gebhart/patrepeval huggingface dataset:
Gas‐Liquid mass transfer in fixed‐bed reactors with cocurrent downflow operating in the pulsing flow regime (1984)

Abstract Liquid‐side mass transfer coefficients were measured for cocurrent two‐phase downflow in 5 and 10 cm diameter columns pakced with 2.5 and 4 mm Raschig rings. Experiments were specifically carried out in the pulsing flow regime. The mass transfer coefficients were determined via absorption of CO 2 into buffer solutions with the advantage of a high absorbing capacity. Thus columns of 1 m length could be used. Relations are proposed based on the hydrodynamic phenomena observed in pulsing flow. From these relations a correlation for k L is found in terms of flow rates and packing characteristics that satisfies the experimental data.
A Low-Power Digital PWM DC/DC Converter based on Passive Sigma-Delta Modulator (2005)

This paper describes a novel method to obtain a digital control for PWM DC/DC switching regulator. A passive sigma-delta modulator for which output is suitably processed obtains the PWM control and makes the control loop. The output of the sigma-delta enables generating the discrete-time PWM control. The proposed method has been extensively simulated at the behavioral level. Results show that the method can be effectively employed in low power DC/DC converters.
Ocean acoustic sensor installation at the South Florida Ocean Measurement Center (2002)

A tri-axial array of acoustic hydrophones has been installed off the South Florida coast in 145 m of water. The installation is one of a number of projects that have begun making use of the new South Florida Ocean Measurement Center facilities in Dania, FL. The arrays are linked to shore via a fiber-optic cable and powered from shore with a separate insulated copper cable. Two of the arms of the array are deployed on the bottom to the east and south of the origin. The third array is a sub-surface vertical mooring which includes a pressure sensor to monitor the depth of the top buoy. Each axis contains 32 hydrophones spaced in a nonlinear distribution to facilitate acoustic coherence measurements. Other sensor configurations are possible, including the replacement of hydrophones with other instruments such as current meters or temperature, pressure, or conductivity sensors. Small projectors are placed at the base of the vertical array and at the ends of the horizontal arrays, making it possible to determine the location of each sensor in real time via time-of-flight measurements. Computers running the Linux operating system control the projectors and process data from each leg of the array. Each of the three computers is connected via fiber-optic lines to a Fast Ethernet switch box and networked to shore. The computers can be accessed via TCP/IP connections and programmed from shore to suit new missions. A wireless link to the Nova Southeastern University network and the Internet makes it possible to access the system and conduct experiments from anywhere in the world. The current mission of this system is to study the coherence of shallow-water acoustic propagation. However, knowledge gained here will facilitate a variety of future projects-which include active and passive sonars, ambient noise study, high-frequency acoustic monitoring of fish migration, and acoustic tomographic monitoring of the Gulf Stream. Excellent data were obtained from several experiments. At the present time, only the vertical array is working but plans to restore the two horizontal arrays are actively pursued.
Low Temperature, Selective Atomic Layer Deposition of Nickel Metal Thin Films (2018)

We report the growth of nickel metal films by atomic layer deposition (ALD) employing bis(1,4-di- tert-butyl-1,3-diazadienyl)nickel and tert-butylamine as the precursors. A range of metal and insulating substrates were explored. An initial deposition study was carried out on platinum substrates. Deposition temperatures ranged from 160 to 220 °C. Saturation plots demonstrated self-limited growth for both precursors, with a growth rate of 0.60 Å/cycle. A plot of growth rate versus substrate temperature showed an ALD window from 180 to 195 °C. Crystalline nickel metal was observed by X-ray diffraction for a 60 nm thick film deposited at 180 °C. Films with thicknesses of 18 and 60 nm grown at 180 °C showed low root mean square roughnesses (<2.5% of thicknesses) by atomic force microscopy. X-ray photoelectron spectroscopies of 18 and 60 nm thick films deposited on platinum at 180 °C revealed ionizations consistent with nickel metal after sputtering with argon ions. The nickel content in the films was >97%, with low levels of carbon, nitrogen, and oxygen. Films deposited on ruthenium substrates displayed lower growth rates than those observed on platinum substrates. On copper substrates, discontinuous island growth was observed at ≤1000 cycles. Film growth was not observed on insulating substrates under any conditions. The new nickel metal ALD procedure gives inherently selective deposition on ruthenium and platinum from 160 to 220 °C.
Induction of the<i>Cyp1a-1</i>dioxin-responsive enhancer in transgenic mice (1991)

