Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
46 result(s) for "Istrate, Andrei"
Sort by:
6’-Fluoro4.3.0bicyclo nucleic acid: synthesis, biophysical properties and molecular dynamics simulations
Here we report on the synthesis, biophysical properties and molecular modeling of oligonucleotides containing unsaturated 6’-fluoro[4.3.0]bicyclo nucleotides (6’F-bc 4,3 -DNA). Two 6’F-bc 4,3 phosphoramidite building blocks (T and C) were synthesized starting from a previously described [3.3.0]bicyclic sugar. The conversion of this sugar to a gem -difluorinated tricyclic intermediate via difluorocarbene addition followed either by a NIS-mediated or Vorbrüggen nucleosidation yielded in both cases the β-tricyclic nucleoside as major anomer. Subsequent desilylation and cyclopropane ring opening of these tricyclic intermediates afforded the unsaturated 6’F-bc 4,3 nucleosides. The successful incorporation of the corresponding phosphoramidite building blocks into oligonucleotides was achieved with tert -butyl hydroperoxide as oxidation agent. Thermal melting experiments of the modified duplexes disclosed a destabilizing effect versus DNA and RNA complements, but with a lesser degree of destabilization versus complementary DNA (Δ T m /mod = −1.5 to −3.7 °C). Molecular dynamics simulation on the nucleoside and oligonucleotide level revealed the preference of the C1’- exo /C2’- endo alignment of the furanose ring. Moreover, the simulation of duplexes with complementary RNA disclosed a DNA/RNA-type duplex structure suggesting that this modification might be a substrate for RNase H.
Automatic Vehicle Recognition: A Practical Approach with VMMR and VCR
Background: Automatic vehicle recognition has recently become an area of great interest, providing substantial support for multiple use cases, including law enforcement and surveillance applications. In real traffic conditions, where for various reasons license plate recognition is impossible or license plates are forged, alternative solutions are required to support human personnel in identifying vehicles used for illegal activities. In such cases, appearance-based approaches relying on vehicle make and model recognition (VMMR) and vehicle color recognition (VCR) can successfully complement license plate recognition. Methods: This research addresses appearance-based vehicle identification, in which VMMR and VCR rely on inherent visual cues such as body contours, stylistic details, and exterior color. In the first stage, vehicles passing through an intersection are detected, and essential visual characteristics are extracted for the two recognition tasks. The proposed system employs deep learning with semantic segmentation and data augmentation for color recognition, while histogram of oriented gradients (HOG) feature extraction combined with a support vector machine (SVM) classifier is used for make-model recognition. For the VCR task, five different neural network architectures are evaluated to identify the most effective solution. Results: The proposed system achieves an overall accuracy of 94.89% for vehicle make and model recognition. For vehicle color recognition, the best-performing models obtain a Top-1 accuracy of 94.17% and a Top-2 accuracy of 98.41%, demonstrating strong robustness under real-world traffic conditions. Conclusions: The experimental results show that the proposed automatic vehicle recognition system provides an efficient and reliable solution for appearance-based vehicle identification. By combining region-tailored data, segmentation-guided processing, and complementary recognition strategies, the system effectively supports real-world surveillance and law-enforcement scenarios where license plate recognition alone is insufficient.
Research on Best Solution for Improving Indoor Air Quality and Reducing Energy Consumption in a High-Risk Radon Dwelling from Romania
The purpose of this article is the assessment of energy efficiency and indoor air quality for a single-family house located in Cluj-Napoca County, Romania. The studied house is meant to be an energy-efficient building with thermal insulation, low U-value windows, and a high efficiency boiler. Increasing the energy efficiency of the house leads to lower indoor air quality, due to lack of natural ventilation. As the experimental campaign regarding indoor air quality revealed, there is a need to find a balance between energy consumption and the quality of the indoor air. To achieve superior indoor air quality, the proposed mitigation systems (decentralized mechanical ventilation with heat recovery combined with a minimally invasive active sub-slab depressurization) have been installed to reduce the high radon level in the dwelling, achieving an energy reduction loss of up to 86%, compared to the traditional natural ventilation of the house. The sub-slab depressurization system was installed in the room with the highest radon level, while the local ventilation system with heat recovery has been installed in the exterior walls of the house. The results have shown significant improvement in the level of radon decreasing the average concentration from 425 to 70 Bq/m3, respectively the carbon dioxide average of the measurements being around 760 ppm. The thermal comfort improves significantly also, by stabilizing the indoor temperature at 21 °C, without any important fluctuations. The installation of this system has led to higher indoor air quality, with low energy costs and significant energy savings compared to conventional ventilation (by opening windows).
