High frequency polarization switching of a thin ferroelectric film

We consider both experimentally and analytically the transient oscillatory process that arises when a rapid change in voltage is applied to a $Ba_xSr_{1-x}TiO_3$ ferroelectric thin film deposited on an $Mg0$ substrate. High frequency ($\approx 10^{8} rad/s$) polarization oscillations are observed in the ferroelectric sample. These can be understood using a simple field-polarization model. In particular we obtain analytic expressions for the oscillation frequency and the decay time of the polarization fluctuation in terms of the material parameters. These estimations agree well with the experimental results

Quantum memory for light via stimulated off-resonant Raman process: beyond the three-level Lambda-scheme approximation

We consider a quantum memory scheme based on the conversion of a signal pulse into a long-lived spin coherence via stimulated off-resonant Raman process. For a storing medium consisting of alkali atoms, we have calculated the Autler-Townes resonance structure created by a strong control field. By taking into account the upper hyperfine states of the D1 optical transition, we show important deviations from the predictions of the usual three-level Lambda-scheme approximation and we demonstrate an enhancement of the process for particular detunings of the control. We estimate the memory efficiency one can obtain using this configuration.Comment: 8 pages, 6 figure

Ferroelectric Nanotubes

We report the independent invention of ferroelectric nanotubes from groups in several countries. Devices have been made with three different materials: lead zirconate-titanate PbZr1-xTixO3 (PZT); barium titanate BaTiO3; and strontium bismuth tantalate SrBi2Ta2O9 (SBT). Several different deposition techniques have been used successfully, including misted CSD (chemical solution deposition) and pore wetting. Ferroelectric hysteresis and high optical nonlinearity have been demonstrated. The structures are analyzed via SEM, TEM, XRD, AFM (piezo-mode), and SHG. Applications to trenching in Si dynamic random access memories, ink-jet printers, and photonic devices are discussed. Ferroelectric filled pores as small as 20 nm in diameter have been studied

Steel septum magnets for the LHC beam injection and extraction

The Large Hadron Collider (LHC) will be a superconducting accelerator and collider to be installed in the existing underground LEP ring tunnel at CERN. It will provide proton-proton collisions with a centre of mass energy of 14 TeV. The proton beams coming from the SPS will be injected into the LHC at 450 GeV by vertically deflecting kicker magnets and horizontally deflecting steel septum magnets (MSI). The proton beams will be dumped from the LHC with the help of two extraction systems comprising horizontally deflecting kicker magnets and vertically deflecting steel septum magnets (MSD). The MSI and MSD septa are laminated iron-dominated magnets using an all welded construction. The yokes are constructed from two different half cores, called coil core and septum core. The septum cores comprise circular holes for the circulating beams. This avoids the need for careful alignment of the usually wedge-shaped septum blades used in classical Lambertson magnets. The MSI and MSD septum magnets were designed and built in a collaboration between IHEP (Protvino) and CERN (Geneva). This paper presents the magnet design, the experience gathered during the preseries construction, and gives the results of detailed magnetic measurements of the MSIB and MSDC preseries magnets

Hernia or hernia Defect? Experimental herniology Models in Laboratory Animals

Hernias of the anterior abdominal wall remain one of the most common surgery pathologies. There is no unified approach to modeling anterior abdominal wall hernias in the world scientific community. In order to systematize the available knowledge in this field and to contribute to the formation of a unified idea of how to create a hernia model in a laboratory animal, it seems logical to study the accumulated experience of researchers in the field of experimental herniology. We found out that hernia defects generally modeled on male laboratory rats. To understand the tissue reaction to the prosthetic material a fenestration was performed in the anterior abdominal wall (including peritoneum) except for the skin and subcutaneous fat. A replacement or prosthetic material tailored to the fenestration was sutured end-to-end into the abdominal wall. We chose laboratory rats because they are easy to take care of and cheaper than larger laboratory animals

Assessment the equivalence of the bioanalogue insulin lizpro biphasic 25 (Geropharm-bio, Russia) and Humalog® Mix 25 (Lilly France, France) using the euglycemic hyperinsulinum clamp method on healthy volonters

