Molecular Dynamics Study of Charged Dendrimers in Salt-Free Solution: Effect of Counterions

Polyamidoamine (PAMAM) dendrimers, being protonated under physiological conditions, represent a promising class of nonviral, nano-sized vectors for drug and gene delivery. We performed extensive molecular dynamics simulations of a generic model dendrimer in a salt-free solution with dendrimer's terminal beads positively charged. Solvent molecules as well as counterions were explicitly included as interacting beads. We find that the size of the charged dendrimer depends non-monotonically on the strength of electrostatic interactions demonstrating a maximum when the Bjerrum length equals the diameter of a bead. Many other structural and dynamic characteristics of charged dendrimers are also found to follow this pattern. We address such a behavior to the interplay between repulsive interactions of the charged terminal beads and their attractive interactions with oppositely charged counterions. The former favors swelling at small Bjerrum lengths and the latter promotes counterion condensation. Thus, counterions can have a dramatic effect on the structure and dynamics of charged dendrimers and, under certain conditions, cannot be treated implicitly

Phase Diagram and Commensurate-Incommensurate Transitions in the Phase Field Crystal Model with an External Pinning Potential

We study the phase diagram and the commensurate-incommensurate transitions in a phase field model of a two-dimensional crystal lattice in the presence of an external pinning potential. The model allows for both elastic and plastic deformations and provides a continuum description of lattice systems, such as for adsorbed atomic layers or two-dimensional vortex lattices. Analytically, a mode expansion analysis is used to determine the ground states and the commensurate-incommensurate transitions in the model as a function of the strength of the pinning potential and the lattice mismatch parameter. Numerical minimization of the corresponding free energy shows good agreement with the analytical predictions and provides details on the topological defects in the transition region. We find that for small mismatch the transition is of first-order, and it remains so for the largest values of mismatch studied here. Our results are consistent with results of simulations for atomistic models of adsorbed overlayers

Oppilaan sosioemotionaaliset taidot:tukikeinot koulussa ja tukemisen laaja-alaiset vaikutukset

