1,553 research outputs found
Structural Geology of the Cariboo Gold Mining District, East-Central British Columbia:
No full textL.C. Struik.Memoir (Geological Survey of Canada) ; 421
Depolarization and decreased surface expression of K+ channels contribute to NSAID-inhibition of intestinal restitution
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) contribute to gastrointestinal ulcer formation by inhibiting epithelial cell migration and mucosal restitution; however, the drug-affected signaling pathways are poorly defined. We investigated whether NSAID inhibition of intestinal epithelial migration is associated with depletion of intracellular polyamines, depolarization of membrane potential (Em) and altered surface expression of K+ channels. Epithelial cell migration in response to the wounding of confluent IEC-6 and IEC-Cdx2 monolayers was reduced by indomethacin (100μM), phenylbutazone (100μM) and NS-398 (100μM) but not by SC-560 (1μM). NSAID-inhibition of intestinal cell migration was not associated with depletion of intracellular polyamines. Treatment of IEC-6 and IEC-Cdx2 cells with indomethacin, phenylbutazone and NS-398 induced significant depolarization of Em, whereas treatment with SC-560 had no effect on Em. The Em of IEC-Cdx2 cells was: −38.5±1.8mV under control conditions; −35.9±1.6mV after treatment with SC-560; −18.8±1.2mV after treatment with indomethacin; and −23.7±1.4mV after treatment with NS-398. Whereas SC-560 had no significant effects on the total cellular expression of Kv1.4 channel protein, indomethacin and NS-398 decreased not only the total cellular expression of Kv1.4, but also the cell surface expression of both Kv1.4 and Kv1.6 channel subunits in IEC-Cdx2. Both Kv1.4 and Kv1.6 channel proteins were immunoprecipitated by Kv1.4 antibody from IEC-Cdx2 lysates, indicating that these subunits co-assemble to form heteromeric Kv channels. These results suggest that NSAID inhibition of epithelial cell migration is independent of polyamine-depletion, and is associated with depolarization of Em and decreased surface expression of heteromeric Kv1 channels.ID: S0006295207001931; M3: Article; Accession Number: S0006295207001931; Author: L.C. Freeman (b); Author: D.F. Narvaez (a); Author: A. McCoy (a); Author: F.B. von Stein (c); Author: S. Young (b); Author: K. Silver (a); Author: S. Ganta (b); Author: D. Koch (b); Author: R. Hunter (b); Author: R.F. Gilmour (c); Author: J.D. Lillich (a, ⁎); Affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States; Keyword: Non-steroidal anti-inflammatory drugs; Keyword: Intestinal epithelial cells; Keyword: Membrane potential; Keyword: Potassium channels; Number of Pages: 12; Language: English;Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=edselp&AN=S0006295207001931&site=eds-live&scope=sit
Les Observations sur l'éloquence de l'abbé de Saint-Pierre
No full textAbbé de Saint-Pierre : Observations sur l'éloquence. Presented by Lawrence Kerslake.
