases with increasing φ and P in and decreases with increasing CA50 and S if other parameters are kept constant. X = 1.55CA50 - 52 can be used to discriminate between conditions of high and low cyclic variation. For X &lt; 0, the coefficient of variation (COV) of indicated mean effective pressure (i.m.e.p.) is less than 10 per cent in about 90 per cent of the cases, but if X&gt;0, COV of i.m.e.p. is less than 10 per cent in only about 12 per cent of the cases. The i.m.e.p. increases with fuel energy content per cycle. The indicated fuel conversion efficiency η i increases with increase in i.m.e.p. With other parameters kept constant, η i decreases with increasing φ, intake air density, and intake temperature and increases with increasing CA50 and maximum pressure. An HCCI engine can be operated with an acceptable noise level and cyclic variation only within a narrow range of CA50 between about –5 and +10° from top dead centre.
Supplementary Fig. S1 from KD5170, a novel mercaptoketone-based histone deacetylase inhibitor that exhibits broad spectrum antitumor activity <i>in vitro</i> and <i>in vivo</i> (2023)

Supplementary Fig. S1 from KD5170, a novel mercaptoketone-based histone deacetylase inhibitor that exhibits broad spectrum antitumor activity &lt;i&gt;in vitro&lt;/i&gt; and &lt;i&gt;in vivo&lt;/i&gt;
Changes in a new type of genomic accordion may open the pallets to increased monkeypox transmissibility (2022)

SUMMARY The currently expanding monkeypox epidemic is caused by a subclade IIb descendant of a monkeypox virus (MPXV) lineage traced back to Nigeria in 1971. In contrast to monkeypox cases caused by clade I and subclade IIa MPXV, the prognosis of current cases is generally favorable, but person-to-person transmission is much more efficient. MPXV evolution is driven by selective pressure from hosts and loss of virus–host interacting genes. However, there is no satisfactory genetic explanation using single-nucleotide polymorphisms (SNPs) for the observed increased MPXV transmissibility. We hypothesized that key genomic changes may occur in the genome’s low-complexity regions (LCRs), which are highly challenging to sequence and have been dismissed as uninformative. Using a combination of highly sensitive techniques, we determined a first high-quality MPXV genome sequence of a representative of the current epidemic with LCRs resolved at unprecedented accuracy. This effort revealed significant variation in short-tandem repeats within LCRs. We demonstrate that LCR entropy in the MPXV genome is significantly higher than that of SNPs and that LCRs are not randomly distributed. In silico analyses indicate that expression, translation, stability, or function of MPXV orthologous poxvirus genes (OPGs) 153, 204, and 208 could be affected in a manner consistent with the established “genomic accordion” evolutionary strategies of orthopoxviruses. Consequently, we posit that genomic studies focusing on phenotypic MPXV clade-/subclade-/lineage-/strain differences should change their focus to the study of LCR variability instead of SNP variability.
Multiscale modeling of nonlinear viscoplastic deformation of geological rocks for subsurface energy storage (2021)

Summary One of the major challenges in achieving the renewable energy transition is to identify suitable and feasible energy storage options. Subsurface geological formations provide opportunities to store such large-scale energy in the form of green gas (e.g., hydrogen) or compressed gas or hot fluids, which are all generated from renewable energy. Geological formations are often highly heterogeneous and, when utilized for cyclic energy storage, entail complex nonlinear rock deformation physics. It is known that the cyclic loading of rocks can trigger their plastic deformation mechanisms, which are then crucial to be quantified and studied for safe storage field developments. In this work, we present a multiscale (MS) modelling framework to study the viscoplastic deformation of rocks using the modified cam clay (MCC) model. A finite element discretization scheme is employed at fine and coarser scales, embedded within an implicit time-integration strategy to achieve stable nonlinear solutions. Firstly, plastic deformation is analyzed at fine-scale. Then, a MS system is developed to study the process at field-scale, accounting for the heterogeneity and nonlinearities at fine scale. Numerical test cases are studied and presented to investigate the performance of the developed method.
Axonal transport of neurofilament proteins in IDPN neurotoxicity. (1985)

