gebhart/patrepeval huggingface dataset:
Drag reduction in turbulent flows over superhydrophobic surfaces (2009)

In this paper, we demonstrate that periodic, micropatterned superhydrophobic surfaces, previously noted for their ability to provide laminar flow drag reduction, are capable of reducing drag in the turbulent flow regime. Superhydrophobic surfaces contain micro- or nanoscale hydrophobic features which can support a shear-free air-water interface between peaks in the surface topology. Particle image velocimetry and pressure drop measurements were used to observe significant slip velocities, shear stress, and pressure drop reductions corresponding to drag reductions approaching 50%. At a given Reynolds number, drag reduction is found to increase with increasing feature size and spacing, as in laminar flows. No observable drag reduction was noted in the laminar regime, consistent with previous experimental results for the channel geometry considered. The onset of drag reduction occurs at a critical Reynolds number where the viscous sublayer thickness approaches the scale of the superhydrophobic microfeatures and performance is seen to increase with further reduction in viscous sublayer height. These results indicate superhydrophobic surfaces may provide a significant drag reducing mechanism for marine vessels.
Proteolytic inactivation of alpha-1-anti-chymotrypsin. Sites of cleavage and generation of chemotactic activity. (1991)

The effect of several microbial and mammalian proteinases on the inhibitory activity of human plasma alpha-1-anti-chymotrypsin (alpha-1-Achy) has been tested. Most of these enzymes caused rapid inactivation of the inhibitor by cleavage at single sites within the reactive-site loop between P5 Lys and P3' Leu, with additional cleavages also being detected in some cases near the NH2 terminus of the native protein. In contrast, two of the enzymes tested failed to inactivate alpha-1-Achy, although they could cause removal of peptides near the NH2 terminus. Studies of neutrophil chemotaxis revealed that native or NH2-terminally truncated alpha-1-Achy was not stimulatory. However, testing of two enzymatically inactivated forms of the inhibitor (alpha-1-Achy), cleaved at widely different positions within the reactive-site loop, indicated that they had become potent chemoattractants at concentrations within the nanomolar range. Competition studies using proteolytically inactivated alpha-1-proteinase inhibitor suggested that the chemotactic activity of the two inactivated serpins was probably mediated by the same mechanism. The physiological relevance of this chemotactic activity is underscored by the results of plasma elimination studies which indicate that alpha-1-Achy is eliminated at approximately the same rate as native alpha-1-Achy, thus prolonging chemotactic stimuli within the tissues.
Some New Developments in Reductive Amtnation with Cofactor Regeneration (1994)

The substrate specificity of LeuDH from Bacillus stearothermophilus and of PheDH from Rhodococcus sp. was investigated and found to be complementary. LeuDH from different organisms have remarkably similar substrate specificity. During optimization of the synthesis of L-tert-leucine, two byproducts (N-α-pivaloyl-tert-leucine amide (I) and 2,4-di-tert-butyl-5-hydroxyimidazol (II)) were found and identified which originate from chemical reactions of keto acid and ammonia.
How the lipid‐free structure of the N‐terminal truncated human apoA‐I converts to the lipid‐bound form: new insights from NMR and X‐ray structural comparison (2002)

The X-ray structure of the N-terminal truncated human apoA-I [Borhani et al., Proc. Natl. Acad. Sci. USA 94 (1997) 12291] and the NMR structure of intact human apoA-I [Okon et al., FEBS Lett. 517 (2002) 139] found similar repeating helices. The crystal structure is a twisted circular four-helix bundle, consisting of four molecules of apoA-I(44-243), where four copies of the lecithin:cholesterol acyltransferase (LCAT)-activating domains are located outside the ring structure, while the aromatic-rich strong lipid-binding domains are inside. This architecture suggests a lipid-binding mechanism that lipids directly enter the hole of the crystal structure. Indeed, four copies of Trp50 and Trp72 are exposed and oriented toward the center of the ring, initiating lipid binding. This is followed by the inside-out rotations of the terminal helices to make a belt with all the hydrophobic faces of the helices facing inward. Such lipid-binding induced rotations have an impact on the conformation of the lipid-free form. Indeed, the structure of residues 78-81 changes from helical (free) to disordered (bound) while the structure of residues 221-227 changes from extended to helical.
Examination of Two Independent Kinetic Assays for Determining the Inhibition of Carbonic Anhydrases I and II: Structure–Activity Comparison of Sulfamates and Sulfamides (2006)

