gebhart/patrepeval huggingface dataset:
Carbon-carbon bond formation in aqueous ethanol: diastereoselective transformation of unprotected carbohydrates to higher carbon sugars using allyl bromide and tin metal (1991)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-carbon bond formation in aqueous ethanol: diastereoselective transformation of unprotected carbohydrates to higher carbon sugars using allyl bromide and tin metalWalther Schmid and George M. WhitesidesCite this: J. Am. Chem. Soc. 1991, 113, 17, 6674–6675Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://pubs.acs.org/doi/10.1021/ja00017a049https://doi.org/10.1021/ja00017a049research-articleACS PublicationsRequest reuse permissionsArticle Views610Altmetric-Citations89LEARN 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-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
An atmospheric water harvester with fast and energy‐saving water removal and recovery (2023)

Abstract Moisture removal and water recovery from the air are vital for regulating indoor humidity and mitigating water scarcity. Most atmospheric water harvesters (AWH) focus primarily on increasing the moisture capture rate, but for it to be economical and sustainable, it is essential to consider the energy required to recover and harvest the captured water. Here, a mechanically flexible, biphilic sorption‐based AWH made of green, environmentally friendly material is presented. It consists of a hygroscopic chitosan polymer embedded within a flexible, hydrophobic silica xerogel that can harvest 86.3 g water/g chitosan at 97% relative humidity and 25°C reaching saturation after 30 days (i.e. 2.88 g water/g chitosan/day). Roughly 88% of the sorbed moisture was recovered by mechanical squeezing (ca. 0.020 MPa) within 150 s. Repeated water harvesting experiments and uniaxial compression tests demonstrate that chitosan‐silica xerogel is durable for long‐term operations, providing a fast, reliable, and sustainable moisture removal and water harvesting tool.
Causality constraints for processor architectures with sub-word parallelism (2003)

Upcoming processor generations increasingly provide instructions for sub-word parallelism. Thus, a parallel execution of 2, 4 or 8 instructions (add, sub) or of complex instructions (sum of differences) with an input of 2, 4 or 8 operand pairs becomes possible. The exploitation of sub-word parallelism is still weakly supported by current compilers. To remedy this we have adapted methods from the design of parallel regular processor arrays. The causality constraints which influence the design flow of processor arrays can be relaxed for processors with sub-word parallelism. An algorithm calculating the Mahalanobis distance is used to illustrate the influence. Based on this extended approach, we have obtained significant speed-ups of our test-vehicle, of up to a factor 3 on an Intel P4. In the conventional approach, assembly-level coding would have been required to achieve this.
Hierarchical Fuel-Cell Airpath Control: an Efficiency-Aware MIMO Control Approach Combined with a Novel Constraint-Enforcing Reference Governor (2023)

This paper presents a hierarchical multivariable control and constraint management approach for an air supply system for a proton exchange membrane fuel cell (PEMFC) system. The control objectives are to track desired compressor mass airflow and cathode inlet pressure, maintain a minimum oxygen excess ratio (OER), and run the system at maximum net efficiency. A multi-input multi-output (MIMO) internal model controller (IMC) is designed and simulated to track flow and pressure set-points, which showed high performance despite strongly coupled plant dynamics. A new set-point map is generated to compute the most efficient cathode inlet pressure from the stack current load. To enforce OER constraints, a novel reference governor (RG) with the ability to govern multiple references (the cascade RG) and the ability to speed up as well as slow down a reference signal (the cross-section RG) is developed and tested. Compared with a single-input single-output (SISO) air-flow control approach, the proposed MIMO control approach shows up to 7.36 percent lower hydrogen fuel consumption. Compared to a traditional load governor, the novel cascaded cross-section RG (CC-RG) shows up to 3.68 percent less mean absolute percent error (MAPE) on net power tracking and greatly improved worst-case OER on realistic drive-cycle simulations. Control development and validations were conducted on two fuel cell system (FCS) models, a nonlinear open-source model and a proprietary Ford high-fidelity model
A Genetic Analysis of Nitrosative Stress (2009)