Tiivistelmä. Sosioemotionaaliset taidot ovat merkittävässä roolissa yksilön kokonaisvaltaisen kehityksen kannalta. Sosioemotionaalisten taitojen on havaittu olevan yhteydessä muun muassa yksilön ajattelukykyyn sekä kykyyn säädellä omia tunteita ja käyttäytymistä, jotka puolestaan auttavat selviytymään elämän haastavista tilanteista. Sosioemotionaalisilla taidoilla on yhteyttä myös yksilön koulumenestykseen sekä sosiaalisten suhteiden solmimiseen ja ylläpitoon. Yksilön sosioemotionaalisilla taidoilla on merkittäviä vaikutuksia myös luokka- ja kouluyhteisölle sekä laajemmin yhteiskunnalle. Tutkimustulokset osoittavat oppilaiden sosioemotionaalisen kyvykkyyden vähentävän aggressiivista käyttäytymistä luokassa sekä lisäävän positiivista luokkailmapiiriä. Yhteiskunnan tasolta tarkasteltuna sosioemotionaaliset taidot ovat merkittäviä monesta eri syystä: hyvät sosioemotionaaliset taidot edistävät yksilön mielenterveyttä ja näin vähentävät muun muassa syrjäytymisriskiä ja työttömyyttä. Sosioemotionaalisesti kyvykkäät yksilöt voidaankin nähdä toimivan aktiivisina yhteiskunnan jäseninä. Tämän vuoksi näiden taitojen harjoitteluun tulisi panostaa jo varhaisina kouluvuosina. Vaikka sosioemotionaalisten taitojen opettaminen kuuluu osaksi opetussuunnitelmaa, ei opettajilla ole yleisesti ottaen tarvittavia työkaluja näiden taitojen opettamiseksi. Tutkielman aineistosta kävi ilmi, että sosioemotionaalisia taitoja voidaan tukea monin keinoin kuten interventioilla, vuorovaikutusta tukemalla sekä oppilaita osallistavalla opetuksella. On myös huomattava, että opettajan olemuksella, opettaja-oppilassuhteella sekä koulun toimintaperiaatteilla on suuri merkitys oppilaiden sosioemotionaalisiin taitoihin. Keskeistä oppilaiden sosioemotionaalisten taitojen tukemisessa on kuitenkin varata riittävästi aikaa näiden taitojen harjoittelemiselle, sillä taitojen omaksuminen ei tapahdu hetkessä. Sosioemotionaalisia taitoja tukevat harjoitteet tulisikin integroida opetuksen jatkuviin käytänteisiin, jotta kestäviä tuloksia voidaan saavuttaa. Tämän kandidaatintutkielman tavoitteena on tuoda näkyväksi keinoja, joilla oppilaiden sosioemotionaalisia taitoja voidaan tukea alakoulussa sekä selvittää, mitä käytetyissä harjoitteissa tulee ottaa huomioon. Tavoitteenamme on myös kuvata sosioemotionaalisten taitojen merkitystä niin yksilön, luokkayhteisön kuin yhteiskunnankin tasoilla.Pupil’s socio-emotional skills : school support and the broad effects of support. Abstract. Socio-emotional skills play a significant role in the individuals’ overall development. Socio-emotional skills have been found to be associated with an individual’s ability to think and ability to regulate their own feelings and behaviors, which in turn help them to cope with challenging situations one may face. Socio-emotional skills are also linked to an individual’s school success and the establishment and maintenance of social relationships. An individual’s socio-emotional skills also have a significant impact on the class, school community and the whole society. The research results show that students’ socio-emotional ability reduces aggressive behavior in the classroom and increases the positive classroom atmosphere. At the societal level, socio-emotional skills are important for several reasons: good socio-emotional skills promote an individual’s mental health and thus reduce the risk of exclusion and unemployment. Thus, socio-emotionally capable individuals can be seen as active members of society and therefore the training of these skills should be invested in the early school years. Although teaching socio-emotional skills is a part of the schools’ curriculum, teachers generally do not have the necessary tools to teach these skills. The data of the research showed that socio-emotional skills can be supported in many ways, such as interventions, supporting interaction and participatory teaching. It should also be noted that the teacher’s characteristics, the teacher-student relationship, and the school’s principles play a major role in students’ socio-emotional skills. However, the key to supporting students’ socio-emotional skills is to set aside enough time to practice these skills, as the acquisition of skills does not happen in an instant. Exercises that support socio-emotional skills should therefore be integrated into ongoing teaching practices to achieve lasting results. The aim of this bachelor’s thesis is to highlight the ways in which students’ socio-emotional skills can be supported in primary school and to find out what should be considered in the exercises used. Our aim is also to describe the importance of socio-emotional skills at the level of the individual, the class community and society

Phase diagram of pinned lattices in the phase field crystal model

We study the phase diagram and the commensurate-incommensurate phase transitions of a two-dimensional phase field crystal model for adsorbed layers. The model allows for both elastic and plastic deformations on atomic and diffusive time-scales, and provides a continuum description of lattice systems, such as adsorbed atomic layers or two-dimensional vortex lattices. Analytically, mode expansion analysis and numerical minimization of the free energy are used to determine the ground states as a function of the pinning potential and lattice mismatch parameter. The results show a rich phase diagram with several different types of commensurate and incommensurate phases.Peer reviewe

Determinants of spatial variability of air pollutant concentrations in a street canyon network measured using a mobile laboratory and a drone

