Reduction of fossil fuel usage, clean energy supply, and dependability are all major benefits of integrating distributed energy resources (DER) with electrical utility grid (UG). Nevertheless, there are difficulties with this integration, most notably accidental islanding that puts worker and equipment safety at risk. Islanding detection methods (IDMs) play a critical role in resolving this problem. All IDMs are thoroughly evaluated in this work, which divides them into two categories: local approaches that rely on distributed generation (DG) side monitoring and remote approaches that make use of communication infrastructure. The study offers a comparative evaluation to help choose the most efficient and applicable IDM, supporting well-informed decision-making for the safe and dependable operation of distributed energy systems within electrical distribution networks. IDMs are evaluated based on NDZ outcomes, detection duration, power quality impact, multi-DG operation, suitability, X/R ratio reliance, and efficient functioning.

• Keywords
• Artificial neural network, Distributed generation, Islanding detection, Microgrid, Non-detection zone, Renewable energy, Signal processing,
• Publication type
• Journal Article MeSH

• MeSH
• Borrelia burgdorferi * MeSH
• Animals, Wild parasitology   MeSH
• Ixodes microbiology   MeSH
• Humans MeSH
• Lyme Disease epidemiology   microbiology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Letter MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Channel Islands epidemiology   MeSH

The transplantation of pancreatic islets containing β-cells, which produce insulin, is an alternative approach to the treatment of type 1 diabetes mellitus. The non-invasive visualization of transplanted islets can be performed using MRI; however, this requires labeling of the islets with a suitable contrast agent prior to transplantation. The detection of islets labeled by iron oxide-based contrast agents and transplanted into the liver tissue can be significantly improved using the intravenous administration of a suitable gadolinium contrast agent prior to MRI. The applied contrast agent not only improves the contrast-to-noise ratio, but also eliminates artifacts that may lead to an overestimation of the number of hypointense spots and their area; thus it improves the accuracy of automated and semi-automated procedures used for transplanted islet segmentation and quantification.

• MeSH
• Contrast Media MeSH
• Rats MeSH
• Islets of Langerhans cytology   metabolism   MeSH
• Magnetic Resonance Imaging methods   MeSH
• In Vitro Techniques MeSH
• Islets of Langerhans Transplantation MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Contrast Media MeSH

The fast growth of hydrogen usage as a clean fuel in civil applications such as transportation, space technology, etc. highlights the importance of the reliable detection of its leakage and accumulation under explosion limit by sensors with a low power consumption at times when there is no accumulation of hydrogen in the environment. In this research, a new and efficient mechanism is presented for hydrogen detection-using the Coulomb blockade effect in a well-arranged 2D array of palladium nano-islands-which can operate at room temperature. We demonstrated that under certain conditions of size distribution and the regularity of palladium nano-islands, with selected sizes of 1.7, 3 and 6.1 nm, the blockade threshold will appear in current-voltage (IV) characteristics. In reality, it will be achieved by the inherent uncertainty in the size of the islands in nano-scale fabrication or by controlling the size of nanoparticles from 1.7 to 6.1 nm, considering a regular arrangement of nanoparticles that satisfies single-electron tunneling requirements. Based on the simulation results, the threshold voltage is shifted towards lower ones due to the expansion of Pd nanoparticles exposed to the environment with hydrogen concentrations lower than 2.6%. Also, exploring the features of the presented structure as a gas sensor, provides robustness against the Gaussian variation in nano-islands sizes and temperature variations. Remarkably, the existence of the threshold voltage in the IV curve and adjusting the bias voltage below this threshold leads to a drastic reduction in power consumption. There is also an improvement in the minimum detectable hydrogen concentration as well as the sensor response.

• Keywords
• Coulomb blockade threshold, hydrogen gas sensor, palladium nanoparticles, room temperature, single-electron tunneling,
• Publication type
• Journal Article MeSH

It is generally acknowledged that microplastic pollutants are prevalent in ocean waters and sediments across a range of tropical, temperate, subpolar, and polar regions. The waters surrounding King George Island are significantly impacted by human activities, particularly those related to scientific stations, fishing, and tourism. Organisms, such as Laternula elliptica, can be used as environmental monitors due to the likelihood that they will bioaccumulate pollutants. The goal of this study was to quantify and identify plastic and cellulosic micro-fragments and microfibers present in the soft body of clams (n = 21), collected from Fildes Bay near sewage and wastewater discharges. Plastic and cellulose microfragments and microfibers were counted, and their compositions were determined using FT-IR. All 21 individuals sampled contained fragments and fibers, with a total of 900 items detected (42.86 ± 25.36 mean ± SD items per individual), or 1.82 items g.wet mass-1. 58 % of items were cellulose and 22 % plastic. Considering the plastic polymer compositions, 28.57 % were polyethylene terephthalate (PET), 21.43 % acrylic, 14.29 % high-density polyethylene (HDPE), 14.29 % Polypropylene (PP), 7.14 % ultra-high drawn polyethylene filament (UHMWPE), 7.14 % polyester and 7.14 % Polyethylene. The quantities and prevalence of MP in L. elliptica were higher than those found in other Antarctic marine species, and even in bivalves from populated regions of the world. Our work assessed the pollution status of L. elliptica near an effluent of wastewater plants and found that 95 % of individuals displayed MP and 100 % microfibers that could impact their population.