Many of the abbé de Saint-Pierre's writings remain little-known or even unpublished. The Observations sur l'éloquence constitute his chief discussion of literature. A preliminary draft appeared in the Mercure in 1726, but the work subsequently underwent two major revisions, both states represented in Ms. R.248 of the Bibliothèque publique et universitaire in Neuchâtel. A further copy (BNF. N.a.fr. 11232), with a few additional changes, is published here. The ideas in the text show the author to be a 'Modern' in his position on beauty and literary effect, and reflect his life-long concern for the improvement of his fellow-citizens.Kerslake L.C. Les Observations sur l'éloquence de l'abbé de Saint-Pierre. In: Dix-huitième Siècle, n°31, 1999. Mouvement des sciences et esthétique(s) sous la direction de Christine Rolland, François Azouvi et Michel Baridon. pp. 305-328
A 0.53pJK<sup>2</sup> 7000μm<sup>2</sup> resistor-based temperature sensor with an inaccuracy of ±0.35°C (3σ) in 65nm CMOS
No full textIn microprocessors and DRAMs, on-chip temperature sensors are essential components, ensuring reliability by monitoring thermal gradients and hot spots. Such sensors must be as small as possible, since multiple sensors are required for dense thermal monitoring. However, conventional BJT-based temperature sensors are not compatible with the sub-1V supply of advanced processes. Subthreshold MOSFETs can operate from lower supplies, but at high temperatures their performance is limited by leakage [1,2]. Thermal diffusivity (TD) sensors achieve sub-1V operation and small area with moderate accuracy, but require milliwatts of power [3]. Recently, resistor-based sensors based on RC WienBridge (WB) filters have realized high resolution and energy efficiency [4,5]. Fundamentally, they are robust to process and supply-voltage scaling. However, their readout circuitry has been based on continuous-time (CT) ΔΣ ADCs or frequency-locked loops (FLLs), which require precision analog circuits and occupy considerable area (>0.7mm 2 ).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microelectronic
A ±4A high-side current sensor with 25V input CM range and 0.9% gain error from -40°C to 85°C using an analog temperature compensation technique
No full textThis paper presents a fully integrated ±4A current sensor that supports a 25V input common-mode voltage range (CMVR) while operating from a single 1.5V supply. It consists of an on-chip metal shunt, a beyond-the-rails ADC [1] and a temperature-dependent voltage reference. The beyond-the-rails ADC facilitates high-side current sensing without the need for external resistive dividers or level shifters, thus reducing power consumption and system complexity. To compensate for the shunt's temperature dependence, the ADC employs a proportional-to-absolute-temperature (PTAT) reference voltage. Compared to digital temperature compensation schemes [2,3], this analog scheme eliminates the need for a temperature sensor, a band-gap voltage reference and calibration logic. As a result, the current sensor draws only 10.9μA and is 10x more energy efficient than [2]. Over a ±4A range, and after a one-point trim, the sensor exhibits a 0.9% (max) gain error from -40°C to 85°C and a 0.05% gain error at room temperature. The former is comparable with that of other fully-integrated current sensors [2-4], while the latter represents the state-of-the-art.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A phase-domain readout circuit for a CMOS-compatible thermal-conductivity-based carbon dioxide sensor
No full textThe measurement of carbon-dioxide (CO2) concentration is very important in home and building automation, e.g. to control ventilation in energy-efficient buildings. This application requires compact, low-cost sensors that can measure CO2 concentration with a resolution of <200 ppm over a 2500ppm range. Conventional optical (NDIR-based) CO2 sensors require components that are CMOS-incompatible, difficult to miniaturize and power-hungry [1]. Due to their CMOS compatibility, thermal-conductivity-based sensors are an attractive alternative [2,3]. They exploit the fact that the thermal conductivity (TC) of CO2 is lower than that of the other constituents of air, so that CO2 concentration can be indirectly measured via the heat loss of a hot wire to ambient. However, this approach requires the detection of very small changes in TC (0.25 ppm per ppm CO2 [3]).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
Performance of Recirculated PAC for Organic Micropollutant Removal – Development of a Quick Lab Test
