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Colloidal synthesis methods and ultrahigh-vacuum molecular beam epitaxy can tailor semiconductor-based nanoscale single emitters—quantum dots—as the building blocks for classical optoelectronic devices, such as lasers, light-emitting devices, and display technologies. These novel light sources have a basic resemblance of luminescent organic molecules, individually and in the aggregated forms. Highly ordered superstructures of quantum dots, obtained via scalable bottom-up self-assembly, exhibit diverse collective phenomena, such as band-like charge transport or superradiant emission. Superradiance emerges from coherent coupling of several emitters via a common radiation field resulting in a single giant dipole leading to short (sub-nanosecond) and intense (proportional to the squared number of coupled emitters) bursts of light. In this article, we review the basic principles and progress in the development of superradiant emitters with organic molecules and inorganic quantum dots, in view of their integration into classical and novel quantum light sources.
Demographical and clinical characteristics have been reported to modulate the risk for suicide. This study analysed demographical and clinical characteristics with respect to lifetime suicide attempts in 500 individuals affected with schizophrenic or affective disorders. Suicide attempts were associated with poor premorbid social adjustment, low age at onset, low scores on the “Global Assessment Scale” and childlessness in females.
There are different age periodizations of human psychological development, but most researchers believe that over time learning in high school matches during youth and early adulthood.
The aim of our research was to investigate the phenomenon of age-perfectionism of medical students.
Materials and methods. The study participated 275 students 1 and 5 courses of different faculties in medical university. The average age of students was expected 1st year lower than students of the 5th year: 18,00 ± 0,11 g. vs 21,41 ± 0,12 g., p <0.001. To analyze the phenomenon of perfectionism was used the questionnaire of Kholmogorova and Garanian (2001).
Discussion. Age was significantly negatively correlated with the rate in the general makeovers cohort study (R = -0,28, p <0.001), lower rate of perfectionism of older students. Indeed, the average score of perfectionism in students age 22 and older was significantly lower compared with other age ranks (p <0.01) (see Fig. 2). In a separate analysis of possible relationships between age and index makeovers at 1 and 5 course reliable correlation was found (R = -0,12, p = 0,16, R = -0,02, p = 0.82).
Study of the phenomenon of perfectionism and its age features obtained significantly negative correlation of age with the index of perfectionism in the overall group. The level of students perfectionism in early adulthood was significantly lower compared with other age grades.
Violation of mental health is common in forced migrants. Lack of positive motivation to move and physical impossibility of further stay at home, mental trauma caused by the history and causes of migration; difficulties in adapting to new location determine the formation of specific experience IDPs. The most common are psychogenic depression, anxiety and somatoform disorders.
We had observed 60 IDPs aged 18 to 80 years: medical history, current complaints and mental state.
We allocated 3 groups: persons of retirement age with severe chronic physical illness or disability on physical illness (1 group); persons with disabilities to mental disease (group 2) and persons without chronic diseases or disability (relatively healthy, caring for the sick) (group 3). Group 1 patients have anxiety (51.4%) and depression (42.8%) syndromes; 25.7% of subjects showed suicidal thoughts and intentions; 25.7% have some PTSD symptoms, including avoidance, overexcited, emotional numbness, pointing to adjustment disorder. In group 2 patients, changes were not found in mental state. Despite traumatic events delusional story does not change, recurrence and relapse rating was stable. In some cases, patients begin to abuse alcohol. In 3 group 31.3% persons experienced depression, 25%-anxiety symptoms, combined with a severe somatic symptoms; 12.5% showed suicidal thoughts; in 18.7% were diagnosed adjustment disorders. So among IDPs the individuals with severe medical conditions are most vulnerable population in the formation of stress-related and neurotic disorders.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
This perspective article summarizes the operational principles of dual-ion batteries and highlights the main issues in the interpretation and reporting of their electrochemical performance.
Secondary dual-ion batteries (DIBs) are emerging stationary energy storage systems that have been actively explored in view of their low cost, high energy efficiency, power density, and long cycling life. Nevertheless, a critical assessment of the literature in this field points to numerous inaccuracies and inconsistencies in reported performance, primarily caused by the exclusion of the capacity of used electrolytes and the use of non-charge-balanced batteries. Ultimately, these omissions have a direct impact on the assessment of the energy and power density of DIBs. Aiming to secure further advancement of DIBs, in this work, we critically review current research pursuits and summarize the operational mechanisms of such batteries. The particular focus of this perspective is put on highlighting the main issues in the interpretation and reporting of the electrochemical performance of DIBs. To this end, we survey the prospects of these stationary storage systems, emphasizing the practical hurdles that remain to be addressed.