Background: Modern medicine requires use of effective antidiabetic drugs that can imitate the natural profile of insulin in the body of patients with diabetes mellitus. Examples of such preparations include biphasic insulin lispro, which is a mixture of insulin lispro ultra-short action and insulin lispro protamine suspension with prolonged effect. The clinical trials (CT) program for biosimilar insulins contains pharmacology studies: pharmacokinetics (PK), pharmacodynamics (PD) and clinical safety studies. Aims: To demonstrate Biphasic Insulin Lispro 25, suspension for subcutaneous administration, 100 U/ml (GEROPHARM-Bio, Russia) and Humalog® Mix 25, suspension for subcutaneous administration, 100 U/ml (Lilly France, France) have comparable pharmacokinetic profiles under conditions of hyperinsulinemic euglycemic clamp (HEC) in healthy volunteers. Materials and methods: The study was conducted on 48 healthy men aged between 18 to 50 years. This was a double-blind, randomized, crossover study of comparative pharmacokinetics of drugs. The investigational products (IP) were administered before the clamp in a single dose of 0.4 U/kg subcutaneously in the abdominal wall. Regular blood sampling was performed during the study. The insulin concentrations in the samples were determined using an ELISA method. The results of the determination were used to calculate the PK parameters and construct the concentration-time curves. Adjust glucose infusion rates were based on blood glucose measurements. These data were used to calculate the PD parameters. Results: Our results demonstrated that Biphasic Insulin Lispro 25 and Humalog® Mix 25 have comparable PK and PD profiles under conditions of HEC in healthy volunteers. The confidence intervals for the ratio of the geometric mean for Cins.max and AUCins.0–12 were 87.75–99.90% and 83.76–96.98% respectively, which were well within 80–125% limits for establishing comparability. Conclusions: Biphasic Insulin Lispro 25 and Humalog® Mix 25 are equivalent based on this CT applying the HEC technique in healthy volunteers

Introducing Quantum Technologies at Secondary School Level: Challenges and Potential Impact of an Online Extracurricular Course

Stimulated by the European project “QTEdu CSA”, within the flagship “Quantum Technologies”, a community of researchers active in the fields of quantum technologies and physics education has designed and implemented an extracurricular course on quantum physics concepts and quantum technologies applications for high school. The course, which featured eight interactive lectures, was organized online between March and May 2021 and attended by about 250 students from all over Italy. In this paper, we describe the main tenets and activities of the course. Moreover, we report on the effectiveness of the course on students’ knowledge of the basic concepts of quantum physics and students’ views about epistemic aspects and applications of quantum technologies. Results show that the designed activities were effective in improving students’ knowledge about fundamental aspects of quantum mechanics and familiarizing them with quantum technology applications

Multicomponent coating in purulent wound healing: A randomised controlled experimental study

Background. Purulent wound healing is a pressing surgical challenge relevant in 30−35% of patient cases. To the more, wound infectious agents elaborate resistance to available drugs warranting the development of new drug combinations exserting a multidirectional effect on the wound process.Objective. Using a purulent wound model to experimentally evaluate the efficiency of a new multicomponent wound coating comprised of polyethylene oxide and carboxymethylcellulose sodium-immobilised dioxidine, methyluracil, metronidazole and lidocaine hydrochloride in comparison with a legal approved wound coating drug preparation of beeswax and propolis-based dioxidine ointment.Methods. The antimicrobial activity range (disk-diffusion method) and local anaesthetic effect (Rainier’s method) of the developed wound coating have been assessed. The healing process was studied in a purulent wound model with 72 Wistar rats divided between two equal groups. The following methods were applied: visual wound inspection (wound cleansing time, absence of wound-surrounding tissue oedema, granulation and epithelisation), planimetric parameter estimation (wound area, healing rate, wound area reduction ratio), wound contamination and pH measurement, wound section cell morphometry (granulocyte, macrophage, lymphocyte and fibroblast counts, cell index estimation). Daily dressings were applied for 15 days.Results. The developed wound coating exhibited high efficiency against Gram-positive and Gram-negative bacteria in the zone of inhibition tests. Its local anaesthetic effect was significantly superior to the approved drug by the duration of action. The wound area reduction was 94.2 (93.7; 94.8)% in the experimental group and 86 (84.2; 88.8)% in the control (differences statistically significant) already on day 10. A maximal healing rate in both groups was registered in phase 1 of the wound process being 1.4 times higher in experiment compared to the control. The wound contamination was significantly lower in experiment vs. control on day 8 (p = 0.0075). Wound pH negatively correlated with the fibroblast count and positively — with the contamination level.Conclusion. The study demonstrates high efficiency of the developed wound coating against infectious agents and its positive healing impact via reducing phase 1 and stimulating proliferation in phase 2 of the wound process

Ultrafast optical generation of coherent phonons in CdTe1-xSex quantum dots

We report on the impulsive generation of coherent optical phonons in CdTe0.68Se0.32 nanocrystallites embedded in a glass matrix. Pump probe experiments using femtosecond laser pulses were performed by tuning the laser central energy to resonate with the absorption edge of the nanocrystals. We identify two longitudinal optical phonons, one longitudinal acoustic phonon and a fourth mode of a mixed longitudinal-transverse nature. The amplitude of the optical phonons as a function of the laser central energy exhibits a resonance that is well described by a model based on impulsive stimulated Raman scattering. The phases of the coherent phonons reveal coupling between different modes. At low power density excitations, the frequency of the optical coherent phonons deviates from values obtained from spontaneous Raman scattering. This behavior is ascribed to the presence of electronic impurity states which modify the nanocrystal dielectric function and, thereby, the frequency of the infrared-active phonons