gebhart/patrepeval huggingface dataset:
Nanofiber scaffold gradients for interfacial tissue engineering (2012)

We have designed a 2-spinnerette device that can directly electrospin nanofiber scaffolds containing a gradient in composition that can be used to engineer interfacial tissues such as ligament and tendon. Two types of nanofibers are simultaneously electrospun in an overlapping pattern to create a nonwoven mat of nanofibers containing a composition gradient. The approach is an advance over previous methods due to its versatility - gradients can be formed from any materials that can be electrospun. A dye was used to characterize the 2-spinnerette approach and applicability to tissue engineering was demonstrated by fabricating nanofibers with gradients in amorphous calcium phosphate nanoparticles (nACP). Adhesion and proliferation of osteogenic cells (MC3T3-E1 murine pre-osteoblasts) on gradients was enhanced on the regions of the gradients that contained higher nACP content yielding a graded osteoblast response. Since increases in soluble calcium and phosphate ions stimulate osteoblast function, we measured their release and observed significant release from nanofibers containing nACP. The nanofiber-nACP gradients fabricated herein can be applied to generate tissues with osteoblast gradients such as ligaments or tendons. In conclusion, these results introduce a versatile approach for fabricating nanofiber gradients that can have application for engineering graded tissues.
Acrosin activation follows its surface exposure and precedes membrane fusion in human sperm acrosome reaction (1990)

Evidence has accumulated suggesting multiple roles of acrosin in fertilization, including its participation in early steps of gamete recognition and binding. However, the implication of acrosin in many of these processes is not compatible with its presumptive sequestration within the sperm acrosome until a late phase of the acrosome reaction. In an earlier study (J. Tesarik, J. Drahorad, J. Peknicova, 1988, Fertil. Steril. 50, 133-141), we reported the binding of an anti-acrosin monoclonal antibody (MO-AKR.1) to the plasma membrane overlying the acrosome of human spermatozoa starting the acrosome reaction. In this study, we characterized further this antibody with regard to its reactivity with different forms of acrosin and found that it recognizes specifically an active form of this enzyme and does not react with its proenzyme form. MO-AKR.1 was thus used as a probe for in situ analysis of acrosin activation during the acrosome reaction. When suspensions of living spermatozoa were incubated with MO-AKR.1 and with another monoclonal antibody (T6) directed to an intra-acrosomal cytoskeletal protein, significantly more spermatozoa reacted with the former antibody than with the latter; this indicated that some of the spermatozoa showing acrosin immunoreactivity carried activated acrosin on the cell surface, while their acrosome was still impermeable to intra-acrosomal-directed probes. The size of this particular sperm subpopulation was increased by the action of follicular fluid (a natural acrosome reaction inducer), but not ionophore A23187 (an artificial acrosome reaction inducer); it corresponded to the proportion of spermatozoa showing acrosin immunoreactivity on the plasma membrane but neither intra-acrosomal staining nor perceptible membrane perturbations when examined by immunoelectron microscopy. When spermatozoa were pre-incubated with protease inhibitors before the addition of acrosome reaction-inducing agents, the percentage of cells binding MO-AKR.1 was markedly reduced. These data suggest that limited acrosin activation on the sperm plasma membrane is an early event in the physiological acrosome reaction.
Processes affecting the remediation of chromium-contaminated sites. (1991)

The remediation of chromium-contaminated sites requires knowledge of the processes that control the migration and transformation of chromium. Advection, dispersion, and diffusion are physical processes affecting the rate at which contaminants can migrate in the subsurface. Heterogeneity is an important factor that affects the contribution of each of these mechanisms to the migration of chromium-laden waters. Redox reactions, chemical speciation, adsorption/desorption phenomena, and precipitation/dissolution reactions control the transformation and mobility of chromium. The reduction of CrVI to CrIII can occur in the presence of ferrous iron in solution or in mineral phases, reduced sulfur compounds, or soil organic matter. At neutral to alkaline pH, the CrIII precipitates as amorphous hydroxides or forms complexes with organic matter. CrIII is oxidized by manganese dioxide, a common mineral found in many soils. Solid-phase precipitates of hexavalent chromium such as barium chromate can serve either as sources or sinks for CrVI. Adsorption of CrVI in soils increases with decreasing chromium concentration, making it more difficult to remove the chromium as the concentration decreases during pump-and-treat remediation. Knowledge of these chemical and physical processes is important in developing and selecting effective, cost-efficient remediation designs for chromium-contaminated sites.
Thermal design and tests for the CMS HCAL readout box (2002)