Community recommendations on cryoEM data archiving and validation
In January 2020, a workshop was held at EMBL-EBI (Hinxton, UK) to discuss data requirements for the deposition and validation of cryoEM structures, with a focus on single-particle analysis. The meeting was attended by 47 experts in data processing, model building and refinement, validation, and archiving of such structures. This report describes the workshop's motivation and history, the topics discussed, and the resulting consensus recommendations. Some challenges for future methods-development efforts in this area are also highlighted, as is the implementation to date of some of the recommendations.
The path from geology to indoor radon
It is generally accepted that radon emission is strongly influenced by the geological characteristics of the bedrock. However, transport in-soil and entry paths indoors are defined by other factors such as permeability, building and architectural features, ventilation, occupation patterns, etc. The purpose of this paper is to analyze the contribution of each parameter, from natural to man-made, on the radon accumulation indoors and to assess potential patterns, based on 100 case studies in Romania. The study pointed out that the geological foundation can provide a reasonable explanation for the majority of the values recorded in both soil and indoor air. Results also showed that older houses, built with earth-based materials, are highly permeable to soil radon. Energy-efficient houses, on the other hand, have a tendency to disregard the radon potential of the geological foundation, causing a higher predisposition to radon accumulation indoors and decreasing the general indoor air quality.
Numerical analysis of the impact of natural ventilation on the Indoor Air Quality and Thermal Comfort in a classroom
Indoor air quality (IAQ) inside educational institutions is an important topic in the field of building and health research. School absenteeism and educational performance have been linked to poor air quality inside classrooms. A numerical simulation software has been used to test 5 different scenarios of natural ventilation during summer and winter. CO 2 levels, air relative humidity, operative temperature and PMV were used as indoor air quality and thermal comfort indicators. Results have shown high CO 2 and humidity levels when all windows are closed, and a variable improvement when different natural ventilations strategies are employed. A detailed procedure for the numerical simulation has been presented.
Perception Towards Organic vs. Conventional Products in Romania
The aim of this study was to elicit answers referring to the consumer perception with respect to organic products. Factors that determine behavior were also considered: Gender, age, education, income, or social status. Analysis of data collected revealed that perception is the psycho-cognitive element that may determine the expression of behavior in relation to the organic production system. Furthermore, organic farming in Romania is a relatively recently formed market segment. The study was carried out by using a questionnaire developed specifically for this purpose, on a sample of 226 respondents. The data obtained from the survey were analyzed by employing the contingency coefficient and Pearson chi-square tests, using the SPSS software version 20. The perception of organic food is associated with its nutritional quality or sensory attributes (appearance, taste, flavor).
Comparison of indoor air pollutants concentration in two Romanian classrooms
This paper investigates the air pollutions in space ventilated in two High School classrooms. The analysis consists of comparison of one classroom with hybrid ventilation system and another one stander-by classroom with natural ventilation. Several studies regarding indoor air quality during the experimental campaign have been done for VOC, CO 2 , CO, other pollutants, keeping monitored for humidity and temperature. The experimental demonstrated that the highest value for CO 2 in stander-by classroom is 2691 ppm and in classroom with hybrid ventilation is 1897 ppm, while values for CO are 1.1 / 1.1 ppm and VOC 0.14 / 0.06 ppm, better use hybrid ventilation.