Nitrosative stress is induced by pathophysiological levels of nitric oxide (NO) and S-nitrosothiols (e.g., S-nitrosoglutathione, GSNO) and arises, at least in significant part, from the nitrosylation of critical protein Cys thiols (S-nitrosylation) and metallocofactors. However, the mechanisms by which NO and GSNO mediate nitrosative stress are not well understood. Using yeast Saccharomyces cerevisiae strains lacking NO- and/or GSNO-consuming enzymes (flavohemoglobin and GSNO reductase, respectively), we measured the individual and combined effects of NO and GSNO on both cell growth and the formation of protein-bound NO species. Our results suggest an intracellular equilibrium between NO and GSNO, dependent in part on cell-catalyzed release of NO from GSNO (i.e., "SNO-lyase" activity). However, whereas NO induces multiple types of protein-based modifications, levels of which correlate with inhibition of cell growth, GSNO mainly affects protein S-nitrosylation, and the relationship between S-nitrosylation and nitrosative stress is more complex. These data support the idea of multiple classes of protein-SNO, likely reflected in divergent routes of synthesis and degradation. Indeed, a significant fraction of protein S-nitrosylation by NO occurs in the absence of O(2), which is commonly assumed to drive this reaction but instead is apparently dependent in substantial part upon protein-bound transition metals. Additionally, our findings suggest that nitrosative stress is mediated principally via the S-nitrosylation of a subset of protein targets, which include protein SNOs that are stable to cellular glutathione (and thus are not metabolized by GSNO reductase). Collectively, these results provide new evidence for the mechanisms through which NO and GSNO mediate nitrosative stress as well as the cellular pathways of protein S-nitrosylation and denitrosylation involving metalloproteins, SNO lyase(s) and GSNO reductase.
Controlled focused electron beam-induced etching for the fabrication of sub-beam-size nanoholes (2008)

Sub-beam-size focused electron beam-induced etching of amorphous carbon membranes was achieved. The size of the tungsten filament generated electron beam was determined from the in situ stage current monitoring and verified by knife edge measurements. The in situ time resolved stage current measurements as an end point detection allowed the fabrication of nanoholes with a diameter of sub-20nm, corresponding to 20%–40% of the full width at half maximum of the incident beam.
Relationship Between Heart Rate Recovery and Disease Severity in Chronic Obstructive Pulmonary Disease Patients (2020)

Chronic obstructive pulmonary disease (COPD) patients exhibit impaired autonomic control which can be assessed by heart rate variability analysis. The study aims to evaluate the cardiac autonomic responses of COPD patients after completing a conventional six-minute walk test (6MWT). Fifty COPD patients were included in the study, for which an ECG signal (lead II) was acquired by a wearable device, before, during, and after the test. We used the heart rate (HR) time-series to assess the heart rate dynamic during recovery. The heart rate recovery (HRR) marker was evaluated every 5 s after the 6MWT and showed different dynamic trends among severity groups. We compared the HRR among patient groups classified according to the GOLD standard. Significantly larger normalized HRR values (nHRR) were found in mild COPD patients (n=23, GOLD={1,2}; nHRR 1 =14.87.5 %, nHRR 2 =18.68.1 %) compared to those with more disease severity (n=23, GOLD={3,4}; nHRR 1 =9.35.8 %, p=0.002; and nHRR 2 = 13.76.7 %, p=0.041). The largest differences were observed around the first 30 s of the recovery phase (nHRR=10.86.6 % vs. nHRR=5.64 % p=0.001). Our results showed a slower recovery for the severest patients, suggesting that cardiac parameters like the ones we propose here, may provide valuable information for a better characterization of COPD severity.
A New Approach of Polycrystalline Silicon Film on Plastic Substrate Prepared by Ion Beam Deposition Followed by Excimer Laser Crystallization at Room Temperature (2006)