Cyp1a-1, whose product, aryl hydrocarbon hydroxylase, assists in detoxification of polycyclic aromatic hydrocarbons, is the best characterized of the murine cytochrome P450 genes. The Cyp1a-1 dioxin-responsive enhancer region has been previously analyzed in vitro and found to induce expression of heterologous genes upon exposure of transfected cells to various aromatic hydrocarbons. A 2.58 kbp DNA fragment containing the Cyp1a-1 enhancer elements and promoter region was coupled to the chloramphenicol acetyltransferase (CAT) reporter gene and used to create transgenic mice. CAT assays were performed on tissues harvested from three different lines of transgenic mice following mock-induction or induction using the aromatic hydrocarbon, 3-methylcholanthrene. Basal levels of expression were detected in the spleen and small bowel of non-induced mice, with little or no expression detected in the liver. Treatment with 3-methylcholanthrene increased hepatic expression levels by as much as 10,000-fold. More modest levels of induction were also recorded in the spleen, small bowel, kidney, and lung. The results indicate that the dioxin-responsive enhancer region functions as a strongly inducible promoter in vivo. Differences in the response to induction between male and female mice suggest that Cyp1a-1 expression may be governed in a gender related manner.
Effects of heat shock on the functional morphology of cell organelles observed by video‐enhanced microscopy (1999)

In living astrocytes and MDCK cells we observed morphological phenomena during and after heat shock (HS) utilizing our new perfusable microchamber system, which monitors pH, pO2, pCO2, and temperature. By means of electronic light microscopy and confocal laser scanning microscopy, mitochondria were demonstrated to swell and to reduce their motility. The specific fluorescent probe MitoTracker Green revealed that the mitochondrial morphology changed from a rodlike into an annular shape with a central vacuole—findings which were corroborated by transmission electron microscopy. After HS (shift from 37°C to 45°C for 15 min) the mitochondrial membrane potential (ΔΨm) was depressed in most but not all mitochondria as monitored with the fluorescent probe JC-1. The dual emission images of JC-1 illustrated a heterogeneous red staining of distinct areas of single mitochondria. The shape changes as well as the drop of the membrane potential of the mitochondria indicated severe cellular stress and a direct intervention on the mitochondrial permeability transition. Anat Rec 255:458–464, 1999. © 1999 Wiley-Liss, Inc.
Grayscale Patterning of Polymer Thin Films with Nanometer Precision by Direct-Write Multiphoton Photolithography (2008)

The fabrication of arbitrary grayscale patterns in poly(ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin films is demonstrated. Patterns are formed by ablative direct-write multiphoton lithography using a sample scanning microscope and 870-nm light from a mode-locked Ti:sapphire laser. The surface profiles of all etched samples are characterized by atomic force microscopy. Grayscale patterns are produced by modulating the laser focus during etching. Quantitative models describing the etch depth as a function of laser power and focus are presented and employed to reproducibly control film patterning. PEDOT:PSS is found to be etched by a combination of linear and nonlinear optical processes. Sensitization by PEDOT in the composite is concluded to facilitiate removal of PSS. An ultimate etch depth precision of 1 nm is achieved.
Bimetallic tubing as an answer to process tubing corrosion (1997)

Outlines how bimetallic tubing can be used to prevent process tubing corrosion. Describes how Sandvik Steel has developed tubes which are used in an industrial urea plant.
The Anti‐Parasitic Effects of Nitric Oxide (2003)

Endogenous and exogenous nitric oxide (NO) possesses antiparasitic effects on both Protozoa and Metazoa. However, NO production requires a tight control to limit cytotoxic damage to the host's own cells. The best known parasitic macromolecular targets for NO(-donors) are cysteine proteases, which are relevant in several aspects of the parasite life cycle and parasite-host relationships, and appear as promising targets for anti-parasitic chemotherapy.
An X-Band EPR Cavity for Fast Magnetic Field Sweep Experiments (1967)

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Measurement of inferior vena cava diameter for evaluation of venous return in subjects on<i>day 10</i>of a bed-rest experiment (2004)

We evaluated the usefulness of measurements of the inferior vena cava (IVC) diameters on abdominal echograms as an indicator of changes of venous return in subjects with orthostatic intolerance (OI) induced by simulated microgravity. We performed a standing test and recorded the IVC diameters on abdominal echograms in 12 subjects placed on a 20-day 6 degrees head-down-tilt bed-rest experiment. We found that different patterns of changes in IVC diameter occurred in the standing test on day 10 of the experiment; in five subjects with a marginal decrease in pulse pressure, IVC diameters in the upright position were markedly decreased compared with those in the supine position. In five subjects with feelings of discomfort, the IVC diameters in the upright position distended or did not decrease from those in the supine position. These results suggested that the changes in IVC diameter on the standing test indicated the presence of various types of hemodynamic responses of OI caused by simulated microgravity. In this study, we also evaluated changes in body-water compartments by conducting multifrequency bioelectrical impedance analysis. Longitudinal data analysis showed that the total body-water-to-fat-free mass and extracellular fluid-to-fat-free mass ratios decreased during the experimental period and recovered thereafter, and that the ratio of intracellular fluid to fat-free mass decreased during the experiment. No significant difference in changes in body-water compartments was seen among subjects with different patterns of changes in IVC diameters. Measurement of IVC diameter was useful to estimate hemodynamic changes in subjects with OI.
Polycentric 384-month study of biofiltration (BF) with AN69s. (1986)