A method is necessary to cool the electronics contained in the readout boxes for the CMS HCAL. The electronics to pre-amplify and digitize signals from the optical detectors will generate a large amount of heat that must be removed from the CMS HCAL system. To accomplish this a thermal management system has been designed that uses metallic extrusions, liquid coolant, and thermal foam to transfer the heat from the electronics to the exterior cooling system. Because the electronics are difficult to access throughout the life of the experiment, the temperature must be kept low to extend life expectancy. In order to test the concepts before the final design is implemented a thermal test station was built. Several methods to are under study to determine the best method of making the thermal routing from source of the heat to the liquid for heat removal. The test bed for this evaluation and methods to monitor the electronics temperature in situ are discussed.
Secretin Receptors in Human Pancreatic Membranes (1988)

Crude membranes (27,000 g pellets) from five normal human pancreases were prepared. In the presence of GTP, the peptides of the secretin family stimulated adenylate cyclase activity, their order of potency being: secretin greater than helodermin greater than peptide histidine isoleucinamide (PHI) greater than or equal to vasoactive intestinal peptide (VIP) greater than growth hormone releasing factor (GRF) (1-29)-NH2. In addition, helodermin and PHI were more efficient than secretin. Secretin (3-27) inhibited fully the secretin stimulation and partially only the helodermin and PHI stimulation of the enzyme. Secretin receptors were investigated by the ability of secretin and related peptides to inhibit tracer binding. [125I]Secretin binding was fully inhibited by secretin (Kd 0.8 nM), helodermin (Kd 200 nM), and PHI (Kd 250 nM). VIP and GRF(1-29)-NH2 induced partial (20%) inhibition at a high 10 microM concentration. The fragments secretin (2-27), (3-27), (4-27), and (7-27) showed the same low potency and efficacy based on their ability to stimulate adenylate cyclase and to occupy secretin receptors. The analogues [Val5]secretin and [Ala2]secretin had a higher potency than secretin. Based on this comparison of adenylate cyclase stimulation and [125I]secretin binding inhibition, it is tempting to conclude that the human pancreas: (a) possesses highly specific secretin receptors and (b) such receptors could not fully account for the whole pattern of adenylate cyclase activation by related peptides, so that the presence of an added type of "helodermin-PHI-preferring" receptors is suggested.
King Shaka International Airport structural engineering and construction features (2011)

The King Shaka International Airport and the Dube Trade Port, located some 35 km north of the Durban City Centre, is a strategic and critical infrastructure development which will serve as a catalyst for economic growth in the KwaZulu-Natal region and South Africa.
Preparation and basic properties of PbTiO<sub>3</sub>ferroelectric thin films and their device applications (1985)

Abstract A series of technical data for preparing PbTiO3 ferroelectric thin films and their applications to some electronic devices have been presented. PbTiO3 thin films having considerably good ferroelectric properties have been obtained by rf sputtering or CVD. Maximum dielectric constant and remanent polarization are about 200 and 27μC/cm2, respectively. Several attempts to fabricate electronic devices such as nonvolatile memory, infrared sensor, ultrasonic sensor and low-threshold electroluminescent devices have been also carried out.
Separation Techniques Used To Prepare Highly Purified Chromosome Populations (1991)

Flow Cytometry analyzes heterogeneous chromosome suspensions and electronically separates desired chromosome types as pure fractions. Adjunct techniques have been used to improve the efficiency of flow sorting. Prefractionation of the initial chromosome suspension has been carried out on sucrose gradients. Concentration of dilute suspensions of mitotic chromosomes has been accomplished using sucrose and Metrizamide interfaces and agarose plugs.
Nanoporous Membranes with Mixed Nanoclusters for Raman-Based Label-Free Monitoring of Peroxide Compounds (2009)

