Impedance spectroscopy of synthetic proustite at high pressures

The effect of high pressure (up to 40 GPa) and alternating electric field frequency (100 Hz-500 kHz) on the electrical properties of synthesized single-crystal proustite Ag3AsS3 is studied. The behavior of real and imaginary parts of impedance upon an increase in pressure confirms earlier data on the closing of valence and conduction zones, and on the material's transition to the metal state at ∼30 GPa. © 2013 Allerton Press, Inc

High pressures, low temperatures, and magnetic field effects on AgFeAsSe3 and AgFeSbSe3 properties

A procedure for synthesizing AgFeAsSe3 and AgFeSbSe3 is presented, and their electric and magnetic properties are investigated over a wide range of temperatures, pressures, and magnetic field variation. At 100-400K, the samples are characterized by semiconductor properties. Under pressures of ∼25 and ∼24 GPa, the electric properties of AgFeAsSe 3 and AgFeSbSe3 change greatly. © 2013 Allerton Press, Inc

Interpreting Attoclock Measurements of Tunnelling Times

Resolving in time the dynamics of light absorption by atoms and molecules, and the electronic rearrangement this induces, is among the most challenging goals of attosecond spectroscopy. The attoclock is an elegant approach to this problem, which encodes ionization times in the strong-field regime. However, the accurate reconstruction of these times from experimental data presents a formidable theoretical challenge. Here, we solve this problem by combining analytical theory with ab-initio numerical simulations. We apply our theory to numerical attoclock experiments on the hydrogen atom to extract ionization time delays and analyse their nature. Strong field ionization is often viewed as optical tunnelling through the barrier created by the field and the core potential. We show that, in the hydrogen atom, optical tunnelling is instantaneous. By calibrating the attoclock using the hydrogen atom, our method opens the way to identify possible delays associated with multielectron dynamics during strong-field ionization.Comment: 33 pages, 10 figures, 3 appendixe

Observation and Control of Laser-Enabled Auger Decay

Single photon laser enabled Auger decay (spLEAD) has been redicted theoretically [Phys. Rev. Lett. 111, 083004 (2013)] and here we report its first experimental observation in neon. Using coherent, bichromatic free-electron laser pulses, we have detected the process and coherently controlled the angular distribution of the emitted electrons by varying the phase difference between the two laser fields. Since spLEAD is highly sensitive to electron correlation, this is a promising method for probing both correlation and ultrafast hole migration in more complex systems.Comment: 5 pages, 3 figure

Fully differential cross sections for photo-double-ionization of D2

We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double-ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis. This effect is reproduced by a model in which a pair of photoionization amplitudes is introduced for the light polarization parallel and perpendicular to the molecular axis

ОПЫТ ПРОВЕДЕНИЯ ТРАНСУРЕТРАЛЬНОЙ БИОПСИИ В РАННЕМ ПОСЛЕОПЕРАЦИОННОМ ПЕРИОДЕ У БОЛЬНЫХ ПОВЕРХНОСТНЫМ РАКОМ МОЧЕВОГО ПУЗЫРЯ

