Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
84
result(s) for
"Preda, Ioana"
Sort by:
Review of Technologies and Materials Used in High-Voltage Film Capacitors
by
Preda, Ioana
,
David, Éric
,
Gnonhoue, Olatoundji Georges
in
Aluminum
,
Capacitors
,
Circuit breakers
2021
High-voltage capacitors are key components for circuit breakers and monitoring and protection devices, and are important elements used to improve the efficiency and reliability of the grid. Different technologies are used in high-voltage capacitor manufacturing process, and at all stages of this process polymeric films must be used, along with an encapsulating material, which can be either liquid, solid or gaseous. These materials play major roles in the lifespan and reliability of components. In this paper, we present a review of the different technologies used to manufacture high-voltage capacitors, as well as the different materials used in fabricating high-voltage film capacitors, with a view to establishing a bibliographic database that will allow a comparison of the different technologies
Journal Article
Current Strategies to Enhance Delivery of Drugs across the Blood–Brain Barrier
by
Niculescu, Adelina-Gabriela
,
Teleanu, Daniel Mihai
,
Teleanu, Raluca Ioana
in
Alzheimer's disease
,
Blood vessels
,
blood–brain barrier
2022
The blood–brain barrier (BBB) has shown to be a significant obstacle to brain medication delivery. The BBB in a healthy brain is a diffusion barrier that prevents most substances from passing from the blood to the brain; only tiny molecules can pass across the BBB. The BBB is disturbed in specific pathological illnesses such as stroke, diabetes, seizures, multiple sclerosis, Parkinson’s disease, and Alzheimer’s disease. The goal of this study is to offer a general overview of current brain medication delivery techniques and associated topics from the last five years. It is anticipated that this review will stimulate readers to look into new ways to deliver medications to the brain. Following an introduction of the construction and function of the BBB in both healthy and pathological conditions, this review revisits certain contested questions, such as whether nanoparticles may cross the BBB on their own and if medications are selectively delivered to the brain by deliberately targeted nanoparticles. Current non-nanoparticle options are also discussed, including drug delivery via the permeable BBB under pathological circumstances and the use of non-invasive approaches to improve brain medication absorption.
Journal Article
Antifungal and Antioxidant Activity of Thiourea Derivatives Against Nosocomial Candida auris Strains Isolated in Romania
by
Popescu, Oana
,
Dragomir, Rareș-Ionuț
,
Tudor, Corneliu
in
Antifungal agents
,
Antifungal Agents - chemistry
,
Antifungal Agents - pharmacology
2025
Nosocomial fungal infections caused by Candida auris pose a threat to public health due to their increased resistance to common antifungal drugs. Four thiourea derivatives of 2-thiophenecarboxylic acid were evaluated for their antifungal and antioxidant activity. The antifungal activity of the compounds was tested against strains of C. auris isolated from a hospital in Romania. With a notable inhibitory effect on C. auris biofilm growth and microbial adherence, the ortho-methylated derivative (SB2) showed the highest antifungal activity. Furthermore, emphasizing the impact of structural factors on the electron-donating capacity of these compounds, antioxidant activity assays (DPPH, FRAP, TEAC and CUPRAC) identified the SB2 compound as having the highest antihemolytic and antioxidant effects. The low cytotoxicity validated by hemocompatibility assays makes these compounds options for antifungal treatment. The results show that antifungal and antioxidant action is greatly influenced by structural modifications, especially the position of the methyl group on the aromatic ring. The possible clinical uses of these molecules as drugs for the treatment of multidrug-resistant C. auris infections needs further investigation.
Journal Article
Short lifespan of syngeneic transplanted MSC is a consequence of in vivo apoptosis and immune cell recruitment in mice
2021
Mesenchymal stromal cells (MSC) are attractive tools for cell-based therapy, yet the mechanisms underlying their migration and survival post-transplantation are unclear. Accumulating evidence indicates that MSC apoptosis modulates both innate and adaptive immune responses which impact on MSC therapeutic effects. Using a dual tracking system, namely the Luciferase expression and VivoTrack680 labelling, and in vivo optical imaging, we investigated the survival and migration of MSC transplanted by various routes (intravenous, subcutaneous, intrapancreatic and intrasplenic) in order to identify the best delivery approach that provides an accumulation of therapeutic cells to the injured pancreas in the non-obese diabetic (NOD) mouse. The results showed that transplanted MSC had limited migration capacity, irrespective of the administration route, and were short-lived with almost total disappearance at 7 days after transplantation. Within one day after transplantation, cells activated hypoxia signalling pathways, followed by Caspase 3-mediated apoptosis. These were subsequently followed by local recruitment of immune cells at the transplantation site, and the engulfment of apoptotic MSC by macrophages. Our results argue for a “hit and die” mechanism of transplanted MSC. Further investigations will elucidate the molecular crosstalk between the inoculated and the host-immune cells.