The problem of binary asteroids orbit determination is of particular interest, given knowledge of the orbit is the best way to derive the mass of the system. Orbit determination from observed points is a classic problem of celestial mechanics. However, in the case of binary asteroids, particularly with a small number of observations, the solution is not evident to derive. In the case of resolved binaries the problem consists in the determination of the relative orbit from observed relative positions of a secondary asteroid with respect to the primary. In this work, the problem is investigated as a statistical inverse problem. Within this context, we propose a method based on Bayesian modelling together with a global optimisation procedure that is based on the simulated annealing algorithm.
We report static and time-resolved terahertz (THz) conductivity measurements of a highperformance thermoelectric material containing tellurium nanowires in a PEDOT:PSS matrix. Composites were made with and without sulfur passivation of the nanowires surfaces. The material with sulfur linkers (TeNW/PD-S) is less conductive but has a longer carrier lifetime than the formulation without (TeNW/PD). We find real conductivities at f = 1THz of σTeNW/PD = 160 S/cm and σTeNW/PD-S = 5.1 S/cm. These values are much larger than the corresponding DC conductivities, suggesting DC conductivity is limited by structural defects. The free-carrier lifetime in the nanowires is controlled by recombination and trapping at the nanowire surfaces. We find surface recombination velocities in bare tellurium nanowires (22m/s) and TeNW/PD-S (40m/s) that are comparable to evaporated tellurium thin films. The surface recombination velocity in TeNW/PD (509m/s) is much larger, indicating a higher interface trap density.
Thermoelectric (TE) materials have been studied during past decades since they can generate electricity directly from waste heat. Antimony chalcogenides (Sb2M3, M = S, Se, Te) are well known as one of the promising candidates among the inorganic TE materials. We report on the synthesis of Sb2Te3 nanoparticle via thermolysis method. A systematic study was done to investigate the effect of reaction time and ratio between the precursors as well as the method of cooling on the morphology and composition of obtained nanoparticles. The ratio between precursors was varied to study the effect on the morphology. Furthermore, the high purity phase Sb2Te3 was obtained by a rapid cooling process.
The maldigestion and malabsorption of fat in infants fed milk formula results due to the minimal production of pancreatic lipase. Thus, to investigate lipid digestion and absorption and mimic the situation in newborns, a young porcine exocrine pancreatic insufficient (EPI) model was adapted and validated in the present study. A total of thirteen EPI pigs, aged 8 weeks old, were randomised into three groups and fed either a milk-based formula or a milk-based formula supplemented with either bacterial or fungal lipase. Digestion and absorption of fat was directly correlated with the addition of lipases as demonstrated by a 30 % increase in the coefficient of fat absorption. In comparison to the control group, a 40 and 25 % reduction in total fat content and 26 and 45 % reduction in n-3 and n-6 fatty acid (FA) content in the stool was observed for lipases 1 and 2, respectively. Improved fat absorption was reflected in the blood levels of lipid parameters. During the experiment, only a very slight gain in body weight was observed in EPI piglets, which can be explained by the absence of pancreatic protease and amylase in the gastrointestinal tract. This is similar to newborn babies that have reduced physiological function of exocrine pancreas. In conclusion, we postulate that the EPI pig model fed with infant formula mimics the growth and lipid digestion and absorption in human neonates and can be used to elucidate further importance of fat and FA in the development and growth of newborns, as well as for testing novel formula compositions.
The paper is devoted to the method of computer simulation of protein interactions taking
part in photosynthetic electron transport reactions. Using this method we have studied
kinetic characteristics of protein-protein complex formation for four pairs of proteins
involved in photosynthesis at a variety of ionic strength values. Computer simulations
describe non-monotonic dependences of complex formation rates on the ionic strength as the
result of long-range electrostatic interactions. Calculations confirm that the decrease in
the association second order rate constant at low values of the ionic strength is caused
by the protein pairs spending more time in “wrong” orientations which do not satisfy the
docking conditions and so do not form the final complex capable of the electron
The synthesis and self-assembly of a water-soluble, tricyclic, self-complementary heterocycle that features the hydrogen bond donor-acceptor arrays of both guanine (G) and cytosine (C) juxtaposed between a pyridine ring is presented. In solution, this tricycle, which has been termed xK1, self-assembles into Rosette Nanotubes (RNTs) that have an inner diameter of 1.4 nm. Unlike the RNTs formed from the bicyclic congener K1, we demonstrate that xK1 with its extended ð system, forms a J-type RNT assembly determined through UV-Vis, CD and fluorescence spectroscopy experiments. This observation brings the possibility of developing electrically conducting RNTs for applications in the areas of photovoltaics and molecular wires.