In this work, we propose a new polycrystalline silicon (poly-Si) film of large grain for thin film transistor on flexible substrate. Thin films of amorphous silicon were deposited on plastic substrate by using ion beam deposition (IBD) and crystallized by excimer laser annealing. The entire process was carried out at room temperature. Si film formed by IBD has much lower impurity such as Ar, O, and H than that deposited by conventional sputtering method. This high purity of Si film makes large grain size (0.5 µm) and shows high endurance of excimer laser energy both on quartz and plastic substrate for flexible active matrix organic light emitting diode (AMOLED).
KCNJ11 gene knockout of the Kir6.2 K ATP channel causes maladaptive remodeling and heart failure in hypertension (2006)

Heart failure is a growing epidemic, with systemic hypertension a major risk factor for development of disease. However, the molecular determinants that prevent the transition from a state of hypertensive load to that of overt cardiac failure remain largely unknown. Here in experimental hypertension, knockout of the KCNJ11 gene, encoding the Kir6.2 pore-forming subunit of the sarcolemmal ATP-sensitive potassium (K(ATP)) channel, predisposed to heart failure and death. Defective decoding of hypertension-induced metabolic distress signals in the K(ATP) channel knockout set in motion pathological calcium overload and aggravated cardiac remodeling through a calcium/calcineurin-dependent cyclosporine-sensitive pathway. Rescue of the failing K(ATP) knockout phenotype was achieved by alternative control of myocardial calcium influx, bypassing uncoupled metabolic-electrical integration. The intact KCNJ11-encoded K(ATP) channel is thus a required safety element preventing hypertension-induced heart failure, with channel dysfunction a molecular substrate for stress-associated channelopathy in cardiovascular disease.
Probing blood cell mechanics of hematologic processes at the single micron level (2017)

Blood cells circulate in a dynamic fluidic environment, and during hematologic processes such as hemostasis, thrombosis, and inflammation, blood cells interact biophysically with a myriad of vascular matrices-blood clots and the subendothelial matrix. While it is known that adherent cells physiologically respond to the mechanical properties of their underlying matrices, how blood cells interact with their mechanical microenvironment of vascular matrices remains poorly understood. To that end, we developed microfluidic systems that achieve high fidelity, high resolution, single-micron PDMS features that mimic the physical geometries of vascular matrices. With these electron beam lithography (EBL)-based microsystems, the physical interactions of individual blood cells with the mechanical properties of the matrices can be directly visualized. We observe that the physical presence of the matrix, in and of itself, mediates hematologic processes of the three major blood cell types: platelets, erythrocytes, and leukocytes. First, we find that the physical presence of single micron micropillars creates a shear microgradient that is sufficient to cause rapid, localized platelet adhesion and aggregation that leads to complete microchannel occlusion; this response is enhanced with the presence of fibrinogen or collagen on the micropillar surface. Second, we begin to describe the heretofore unknown biophysical parameters for the formation of schistocytes, pathologic erythrocyte fragments associated with various thrombotic microangiopathies (poorly understood, yet life-threatening blood disorders associated with microvascular thrombosis). Finally, we observe that the physical interactions with a vascular matrix is sufficient to cause neutrophils to form procoagulant neutrophil extracellular trap (NET)-like structures. By combining electron beam lithography (EBL), photolithography, and soft lithography, we thus create microfluidic devices that provide novel insight into the response of blood cells to the mechanical microenvironment of vascular matrices and have promise as research-enabling and diagnostic platforms.
Fast lane changing computations using polynomials (2004)

This paper presents a fast lane changing algorithm for intelligent vehicle highway systems. The algorithm is based on the use of polynomials for trajectory planning and the use of simplified s-topes for obstacle representation. Dynamic constraints are also taken into account. The resulting criterion for the selection of the desired and achievable trajectory involves the selection of a single coefficient. Illustrative examples show the main advantages of the algorithm especially in the case of lane changing with multiple obstacles.
Endogenous IL-32 Controls Cytokine and HIV-1 Production (2008)

