335 research outputs found
Nephrotic hyperlipidemia: is inhibition of receptor-mediated edocytosis involved?
Hyperlipidemia is a consistent feature of the nephrotic syndrome (NS) and is usually of the IIa or IIb Fredrickson type. In cases with severe hypoalbuminemia (15 g/l or less) very low density lipoproteins (VLDL) also increase and the ratio of cholesterol to triglyceride falls. The nephrotic hyperlipidemia is generally considered to be due to increased hepatic synthesis and secretion of lipoproteins, but there are also investigations showing altered lipoprotein clearance. Warwick et al have found a trend towards lower fractional catabolic rate of intermediate density lipoproteins (IDL) and low density lipoproteins (LDL) in nephrotic patients with relatively well maintained serum albumin despite the heavy proteinuria. In another group of nephrotic patients with lower plasma albumin levels, the amount of LDL cleared by receptor-mediated endocytosis (RME) was only 55% of the value seen in controls, while 60% more LDL were channeled into alternative catabolic pathways. In experimental NS, delayed removal of chylomicron remnants was revealed as well. Chylomicron remnants are taken up by the liver via the LDL receptor-related protein (LRP). Recently, evidences were provided that receptor for activated α2-macroglobulin (α2-macroglobulin-proteinase complex) and the LRP are one and the same entity. α2-macroglobulin seems to control the activity of proteinases not by active site-directed inhibition but by steric shielding and rapid clearance. The plasma levels of α2-macroglobulin are consistently elevated in NS, but to the best of my knowledge, there are insufficient data about the uptake of α2-macroglobulin-proteinase complexes. Asami et al reported a glomerular deposition of α2-macroglobulin in a child with steroid refractory NS, but such depositions were not detected in other nephrotic patients. Biochemical and clinical improvement was observed in this case after treatment with the synthetic proteinase inhibitor camostat mesylate, but the dynamics of α2-macroglobulin depositions was not examined.Biomedical Reviews 1994; 3: 77-79
Objective and efficient terahertz signal denoising by transfer function reconstruction
As an essential processing step in many disciplines, signal denoising efficiently improves data quality without extra cost. However, it is relatively under-utilized for terahertz spectroscopy. The major technique reported uses wavelet denoising in the time-domain, which has a fuzzy physical meaning and limited performance in low-frequency and water-vapor regions. Here, we work from a new perspective by reconstructing the transfer function to remove noise-induced oscillations. The method is fully objective without a need for defining a threshold. Both reflection imaging and transmission imaging were conducted. The experimental results show that both low- and high-frequency noise and the water-vapor influence were efficiently removed. The spectrum accuracy was also improved, and the image contrast was significantly enhanced. The signal-to-noise ratio of the leaf image was increased up to 10 dB, with the 6 dB bandwidth being extended by over 0.5 THz
Real-time terahertz imaging with a single-pixel detector
Terahertz (THz) radiation is poised to have an essential role in many imaging applications, from industrial inspections to medical diagnosis. However, commercialization is prevented by impractical and expensive THz instrumentation. Single-pixel cameras have emerged as alternatives to multi-pixel cameras due to reduced costs and superior durability. Here, by optimizing the modulation geometry and post-processing algorithms, we demonstrate the acquisition of a THz-video (32 × 32 pixels at 6 frames-per-second), shown in real-time, using a single-pixel fiber-coupled photoconductive THz detector. A laser diode with a digital micromirror device shining visible light onto silicon acts as the spatial THz modulator. We mathematically account for the temporal response of the system, reduce noise with a lock-in free carrier-wave modulation and realize quick, noise-robust image undersampling. Since our modifications do not impose intricate manufacturing, require long post-processing, nor sacrifice the time-resolving capabilities of THz-spectrometers, their greatest asset, this work has the potential to serve as a foundation for all future single-pixel THz imaging systems
Is uremia an example of acquired inhibition of receptor-mediated endocytosis?
Many factors that inhibit receptor-mediated endocytosis (RME) at postreceptor level in vitro have been described: (i) high concentration of urea, (ii) lowering of intracellular pH, (iii) hypotonic or hypertonic media, (iv) intracellular potassium depletion, (v) depletion of cellular ATP, (vi) inhibition of the enzyme transglutaminase, (vii) impairment of receptor recycling by rising of the endosomal pH, (viii) disruption of microtubules. Nearly all or all of the factors mentioned above are present as disturbances of homeostasis in uremia. The magnitude of the factors inhibiting RME in vitro is considerably greater than the deviations observed in uremia, but in vitro almost complete inhibition of RME is aimed and also in uremia all of the factors act together. The hypothesis that RME is inhibited in uremia is supported by the metabolism of macromolecules known or supposed to be internalized by this process. Although glucose intolerance in uremia is due to a postreceptor defect in insulin action, impaired RME at postreceptor level, to the best of my knowledge, has not been pointed as a general feature of uremia. In addition to uremia, there might be other clinical examples of inhibited RME at postreceptor level as well.Biomedical Reviews 1993; 2: 57-75
Compressed sensing with near-field THz radiation
We demonstrate a form of near-field terahertz (THz) imaging that is compatible with compressed sensing algorithms. By spatially photomodulating THz pulses using a set of shaped binary optical patterns and employing a 6-μm-thick silicon wafer, we are able to reconstruct THz images of an object placed on the exit interface of the wafer. A single-element detector is used to measure the electric field amplitude of transmitted THz radiation for each projected pattern, with the ultra-thin wafer allowing us to access the THz evanescent near fields to achieve a spatial resolution of ∼9 μm∼9 μm
Dvije slavenske tiskovine 16. stoljeća iz hrvatskog područja otkrivene u biblioteci Civica u Vicenzi Knižice krsta Šimuna Kožičića (Rijeka 1531.) i Molitvenik (Venecija 1571.)
