Enhanced dielectrophoresis of nanocolloids by dimer formation

We investigate the dielectrophoretic motion of charge-neutral, polarizable nanocolloids through molecular dynamics simulations. Comparison to analytical results derived for continuum systems shows that the discrete charge distributions on the nanocolloids have a significant impact on their coupling to the external field. Aggregation of nanocolloids leads to enhanced dielectrophoretic transport, provided that increase in the dipole moment upon aggregation can overcome the related increase in friction. The dimer orientation and the exact structure of the nanocolloid charge distribution are shown to be important in the enhanced transport

Finite Mixture Modelling of Survival Data : With Applications to Pensioner Lifetime

Peer reviewe

Sähkötupakka ja parodontiitti

Tiivistelmä. Sähkötupakka on varsin uusi tekninen laite, joka on kehitetty Kiinassa 2000- luvun puolessa välissä. Sähkösavuke imitoi perinteistä tupakkaa käyttötavaltaan ja ulkonäöltään. Sähkötupakan käyttö Suomessa on toistaiseksi ollut suhteellisen vähäistä, mutta maailmalla, etenkin Yhdysvalloissa sähkötupakka on saavuttanut suuren suosion varsinkin nuorison keskuudessa. Suosion syitä ovat esimerkiksi sähkötupakan laajat makuvaihtoehdot, ja sähkötupakoinnin ympärille kehittynyt internetilmiö. Yhtenä syynä voidaan pitää myös sitä, että sähkötupakkaa on markkinoitu vähemmän epäterveellisenä tupakkatuotteena verrattuna perinteiseen tupakkaan. Sähkötupakkaa käytettäessä ei tapahdu perinteiselle tupakalle ominaista palamisreaktiota, jolloin käyttäjä ei altistu perinteisen tupakoinnin tavoin savulle, tervalle, häkälle tai muille palamisessa muodostuville yhdisteille. Sähkösavukkeesta on toistaiseksi hyvin rajallisesti tutkimustietoa, koska se on varsin tuore keksintö. Tässä kirjallisuuskatsauksessa on tutustuttu tällä hetkellä saatavissa olevaan tutkimustietoon sähkötupakan vaikutuksista parodontiittiin, eli hampaiden kiinnityskudosten sairauteen. Sähkötupakan nikotiini supistaa ikenen verisuonia ja siten peittää parodontiitin oireita, kuten ienverenvuotoa. Tutkimusten mukaan sähkötupakoijilla on tupakoimattomiin verrattuna enemmän ja syvempiä ientaskuja, sekä enemmän luukatoa. Lisäksi proinflammatoristen sytokiinien (IL-1β, IL-6, TNF-α) pitoisuudet ovat suurempia sähkötupakoijilla verrattuna tupakoimattomiin. Sähkötupakointi lisää solujen apoptoosia ja oksidatiivista stressiä. In-vitro tutkimuksissa on ilmennyt, että sähkötupakalla on vakaviakin karsinogeenisiä, sytotoksisia ja genotoksisia vaikutuksia. Tutkimusten mukaa näyttäisi kuitenkin siltä, että sähkötupakoinnin vaikutukset parodontiittiin ovat vähäisemmät kuin perinteisen tupakan. Tulevaisuudessa tarvitaan lisää tutkimustietoa, sillä pitkäaikaistutkimuksia aiheesta ei juurikaan ole

A Frequency Tuning Method for a Planar Inverted-F Antenna

A novel method is presented for electrically tuning the frequency of a planar inverted-F antenna (PIFA). A tuning circuit, comprising an RF switch and discrete passive components, has been completely integrated into the antenna element, which is thus free of dc wires. The proposed tuning method has been demonstrated with a dual-band PIFA capable of operating in four frequency bands. The antenna covers the GSM850, GSM900, GSM1800, PCS1900 and UNITS frequency ranges with over 40% total efficiency. The impact of the tuning circuit on the antenna's efficiency and radiation pattern have been experimentally studied through comparison with the performance of a reference antenna not incorporating the tuning circuit. The proposed frequency tuning concept can be extended to more complex PIFA structures as well as other types of antennas to give enhanced electrical performance.</p