Objective: to monitor the efficacy of transurethral resection (TUR) of a urinary bladder tumor, which has performed under the standard conditions and by using fluorescence cystoscopy (FCS), to diagnose early bladder cancer (BC), and to determine tumor aggression and prognosis of the disease.Subjects and methods. 174 BC patients, who had undergone 4-6 weeks postoperatively re-endoscopy comprising routine cystoscopy (CS), FCS, and TUR biopsy of a postoperative scar area and fluorescent portions, were examined. Group 1 included 95 patients who had under- gone routine TUR; Group 2 consisted of 79 patients in whom TUR had performed under fluorescence guidance.  Results. Re-endoscopy revealed fluorescence portions in 56 (58.9%) patients in Group 1 and in 28 (35.4%) in Group 2. Endothelial tumors were found in 45 (47.4%) patients from Group 1 and in 19 (24.1%) from Group 2. In the latter, residual tumors were less frequently observed than those in Group 1 (24.1 and 47.4%, respectively; p < 0.005). Control endoscopic study of Tis identified in 15 (15.8%) of the 95 examinees in Group 1 and only in 4 (5.1%) of 79 in Group 2 (p < 0.001). There was a significant difference in the frequency of residual tumors (Ta stage) in Groups 1 and 2 patients (16.8 and 8.9%; p < 0.005). The differences in the frequency of residual papillary tumors at T1 stage were also significant in the analyzed groups (10.5 and 6.3%, respectively; p < 0.05). At the same time, the difference was insignificant in the incidence of a recurrence at T2 stage. Amongst 27 Group 1 patients with multiple urinary bladder involvement, residual tumors were identified in 14 (51.9%); these were present only in 4 (18.2%) of 22 patients from Group 2 (p < 0.001). Conclusion. Early repeated CS and biopsy under fluorescence guidance should be recommended to patients with BC at stages Tis and Ta— T1 for the timely detection and removal of residual tumors and for the prevention of recurrences.  Цель исследования — контроль радикальности трансуретральной резекции (ТУР) опухоли мочевого пузыря, выполненной в стандартных условиях и с применением флюоресцентной цистоскопии (ФЦС), для диагностики ранних рецидивов рака мочевого пузыря (РМП) и определения степени агрессивности опухоли и прогноза течения заболевания.Материалы и методы. Обследованы 174 больных РМП, которым через 4—6 нед после операции выполнено повторное эндоскопическое исследование, включающее стандартную цистоскопию (ЦС), ФЦС и ТУР-биопсию области послеоперационного рубца и флюоресцирующих участков. 1-ю группу составили 95 больных, которым выполнялась традиционная ТУР, 2-ю — 79 пациентов, подвергшихся ТУР под флюоресцентным контролем.  Результаты. При повторном эндоскопическом обследовании участки флюоресценции обнаружены у 56 (58,9%) больных 1-й группы и у 28 (35,4%) — 2-й. Среди пациентов 1-й группы эндотелиальные опухоли выявлены у 45 (47,4%) человек, а среди больных 2-й группы — у 19 (24,1%). У больных 2-й группы резидуальные опухоли встречаются достоверно реже по сравнению с пациентами 1-й группы (24,1 и 47,4% соответственно, р<0,005). В 1-й группе при контрольном эндоскопическом обследовании Тis обнаружена у 15 (15,8%) из 95 обследованных больных, а во 2-й группе — только у 4 (5,1%) из 79 (р<0,001). Определена достоверная разница в частоте резидуальных опухолей стадии рТа у больных 1-й и 2-й групп (16,8 и 8,9%, p<0,005). Различия в частоте резидуальных папиллярных опухолей в стадии рТ1 в анализируемых группах также были достоверны (10,5 и 6,3% соответственно, р<0,05 ). В то же время разница в частоте встречаемости рецидива в стадии рТ2 была недостоверна. Среди 27 больных 1-й группы с множествен- ным поражением мочевого пузыря резидуальные опухоли обнаружены у 14 (51,9%), а из 22 больных 2-й группы — лишь у 4 (18,2%, р<0,001).Выводы. Ранняя повторная ЦС и биопсия с применением флюоресцентного контроля должны быть рекомендованы пациентам с РМП в стадиях Тis и Та—Т1 для своевременного выявления и удаления резидуальных опухолей и рецидивов.

Characterization of Indoor Extremely Low Frequency and Low Frequency Electromagnetic Fields in the INMA-Granada Cohort

Objective: To characterize the exposure to electric fields and magnetic fields of non-ionizing radiation in the electromagnetic spectrum (15 Hz to 100 kHz) in the dwellings of children from the Spanish Environment and Childhood-“INMA” population-based birth cohort. Methodology: The study sample was drawn from the INMA-Granada cohort. Out of 300 boys participating in the 9–10 year follow-up, 123 families agreed to the exposure assessment at home and completed a specific ad hoc questionnaire gathering information on sources of non-ionizing radiation electric and magnetic fields inside the homes and on patterns of use. Long-term indoor measurements were carried out in the living room and bedroom. Results: Survey data showed a low exposure in the children's homes according to reference levels of the International Commission on Non-Ionizing Radiation Protection but with large differences among homes in mean and maximum values. Daytime electrostatic and magnetic fields were below the quantification limit in 78.6% (92 dwellings) and 92.3% (108 dwellings) of houses, with an arithmetic mean value (± standard deviation) of 7.31±9.32 V/m and 162.30±91.16 nT, respectively. Mean magnetic field values were 1.6 lower during the night than the day. Nocturnal electrostatic values were not measured. Exposure levels were influenced by the area of residence (higher values in urban/semi-urban versus rural areas), type of dwelling, age of dwelling, floor of the dwelling, and season. Conclusion: Given the greater sensitivity to extremely low-frequency electromagnetic fields of children and following the precautionary principle, preventive measures are warranted to reduce their exposure.This work was supported by the Spanish Ministry of Health (CIBERESP and FIS PI11/0610) and the Andalusia Regional Government, Council of Innovation, Science and Enterprise (Excellence Project P09-CTS-5488) and Council of Health (SAS PI-0675-2010)