No full textOver the last decade, a wide range of organic micropollutants (OMP) has been regularly detected in surface water, groundwater and wastewater treatment plant (WWTP) effluent. These OMPs consist mainly of synthetic organic compounds (SOC) such as pharmaceuticals and pesticides. Although their concentrations in water bodies are usually low, they can cause potential risks to disturbance and affect human as well as environmental health, which has attracted the attention of governments and institutions to search for reliable and simple methods with low cost to remove them. Powdered activated carbon (PAC) adsorption is considered to be an efficient, convenient and cheap method to remove OMPs with low concentrations. However, the adsorption capacity of PAC is not fully used due to a short contact time in the traditional adsorption treatment of dosing PAC into water directly. Therefore, some processes such as the Actiflo Carb or PAC membrane reactors, recirculate PAC in order to increase the contact time. Predicting the performance of older, recirculated PAC is difficult. The objective of this project was to simulate performance of aged PAC using a simple lab-scale experiment. Three different water matrices (tap water, WWTP effluent and diluted WWTP effluent) were used to make the OMPs solutions with 18 selected OMPs of 10 ug/L. PAC was added into the OMPs solutions to make two concentrations of PAC suspension (0.5 g/L and 0.25 g/L). Samples were collected at fixed time intervals. The breakthrough behavior of selected OMPs for aged PAC was then investigated and determined by analyzing the OMPs concentration, UV254 and DOC of samples. The setup was successfully used to record breakthrough curves of 5 different OMPs (Gabapentin, Sulfadimethoxine, Sulfamethoxazole, Metformin and Clofibric acid) and UV254 in 3 different water matrices. Gabapentin was the least adsorbable in tap water and the breakthrough occurred after 10 hours, while in WWTP effluent, Sulfadimethoxine was the least adsorbable OMP with the complete breakthrough time of 14 hours. Propranolol was the most adsorbable compound in both tap water and WWTP effluent. The breakthrough of UV254 was observed later in tap water and WWTP effluent, about 24 hours and 22 hours, respectively. However, parameter DOC can not be used to predicate the breakthrough of OMPs accurately. Model fitting based on the experimental adsorption data was also included.C53cc5303Civil Engineering | Environmental Engineerin
Author Correction: Imaging-based representation and stratification of intra-tumor heterogeneity via tree-edit distance
No full textMartina Sollini and Paola Anna Erba were omitted from the author list in the original version of this Article. The Author Contributions section now reads: “L.C. conceived the pipeline, set up the case study, analysed the results, prepared the figures, and wrote the manuscript. M.P. formulated and tuned the pruned tree edit distance, provided the mathematical proofs and the simulation study, and wrote the manuscript. A.R. contributed to implement the patient representation pipeline. M.S. segmented the Prostate Cancer lesions and extracted the radiomic features for all patients in the case study. P.A.E collected the data and enrolled the patients in the clinical study. F.I. supervised the analyses and the conception of the pipeline. L.C., M.P., A.R. and F.I. reviewed and approved the manuscript.” The original Article and accompanying Supplementary Information file have been corrected.</p
Integration of drinking water treatment plant process models and emulated process automation software
No full textThe objective of this research is to limit the risks of fully automated operation of drinking water treatment plants and to improve their operation by using an integrated system of process models and emulated process automation software. This thesis contains the design of such an integrated system. The use of the system is investigated in the three identified applications, i) optimization of process control, ii) training of operation supervisors and iii) virtual commissioning of process automation software.Water ManagementCivil Engineering and Geoscience
Discolouration loose deposits in distribution systems: Composition, behaviour and practical aspects
No full textThe main objective of the thesis is to contribute to a better understanding of the possible origins and development processes underlying tap water discolouration. With that purpose, qualitative and practical approaches were used for collecting loose deposits samples from distribution networks, i.e., methodologies that may be used together with daily routine procedures by the water companies to prevent and interpret loose deposits accumulation. To investigate the origins of loose deposits, samples were subjected to physical?chemical characterisation, not only for their typical components (Fe, VS), but also for some organic constituents (i.e., EPS). To study loose deposits behaviour, loose deposits observations were followed by stereoscope and microscopy visualizations, as well as turbidity decrease measurements. Studies on loose deposits build?up were assessed with pilot scale experiments, for better knowledge on the loose deposits formation processes taking place at drinking water distribution systems. The microbiological relevance of discolouration loose deposits was also evaluated, including the possible role of bacteria in loose deposits accumulation, in order to appraise the possible effects on water quality upon loose deposits resuspension. Thus, this thesis aims to improve knowledge on the “whys” and “hows” of discolouration events in drinking water distribution systems. More specifically, emphasis was given to understand how such light particulates may accumulate and resist to the shear stresses occurring in drinking water distribution systems, before loose deposits resuspend at one time and cause tap water discolouration.Water ManagementCivil Engineering and Geoscience
- …