Age, breed, sex and diet influence serum metabolite profiles of 2000 pet dogs

As an individual's metabolism reflects health and disease states well, metabolomics holds a vast potential in biomedical applications. However, normal physiological factors, such as age, can also influence metabolism, challenging the establishment of disease-specific metabolic aberrations. Here, we examined how physiological and diet-related factors drive variance in the metabolism of healthy pet dogs. We analysed 2068 serum samples using a canine nuclear magnetic resonance (NMR) spectroscopy-based metabolomics platform. With generalized linear models, we discovered that age, breed, sex, sterilization, diet type and fasting time significantly affected the canine metabolite profiles. Especially, breed and age caused considerable variation in the metabolite concentrations, and breeds with very different body conformations systematically differed in several lipid measurands. Our results enhance the understanding how normal physiological factors influence canine metabolism, aid accurate interpretation of the NMR results, and suggest the NMR platform might be applied in identifying aberrations in nutrient absorption and metabolism.Peer reviewe

Metabarcoding successfully tracks temporal changes in eukaryotic communities in coastal sediments

Metabarcoding is a method that combines high-throughput DNA sequencing and DNA-based identification. Previously, this method has been successfully used to target spatial variation of eukaryote communities in marine sediments, however, the temporal changes in these communities remain understudied. Here, we follow the temporal changes of the eukaryote communities in Baltic Sea surface sediments collected from two coastal localities during three seasons of two consecutive years. Our study reveals that the structure of the sediment eukaryotic ecosystem was primarily driven by annual and seasonal changes in prevailing environmental conditions, whereas spatial variation was a less significant factor in explaining the variance in eukaryotic communities over time. Therefore, our data suggests that shifts in regional climate regime or large-scale changes in the environment are the overdriving factors in shaping the coastal eukaryotic sediment ecosystems rather than small-scale changes in local environmental conditions or heterogeneity in ecosystem structure. More studies targeting temporal changes are needed to further understand the long-term trends in ecosystem stability and response to climate change. Furthermore, this work contributes to the recent efforts in developing metabarcoding applications for environmental biomonitoring, proving a comprehensive option for traditional monitoring approaches.Peer reviewe

Arresting bubble coarsening: A two-bubble experiment to investigate grain growth in presence of surface elasticity

Many two-phase materials suffer from grain-growth due to the energy cost which is associated with the interface that separates both phases. While our understanding of the driving forces and the dynamics of grain growth in different materials is well advanced by now, current research efforts address the question of how this process may be slowed down, or, ideally, arrested. We use a model system of two bubbles to explore how the presence of a finite surface elasticity may interfere with the coarsening process and the final grain size distribution. Combining experiments and modelling in the analysis of the evolution of two bubbles, we show that clear relationships can be predicted between the surface tension, the surface elasticity and the initial/final size ratio of the bubbles. We rationalise these relationships by the introduction of a modified Gibbs criterion. Besides their general interest, the present results have direct implications for our understanding of foam stability

Hip and Groin Pain in the Professional Athlete

AbstractHip and groin pain is a common condition in professional athletes and may result from an acute injury or from chronic, repetitive trauma. It is responsible for significant morbidity, which leads to time away from training and competition, and may result in a career-ending injury. The anatomic and biomechanical causes for hip and groin injuries are among the most complex and controversial in the musculoskeletal system. This makes clinical differentiation and subsequent management difficult because of the considerable overlap of symptoms and signs. This review article will evaluate several pathologic conditions of the hip and groin in athletes, divided into acute (secondary to single event) and chronic (secondary to altered biomechanical load or repetitive microtrauma) injuries, with an emphasis on imaging in the diagnosis of these injuries. Appropriate use of imaging along with clinical findings can allow accurate diagnosis and subsequent appropriate management of these patients to ultimately allow return to athletic activity