Journal Article
Alien plant species distribution in Romania: a nationwide survey following the implementation of the EU Regulation on Invasive Alien Species
by
Radutoiu, Daniel
,
Soare, Liliana
,
Milanovici, Sretco
in
Angiospermae
,
Asteraceae
,
Biodiversity
2024
Biological invasions pose an increasing risk to nature, social security and the economy, being ranked amongst the top five threats to biodiversity. Managing alien and invasive species is a priority for the European Union, as outlined in the EU Biodiversity Strategy for 2030 and the Kunming-Montreal Global Biodiversity Framework. Alien plant species are acknowledged to impact the economy and biodiversity; thus, analysing the distribution of such species provides valuable inputs for the management and decision-making processes. The database presented in the current study is the first consolidated checklist of alien plant species that are present in Romania, both of European Union concern and of national interest. This database complements a prior published distribution, based only on records from literature, bringing new information regarding the occurrence of alien plants in Romania, as revealed by a nationwide field survey. We consider this database a valuable instrument for managing biological invasions at both national and regional levels, as it can be utilised in further research studies and in drafting management and action plans, assisting stakeholders in making informed decisions and implementing management actions. We present the results of the first nationwide survey of alien plant species in Romania, conducted between 2019 and 2022, in the framework of a national project coordinated by the Ministry of Environment, Waters and Forests and the University of Bucharest. The present database complements and updates the database published by Sirbu et. al (2022), which included occurrence records published until 2019. The new database includes 98323 occurrence records for 396 alien plant species in 77 families, with most species belonging to the Asteraceae family. One alien plant species in our database, the black locust Robinia pseudoacacia L., had more than 10,000 occurrence records. The distribution database also includes information on newly-reported invasive alien plant species of European Union concern in Romania (i.e. the floating primrose-willow Ludwigia peploides (Kunth) P.H.Raven) and documents the presence of plants in 44 additional families compared to Sirbu et al. (2022). Each entry includes information on species taxonomy, location, year, person who recorded and identified the alien plant, geographical coordinates and taxon rank.
Journal Article
IoT Botnet Anomaly Detection Using Unsupervised Deep Learning
by
Nila, Constantin
,
Apostol, Ioana
,
Bica, Ion
in
Algorithms
,
Anomalies
,
Artificial intelligence
2021
The Internet of Things has become a cutting-edge technology that is continuously evolving in size, connectivity, and applicability. This ecosystem makes its presence felt in every aspect of our lives, along with all other emerging technologies. Unfortunately, despite the significant benefits brought by the IoT, the increased attack surface built upon it has become more critical than ever. Devices have limited resources and are not typically created with security features. Lately, a trend of botnet threats transitioning to the IoT environment has been observed, and an army of infected IoT devices can expand quickly and be used for effective attacks. Therefore, identifying proper solutions for securing IoT systems is currently an important and challenging research topic. Machine learning-based approaches are a promising alternative, allowing the identification of abnormal behaviors and the detection of attacks. This paper proposes an anomaly-based detection solution that uses unsupervised deep learning techniques to identify IoT botnet activities. An empirical evaluation of the proposed method is conducted on both balanced and unbalanced datasets to assess its threat detection capability. False-positive rate reduction and its impact on the detection system are also analyzed. Furthermore, a comparison with other unsupervised learning approaches is included. The experimental results reveal the performance of the proposed detection method.
Journal Article
Phenotypic and genotypic virulence features of staphylococcal strains isolated from difficult-to-treat skin and soft tissue infections
by
Holban, Alina Maria
,
Dițu, Lia-Mara
,
Popa, Gabriela-Loredana
in
Antibiotics
,
Antigens
,
Apoptosis
2021
Chronic infections represent an important burden on the healthcare system and have a significant impact on the patients’ quality of life. While Staphylococcus spp. are commensal bacteria, they can become pathogenic, leading to various types of infections. In this study we aimed to characterize the virulence profiles of staphylococcal strains involved in difficult-to-treat skin and soft tissue infections, from both phenotypic and genotypic points of view. Phenotypic ability of the strains to secrete soluble virulence factors was assessed by a culturing dependent assay and their capacity to develop biofilms on inert substrate was screened by an adapted crystal violet microtiter method. We also tested the presence of several virulence genes by PCR. Most of the studied strains were isolated from purulent secretions of acne lesions and frequently secreted two or three soluble virulence factors. Most frequently secreted soluble virulence factors were caseinase (89%), lipase (71%) and lecithinase (67%). Almost half of the strains produced a well-represented biofilm. The molecular characterization showed the presence of the genes cna , hlg , clfA , and clfB . Staphylococcal strains that produce difficult-to-treat skin and soft tissue infections seem to be characterized by an enhanced ability to produce different soluble virulence factors and to develop biofilms in vitro . Further studies need to be developed in other Staphylococcus spp. infections in order to confirm this hypothesis.