Monitoring trace amounts of peroxide-based molecules is challenging because of the lack of common optical signatures (fluorescence or absorption in UV-vis range) or chemical functionality easily detectable with common routines. To overcome this issue, we suggest a photochemical decomposition approach followed by the analysis of chemical fragments by a fast, sensitive, and reliable Raman spectroscopic method. To facilitate this approach, we employed a novel design of surface-enhanced Raman scattering (SERS)-active nanoporous substrate based on porous alumina membranes decorated with mixed nanoclusters composed of gold nanorods and nanoparticles. The detectable amount of HMTD below 2 pg demonstrated here is about 3 orders of magnitude lower than the current limit of detection. We suggest that laser-induced photocatalytic decomposition onto nanoparticle clusters is critical for achieving label-free detection of unstable and nonresonant organic molecules.
The Chiral Auxiliary <i>N</i>-1-(1′-Naphthyl)ethyl-<i>O</i>-<i>tert</i>-butylhydroxylamine: A Chiral Weinreb Amide Equivalent (2009)

The chiral auxiliary N-1-(1'-naphthyl)ethyl-O-tert-butylhydroxylamine is readily prepared from N-hydroxyphthalimide in four steps, with resolution giving access to both enantiomers in > 98% ee, on a multigram (> 25 g) scale. Conversion to a range of N-acyl derivatives, followed by highly diastereoselective alkylation (> or = 94% de) gives the corresponding chiral, 2-substituted derivatives as single diastereoisomers (> 98% de) after chromatography. Reductive cleavage with LiAlH(4) allows direct access to chiral aldehydes, and treatment with MeLi gives chiral methyl ketones in excellent enantiopurity (> or = 94% ee). The auxiliary can be recovered in > 98% ee and recycled.
Editorial (2018)

In this Festschrift we want to both celebrate Professor Dr. Martin Prozesky's academic career as student and scholar in Religious Studies and Ethics, and his substantial impact on South Africans of all walks of life through his thought, publications, and practical ethics training in the academy, and in the corporate and public domains. This comes after nearly 50 years since he started teaching Comparative Religion in the then Rhodesia (now Zimbabwe) in 1969, and also 40 years, since he started as Senior Lecturer in 1977, at the then University of Natal, Pietermaritzburg campus, teaching Philosophy of Religion in the Department of Divinity1. It is also nearly 40 years since he was introduced to Process Philosophy and wrote his review of Process Theology: An Introductory Exposition, by John B. Cobb Jr. and David Ray Griffin (1979). It is also now 10 years since he took early retirement from the University of KwaZulu-Natal in 2007, and the publication of his very significant Conscience: Ethical Intelligence for Global Well-Being (2007). This year, Prof. Dr. Prozesky will celebrate his seventy-fourth birthday, and we are celebrating his contributions to our discipline, and its sub-disciplines, at the 40th Congress of the Association for the Study of Religion in Southern Africa (ASRSA).
The price of debiasing automatic metrics in natural language evaluation (2018)

For evaluating generation systems, automatic metrics such as BLEU cost nothing to run but have been shown to correlate poorly with human judgment, leading to systematic bias against certain model improvements. On the other hand, averaging human judgments, the unbiased gold standard, is often too expensive. In this paper, we use control variates to combine automatic metrics with human evaluation to obtain an unbiased estimator with lower cost than human evaluation alone. In practice, however, we obtain only a 7-13% cost reduction on evaluating summarization and open-response question answering systems. We then prove that our estimator is optimal: there is no unbiased estimator with lower cost. Our theory further highlights the two fundamental bottlenecks---the automatic metric and the prompt shown to human evaluators---both of which need to be improved to obtain greater cost savings.
An in-vitro test system for electrochemical sensors (1988)

A computer system has been developed to automate the in-vivo evaluation of amperometric electrochemical sensors in unanesthetized, tethered rabbits. Subcutaneous glucose, oxygen and temperature are monitored. Continuous, simultaneous monitoring of eight animals for several weeks is possible. Data collection rates are adjustable up to once every five minutes. Blood sample withdrawal and intravenous injection are carried out manually through a remote access port with computer prompting. Blood chemistry results are entered via keyboard and merged with the database from the sensor outputs. This multiple, parallel testing with minimal personnel intervention has made in-vivo statistical analysis of experimental electrochemical sensors feasible.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Efficient oxygen reduction catalysis by subnanometer Pt alloy nanowires (2017)