Enzyme inhibition assays often require deviations from physiological conditions. For carbonic anhydrases, procedures involving native CO(2) and non-native substrates have been used. We compared a native and a non-native substrate in the context of inhibition of human carbonic anhydrases I and II by examining various sulfamate and sulfamide compounds in two kinetic assays: hydration of CO(2) and hydrolysis of 4-nitrophenylacetate. For carbonic anhydrase II, the two assays consistently generated similar K(i) values, with the relative difference between the assays never exceeding 2.5-fold. However, for carbonic anhydrase I there was more variability between the two assays, with K(i) values for three compounds differing by more than 2.5-fold, up to eightfold. In the CO(2) hydration assay, some sulfamates and sulfamides exhibited mixed kinetics or partial inhibition. Our results indicate that K(i) or K(d) values from carbonic anhydrase assays involving non-native substrates should be confirmed by assays that use CO(2) (or HCO), to establish pharmacological relevance. From structure-activity comparisons, the sulfamate is more effective than the sulfamide in inhibiting carbonic anhydrase I and II, but the sulfamate does not confer selectivity. In contrast, the sulfonamide confers selectivity for carbonic anhydrase I (10- to 30-fold). Selectivity for carbonic anhydrase II occurred with the substituted fructose moiety, especially the d-enantiomer (>100-fold).
MR Artifacts, Safety, and Quality Control (2006)

Artifacts in magnetic resonance (MR) imaging result from the complex interaction of contemporary imager subsystems, including the main magnet, gradient coils, radiofrequency (RF) transmitter and receiver, and reconstruction algorithm used. An understanding of the sources of artifacts enables optimization of the MR imaging system performance. The increasing clinical use of very high magnetic field strengths, high-performance gradients, and multiple RF channels also mandates renewed attention to the biologic effects and physical safety of MR imaging. Radiologists should be aware of the potential physiologic effects of prolonged exposure to magnetic fields, acoustic noise, and RF energy during MR imaging and should use all the available methods for avoiding accidents and adverse effects. Imaging equipment should be regularly tested and monitored to ensure its stability and the uniformity of its functioning. Newly installed or upgraded MR systems should be tested by a physicist or qualified engineer before use. In addition, the authors recommend participation in the MR imaging accreditation program of the American College of Radiology to establish the initial framework for an adequate quality assurance program, which then can be further developed to fulfill local institutional needs.
Regulation of Cell Proliferation, Apoptosis, and Carcinogenesis by Activin (2002)

The aim of this review is to provide insight into the molecular mechanisms by which activin A modulates cell proliferation, apoptosis, and carcinogenesis in vitro and in vivo. Activin A, a member of the TGFbeta superfamily, has various effects on diverse biological systems, including cell growth inhibition in many cell types. However, the mechanism(s) by which activin exerts its inhibitory effects are not yet understood. This review highlights activin's effects on activin receptors and signaling pathway, modulation of activin signaling, and regulation of cell proliferation and apoptosis by activin. Based on the experiences of all the authors, we emphasized cell cycle inhibitors such as p16 and p21 and regulators of apoptosis such as p53 and members of the bcl-2 family. Aside from activin's inhibition of cell proliferation and enhancement of apoptosis, other newly developed methods for molecular studies of apoptosis by activin were briefly presented that support the role of activin as an inhibitor of carcinogenesis and cancer progression. These methods include subtractive hybridization based on covalent bonding, a simple and accurate means to determine molecular profile of as few as 20 cells based on an RNA-PCR approach, and a messenger RNA-antisense DNA interference phenomenon (D-RNAi), resulting in a long-term gene knockout effects.
The Retinal Vasculature and Function of the Neural Retina in a Rat Model of Retinopathy of Prematurity (2006)