6'-Fluoro4.3.0bicyclo nucleic acid: synthesis, biophysical properties and molecular dynamics simulations
Here we report on the synthesis, biophysical properties and molecular modeling of oligonucleotides containing unsaturated 6'-fluoro[4.3.0]bicyclo nucleotides (6'F-bc4,3-DNA). Two 6'F-bc4,3 phosphoramidite building blocks (T and C) were synthesized starting from a previously described [3.3.0]bicyclic sugar. The conversion of this sugar to a gem-difluorinated tricyclic intermediate via difluorocarbene addition followed either by a NIS-mediated or Vorbrüggen nucleosidation yielded in both cases the β-tricyclic nucleoside as major anomer. Subsequent desilylation and cyclopropane ring opening of these tricyclic intermediates afforded the unsaturated 6'F-bc4,3 nucleosides. The successful incorporation of the corresponding phosphoramidite building blocks into oligonucleotides was achieved with tert-butyl hydroperoxide as oxidation agent. Thermal melting experiments of the modified duplexes disclosed a destabilizing effect versus DNA and RNA complements, but with a lesser degree of destabilization versus complementary DNA (ΔT m/mod = -1.5 to -3.7 °C). Molecular dynamics simulation on the nucleoside and oligonucleotide level revealed the preference of the C1'-exo/C2'-endo alignment of the furanose ring. Moreover, the simulation of duplexes with complementary RNA disclosed a DNA/RNA-type duplex structure suggesting that this modification might be a substrate for RNase H.Here we report on the synthesis, biophysical properties and molecular modeling of oligonucleotides containing unsaturated 6'-fluoro[4.3.0]bicyclo nucleotides (6'F-bc4,3-DNA). Two 6'F-bc4,3 phosphoramidite building blocks (T and C) were synthesized starting from a previously described [3.3.0]bicyclic sugar. The conversion of this sugar to a gem-difluorinated tricyclic intermediate via difluorocarbene addition followed either by a NIS-mediated or Vorbrüggen nucleosidation yielded in both cases the β-tricyclic nucleoside as major anomer. Subsequent desilylation and cyclopropane ring opening of these tricyclic intermediates afforded the unsaturated 6'F-bc4,3 nucleosides. The successful incorporation of the corresponding phosphoramidite building blocks into oligonucleotides was achieved with tert-butyl hydroperoxide as oxidation agent. Thermal melting experiments of the modified duplexes disclosed a destabilizing effect versus DNA and RNA complements, but with a lesser degree of destabilization versus complementary DNA (ΔT m/mod = -1.5 to -3.7 °C). Molecular dynamics simulation on the nucleoside and oligonucleotide level revealed the preference of the C1'-exo/C2'-endo alignment of the furanose ring. Moreover, the simulation of duplexes with complementary RNA disclosed a DNA/RNA-type duplex structure suggesting that this modification might be a substrate for RNase H.
Research Regarding the Behavior of Corn Hybrids under Natural and Artificial Infection with Fusarium sp
In the context of climate change, the pressure exercised by pathogens can increase and otherwise resistant genotypes can become vulnerable to the attack of phytopathogens. Maize hybrids are created to be resistant against fusariosis, but under conditions of high infection pressure they may be sensitive to the attack of Fusarium sp. which leads to a lower quantity and quality of the yield. This paper presents a study on the behavior of corn hybrids under the Fusarium spp. attack in natural and artificial conditions of infection. In this context, artificial infections simulate a high pressure of infection. The biological material was represented by three maize hybrids Turda 322, Turda 344 and Marius TD. The experimental variants were: control (natural infection) and artificial infection through inoculation with 4 ml suspension and 8 ml suspension. Following this study, was determined that under conditions of high Fusarium sp. pressure, the frequency of the attack on corn cobs may increase, reaching up to about 90%, but the high pressure of infection and the climatic conditions in 2020 did not influence the intensity of the fusariosis. The yields obtained for the three maize hybrids were between 9.3 and 10.3 t/ha, with the highest value under conditions of low infection pressure (natural infection).