Polycentric 384-month study of biofiltration (BF) with AN69s. Since January 1984, 39 uremic dialyzed patients have been included in a randomized prospective study, to evaluate the clinical utility of BF. The trial lasted 9.85 months/pt (384.15 months of total observations) and patients admitted had some not well controlled clinical signs: major acidosis, intradialytic cardiovascular instability, intolerance to acetate dialysis, hypercatabolism, neuropathy, etc. We obtained some positive effects: the incidence of intradialytic hypotension decreased 26.6%; interdialytic body weight gain fell from 3.1 to 2.7 kg (p less than 0.05) and the dialytic time per week was reduced from 12.3 to 10.0 hours (p less than 0.01). At the same time dry body weight increased from 62.4 to 64.6 kg with worthwhile improvement of the acid-base status (ABS) in all patients. This controlled trial showed that BF is particularly useful for patients suffering from severe acidosis and/or cardiovascular instability.
Microbial synthesis of <i>p</i>‐hydroxybenzoic acid from glucose (2001)

A series of recombinant Escherichia coli strains have been constructed and evaluated for their ability to synthesize p-hydroxybenzoic acid from glucose under fed-batch fermentor conditions. The maximum concentration of p-hydroxybenzoic acid synthesized was 12 g/L and corresponded to a yield of 13% (mol/mol). Synthesis of p-hydroxybenzoic acid began with direction of increased carbon flow into the common pathway of aromatic amino acid biosynthesis. This was accomplished in all constructs with overexpression of a feedback-insensitive isozyme of 3-deoxy-D-arabino-heptulosonic acid 7-phosphate synthase. Expression levels of enzymes in the common pathway of aromatic amino acid biosynthesis were also increased in all constructs to deliver increased carbon flow from the beginning to the end of the common pathway. A previously unreported inhibition of 3-dehydroquinate synthase by L-tyrosine was discovered to be a significant impediment to the flow of carbon through the common pathway. Chorismic acid, the last metabolite of the common pathway, was converted into p-hydroxybenzoic acid by ubiC-encoded chorismate lyase. Constructs differed in the strategy used for overexpression of chorismate lyase and also differed as to whether mutations were present in the host E. coli to inactivate other chorismate-utilizing enzymes. Use of overexpressed chorismate lyase to increase the rate of chorismic acid aromatization was mitigated by attendant decreases in the specific activity of DAHP synthase and feedback inhibition caused by p-hydroxybenzoic acid. The toxicity of p-hydroxybenzoic acid towards E. coli metabolism and growth was also evaluated.
Liquid chromatography: theory and methodology (1990)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid chromatography: theory and methodologyJohn G. DorseyJohn G. DorseyMore by John G. Dorsey, Joe P. FoleyJoe P. FoleyMore by Joe P. Foley, William T. CooperWilliam T. CooperMore by William T. Cooper, Robert A. BarfordRobert A. BarfordMore by Robert A. Barford, and Howard G. BarthHoward G. BarthMore by Howard G. BarthCite this: Anal. Chem. 1990, 62, 12, 324–356Publication Date (Print):June 15, 1990Publication History Published online1 May 2002Published inissue 15 June 1990https://pubs.acs.org/doi/10.1021/ac00211a022https://doi.org/10.1021/ac00211a022research-articleACS PublicationsRequest reuse permissionsArticle Views502Altmetric-Citations185LEARN 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-Alertsclose Get e-Alerts
Mild Hypothermia Reduces Apoptosis of Mouse Neurons <i>In vitro</i> Early in the Cascade (2002)