The neurofibrillary changes produced by IDPN are the consequence of the ability of the agent to impair the slow axonal transport of neurofilaments. The susceptibility of various neurons to this effect depends upon their neurofilament content; neurofilament-rich large caliber axons are severely affected. In motor neurons the half-velocities of neurofilament proteins are reduced 2-10 fold, while tubulin and other slow component constituents are only mildly altered. Optic nerve fibers are intermediate in vulnerability, and small neurofilament-poor fibers have little change in slow transport. The agent acts directly on the axon, and the transport defect is expressed all along the course of susceptible axons. Similar alterations in neurofilament transport have recently been found with 3,4-dimethyl-2,5-hexanedione, indicating that similar pathogenetic mechanisms can occur with toxic agents other than IDPN.
Properties and Potential Applications of Poly(arylene ether benzimidazole)s (1995)

As part of a NASA program on high performance polymers for potential aerospace applications, poly(arylene ether benzimidazole)s (PAEBIs) are under evaluation. The polymers are prepared by the aromatic nucleophilic displacement reaction of 5,5′-bis[2-(4-hydroxyphenyl)benzimidazole] with activated aromatic difluorides in a polar aprotic solvent using potassium carbonate at elevated temperatures under nitrogen. Based on preliminary screening of various material properties, two polymers were selected for more extensive evaluation. An isophthaloyl-containing PAEBI was evaluated for potential use as an adhesive and composite resin matrix. Controlled molecular weight versions of this material exhibited a good combination of processability and high unidirectional composite properties up to 232°C. This polymer also exhibited excellent adhesion to copper and polyimide, and moderate adhesion to titanium. A phosphine oxide-containing PAEBI was screened for potential use on spacecraft in low Earth orbit where resistance to atomic oxygen is required. Thin films of this material were exposed to an oxygen plasma under vacuum and the weight loss of the film was monitored as a function of exposure time. Relative to uncoated Kapton®HN film, the phosphine oxidecontaining poly(arylene ether benzimidazole) film exhibited significantly lower weight loss rates. In addition, this material exhibited a non-linear weight loss rate as compared to Kapton® HN film which exhibited a linear weight loss rate. Upon exposure to the oxygen plasma, the phosphine oxide-containing poly(arylene ether benzimidazole) formed a phosphate-type surface coating as evidenced by x-ray photoelectron spectroscopy.
Author Correction: Lattice strain-enhanced exsolution of nanoparticles in thin films (2019)

The original version of this Article contained an error in the Data Availability section, which incorrectly read 'The data that support the findings of this study are available from the corresponding authors upon request.' The correct version replaces this sentence with 'The research data underpinning this publication can be accessed at https://doi.org/10.17630/21d12144-58ef-4f82-acd0-ba3c9a44ed72'. This has been corrected in both the PDF and HTML versions of the Article.
[Development of heart rate in newborn infants during quiet sleep]. (1995)

The small number of investigations of the development of heart rhythm during the first half year of life provide only rough ideas regarding the maturation of heart rate control. In the present study, in 10 newborns, ECG and respiratory effort were recorded in 13 sessions from birth up to the sixth month. The total power (TP), power in the low (LF) and high frequency range (HF), and the ratio LF/HF were used from the heart rate power spectra. All parameters reveal no linear developmental patterns: TP, LF, and HF increase during the first days to a maximum, then decrease subsequently and remain low until the second month. TP and HF increase between the second and sixth month. LF/HF increases up to the second month followed by a decrease down to the sixth month. The developmental courses of TP, HF and LF/HF correlate with the course of breathing rate (BR), whereby high BR is associated with low HF and TP. The results hint at a maturated cardiorespiratory system.
Physical-State-Aware Dynamic Slack Management for Mixed-Criticality Systems (2018)

