Optical nonlinearity of a dual-frequency nematic liquid crystal via temperature-mediated mapping of dielectric anisotropy

Liquid crystals are of great interest in the field of nonlinear optics due to their efficient response to low intensity light fields. Here we present a new, to the best of our knowledge, mechanism of a nonlinear optical response which is observed for a dye-doped dual-frequency nematic liquid crystal. The local increase in temperature caused by the absorption of light beam in the liquid crystal medium leads to spatial variation and inversion of the sign of the dielectric anisotropy. When an alternating current electric field with a frequency close to the cross-over frequency is applied to the liquid crystal cell, the planar orientation sustains at the beam periphery, but elastic deformation occurs in the irradiation region. In the case of a dye dopant with negative absorption dichroism, a first-order orientational transition with large bistability region is obtained.

[MEDICAL AND LEGAL ASPECTS IN PROOF OF RAPES]

The purpose of the study is to analyze new edition of the article 152 of the Criminal Code of Ukraine «Rape», which was adopted with the aim of implementing the Council of Europe Convention on preventing and combating violence against women and domestic violence. The analysis was carried out in terms of the possibility of implementing legal definitions in evidence, taking into account the fundamental medical scientific provisions related to sexual relations. The authors, taking into account the study of more than 100 sentences handed down by the courts of Ukraine in 2010-2018 in criminal cases of rape from the point of view of using medical knowledge in evidence, found a significant change in the objective side of rape, which affected the subject of evidence in criminal proceedings. Now rape is defined as committing acts of a sexual nature associated with vaginal, anal or oral penetration into the body of another person using the genitals or any other object, without the voluntary consent of the victim. A significant change in the rape modus operandi leads to a number of problematic issues in the practical application of these provisions by law enforcement agencies and courts. These issues can be solved, according to the authors' opinion, only by taking into consideration medical and legal aspects of rape. The medical aspect of rape is very important because the concept of rape is legal, but its interpretation is based on the use of medical concepts. The concept of "committing acts of a sexual nature associated with vaginal, anal or oral penetration into the body of another person using the genitals or any other object" is analyzed taking into account the existing and well-established in Forensic Medicine notions of sexual intercourse. The legal aspect of rape is not only to give a legal interpretation of the medical facts of committing sexual acts, but also to establish the absence of the voluntary consent of the victim. The problem of false statements about rape is analyzed, possible indicators of such statements are identified. This problem is quite topical in many countries with a similar interpretation of rape. It is concluded that the medical and legal aspects of rape are closely interrelated, since mechanism of this crime is based on physiological sexual act that is subject to legal assessment.

Use of recombinant alpha-2b-interferon in combination with antioxidants in the form of rectal suppositories (viferon) in children with chronic hepatitides B and C

A new antiviral and immunomodulating preparation Viferon, produced as rectal suppositories containing recombinant alpha-2b-interferon (IFN) and antioxidants, was used in complex therapy of viral chronic hepatitides B and C (ChHB and ChHC) in children. Results of our investigation showed a high efficiency of Viferon. Viferon was found to suppress replication of hepatotropic viruses and to decrease activity of the pathologic process in the liver of children with ChHB and ChHC. After a Viferon treatment with daily doses of (1-2) x 10(6) IU of IFN (3.0 x 10(6) IU/m2) primary remission was registered in 78% of patients with ChHB and in 44% of patients with ChHC, while lasting remission was found in 82% of ChHB and in 33% of ChHC patients. Thus, a more marked effect was observed with ChHB, in which 3.0 x 10(6) IU/m2 was the optimal daily dose for children. Increasing the dose to 5.0 x 10(6) IU/m2 did not result in rise of the percentage of the remissions. Side effects, which are characteristic for injection of IFN preparations, were never found even after a longterm treatment. Absence of induction of neutralizing antibodies was observed after administration of alpha-2b-IFN, an integral part of Viferon. In pediatrics, the method of rectal administration has advantages over parenteral delivery due to its convenience, non-traumatic character and possibility of use for prolonged periods.

Effect of SLS-2 spaceflight on immunologic parameters of rats

During the Spacelab Life Sciences-2 mission, rats were dissected in space and biosamples were returned to Earth for analysis. Immunologic studies addressed the kinetics of T lymphocyte proliferative responses, cytotoxic activity of natural killer cells, and cytokine production. Experiments were performed by using spleen and bone marrow of rats dissected before flight, during flight, immediately after landing of the space shuttle (R + 0), or 14 days after landing (R + 14), as well as those of respective control animals. Each group consisted of five male Sprague-Dawley rats. It was demonstrated that T lymphocyte activity of rats dissected in flight was significantly decreased compared with the controls. This was observed during 48-, 72-, and 96-h cultivation and stimulation with the following mitogenic stimuli: concanavalin A (Con A; 0.1, 1.0, and 10.0 mg/ml), phytohemagglutinin (PHA; 2.5 mg/ml), and interleukin-2 (IL-2; 1 U/ml). The cell proliferation rate in rats dissected immediately after landing did not decrease, whereas that in rats dissected at R + 14 increased. The activity of spleen natural killer cells was reduced in response to 51Cr-labeled target cells during flight (YAC-1 and K-562) and after flight (YAC-1). At R + 14, their activity returned to normal. Another technique employed to measure natural cytotoxicity, using [3H]uridine-labeled target cells and ribonuclease, did not reveal any differences between control and experimental groups. In bone marrow, the activity of natural killer cells did not vary significantly. The production of IL-1, IL-2, tumor necrosis factor (TNF)-alpha, and TNF-beta in spleen cell cultures of the flight rats was reduced. At R + 0, IL-1 and TNF-beta levels remained lowered, whereas TNF-alpha was increased. At R + 0, interferon-alpha and interferon-gamma levels were diminished. In summary, cell-mediated immunity in rats was significantly suppressed during flight. The time course variation of immune parameters after flight suggests that the changes may truly indicate a response of the immune system to spaceflight conditions that could increase over time.