L’autore descrive le copie di due paleotipi di area croata recentemente ritrovate nella Biblioteca Bertoliana di Vicenza: del glagolitico Knižice krsta di Šimun Kožičić, stampato a Rijeka (Fiume) nel 1531, la cui copia vicentina e la terza sinora nota al mondo, e del cirillico Ofi čje svete dieve Marie comprensivo delle Preghiere di santa Brigida, noto anche come Libro d’Ore (Molitvenik), stampato a Venezia nel 1571. In relazione al Libro d’Ore si rimettono in discussione sia la personalita di uno dei suoi editori che fi rma come Jakob’ de Barom’, sia il rapporto tra questo libro e le edizioni veneziane del 1512 degli Uffi ci della Santa Vergine Maria e delle 15 preghiere della santa Brigida.Autor opisuje dvije stare slavenske tiskovine iz hrvatskoga područja nedavno otkrivene u Biblioteci Bertoliana u Vicenzi: glagoljske Knižice krsta Šimuna Kožičića tiskane u Rijeci 1531., čiji je primjerak iz Vicenze treći dosad poznati, te ćirilsko izdanje Ofičje svete dieve Marie s Molitvama svete Brigite, poznato i kao Molitvenik tiskan u Veneciji 1571. Raspravlja se o identifikaciji jednoga od izdavača Molitvenika koji se potpisao kao Jakob’ de Barom’ te o odnosu te knjige i venecijanskoga izdanja Ofičja svete dieve Marie iz 1512., koje sadrži 15 molitava sv. Brigite
Introducing a novel multi-objective optimization model for volunteer assignment in the post-disaster phase: Combining fuzzy inference systems with NSGA-II and NRGA
Each year, disasters (natural or man-made) cause a lot of damage and take many people’s lives. In this situation,
many volunteers come to help. While the proper management of volunteers is very effective in controlling the
crisis, the lack of proper management of volunteers can create another crisis. Therefore, we introduce a model to
deal with the volunteer assignment problem by considering two qualitative objective functions: The first one is
minimizing the mean importance of Emergency Department (ED) centers’ unmet needs by volunteers, and the
second one is minimizing the mean degree of unsatisfied preferences of selected volunteers. To evaluate the
introduced qualitative indexes, two Fuzzy Inference Systems (FISs) are used to encapsulate decision makers’
knowledge as well as the human reasoning process. FISs are embedded in two evolutionary algorithms for solving
the proposed model: Non-Dominated Sorting Genetic Algorithm II (NSGA-II) and Non-Dominated Ranked Genetic
Algorithm (NRGA). Also, 30 small-size problems, as well as 30 large-size problems, are randomly generated
and solved by both metaheuristic algorithms. Using the obtained data, the performance of NSGA-II and NRGA is
measured and compared based on four criteria: CPU Time, Number of Non-dominated Solutions (NNS), Mean
Ideal Distance (MID), and Spacing Metric (SM). Statistical tests show that both algorithms have the same performance
in small-size problems. However, in large-size problems, NSGA-II is faster, and NRGA produces more
optimal solutions. The proposed model is flexible enough to adapt to different scenarios just by updating linguistic
rules in FISs. Also, since employed algorithms produce a set of optimal solutions, decision-makers can
easily choose the most appropriate solution among the Pareto front based on the circumstancesH2020-EU.1.3. – EXCELLEN
Dvije slavenske tiskovine 16. stoljeća iz hrvatskog područja otkrivene u biblioteci Civica u Vicenzi Knižice krsta Šimuna Kožičića (Rijeka 1531.) i Molitvenik (Venecija 1571.)
L’autore descrive le copie di due paleotipi di area croata recentemente ritrovate nella Biblioteca Bertoliana di Vicenza: del glagolitico Knižice krsta di Šimun Kožičić, stampato a Rijeka (Fiume) nel 1531, la cui copia vicentina e la terza sinora nota al mondo, e del cirillico Ofi čje svete dieve Marie comprensivo delle Preghiere di santa Brigida, noto anche come Libro d’Ore (Molitvenik), stampato a Venezia nel 1571. In relazione al Libro d’Ore si rimettono in discussione sia la personalita di uno dei suoi editori che fi rma come Jakob’ de Barom’, sia il rapporto tra questo libro e le edizioni veneziane del 1512 degli Uffi ci della Santa Vergine Maria e delle 15 preghiere della santa Brigida.Autor opisuje dvije stare slavenske tiskovine iz hrvatskoga područja nedavno otkrivene u Biblioteci Bertoliana u Vicenzi: glagoljske Knižice krsta Šimuna Kožičića tiskane u Rijeci 1531., čiji je primjerak iz Vicenze treći dosad poznati, te ćirilsko izdanje Ofičje svete dieve Marie s Molitvama svete Brigite, poznato i kao Molitvenik tiskan u Veneciji 1571. Raspravlja se o identifikaciji jednoga od izdavača Molitvenika koji se potpisao kao Jakob’ de Barom’ te o odnosu te knjige i venecijanskoga izdanja Ofičja svete dieve Marie iz 1512., koje sadrži 15 molitava sv. Brigite
- …