Recent experimental work has shown that hypothermia with even small decreases in temperature is broadly neuroprotective, but the mechanism of this protection remains unclear. Although reduction of metabolism could explain protection by deep hypothermia, it does not explain the robust protection found with mild hypothermia. Several reports have suggested that ischemic apoptosis is reduced by hypothermia. The authors examined the effects of hypothermia on neuronal apoptosis using serum deprivation, a well-accepted model that induces neuronal apoptosis. Mild hypothermia (33 degrees C) significantly reduced the number of morphologically apoptotic neurons to less than half the number seen in normothermic culture temperatures (37 degrees C) after 48 hours. They examined the effect of hypothermia on several steps in the cascade. Caspase-3, -8, and -9 activity was significantly increased after 24 hours at 37 degrees C, and was significantly lower in cultures deprived of serum at 33 degrees C. Cytochrome c translocation was reduced by hypothermia. Western blot analysis failed to detect significant changes in Bax, bcl -2, or hsp -70 at early time points, whereas hypothermia significantly reduced cJun N-terminal kinase activation. The authors conclude that small decreases in temperature inhibit apoptosis very early, possibly at the level of the initiation of apoptosis, as suggested by reduced cJun N-terminal kinase activation and before the translocation of cytochrome c, with subsequent prevention of caspase activation.
Downregulation of GMP-140 (CD62 or PADGEM) expression on platelets by N,N-dimethyl and N,N,N-trimethyl derivatives of sphingosine (1991)

GMP-140 (CD62 or PADGEM), a member of the selectin family, is a membrane glycoprotein in secretory granules of platelets and endothelial cells. When these cells are activated by agonists such as thrombin or AMP, GMP-140 is rapidly redistributed to the cell surface. The carbohydrate epitope defined by GMP-140 was identified as sialosyl-Le(x) (as for ELAM-1), which may play an essential role in adhesion of leukocytes or tumor cells on endothelial cells, through aggregation with platelets. Redistribution of GMP-140 from alpha-granules of platelets to the cell surface, induced by thrombin and PMA, was strongly inhibited by preincubation of platelets with N,N-dimethylsphingosine (DMS) or N,N,N-trimethylsphingosine (TMS) at 10-20 microM concentration for a brief period (5 min). Inhibition of GMP-140 redistribution to the cell surface by DMS or TMS was also detected by a cell adhesion assay using HL60 cells, which highly express sialosyl-Le(x); i.e., HL60 cells adhered on platelets activated by thrombin or PMA but not on platelets which were briefly preincubated with DMS or TMS followed by activation. The inhibitory effect of DMS or TMS on GMP-140 redistribution is not due to cytotoxicity, since the TMS-treated platelets were fully capable of aggregating in the presence of ristocetin. Sphingosine (SPN) and protein kinase C inhibitors such as H-7 and calphostin C showed weaker inhibitory activity than DMS and TMS. Our results indicate that both DMS and TMS could be useful reagents to inhibit cell surface expression of crucial selectins which promote adhesion of Le(x-) or sialosyl-Le(x)-expressing cells with platelets and endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Vibrational spectra and assignments for cis- and trans-1,2-difluorocyclopropane and three deuterium substituted modifications of each isomer (1975)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVibrational spectra and assignments for cis- and trans-1,2-difluorocyclopropane and three deuterium substituted modifications of each isomerNorman C. Craig, T. N. Hu Chao, Enrique Cuellar, Dan E. Hendriksen, and Jeffery W. KoepkeCite this: J. Phys. Chem. 1975, 79, 21, 2270–2282Publication Date (Print):October 1, 1975Publication History Published online1 May 2002Published inissue 1 October 1975https://doi.org/10.1021/j100588a014RIGHTS & PERMISSIONSArticle Views55Altmetric-Citations13LEARN 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 InReddit PDF (1 MB) Supporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Structural and functional connectivity of the human brain in autism spectrum disorders and attention-deficit/hyperactivity disorder: A rich club-organization study (2014)

Attention-deficit/hyperactive disorder (ADHD) and autism spectrum disorders (ASD) are two of the most common and vexing neurodevelopmental disorders among children. Although the two disorders share many behavioral and neuropsychological characteristics, most MRI studies examine only one of the disorders at a time. Using graph theory combined with structural and functional connectivity, we examined the large-scale network organization among three groups of children: a group with ADHD (8-12 years, n = 20), a group with ASD (7-13 years, n = 16), and typically developing controls (TD) (8-12 years, n = 20). We apply the concept of the rich-club organization, whereby central, highly connected hub regions are also highly connected to themselves. We examine the brain into two different network domains: (1) inside a rich-club network phenomena and (2) outside a rich-club network phenomena. The ASD and ADHD groups had markedly different patterns of rich club and non rich-club connections in both functional and structural data. The ASD group exhibited higher connectivity in structural and functional networks but only inside the rich-club networks. These findings were replicated using the autism brain imaging data exchange dataset with ASD (n = 85) and TD (n = 101). The ADHD group exhibited a lower generalized fractional anisotropy and functional connectivity inside the rich-club networks, but a higher number of axonal fibers and correlation coefficient values outside the rich club. Despite some shared biological features and frequent comorbity, these data suggest ADHD and ASD exhibit distinct large-scale connectivity patterns in middle childhood.