Noninvasive, longitudinal measures in this model of ROP showed significant abnormalities in both the retinal vasculature and function of the neural retina that were most marked at age 18 days. However, vascular and neural abnormalities did not correlate.
Highly tunable single step selective emitter diffusion process using Silicon Ink Technology (2011)

A key feature of the Innovalight™ Cougar™ Platform is the single step selective emitter diffusion process employing Silicon Ink Technology. Both the lightly doped emitter and the heavily doped contacting areas are formed simultaneously during one diffusion process. The tuning of doping strengths of both regions is decoupled and allows for a large separation in field and contact region sheet resistance. This paper will highlight the ability to achieve a wide range of dual doping strengths using the Cougar diffusion process and the corresponding impact of this tuning on cell performance.
Residues in the Membrane-spanning and Extracellular Loop Regions of the Parathyroid Hormone (PTH)-2 Receptor Determine Signaling Selectivity for PTH and PTH-related Peptide (1997)

The parathyroid hormone (PTH)-2 receptor displays strong ligand selectivity in that it responds fully to PTH but not at all to PTH-related peptide (PTHrP). In contrast, the PTH-1 receptor (PTH/PTHrP receptor) responds fully to both ligands. Previously it was shown that two divergent residues in PTH and PTHrP account for PTH-2 receptor selectivity; position 23 (Trp in PTH and Phe in PTHrP) determines binding selectivity and position 5 (Ile in PTH and His in PTHrP) determines signaling selectivity. To identify sites in the PTH-2 receptor involved in discriminating between His5 and Ile5, we constructed PTH-2 receptor/PTH-1 receptor chimeras, expressed them in COS-7 cells, and tested for cAMP responsiveness to [Trp23] PTHrP-(1-36), and to the nondiscriminating peptide [Ile5, Trp23]PTHrP-(1-36) (the Phe23 --> Trp modification enabled high affinity binding of each ligand to the PTH-2 receptor). The chimeras revealed that the membrane-spanning/loop region of the receptor determined His5/Ile5 signaling selectivity. Subsequent analysis of smaller cassette substitutions and then individual point mutations led to the identification of two single residues that function as major determinants of residue 5 signaling selectivity. These residues, Ile244 at the extracellular end of transmembrane helix 3, and Tyr318 at the COOH-terminal portion of extracellular loop 2, are replaced by Leu and Ile in the PTH-1 receptor, respectively. The results thus indicate a functional interaction between two residues in the core region of the PTH-2 receptor and residue 5 of the ligand.
Microfluidic ELISA on non-passivated PDMS chip using magnetic bead transfer inside dual networks of channels (2007)

Achieving efficient passivation of micro-channels against non-specific adsorption of biomolecules is a critical aspect in the development of microfluidic ELISA systems. Usual surface treatments such as pre-coating of the channels with serum albumin, exposure to oxygen plasma, polyethylene glycol grafting however exhibit a lack of long-term stability, with procedures that can be time-consuming, complex or associated with costly materials and instruments. In this paper, we present a new fluidic design combined with an original strategy of manipulating magnetic beads in order to reduce assay noise in bead-based microfluidic ELISA without the need for prior channel pre-treatment. The novelty of the system relies on the physical separation of the immune complex formation phase and the enzymatic reaction phase into two independent networks of channels. These networks are linked by fluidic bridges, whose openings are controlled by pressure valves, and through which the beads are magnetically transferred. A standard curve for the quantification of a model antibody was obtained within 30 minutes. A detection limit of 100 pg mL(-1) (660 fM) and good linearity of the signal up to 4 ng mL(-1) were observed.
Thymus Independent T Cell Development and Selection in the Intestinal Epithelium (1994)

