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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. CO2 levels, air relative humidity, operative temperature and PMV were used as indoor air quality and thermal comfort indicators. Results have shown high CO2 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.

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, CO2, CO, other pollutants, keeping monitored for humidity and temperature. The experimental demonstrated that the highest value for CO2 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.

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). [ABSTRACT FROM AUTHOR]

A recent challenge in research dedicated to residential exposure to radon comes from the growing number of houses retrofitted to reduce energy consumption. Efficiently insulated buildings and modern architectural solutions can lead to the accumulation of high levels of indoor pollutants. A systematic analysis was conducted in a residential complex (consisting of six houses) in order to assess the annual radon concentration and to evaluate the intensity of the relationships with various factors, such as the indoor-outdoor temperature differences, wind speed and wind direction. Three types of occupational behaviour, influencing the ventilation rate of the dwellings and, implicitly, the indoor radon activity concentration were observed. By calculating the partial correlation coefficient between the radon concentration and the wind direction, with the wind speed as the control variable, for all six houses the correlation coefficient presents negative values. [ABSTRACT FROM AUTHOR]

Copyright of Romanian Journal of Civil Engineering / Revista Română de Inginerie Civilă is the property of Matrix Rom and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Romanian Journal of Civil Engineering / Revista Română de Inginerie Civilă is the property of Matrix Rom and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Radon is a natural radioactive gas that occurs due to the radioactive decay of radium (226Ra) present in rocks which, in turn, cames from the radioactive decay of uranium (238U), a primordial natural element. Along with factors such as porosity, permeability and humidity of the rocks and soils, pressure and temperature, geology setting plays one of the most important roles in the release of radon into the environment. Depending on the mineralogical compositions and characteristics of the bedrock from a certain area, a higher or lower concentration of radioactive minerals can be found in the rocks, which will directly influence the level of radon in the atmosphere, implicitly the concentration of radon measured in houses. In this study, a six months concentration of radon (222Rn) was assessed in 256houses from Cluj-Napoca area using CR-39 nuclear track detectors. Correlations between the indoor radon levels and the geological setting was further analyzed. The aim is to better understand the influence of geology on the concentration of radon levels in homes, in order to further identify other risk areas in terms of exposure to radon. Further investigation is needed on other factors influencing the accumulation of radon in high concentrations indoor, such as ventilation, occupation patterns or constructive and architectural features for typical houses. Therefore, the results of this work are considered to be important for indoor radon management in Romania. [ABSTRACT FROM AUTHOR]

Indoor air quality in schools is one of the main concerns for the health of children. Inside a classroom there are high levels of different pollutants concentrations along with high levels of particulate matter (PM). Many studies showed that PM can severely affect the health of children, especially those with asthma problems. In this article an experimental campaign was conducted in two identical classrooms as size, orientation and number of persons with the purpose to evaluate the PM concentration. The only difference is one classroom is ventilated with fresh air while the other one is not. With two GRIMM measurement equipment we have measured for two days the indoor levels. In fact, the ventilation system was found efficient especially for larger particles (PM10) of dust while for smaller ones (PM1) the results were similar. We have calculated a reduction of PM concentration of 10%,...,12% on the mean values. It is concluded that ventilation of schools has multiple benefits on the indoor air quality. [ABSTRACT FROM AUTHOR]

We describe the synthesis, thermal stability, structural and RNase H activation properties of 2′β-fluoro-tricyclo nucleic acids (2′F-tc-ANA). Three 2′F-tc-ANA nucleosides (T, 5MeC and A) were synthesized starting from a previously described fluorinated tricyclo sugar intermediate. NMR analysis and quantum mechanical calculations indicate that 2′F-tc-ANA nucleosides prefer sugar conformations in the East and South regions of the pseudorotational cycle. UV-melting experiments revealed that non-consecutive insertions of 2′F-tc-ANA units in DNA reduce the affinity to DNA and RNA complements. However, an oligonucleotide with five contiguous 2′F-tc-ANA-T insertions exhibits increased affinity to complementary RNA. Moreover, a fully modified 10-mer 2′F-tc-ANA oligonucleotide paired to both DNA (+1.6 °C/mod) and RNA (+2.5 °C/mod) with significantly higher affinity compared to corresponding unmodified DNA, and similar affinity compared to corresponding tc-DNA. In addition, CD spectroscopy and molecular dynamics simulations indicate that the conformation of the 2′F-tc-ANA/RNA duplex is similar to that of a DNA/RNA duplex. Moreover, in some sequence contexts, 2′F-tc-ANA promotes RNase H-mediated cleavage of a complementary RNA strand. Taken together, 2′F-tc-ANA represents a nucleic acid analogue that offers the advantage of high RNA affinity while maintaining the ability to activate RNase H, and can be considered a prospective candidate for gene silencing applications. [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

What a difference a fluorine makes when introduced into the 2′ ‐ β ‐ position of the tricyclo ‐ DNA skeleton (2′F ‐ tc ‐ ANA). It steers the conformation of the furanose unit into an eastern conformation. Fully modified 2′F ‐ tc ‐ ANA shows enhanced binding to complementary RNA in the same way as parent tc ‐ DNA. Embedded in a 2′OMe ‐ RNA hybrid construct it enables RNaseH cleavage of a complementary RNA target, thus enhancing the application range of the tc ‐ DNA family as antisense agents. More information can be found in the Full Paper by C. J. Leumann et al. on page 10310. [ABSTRACT FROM AUTHOR]

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., (open access.)

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.

We describe the synthesis, thermal stability, structural and RNase H activation properties of 2'β-fluoro-tricyclo nucleic acids (2'F-tc-ANA). Three 2'F-tc-ANA nucleosides (T, 5Me C and A) were synthesized starting from a previously described fluorinated tricyclo sugar intermediate. NMR analysis and quantum mechanical calculations indicate that 2'F-tc-ANA nucleosides prefer sugar conformations in the East and South regions of the pseudorotational cycle. UV-melting experiments revealed that non-consecutive insertions of 2'F-tc-ANA units in DNA reduce the affinity to DNA and RNA complements. However, an oligonucleotide with five contiguous 2'F-tc-ANA-T insertions exhibits increased affinity to complementary RNA. Moreover, a fully modified 10-mer 2'F-tc-ANA oligonucleotide paired to both DNA (+1.6 °C/mod) and RNA (+2.5 °C/mod) with significantly higher affinity compared to corresponding unmodified DNA, and similar affinity compared to corresponding tc-DNA. In addition, CD spectroscopy and molecular dynamics simulations indicate that the conformation of the 2'F-tc-ANA/RNA duplex is similar to that of a DNA/RNA duplex. Moreover, in some sequence contexts, 2'F-tc-ANA promotes RNase H-mediated cleavage of a complementary RNA strand. Taken together, 2'F-tc-ANA represents a nucleic acid analogue that offers the advantage of high RNA affinity while maintaining the ability to activate RNase H, and can be considered a prospective candidate for gene silencing applications., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)