Non-magnetic semiconductor spin transistor

We propose a spin transistor using only non-magnetic materials that exploits the characteristics of bulk inversion asymmetry (BIA) in (110) symmetric quantum wells. We show that extremely large spin splittings due to BIA are possible in (110) InAs/GaSb/AlSb heterostructures, which together with the enhanced spin decay times in (110) quantum wells demonstrates the potential for exploitation of BIA effects in semiconductor spintronics devices. Spin injection and detection is achieved using spin-dependent resonant interband tunneling and spin transistor action is realized through control of the electron spin lifetime in an InAs lateral transport channel using an applied electric field (Rashba effect). This device may also be used as a spin valve, or a magnetic field sensor. The electronic structure and spin relaxation times for the spin transistor proposed here are calculated using a nonperturbative 14-band k.p nanostructure model.Comment: Accepted for publication in Applied Physics Letter

Risultati audiologici e rate di attecchimento dell'innesto di cartilagine con pericondrio nella timpanoplastica: PACIT

La cartilagine rappresenta una delle opzioni più interessanti per il confezionamento dell'innesto nella timpanoplastica (TPL). Col presente studio presentiamo i nostri risultati audiologici e il rate di attecchimento nei casi di TPL trattati con innesto di cartilagine con pericondrio (PACIT). Sono stati analizzati, in termini di tipo di chirurgia effettuata, attecchimento dell'innesto e risultati audiologici, 194 orecchi di 191 pazienti (108 maschi, 83 donne). Sono state effettuate 127 (65,46%) TPL tipo I, 45 (23,20%) tipo II e 22 (11,34%) tipo III. Il gap medio fra via aerea e via ossea all'audiometria tonale preoperatoria è stato rispettivamente 33,74 ± 9,60, 52,58 ± 9,07, e 56,58 ± 10,27 dB HL; i valori nel postoperatorio sono stai invece 18,55 ± 9,25, 31,21 ± 4,36, and 44,84 ± 12,45 dB HL. Nel postoperatorio di è registrato un miglioramento della soglia (≥ 10dB) nel 76,81% degli orecchi valutati, con un recupero medio di 20 dB HL (range 10-40 dB). Tuttavia il 19,07% degli orecchi valutati non ha mostrato un miglioramento della soglia uditiva, e il 4,12% ha manifestato un peggioramento della soglia. L'innesto ha attecchito correttamente nel 91,24% dei casi con follow-up di almeno 13 mesi con una media di 68,64 mesi, mentre si è registrato un fallimento nel 8,76% dei casi. In considerazione dei livelli postoperatori della soglia uditiva e dell'elevato rate di attecchimenti registrato, il presente studio ha evidenziato l'efficacia a lungo termine dell'innesto di cartilagine con pericondrio

Yükseköğretimde Spor Eğitimi Veren Kurumlarda Görev Yapan Akademik Personelin Elektronik Ticaret Hakkındaki Görüşleri,

In this study the views of the academic personnel working in institutions giving sports training at higher education level in Turkey about electronic trade has been researched. Sample of the study is constituted by 214 academic personnel working in institutions giving sports training at higher education level in Turkey. Validity and reliability study improved by Sevindik (16) was made to determine the views of the participants and “e-Trade User View Form” was used. SPSS 11.5 package program was used in assessment of the questionnaires and t-test, Variance Analysis (ANOVA), Kruskal Wallis Test and LSD test analyses were made. As a result it was observed that, 86% of the academic personnel working in institutions giving sports training at higher education level in Turkey expressed the importance of electronic trade, 81,3% of them expressed that they used electronic banking system and 59,9% of them emphasized that electronic trade eliminates the traditional trade. Furthermore it was determined that there was a significant difference between the views of the participants towards electronic trade according to the variants of sex and education

Spin relaxation in (110) and (001) InAs/GaSb superlattices

We report an enhancement of the electron spin relaxation time (T1) in a (110) InAs/GaSb superlattice by more than an order of magnitude (25 times) relative to the corresponding (001) structure. The spin dynamics were measured using polarization sensitive pump probe techniques and a mid-infrared, subpicosecond PPLN OPO. Longer T1 times in (110) superlattices are attributed to the suppression of the native interface asymmetry and bulk inversion asymmetry contributions to the precessional D'yakonov Perel spin relaxation process. Calculations using a nonperturbative 14-band nanostructure model give good agreement with experiment and indicate that possible structural inversion asymmetry contributions to T1 associated with compositional mixing at the superlattice interfaces may limit the observed spin lifetime in (110) superlattices. Our findings have implications for potential spintronics applications using InAs/GaSb heterostructures.Comment: 4 pages, 2 figure

Possible role of SCN4A skeletal muscle mutation in apnoea during seizure

SCN4A gene mutations cause a number of neuromuscular phenotypes including myotonia. A subset of infants with myotonia‐causing mutations experience severe life‐threatening episodic laryngospasm with apnea. We have recently identified similar SCN4A mutations in association with sudden infant death syndrome. Laryngospasm has also been proposed as a contributory mechanism to some cases of sudden unexpected death in epilepsy (SUDEP). We report an infant with EEG‐confirmed seizures and recurrent apneas. Whole‐exome sequencing identified a known pathogenic mutation in the SCN4A gene that has been reported in several unrelated families with myotonic disorder. We propose that the SCN4A mutation contributed to the apneas in our case, irrespective of the underlying cause of the epilepsy. We suggest this supports the notion that laryngospasm may contribute to some cases of SUDEP, and implicates a possible shared mechanism between a proportion of sudden infant deaths and sudden unexpected deaths in epilepsy

Hannah Arendt

Peer reviewe

Microplastic pollution in Turkish aquatic ecosystems: Sources, characteristics, implications, and mitigation strategies

Aquatic environments are one of the final destinations for microplastics. In this review, a combination of systematic and narrative literature review was conducted to identify and summarise advances, gaps, and future directions in microplastic monitoring studies in the Turkish aquatic environment and in inhabiting aquatic organisms. A total of 62 peer-reviewed publications available on Web of Science were considered in the systematic review. Additionally, the current state of microplastic pollution in Turkish aquatic environments which includes marine and freshwater ecosystems, as well as aquatic organisms, and sources and characteristics of microplastics were reviewed narratively. Turkiye's position on the global plastic treaty and mitigation practices were also addressed. Although an increase in the number of publications over time was observed, the number and extent of studies carried out in freshwater ecosystems are limited. Strict legislation should be enacted and enforced to tackle plastic pollution in Turkiye. Additionally, nationwide, long-term monitoring studies at sufficiently regular intervals in aquatic environments should be considered

Large ring polymers align FtsZ polymers for normal septum formation

The bacterial cell division protein FtsZ assembles into a circular structure at the site of cell division. SepF is important for cell division, but how it functions is not clear. Here, the findings show that SepF polymerizes into large rings that promote the assembly of FtsZ during septum formation

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function