The common knowledge is that Pt and Pt alloy nanoparticles (NPs) less than 2 nm are not desirable for oxygen reduction reaction (ORR). However, whether the same trend is expected in Pt-based nanowires (NWs) and nanoplates remains questionable because there is no scalable approach to make such Pt nanostructures. We report a general approach for preparing subnanometer Pt alloy NWs with a diameter of only 4 to 5 atomic layer thickness, ranging from monometallic Pt NWs to bimetallic PtNi and PtCo NWs and to trimetallic PtNiCo NWs. In a sharp contrast to Pt alloy NPs, the subnanometer Pt alloy NWs demonstrate exceptional mass and specific activities of 4.20 A/mg and 5.11 mA/cm<sup>2</sup> at 0.9 V versus reversible hydrogen electrode (RHE), respectively, 32.3 and 26.9 times higher than those of the commercial Pt/C. Density functional theory simulations reveal that the enhanced ORR activities are attributed to the catalytically active sites on high-density (111) facets in the subnanometer Pt alloy NWs. They are also very stable under the ORR condition with negligible activity decay over the course of 30,000 cycles. Our work presents a new approach to maximize Pt catalytic efficiency with atomic level utilization for efficient heterogeneous catalysis and beyond.
Preventing Thin Film Dewetting via Graphene Capping (2017)

A monolayer 2D capping layer with high Young's modulus is shown to be able to effectively suppress the dewetting of underlying thin films of small organic semiconductor molecule, polymer, and polycrystalline metal, respectively. To verify the universality of this capping layer approach, the dewetting experiments are performed for single-layer graphene transferred onto polystyrene (PS), semiconducting thienoazacoronene (EH-TAC), gold, and also MoS<sub>2</sub> on PS. Thermodynamic modeling indicates that the exceptionally high Young's modulus and surface conformity of 2D capping layers such as graphene and MoS<sub>2</sub> substantially suppress surface fluctuations and thus dewetting. As long as the uncovered area is smaller than the fluctuation wavelength of the thin film in a dewetting process via spinodal decomposition, the dewetting should be suppressed. The 2D monolayer-capping approach opens up exciting new possibilities to enhance the thermal stability and expands the processing parameters for thin film materials without significantly altering their physical properties.
Inhibition of chemotaxis by organic acids from anaerobes may prevent a purulent response in bacterial vaginosis (2000)

It has been postulated that certain organic acids produced by the anaerobes associated with bacterial vaginosis (BV) could prevent a purulent response in this infection. Varying concentrations of pure succinic, acetic and lactic acids were incubated in vitro with a monocytic cell line (MonoMac 6). High inhibition of chemotaxis was produced by succinic acid; lower inhibition and no inhibition was shown by acetic acid and lactic acid respectively. Succinic and acetic acids were detected in high concentrations in the vaginal fluid of women with BV and in culture supernates of Prevotella and Mobiluncus spp.; these acids impaired chemotaxis of MonoMac 6 cells in vitro. The vaginal fluids of normal women and the culture supernates of Lactobacillus spp. had no effect on chemotaxis.
Carbon Dioxide Sequestering Using Ultramaf ic Rocks (1998)

Abstract Fossil fuels continue to provide major sources of energy to the modern world even though global emissions of CO2 are presently at levels of ≥ 19 gigatons/yr. Future antipollution measures may include sequestering of waste CO2 as magnesite (MgCO3) by processing ultramafic rocks. Common ultramafic rocks react easily with HCl to form MgCl2 which is hydrolyzed to form Mg(OH)2. CO2 would be transported by pipeline from a fossil fuel power plant to a sequestering site and then reacted with Mg(OH)2 to produce thermodynamically stable magnesite. Huge ultramafic deposits consisting of relatively pure Mg-rich silicates exist throughout much of the world in ophiolites and, to a lesser extent, in layered intrusions. Peridotites and associated serpentinite are found in discontinuous ophiolite belts along both continental margins of North America. Serpentinites and dunites comprise the best ores because they contain the most Mg by weight (35 to 49 wt-% MgO) and are relatively reactive to hot acids such as HCl. Small ultramafic bodies (~1 km3) can potentially sequester ~1 gigatons of CO2 or ~20% of annual U.S. emissions. A single large deposit of dunite (~30 km3) could dispose of nearly 20 years of current U.S. CO2 emissions. The sequestering process could provide Mg, Si, Fe, Cr, Ni, and Mn as by products for other industrial and strategic uses. Because “white” asbestos (chyrsotile) is a serpentine mineral, CO2 sequestering could dispose of some waste asbestos. The cost and environmental impact of exploiting ultramafic deposits must be weighed against the increased costs of energy and benefits to the atmosphere and climate.
Apoferritin protein cages: a novel drug nanocarrier for photodynamic therapy (2008)