Urban air pollutant concentrations are highly variable both in space and time. In order to understand these variabilities high-resolution measurements of air pollutants are needed. Here we present results of a mobile laboratory and a drone measurements made within a street-canyon network in Helsinki, Finland, in summer and winter 2017. The mobile lab-oratory measured the total number concentration (N) and lung-deposited surface area (LDSA) of aerosol particles, and the concentrations of black carbon, nitric oxide (NOx) and ozone (O3). The drone measured the vertical profile of LDSA. The main aims were to examine the spatial variability of air pollutants in a wide street canyon and its immediate surroundings, and find the controlling environmental variables for the observed variability's.The highest concentrations with the most temporal variability were measured at the main street canyon when the mo-bile laboratory was moving with the traffic fleet for all air pollutants except O3. The street canyon concentration levels were more affected by traffic rates whereas on surrounding areas, meteorological conditions dominated. Both the mean flow and turbulence were important, the latter particularly for smaller aerosol particles through LDSA and N. The formation of concentration hotspots in the street network were mostly controlled by mechanical processes but in winter thermal processes became also important for aerosol particles. LDSA showed large variability in the profile shape, and surface and background concentrations. The expected exponential decay functions worked better in well -mixed conditions in summer compared to winter. We derived equation for the vertical decay which was mostly con-trolled by the air temperature. Mean wind dominated the profile shape over both thermal and mechanical turbulence. This study is among the first experimental studies to demonstrate the importance of high-resolution measurements in understanding urban pollutant variability in detail.Peer reviewe

Lithium‐ion mobility in Li6B18(Li3N) and Li vacancy tuning in the solid solution Li6B18(Li3N)1−x(Li2O)x

All-solid-state batteries are promising candidates for safe energy-storage systems due to non-flammable solid electrolytes and the possibility to use metallic lithium as an anode. Thus, there is a challenge to design new solid electrolytes and to understand the principles of ion conduction on an atomic scale. We report on a new concept for compounds with high lithium ion mobility based on a rigid open-framework boron structure. The host–guest structure Li6B18(Li3N) comprises large hexagonal pores filled with urn:x-wiley:14337851:media:anie202213962:anie202213962-math-0001 Li7N] strands that represent a perfect cutout from the structure of α-Li3N. Variable-temperature 7Li NMR spectroscopy reveals a very high Li mobility in the template phase with a remarkably low activation energy below 19 kJ mol−1 and thus much lower than pristine Li3N. The formation of the solid solution of Li6B18(Li3N) and Li6B18(Li2O) over the complete compositional range allows the tuning of lithium defects in the template structure that is not possible for pristine Li3N and Li2O

Flux transitions in a superconducting ring

We perform a numeric study of the flux transitions in a superconducting ring at fixed temperature, while the applied field is swept at an ideally slow rate. The current around the ring and its free energy are evaluated. We partially explain some of the known experimental features, and predict a considerably large new feature: in the vicinity of a critical field, giant jumps are expected

Phase-field approach to heterogeneous nucleation

We consider the problem of heterogeneous nucleation and growth. The system is described by a phase field model in which the temperature is included through thermal noise. We show that this phase field approach is suitable to describe homogeneous as well as heterogeneous nucleation starting from several general hypotheses. Thus we can investigate the influence of grain boundaries, localized impurities, or any general kind of imperfections in a systematic way. We also put forward the applicability of our model to study other physical situations such as island formation, amorphous crystallization, or recrystallization.Comment: 8 pages including 7 figures. Accepted for publication in Physical Review

Фармакокинетика теофиллина в ночное время при однократном приеме: сравнение трех препаратов в одинаковых условиях

We have carried out a stead y state pharmacokynetic comparison of three different theophylline preparations in nine healthy volunteers using a once a day dosage schedule of 600 mg theophylline given before bedtime for four days. The preparations tested were Retafyllin 200 mg depot tablet (R), Theo-Dur 200 mg depot tablet (T) and Uniphyllin 200 mg tablet (U). All preparations in steady state reached the serum level of 8.9— 10.2 microg/ml after a single evening dose of theophylline 600 mg. The pharmacokinetic profile of these slow release theophylline preparations was such that there is no risk of exceeding the therapeutic range even after a rather high evening dose. Individual variation was also observed in the present study but nobody exceeded the therapeutic range. The pharmacokinetic profiles of R and U were quite similar and they seemed to have suitable pharmacokinetic properties for once a day dosage, and they showed a more sustained action than T. Only minimal gastrointestinal side effects were reported during this study.