Excitonic effects on the two-color coherent control of interband transitions in bulk semiconductors

Quantum interference between one- and two-photon absorption pathways allows coherent control of interband transitions in unbiased bulk semiconductors; carrier population, carrier spin polarization, photocurrent injection, and spin current injection may all be controlled. We extend the theory of these processes to include the electron-hole interaction. Our focus is on photon energies that excite carriers above the band edge, but close enough to it so that transition amplitudes based on low order expansions in $\mathbf{k}$ are applicable; both allowed-allowed and allowed-forbidden two-photon transition amplitudes are included. Analytic solutions are obtained using the effective mass theory of Wannier excitons; degenerate bands are accounted for, but envelope-hole coupling is neglected. We find a Coulomb enhancement of two-color coherent control process, and relate it to the Coulomb enhancements of one- and two-photon absorption. In addition, we find a frequency dependent phase shift in the dependence of photocurrent and spin current on the optical phases. The phase shift decreases monotonically from $\pi /2$ at the band edge to 0 over an energy range governed by the exciton binding energy. It is the difference between the partial wave phase shifts of the electron-hole envelope function reached by one- and two-photon pathways.Comment: 31 pages, 4 figures, to be published in Phys. Rev.

Evolutionarily new sequences expressed in tumors

BACKGROUND: Earlier we suggested the concept of the positive evolutionary role of tumors. According to this concept, tumors provide conditions for the expression of evolutionarily new and/or sleeping genes in their cells. Thus, tumors are considered as evolutionary proving ground or reservoir of expression. To support this concept we have previously characterized in silico and experimentally a new class of human tumor-related transcribed sequences. RESULTS: In this article we describe results of further studies of previously described tumor-related sequences. The results of molecular phylogeny studies, Southern hybridization experiments and computational comparison with genomes of other species are presented. CONCLUSION: These results suggest that these previously described tumor-related human transcripts are also relatively evolutionarily new

Testing of CP, CPT and causality violation with the light propagation in vacuum in presence of the uniform electric and magnetic fields

We have considered the structure of the fundamental symmetry violating part of the photon refractive index in vacuum in the presence of constant electric and magnetic fields. This part of the refractive index can, in principle, contain CPT symmetry breaking terms. Some of the terms violate Lorentz invariance, whereas the others violate locality and causality. Estimates of these effects, using laser experiments are considered.Comment: 12 page

The distribution of extremal points of Gaussian scalar fields

We consider the signed density of the extremal points of (two-dimensional) scalar fields with a Gaussian distribution. We assign a positive unit charge to the maxima and minima of the function and a negative one to its saddles. At first, we compute the average density for a field in half-space with Dirichlet boundary conditions. Then we calculate the charge-charge correlation function (without boundary). We apply the general results to random waves and random surfaces. Furthermore, we find a generating functional for the two-point function. Its Legendre transform is the integral over the scalar curvature of a 4-dimensional Riemannian manifold.Comment: 22 pages, 8 figures, corrected published versio

EU Cultural Projects in Ukraine and the Impact of the Pandemic on Their Realization

События 2014 года стали поворотными в истории культурного самоопределения Украины. В обществе произошел давно наметившийся цивилизационный раскол. Тесные культурно-исторические связи ЕС и Западной Украины позволяют рассматривать последнюю в качестве части западной цивилизации.The events of 2014 marked a turning point in the history of cultural self-determination in Ukraine. There has been a long-standing division of civilization in society. Close cultural-historical ties between the EU and Western Ukraine make it possible to consider the latter as part of Western civilization

Prevention and contrast of child abuse and neglect in the practice of European paediatricians: a multi-national pilot study