Safety-critical cyber-physical systems like autonomous cars require not only different levels of assurance, but also close interactions with dynamically-changing physical environments. While the former has been studied extensively by exploiting the notion of mixed-criticality (MC) systems, the latter has not, especially in conjunction with MC systems. To fill this important gap, we conduct an in-depth case study, demonstrating the importance of capturing current physical states, and introduce the problem of achieving efficient utilization of computing resources under varying physical states in MC systems. To solve this problem, we first develop a physical-state-aware MC task model, which is a generalization of the existing basic MC task model. We then propose new slack concepts tailored to the new task model, which enable efficient utilization of computing resources for MC systems. Finally, we develop a physical-state-aware dynamic slack management framework and demonstrate how to utilize the new MC task model and slack concepts towards efficient system utilization. We show, via a case study and in-depth evaluation, that the proposed framework makes 20x less low-criticality jobs dropped over a popular MC scheduling algorithm without compromising the MC-schedulability requirements.
Major achievements reached through the LAPLACE-BCER cavitation test turbopump program (2012)

The understanding of cavitation and the characterization of cavitating conditions is of prime importance for a liquid rocket engine both for the launch system performance and for reliability since the dynamic loads generated by cavitation can be detrimental to the life of turbo-machinery components and structures. In the continuation of previous research work dedicated to cavitation over the past years, the LAPLACE-BCER LH2 cavitation program was launched in 2006 by CNES (French national space agency) as part of the French national Research & Technology effort which aims to prepare future development and increase launcher reliability and performance. The main objective of the LAPLACE BCER LH2 program is to perform a detailed investigation and characterization of the cavitating conditions of a typical inducer in liquid hydrogen with a focus on the evaluation of dynamic loads generated by cavitating conditions. This investigation utilizes a test turbo-pump which by it-self is very similar to a real rocket engine turbopump. The LAPLACE-BCER turbo-pump features innovative instrumentation technologies in order to increase the knowledge acquired from the LH2 cavitation tests, such as pressure, temperature and forces sensors embedded on the rotor. The main challenge basically consists in finding the optimum compromise between the accuracy of the measurements and the reliability of the tested turbo-machine which has to operate over a sufficiently large domain in order to explore a wide range of operating conditions. The program reached its conclusion at mid 2012 through the test campaign of the highly instrumented BCER test turbo-pump in liquid hydrogen conditions. The present publication provides an overview of the test turbo-pump design and tests performed at Snecma cryogenic test facilities. After presenting the major issues related to instrumentation and turbo-pump design, the results of the test campaign will be discussed and summarized. Finally, the main achievements and lessons learned from the LAPLACE-BCER project are addressed in the perspective of the French national cavitation research & technology program.
Ensuring Network Connectivity for Decentralized Planning in Dynamic Environments (2011)

This work addresses the issue of network connectivity for a team of heterogeneous agents operating in a dynamic environment. The Consensus-Based Bundle Algorithm (CBBA), a distributed task allocation framework previously developed by the authors and their colleagues, is introduced as a methodology for complex mission planning, and extensions are proposed to address limited communication environments. In particular, CBBA with Relays leverages information available through already existing consensus phases to predict the network topology at select times and creates relay tasks to strengthen the connectivity of the network. By employing underutilized resources, the presented approach improves network connectivity without limiting the scope of the active agents, thus improving mission performance.
Optical binary-matrix synthesis for solving bounded NP-complete combinatorial problems (2007)

An optical method for synthesizing a binary matrix representing all feasible solutions of a bounded (input length restricted) NP-complete combinatorial problem is presented. After the preparation of this matrix, an optical matrix-vector multiplier can be used in order to multiply the synthesized binary matrix and a grayscale vector representing the weights of the problem. This yields the required solution vector. The synthesis of the binary matrix is based on an efficient algorithm that utilizes a small number of long-vector duplications. These duplications are performed optically by using an optical correlator. Simulations and experimental results are given.
Iterative Resolution and Optimal Scheduling of Blind Retransmissions for Multi-user URLLC (2021)