Our present study is the first attempt to characterize Leishmania parasites from foci in Uzbekistan and Tajikistan endemic for visceral leishmaniasis (VL). PCR-sequencing of the ribosomal internal transcribed spacer 1 and multilocus microsatellite typing (MLMT) were applied to DNA extracted from preparations of Giemsa-stained bone marrow aspirates from 13 cases of VL. L. infantum was shown to cause VL currently occurring in this area. MLMT applying 14 microsatellite markers, previously shown to be polymorphic for strains of the L. donovani complex, revealed that microsatellite profiles of parasites causing human VL in the Namangan and Jizzakh regions in Uzbekistan, and Penjikent region in Tajikistan, basically coincide with those of strains of L. infantum MON-1. Furthermore, these parasites were assigned to a distinct cluster genetically clearly separated from the populations of L. infantum MON-1 from Europe, the Middle East and North Africa. The existence of a genetically homogeneous but distinct group of L. infantum MON-1 indicates that the parasites circulating in the Uzbeki and Tajiki foci studied have been restricted there for a long time rather than having been recently introduced from elsewhere by human or animal reservoir migration.
Detection in most surveillance radars is based on the condition of point targets against a more or less homogeneous background. Currently, the resolution of many new types of radar is increasing, at least in the range dimension. Therefore many objects can no longer be considered as points. Also as a consequence, the background is becoming more diverse, in statistical terms. The scene addressed in this paper concerns a ground clutter environment, and extended objects observed with a polarimetric radar with modestly high resolution (i.e. 6 m in range). A step-by-step approach is proposed for the detection and parameter assessment of extended objects and adding classification based on polarimetric features. The evaluation of this approach is based on recordings of real natural scenes and artificially inserted extended objects. It has been observed that in multi-stage detection object classification benefits from several features, including polarimetric ones. It is proposed that the quality of the contour circumscribing the object is the prime factor for quality of features next to polarimetric features. Clutter is affecting, however, the edges of the contours, and therefore may have a major impact on features that are dependent on the shape of these contours. The results also suggest that in the case of large targets with a basically simple shape, like ships, the eccentricity of the shape of the extended object is consistent from scan to scan and probably could support the target tracking.
Carbon nanomaterials especially ultrananocrystalline diamond and nanocrystalline diamond films have attracted more and more interest due to their unique electrical, optical and mechanical properties, which make them widely used for different applications (e.g. MEMS devices, lateral field emission diodes, biosensors and thermoelectrics). Nanocrystalline diamond can also offer novel advantages for drug delivery development. Recent studies have begun to use nanocrystalline diamond for in-vivo molecular imaging and bio-labeling. To enable grafting of complex bio-molecules (e.g. DNA) the surface of ND requires specific fictionalization (e.g. H, OH, COOH & NH2). Due to the surface dipoles of functionalised nanodiamond band bending at the surface can be easily induced and from the measured band bending we can deduce the type of the fictionalization on the surface. The surface potential of H-terminated and OH terminated nanodiamond layers was investigated by Kelvin probe microscope. From the change of the surface potential value (as the departure of the material surface from the state of electrical neutrality is reflected in the energy band bending) the work function of the H-terminated nanodiamond layer was established to be lower than OH-terminated nanodiamond layer. The surface potential difference can be explained by the surface dipole induced by the electro-negativity difference between the termination atoms.
We characterized the optical nonlinearities of CdSe nanocrystals surrounded by rod-like CdS shells with ultrafast measurements of time-resolved photoluminescence. We measured the exciton-exciton interaction to be, depending on structure details, attractive or repulsive, by as much as 29 meV, due to the unique band alignment in the CdSe/CdS. This feature makes CdSe/CdS dot/rods promising gain media for solution-processable lasers, as it appears combined with 80% photoluminescence quantum yield, narrow size and shape distributions and the antenna effect of the CdS rod shell enhancing optical absorption by more than a factor 50 with respect to bare dots.
It has been reported that physico-chemical properties of diamond surfaces are closely related to the surface chemisorbed species on the surface. Hydrogen chemisorption on a chemical vapor deposition grown diamond surface is well-known to be important for stabilizing diamond surface structures with sp3 hybridization. It has been suggested that an H-chemisorbed structure is necessary to provide a negative electron affinity condition on the diamond surfaces. Negative electron affinity condition could change to a positive electron affinity by oxidation of the H-chemisorbed diamond surfaces. Oxidized diamond surfaces usually show characteristics completely different from those of the H-chemisorbed diamond surfaces. The unique electron affinity condition, or the surface potential, is strongly related to the chemisorbed species on diamond surfaces. The relationship between the surface chemisorption structure and the surface electrical properties, such as the surface potential of the diamond, has been modelled using DFT based calculations.
Poltava chickens are native to Ukraine, with a remarkable history, genetics and economic traits. They include three varieties: Clay, Cuckoo and Black. The Poltava Clay variety exemplifies what can be achieved by thorough selection in transforming a local, low production chicken population into an established breed with high performance characteristics and selected line structure. Two other varieties, the Cuckoo and Black, are extinct but plans for their restoration are underway.