Journal Article
Structural, morphological and magnetic investigations on cobalt ferrite nanoparticles obtained through green synthesis routes
by
Bartha, Cristina
,
Iacob, Nicusor
,
Mindru, Ioana
in
Applied physics
,
Characterization and Evaluation of Materials
,
Chemical synthesis
2021
This paper describes for the first time two processing routes—the precursor method and the two-step wet chemical process—for the synthesis of magnetic cobalt ferrite using the
Tamarindus indica
fruit extract. These green approaches are eco-friendly, safe and efficient alternatives to classical chemical methods. The aqueous extract from tamarind fruit contains numerous metabolites (organic acids, aminoacids). All these bioactive components are able to chelate metal ions leading to the formation of the multimetallic complex (precursor of cobalt ferrite). The obtained precursor was characterized by Fourier transform infrared spectroscopy (FTIR), thermal analysis, X-ray diffraction analysis (XRD) and magnetic measurements. The structure, morphology and magnetic behavior of the cobalt ferrite samples prepared through both synthesis routes were investigated by various characterization techniques: FTIR, XRD, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), Mössbauer spectroscopy and magnetic measurements. XRD data confirmed that a cubic spinel structure was obtained for both ferrite powders with average crystallite size of 13 and 5 nm, respectively. The microstructure study by SEM revealed the formation of nanocrystallites assemblies using the precursor method and carbon-rich particles forming granulated micron-sized agglomerates, embedding ferrite nanocrystallites obtained through the two-step wet chemical process. Mössbauer spectroscopy results evidenced relaxation processes in the CoFe
2
O
4
samples at room temperature, and the main characteristics of the involved sublattices were derived. The magnetic investigation revealed a typical magnetic behavior for a spinel, with CoFe
2
O
4
nanoparticles ferrimagnetic at low temperature and superparamagnetic at room temperature.
Journal Article
Tsallis Entropy for Loss Models and Survival Models Involving Truncated and Censored Random Variables
2022
The aim of this paper consists in developing an entropy-based approach to risk assessment for actuarial models involving truncated and censored random variables by using the Tsallis entropy measure. The effect of some partial insurance models, such as inflation, truncation and censoring from above and truncation and censoring from below upon the entropy of losses is investigated in this framework. Analytic expressions for the per-payment and per-loss entropies are obtained, and the relationship between these entropies are studied. The Tsallis entropy of losses of the right-truncated loss random variable corresponding to the per-loss risk model with a deductible d and a policy limit u is computed for the exponential, Weibull, χ2 or Gamma distribution. In this context, the properties of the resulting entropies, such as the residual loss entropy and the past loss entropy, are studied as a result of using a deductible and a policy limit, respectively. Relationships between these entropy measures are derived, and the combined effect of a deductible and a policy limit is also analyzed. By investigating residual and past entropies for survival models, the entropies of losses corresponding to the proportional hazard and proportional reversed hazard models are derived. The Tsallis entropy approach for actuarial models involving truncated and censored random variables is new and more realistic, since it allows a greater degree of flexibility and improves the modeling accuracy.
Journal Article
Assessment of SiO2 Nanotube Activity to Modify DL α-Tocopherol via 1O2 Generation Under Visible Light Irradiation
by
Socoteanu, Radu
,
Bratan, Veronica
,
Zaharescu, Maria
in
Antimicrobial agents
,
Biocompatibility
,
Biomedical materials
2025
This work investigates photoactive inorganic powders (SiO2, IrSiO2, and IrO2/IrSiO2) and their derivatives modified with metallated porphyrin, focusing on their ability to generate reactive oxygen species (ROS) under visible light exposure. The core material, SiO2, exhibits a tubular morphology and a high density of optically active defects. Modifiers such as metallic and iridium oxide nanoparticles, along with porphyrin, are employed to enhance light absorption and the generation of singlet oxygen (1O2) for potential biomedical applications. The time-dependent photogeneration of singlet oxygen is monitored using a Singlet Oxygen Green Sensor (SOSG), and its reactivity is evaluated in relation to DL α-Tocopherol through a spectrofluorimetric analysis. The photoactive materials, both before and after porphyrin modification, are characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), X-ray Fluorescence (XRF), UV–Vis Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), N2 adsorption–desorption measurements, and zeta potential measurements.
Journal Article