• Keywords
• Contaminant of emerging concern, Microplastics, Mollusk, Pollution, Western Antarctic Peninsula,
• MeSH
• Cellulose MeSH
• Water Pollutants, Chemical * analysis   MeSH
• Humans MeSH
• Bivalvia * MeSH
• Environmental Monitoring MeSH
• Wastewater MeSH
• Plastics MeSH
• Polyethylene MeSH
• Spectroscopy, Fourier Transform Infrared MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Antarctic Regions MeSH
• Names of Substances
• Cellulose MeSH
• Water Pollutants, Chemical * MeSH
• Wastewater MeSH
• Plastics MeSH
• Polyethylene MeSH

• MeSH
• Blood Vessels anatomy & histology   MeSH
• Surgical Flaps * MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Rheology * MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Ultra-thin, densely packed polymer brushes (PBs) with ultra-low fouling properties play a crucial role in recent developments of surface modification strategies for biomedical and biosensing technologies. However, micro-defects within PB structures can significantly impair their ultra-low fouling performance, thereby reducing their effectiveness and the application potential. Reliable detection of these micro-defects is essential for further evaluation and optimization of brush-based surfaces. In this study, we present a straightforward spectroscopic method for detection of micro-defects in PBs using Raman mapping. We employed random copolymer brushes of carboxybetaine methacrylamide (CBMAA) and N-(2-hydroxypropyl) methacrylamide (HPMAA) as examples of state-of-the-art ultra-low fouling PB systems prepared on a surface-enhanced Raman scattering (SERS)-active Ag nano-island layer fabricated on Au-coated glass substrates. Methylene blue, drop-deposited on the PB surface, is demonstrated as a suitable reporter molecule, providing spectroscopic information via both Raman and fluorescence signals. Analysis of the spectroscopic maps enabled not only the detection of micro-defects but also the differentiation between "shallow" and "deep" defects, providing detailed insights into the structural integrity of ultra-low fouling PBs.

• Keywords
• Low-fouling coating, Micro-defects, Polymer brush, Surface-enhanced Raman scattering, Surface-enhanced fluorescence,
• Publication type
• Journal Article MeSH

This study evaluated the ability of magnetic resonance imaging (MRI) to predict failure of pancreatic islets (PI) transplanted into the hepatic portal vein. Brown-Norway (n = 18) and Lewis (n = 6) rats received islets isolated from Lewis donors. The rejection process in Brown-Norway recipients was mitigated by two different immunosuppressive regimens [tacrolimus + hydrocortisone for 3 months (n = 6) or tacrolimus for 12 days (n = 12)]. Longitudinal MRI monitoring of recipients at post-transplantation weeks 1, 2, 3, 4, 6, 8, 10, and 12 confirmed the ability to detect SPIO labeled PI after transplantation into the liver. The relative number of MRI signals related to PI isografts remained stable up to study completion. Recipients of PI allografts were normoglycemic until the end of study; signals declined gradually to 44 ± 17% in these animals. In animals with islets failure during post-transplant week 12, the number of signals decreased to 25 ± 10% of initial values. The difference between groups (islet function/failed) became significant post-transplant week 3. Our data demonstrate that the MRI changes attributable to rejection become apparent within 3 weeks after transplantation, i.e. at least 8 weeks before functional allograft failure.

• MeSH
• Transplantation, Homologous MeSH
• Rats MeSH
• Islets of Langerhans physiology   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Rats, Inbred BN MeSH
• Rats, Inbred Lew MeSH
• Graft Rejection MeSH
• Islets of Langerhans Transplantation adverse effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

In vitro labeling of pancreatic islets with iron nanoparticles enables their direct posttransplant visualization by magnetic resonance; however, there is still a discrepancy in the fate of iron nanoparticles. This study was performed to detail the labeling process, consequently to improve the labeling efficacy and to confirm safety for islet cells. The islets were visible on T2*-weighted magnetic resonance images as hypointense spots immediately after 1-hr cultivation. Although at this time already the sufficient superparamagnetic effect was achieved, most of the particles were deposed in islet macrophages and only later were they found in endosomes of endocrine islet cells. The iron content depended on length of culture period. The labeled islets showed an intact ultrastructure, responded normally to glucose stimulation in vitro, and were able to treat experimental diabetes. For purpose of subsequent magnetic resonance imaging, a 24-hr culture with ferucarbotran leads to sufficient labeling with no apparent adverse effect on beta cell morphology or function.

• MeSH
• Staining and Labeling methods   MeSH
• Insulin-Secreting Cells pathology   MeSH
• Time Factors MeSH
• Metal Nanoparticles * MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Islets of Langerhans pathology   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Macrophages pathology   MeSH
• Islets of Langerhans Transplantation methods   MeSH
• Ferric Compounds * MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• ferric oxide MeSH Browser
• Ferric Compounds * MeSH

The aim of this study is the analysis of continuous speech signals of people with Parkinson's disease (PD) considering recordings in different languages (Spanish, German, and Czech). A method for the characterization of the speech signals, based on the automatic segmentation of utterances into voiced and unvoiced frames, is addressed here. The energy content of the unvoiced sounds is modeled using 12 Mel-frequency cepstral coefficients and 25 bands scaled according to the Bark scale. Four speech tasks comprising isolated words, rapid repetition of the syllables /pa/-/ta/-/ka/, sentences, and read texts are evaluated. The method proves to be more accurate than classical approaches in the automatic classification of speech of people with PD and healthy controls. The accuracies range from 85% to 99% depending on the language and the speech task. Cross-language experiments are also performed confirming the robustness and generalization capability of the method, with accuracies ranging from 60% to 99%. This work comprises a step forward for the development of computer aided tools for the automatic assessment of dysarthric speech signals in multiple languages.

• MeSH
• Speech Acoustics MeSH
• Reading MeSH
• Adult MeSH
• Phonetics MeSH
• Language * MeSH
• Middle Aged MeSH
• Humans MeSH
• Parkinson Disease diagnosis   physiopathology   MeSH
• Area Under Curve MeSH
• Speech physiology   MeSH
• Recognition, Psychology MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Germany MeSH
• Spain MeSH