The presence of intestinal intra-epithelial lymphocytes (IEL) has been appreciated for over 100 years. However, until recently, the IEL were thought to be simply another specialized component of the gut-associated lymphoid tissue (GALT), sharing the same origin as lymphocytes found in other GALT compartments such as the lamina propria, the Peyer's patches, and the mesenteric lymph nodes. While the IEL remain functionally enigmatic, over the last ten years increasing evidence, originally based on the phenotypic complexity of IEL, has led to the conclusion that the intestinal epithelium comprises a distinct and unique lymphoid compartment within the organism. The recent discovery that the intestinal epithelium is a primary T lymphopoietic organ provides obvious potential explanations for the phenotypic peculiarities of IEL. The following discussion reviews the experiments that established that the intestinal epithelium is a site of T cell development and selection, and the discussion correlates phenotypic and functional heterogeneity of IEL within this context.
A point mutation that decreases the thermal stability of human interferon γ (1992)

We have identified a mutation of human gamma-interferon (IFN gamma) causing a temperature-sensitive phenotype. We used a randomized oligonucleotide to mutagenize a synthetic human IFN gamma gene, then screened the resulting mutants produced in Escherichia coli for proteins with altered biological activity. One mutant protein selected for detailed characterization exhibited less than 0.3% of the specific biological activity of native IFN gamma in an antiviral activity assay performed at 37 degrees C. However, the protein bound the human IFN gamma receptor with native efficiency at 4 degrees C. Sequencing the plasmid DNA encoding this protein showed that the mutation changed the lysine residue at amino acid 43 to glutamic acid (IFN gamma/K43E). Site-specific mutagenesis at amino acid 43 showed that this protein's phenotype resulted from positioning a negative charge at position 43. Structural characterization of IFN gamma/K43E using CD demonstrated that the protein had native conformation at 25 degrees C, but assumed an altered conformation at 37 degrees C. IFN gamma/K43E in this altered conformation bound poorly to the IFN gamma receptor at 37 degrees C, providing a rationale for the mutant's decreased antiviral activity.
Ion-Specific Aggregation in Conjugated Polymers: Highly Sensitive and Selective Fluorescent Ion Chemosensors (2000)

Two polymer chains are forced into contact by 2:1 sandwich complex formation between K+ ions and [15]crown-5 groups. By controlling the steric bulk of the side groups of the repeating units and the distance between [15]crown-5 groups on the polymer main chain (see picture) the interpolymer interactions induced by K+ ions can be tuned. Four poly(p-phenylene ethynylene)s with [15]crown-5 side groups were prepared, two of which were designed to function as potassium sensory materials.
Effect of Terminalia chebula fruit on anaphylaxis by anal therapy (2003)

The effect of aqueous extract of Terminalia chebula fruit (Combretaceae) (TCAE) by anal administration on mast cell-dependent immediate-type anaphylactic reactions was investigated. TCAE (0.005 to 1 g/kg) inhibited systemic anaphylaxis induced by compound 48/80 in mice. When TCAE was pretreated at the same concentrations with systemic anaphylaxis, the plasma histamine levels were reduced in a dose-dependent manner. TCAE (0.1 and 1 g/kg) also significantly inhibited local anaphylaxis activated by anti-DNP IgE. TCAE (0.001 to 1 mg/ml) dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. Moreover, TCAE (0.01 and 0.1 mg/ml) had a significant inhibitory effect on anti-DNP IgE-mediated tumor necrosis <TEX>$factor-{\alpha}$</TEX> <TEX>$(TNF-{\alpha})$</TEX> production from RPMC. These results provide evidence that anal therapy of TCAE may be beneficial in the treatment of systemic and local mast cell-dependent anaphylaxis.
Interleukin (IL)-22 and IL-17 are coexpressed by Th17 cells and cooperatively enhance expression of antimicrobial peptides (2006)