IL-32, a proinflammatory cytokine that activates the p38MAPK and NF-kappaB pathways, induces other cytokines, for example, IL-1beta, IL-6, and TNF-alpha. This study investigated the role of endogenous IL-32 in HIV-1 infection by reducing IL-32 with small interfering (si)RNA in freshly infected PBMC and in the latently infected U1 macrophage cell line. When PBMC were pretreated with siRNA to IL-32 (siIL-32), IL-6, IFN-gamma, and TNF-alpha were reduced by 57, 51, and 36%, respectively, compared with scrambled siRNA. Cotransfection of NF-kappaB and AP-1 reporter constructs with siIL-32 decreased DNA binding of these transcription factors by 42 and 46%, respectively. Cytokine protein array analysis revealed that the inhibitory activity of siIL-32 primarily targeted Th1 and proinflammatory cytokines and chemokines, e.g., MIP-1alpha/beta. Unexpectedly, HIV-1 production (as measured by p24) increased 4-fold in these same PBMC when endogenous IL-32 was reduced. Because IFN-gamma was lower in siIL-32-treated PBMC, we blocked IFN-gamma bioactivity, which enhanced the augmentation of p24 by siIL-32. Furthermore, siIL-32 reduced the natural ligands of the HIV-1 coreceptors CCR5 (MIP-1alpha/beta and RANTES) and CXCR4 (SDF-1). Inhibition of endogenous IL-32 in U1 macrophages also increased HIV-1. When rhIL-32gamma was added to these cells, p24 levels fell by 72%; however, in the same cultures IFN-alpha increased 4-fold. Blockade of IFN-alpha/beta bioactivity in IL-32gamma-stimulated U1 cells revealed that IFN-alpha conveys the anti-HIV-1 effect of rhIL-32gamma. In summary, depletion of endogenous IL-32 reduced the levels of Th1 and proinflammatory cytokines but paradoxically increased p24, proposing IL-32 as a natural inhibitor of HIV-1.
A Theoretical Study on the Biophysical Mechanisms by Which Tumor Treating Fields Affect Tumor Cells During Mitosis (2020)

Previously suggested mechanisms of tumor cell death from TTFields are found lacking. The effect of TTFields on the tumor cell membrane potential warrants further research.
Platelet activation, coagulation activation and C‐reactive protein in simultaneous samples from the vascular access and peripheral veins of haemodialysis patients (2011)

There are statistically significant differences between sampling sites, although samples from the VA do not appear to be more pro-thrombotic. Future studies comparing HD patients with controls should ensure uniformity of sampling sites to prevent inaccurate conclusions being drawn.
Modelle für kovalent verknüpfte Watson-Crick-Basenpaare (1999)

Ob klassisch H-verbrückt oder kovalent verknüpft: Strukturuntersuchungen an methylenverbrückten Basenpaaren vom Typ A zufolge haben diese mit den H-verbrückten Watson-Crick-Basenpaaren einiges gemeinsam. Die abgebildete Überlagerung der röntgenographisch ermittelten Strukturen des Basenpaars A (Rib1 = Et, Rib2 = Me) und des klassischen C-G-Basenpaars zeigt deren nahezu identische Ausfüllung der Fläche. Temperaturabhängige 1H-NMR-Spektren weisen auf ein bevorzugtes Konformer bei −70°C mit einer Rotationsbarriere entlang der Methylenbrücke von ca. 10 kcal mol−1 hin.
Differentiation of Human Limbal-Derived Induced Pluripotent Stem Cells Into Limbal-Like Epithelium (2014)