Background: Child abuse and neglect, or maltreatment, is a serious public health problem, which may cause long-term effects on children's health and wellbeing and expose them to further adulthood vulnerabilities. Studies on child maltreatment performed in Europe are scarce, and the number of participants enrolled relatively small. The aim of this multi-national European pilot study, was to evaluate the level of understanding and perception of the concepts of child abuse and neglect by European paediatricians working in different medical settings, and the attitude toward these forms of maltreatment in their practice. Methods: The study was performed by a cross-sectional, descriptive, online survey, made available online to European paediatricians members of 50 national paediatric, who belonged to four different medical settings: hospital, family care, university centres and private practice. The questionnaire, designed as a multiple choice questions survey, with a single answer option consisted of 22 questions/statements. Frequency analyses were applied. Most of the data were described using univariate analysis and Chi-squared tests were used to compare the respondents and answers and a significance level of p ≤ 0.05 applied. Results: Findings show that European paediatricians consider the training on child maltreatment currently provided by medical school curricula and paediatric residency courses to be largely insufficient and continuing education courses were considered of great importance to cover educational gaps. Physical violence was recognized by paediatricians mostly during occasional visits with a significant correlation between detecting abuse during an occasional visit and being a primary care paediatrician. Results also showed a reluctance by paediatricians to report cases of maltreatment to the competent judicial authorities. Conclusions: Data of this study may provide useful contribution to the current limited knowledge about the familiarity of European paediatricians with child maltreatment and their skills to recognize, manage and contrast abusive childhood experiences in their practice. Finally, they could provide local legislators and health authorities with information useful to further improve public health approaches and rules able to effectively address shared risk and protective factors, which could prevent child abuse and neglect from ever occurring

Chemical Bath Deposition of In2S3 Thin Films as a Promising Material and Buffer Layer for Solar Cells

Authors thank scientific chief V. F. Markov, M. V. Kuznetsov for the X-ray phase analysis and A. A. Pankratov for the scanning electron microscopy (UB RAS)

Total alopecia and a common form of dermatitis at a patient with HIV on antiretroviral therapy

The purpose of the study is to research the side effects of ARVT for early detection, timely treatment and further control.Цель исследования - изучение побочных эффектов АРТВ для раннего выявления, своевременного лечения и дальнейшего контроля

CLINICAL NUTRITION INVOLVING A SPECIALIZED PROTEINAND CALORIE-RICH PEDIATRIC MILK PRODUCT FOR ENTERAL FEEDING OF INFANTS WITH PROTEIN-CALORIE DEFICIENCY

Background: Premature infants with extremely low and very low birth weight with a severe overlapping perinatal pathology often feature slower growth rate within the first year of life and require special nutritional support.Objective: Our aim was to study physical development of infants with protein-calorie deficiency in the setting of using a specialized protein- and calorie-rich pediatric milk product for enteral feeding.Methods: We analyzed tolerability and efficacy of clinical nutrition within the framework of a prospective two-month-long case series. We assessed actual children’s diets and the chemical composition thereof. We determined body weight and length, body mass index (BMI), adipodermal flap thickness over the triceps. Anabolic effect of clinical nutrition was assessed on the basis of transthyretin concentration dynamics.Results: The study involved 30 infants with protein-calorie deficiency (7 term infants and 23 premature infants) with a severe perinatal pathology. High tolerability of the formula under analysis was registered in most patients. Termination of functional gastrointestinal tract disorders (posseting, colics, flatulence, constipations) was observed in 23 (87%) patients. In most cases, the use of a protein- and calorie-rich formula as a part of a therapeutic diet helped to satisfy children’s protein demand and improve their weight/length parameters: BMI increased in 19 (72%) children, body weight — in 16 (63%), body length — in 24 (92%), adipodermal flap thickness over the triceps — in all the children (100%). We observed transthyretin concentration increase from 162 (157; 171) in the beginning of the study to 187 (170; 208) mg/l in the end thereof (p = 0.028).Conclusion: A specialized protein- and calorie-rich product for enteral feeding may be used for feeding infants with protein-calorie deficiency born with a severe a perinatal pathology, including premature infants