Industrial applications have challenging requirements for wireless communication systems in terms of reliability and latency. Addressing these requirements without excessively consuming radio resources has led to the design of new communication services and resource management schemes. Blind repetition has been proposed as one of the promising features to increase reliability while satisfying the latency constraint by avoiding extra delays existent on feedback-based retransmission schemes. Moreover, performing transmissions of multiple users on the shared resources simultaneously could enhance the resource efficiency, by applying successive interference cancellations for decoding. In this work, we propose a scheduling scheme of multiple blind retransmissions on shared resources, which is based on an optimal shared resources allocation and on an iterative collision resolution algorithm. In addition, following the characterization of the iterative resolution chain, we refine our solution to increasing its robustness against transmission errors. Numerical simulations confirm that the proposed shared resource allocation design requires fewer shared radio resources to achieve the same reliability target compared with the scheme based on non-scheduled blind retransmission on shared resources.
Vitamin E can be used to hinder scissioning in radiation cross‐linked UHMWPE during high‐temperature melting (2015)

ABSTRACT High‐temperature melting (HTM) of ultrahigh molecular weight polyethylene (UHMWPE) was shown to improve its elongation and toughness. This was believed to be due to increased scissioning and increased diffusion of polymer chains. It was hypothesized here that the toughness of previously radiation cross‐linked UHMWPEs could also be improved by HTM. To test this hypothesis, the wear resistance, tensile mechanical properties, and Izod impact strength of radiation cross‐linked virgin (no additive) and antioxidant‐blended (with vitamin E) UHMWPEs were tested. The results suggested that although the impact strength of cross‐linked UHMWPEs could be improved significantly by HTM, the wear resistance was decreased. Thus, this procedure can be optimized to be especially suited in high‐stress applications, such as total knee replacements with lessened wear concerns. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42735.
In vivo study of self‐assembled alkylsilane coated degradable magnesium devices (2018)

Magnesium (Mg) and its alloys are candidate materials for resorbable implantable devices, such as orthopedic devices or cardiovascular stents. Mg has a number advantages, including mechanical properties, light weight, its osteogenic effects and the fact that its degradation products are nontoxic and naturally present in the body. However, production of H<sub>2</sub> gas during the corrosion reaction can cause formation of gas pockets at the implantation site, posing a barrier to clinical applications of Mg. It is therefore desirable to develop methods to control corrosion rate and gas pocket formation around the implants. Here we evaluate the potential of self-assembled multilayer alkylsilane (AS) coatings to control Mg device corrosion and formation of gas pockets in vivo and to assess effects of the AS coatings on the surrounding tissues in a subcutaneous mouse model over a 6 weeks' period. The coating significantly slowed down corrosion and gas pocket formation as evidenced by smaller gas pockets around the AS coated implants (ANOVA; p = 0.013) and decrease in the weight loss values (t test; p = 0.07). Importantly, the microCT and profilometry analyses demonstrated that the coating inhibited the pitting corrosion. Specifically, the roughness of the coated samples was ∼30% lower than uncoated specimen (p = 0.02). Histological assessment of the tissues under the implant revealed no inflammation or foreign body reaction. Overall, our results demonstrate the feasibility of use of the seld assembled AS coatings for reduction of gas pocket formation around the resorbable Mg devices. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 342-351, 2019.
Exact wavefield reconstruction on finite-difference grids with minimal memory requirements (2016)

ABSTRACT Wavefield injection in finite-difference (FD) grids can be described by the method of multiple point sources. The method teaches how synthetically generated wavefields and wavefield constituents can be reconstructed from surface recordings using a combination of monopole and dipole sources on an injection surface surrounding the model. We show how to properly record surface wavefields and inject point sources in staggered FD grids, in a way that is consistent with the order of spatial accuracy of the FD scheme. The description is general and can be used for schemes of any order. Only one or two surface wavefields are required to reconstruct the original wavefields or wavefield constituents to numerical precision, independent of the order of spatial accuracy of the FD stencil. We have applied the method for the separation of up- and downgoing wavefields and for source wavefield reconstruction for reverse time migration. Our implementation enables accurate source wavefield reconstruction with optimally minimal memory requirements.