Limbal epithelial stem cell (LESC) deficiency (LSCD) leads to corneal abnormalities resulting in compromised vision and blindness. LSCD can be potentially treated by transplantation of appropriate cells, which should be easily expandable and bankable. Induced pluripotent stem cells (iPSCs) are a promising source of transplantable LESCs. The purpose of this study was to generate human iPSCs and direct them to limbal differentiation by maintaining them on natural substrata mimicking the native LESC niche, including feederless denuded human amniotic membrane (HAM) and de-epithelialized corneas. These iPSCs were generated with nonintegrating vectors from human primary limbal epithelial cells. This choice of parent cells was supposed to enhance limbal cell differentiation from iPSCs by partial retention of parental epigenetic signatures in iPSCs. When the gene methylation patterns were compared in iPSCs to parental LESCs using Illumina global methylation arrays, limbal-derived iPSCs had fewer unique methylation changes than fibroblast-derived iPSCs, suggesting retention of epigenetic memory during reprogramming. Limbal iPSCs cultured for 2 weeks on HAM developed markedly higher expression of putative LESC markers ABCG2, ΔNp63α, keratins 14, 15, and 17, N-cadherin, and TrkA than did fibroblast iPSCs. On HAM culture, the methylation profiles of select limbal iPSC genes (including NTRK1, coding for TrkA protein) became closer to the parental cells, but fibroblast iPSCs remained closer to parental fibroblasts. On denuded air-lifted corneas, limbal iPSCs even upregulated differentiated corneal keratins 3 and 12. These data emphasize the importance of the natural niche and limbal tissue of origin in generating iPSCs as a LESC source with translational potential for LSCD treatment.
Database Access Control and Privacy: Is there a common ground? (2011)

Data privacy issues are increasingly becoming important for many applications. Traditionally, research in the database community in the area of data security can be broadly classified into access control research and data privacy research. Surprisingly, there is little overlap between these two areas. In this paper, we open up a discussion that asks if there is a suitable middle-ground between these areas. Given that the only infrastructure provided by database systems where much sensitive data resides is access control, we ask the question how the database systems infrastructure can step up to assist with privacy needs.
Measurement of ultra low passive intermodulation with ability to separate current/voltage induced nonlinearities (2009)

A measurement technique is proposed which exploits the standing wave in a microstrip resonator to more thoroughly measure passive nonlinearities. The measurement technique is demonstrated to be able to measure the difference between current induced and voltage induced passive nonlinearities. By placing the device under test in a resonator three times higher voltage and current magnitudes are created compared to traveling wave passive intermodulation measurement systems. This increases the effective power only at the device under test and increases the measurement sensitivity of the original traveling wave measurement system. Based on our measurements we project the ability to characterize devices at -196 dBc, a 29 dB improvement over the original system.
Factors Influencing Release of Fenac from Polyethylene Matrices (1973)

Fenac [(2,3,6-trichlorophenyl)acetic acid] and its sodium salt were incorporated in polyethylene matrices under varied conditions to afford a series of herbicide-polyethylene formulations. Diffusion within the matrix determined the rates at which the herbicides were released from the formulations into water. Release rates of the herbicides were altered significantly if (a) the formulation curing conditions were varied, (b) the initial amount of herbicide in the matrix was varied, (c) the solubility of the herbicide was changed, or (d) if an additive was used. The results indicate that herbicide diffuses from the matrix through water-filled cracks and capillary channels.
A Scalable Synthesis of an Azabicyclooctanyl Derivative, a Novel DPP-4 Inhibitor (2008)

A practical synthetic strategy to a chiral azabicycclooctanyl derivative (1), a potent DPP-4 inhibitor, starting from a commercially available nortropine is described. The stereogenic center of 1 was established employing a modified protocol of Ellman's diastereoselective addition of a benzylic nucleophile to tert-butanesulfinimine. Other key steps include Corey-Chaykovsky reaction, Meinwald rearrangement, and CDMT-promoted amide bond formation involving a sterically hindered amine 2.
Model-Driven Placement of Compute Tasks and Data in a Networked Utility (2005)

An important problem in resource management for networked resource-sharing systems is the simultaneous allocation of multiple resources to an application. Self-optimizing systems must co-allocate resources in a way that reconciles competing demands and maximizes global system objectives under dynamic conditions. We propose a simple model-driven approach to estimate the performance of a candidate assignment of resources, and select the best candidate to meet local or global goals. In this work, we address the placement of batch compute tasks and data in a network of compute and storage sites. We use the model to select placements for a set of synthetic benchmarks and a functional MRI processing application. Our experiments show that the model predicts the performance of candidate assignments within 10% of the empirical values
Over-the-counter drugs : harmless or hazardous? (1986)

Examines psychoactive drugs which are available without a doctor's prescription, discussing which are effective and which are harmful.