Th17 cells are a distinct lineage of effector CD4(+) T cells characterized by their production of interleukin (IL)-17. We demonstrate that Th17 cells also expressed IL-22, an IL-10 family member, at substantially higher amounts than T helper (Th)1 or Th2 cells. Similar to IL-17A, IL-22 expression was initiated by transforming growth factor beta signaling in the context of IL-6 and other proinflammatory cytokines. The subsequent expansion of IL-22-producing cells was dependent on IL-23. We further demonstrate that IL-22 was coexpressed in vitro and in vivo with both IL-17A and IL-17F. To study a functional relationship among these cytokines, we examined the expression of antimicrobial peptides by primary keratinocytes treated with combinations of IL-22, IL-17A, and IL-17F. IL-22 in conjunction with IL-17A or IL-17F synergistically induced the expression of beta-defensin 2 and S100A9 and additively enhanced the expression of S100A7 and S100A8. Collectively, we have identified IL-22 as a new cytokine expressed by Th17 cells that synergizes with IL-17A or IL-17F to regulate genes associated with skin innate immunity.
Energy Transfer from the Phycobilisomes to Photosystem II Reaction Centers in Wild Type Cyanidium caldarium (1979)

Nonsaturating light at 600 or 436 nanometers was used to excite specifically phycocyanin or chlorophyll a, respectively, both of which participate in light capture in photosystem II of Cyanidium caldarium. The ratio of absorption of light by phycocyanin to chlorophyll in photosystem II in this organism is >20 at 600 nanometers and </=0.2 at 436 nanometers.The distribution of the absorbed light energy at these two wavelengths was followed by detecting the flash yields of O(2) during each illumination. We found that light absorbed by phycocyanin was transferred to only half of the reaction centers of photosystem II. This heterogeneity of energy distribution arises because only half of the centers and their associated antennae of 40 chlorophyll a are attached to phycobilisomes.
Toward Improved Catalytic Low-Temperature NOx Removal in Diesel-Powered Vehicles (2006)

The potential of different catalytic after treatment techniques to meet future diesel emission standards, which are strongly shifted toward urban driving conditions including cold start, are critically discussed in this Account and evaluated for their suitability for commercial applications. The dominating techniques in this field are NO(x) storage, urea-selective catalytic reduction (SCR), and HC-SCR. Each of these techniques have significant disadvantages such as sulfur sensitiveness and regeneration requirements of NO(x)-storage materials, infrastructure issues and formation of ammonium nitrate (at low temperatures) for urea-SCR, and low-temperature activity of HC-SCR catalysts. Ways to overcome these disadvantages in commercial applications may involve optimized regeneration strategies, reactor modifications, flow reversal, closed-loop NO(x) feedback systems, nonthermal plasma, and/or hydrogen-assisted catalyses, etc.
1,3‐Dihydro‐1‐hydroxy‐3‐morpholin‐4‐yl‐2,1‐benzoxaborole: product of the reaction of o‐formylphenylboronic acid with morpholine (2005)

Abstract o ‐Formylphenylboronic acid reacts with morpholine to form 1,3‐dihydro‐1‐hydroxy‐3‐morpholin‐4‐yl‐2,1‐benzoxaborole. The typical hydrogen‐bonded dimer motif with a planar benzoxaborole fragment has been obtained in the solid state. Copyright © 2005 John Wiley &amp; Sons, Ltd.
Molecular Transformations in Connective Tissue Hyaluronic Acid (1992)

Free radicals, either induced by the action of ionizing radiations or produced by metal ion induced electron transfer reactions in situ, can initiate a marked reduction in the viscoelasticity of the connective tissue matrix. This paper examines the dominant role of hyaluronic acid in controlling this behavior at molecular level. Our results indicate that after a dose of 5Gy (500 rads), the average molecular weight of hyaluronic acid in skin would be reduced by a factor of 4, which would lead to a 60-fold reduction in viscosity of the glycosaminoglycan. Shorter chains so produced would further inhibit hyper-entanglement and chain-chain interactions which are responsible for the viscoelasticity of the hyaluronic acid-polymer network.
A GIP Receptor Agonist Exhibits β-Cell Anti-Apoptotic Actions in Rat Models of Diabetes Resulting in Improved β-Cell Function and Glycemic Control (2010)

These findings demonstrate that truncated forms of GIP exhibit potent anti-diabetic actions, without pro-obesity effects, and that the C-terminus contributes to the lipogenic actions of GIP.