A methylene blue-encapsulated apoferritin complex shows cytotoxic effects on MCF-7 human breast adenocarcinoma cells when irradiated at the appropriate wavelength.
Changing patterns of actin localization during cell division. (1975)

Changing patterns of actin localization have been studied on a light microscopic level by means of fluorescently labeled heavy meromyosin. The cellular distribution of actin is characterized by four major patterns, each of which corresponds to a particular phase of cell division. Long actin fibers are a prominent feature of the interphase cell. They disappear as the cell rounds up for mitosis and are replaced by a diffuse distribution of actin throughout the cytoplasm. During cytokinesis, the actin is localized predominantly in the cleavage furrow. The final shift of actin occurs after the completion of cytokinesis. At this time the actin becomes concentrated in the distal poles of the cell where pseudopods form to pull the daughter cells apart. When the daughter cells have separated, they flatten on the culture dish and the fibrous pattern of actin characteristic of interphase cells returns. All of these changes take place during the 1-hr period required for cell division.
Biochemical Markers for Alcoholism (1984)

A panel of blood tests, purportedly markers for alcohol abuse, were examined in 543 relatively healthy alcoholics entering ambulatory rehabilitation treatment. Individual tests were too low in sensitivity: gamma-glutamyl transpeptidase was abnormally high in only 49%, then mean corpuscular volume (45%), high density lipoprotein cholesterol (HDLC) (25%), serum glutamic oxaloacetic transaminase (SGOT) (28%), and blood alcohol (21%). HDLC was of low sensitivity, generally unaffected by liver disease, and related to quantitation of recent alcohol consumed. Combining seven markers, 82% of males and 71% females had at least one abnormally high value. Histories of heavy recent drinking, positive blood alcohol levels on admission, and manifest liver disease on physical examination or by hyperbilirubinemia were associated with high sensitivities of individual and pooled markers. The biochemical markers studied can be useful to suggest alcohol abuse, especially in some populations of drivers. In other populations of alcoholics, especially with intermittent alcohol or recent abstinence, their sensitivities were so low as to discourage extensive reliance on their use. The diagnosis of alcoholism continues to depend on clinical history of alcohol-related problems, including social, familial, legal, medical, psychological, and economic.
Expression of epidermal growth factor (EGF) receptor and its ligands, EGF and transforming growth factor-alpha, in human fallopian tubes. (1992)

Although human uterus is known to contain epidermal growth factor (EGF) and its receptors, it is virtually unknown whether human fallopian tubes, which are an anatomical continuation of the uterus, also contain them. Therefore, the present studies investigated whether EGF and its structural and functional homolog, i.e. transforming growth factor-alpha (TGF-alpha), and their common receptor are expressed in human fallopian tubes. Human fallopian tubes contain major 10.5-kilobase (kb) and minor 6.0-kb receptor messenger RNA (mRNA) transcripts, a single 5.0-kb EGF mRNA transcript, and a single 170-kilodalton receptor protein. The transcripts, along with their corresponding proteins and TGF-alpha protein, are present in ciliated and nonciliated epithelial cells, tubal smooth muscle, vascular smooth muscle, and endothelium. The cellular distribution and reproductive state dependency of these three regulatory molecules varied. For all of them, however, ampullary segments contained more than isthmus; proliferative phase and/or postpartum specimens contained more than secretory phase; and postmenopausal specimens contained the lowest amounts. The cell periphery and nuclear/perinuclear area of the cells contained EGF, TGF-alpha, and their receptors. Immunogold electron microscopy showed the receptors to be present in cell membranes, cilia, basal bodies which control ciliary activity, endoplasmic reticulum, nuclear membranes, and chromatin. In summary, human fallopian tubes contain EGF, EGF/TGF-alpha receptor mRNA and protein, and TGF-alpha protein. The expression of all these regulatory molecules was dependent on anatomical region, cell type, and reproductive state of the fallopian tubes. These findings suggest that EGF and TGF-alpha may regulate numerous tubal functions, thus potentially influencing fertility in women.