SOME CURVATURE PROPERTIES ON PARACONTACT METRIC (k;μ)-MANIFOLDS WITH RESPECT TO THE SCHOUTEN-VAN KAMPEN CONNECTION

The object of the present paper is to characterize paracontact metric (k;μ)-manifolds satisfying certain semisymmetry curvature conditions with respect to the Schouten-van Kampen connection

Indefinite almost paracontact metric manifolds

In this paper we introduce the concept of $(\varepsilon)$-almost paracontact manifolds, and in particular, of $(\varepsilon)$-para Sasakian manifolds. Several examples are presented. Some typical identities for curvature tensor and Ricci tensor of $(\varepsilon)$-para Sasakian manifolds are obtained. We prove that if a semi-Riemannian manifold is one of flat, proper recurrent or proper Ricci-recurrent, then it can not admit an $(\varepsilon)$-para Sasakian structure. We show that, for an $(\varepsilon)$-para Sasakian manifold, the conditions of being symmetric, semi-symmetric or of constant sectional curvature are all identical. It is shown that a symmetric spacelike (resp. timelike) $(\varepsilon)$-para Sasakian manifold $M^{n}$ is locally isometric to a pseudohyperbolic space $H_{\nu}^{n}(1)$ (resp. pseudosphere $S_{\nu}^{n}(1)$). In last, it is proved that for an $(\varepsilon)$-para Sasakian manifold, the conditions of being Ricci-semisymmetric, Ricci-symmetric and Einstein are all identical

The genotoxicity of Tenofovir disoproxil fumarate in HBV-infected patients

Tenofovir disoproxil fumarate (TDF) is an acyclic nucleotide reverse transcriptase inhibitor used as antiviral therapeutic drug in hepatitis B virus (HBV) infection treatment. We investigated whether HBV itself or TDF could enhance genotoxicity in HBV infected patients. A total of 30 HBV-infected patients were included in this study: 10 were untreated, 10 took therapy for 6 months, 10 took therapy for 12 months and a further 15 were control group. We used the micronucleus test (MN) and mitotic index (MI) to assess the genotoxic effects of TDF. MN and MI frequency were significantly increased in all the HBV-infected patient groups when compared to control. However, significant differences were not found between different time points within the therapy groups. The current data indicate that chronic HBV infection without treatment has an effect on MN and MI. TDF administration at therapeutic doses for 12 months also did not reduce the MI and MN, suggesting its protective action against HBV induced genotoxic damage. Larger-scale and longtime studies are required for a better understanding of the genotoxicity of TDF. [Med-Science 2018; 7(3.000): 600-3

Tachyphylaxis during ranibizumab treatment of exudative age-related macular degeneration.

Letter to the Edito

LIGHTLIKE HYPERSURFACES WITH PLANAR NORMAL SECTIONS IN R-1(4)

WOS: 000499091900022In the present paper our aim is to investigate lightlike hypersurfaces of R-1(4) having degenerate or non-degenerate planar normal sections. Firstly, we prove that lightlike hypersurfaces in R-1(4) always have degenerate planar normal sections. Then we examine the conditions for lightlike hypersurfaces in R-1(4) to have non-degenerate planar normal sections and obtain some characterizations for such lightlike hypersurfaces

A Delphi consensus study on the treatment of slipped capital femoral epiphysis: Considerable consensus in mild and moderate slips and limited consensus in severe slips

Purpose:The aim of this expert consensus study was to establish consensus on the treatment of different types of slipped capital femoral epiphysis and on the use of prophylactic screw fixation of the contralateral unaffected side. Methods:In this study, a four-round Delphi method was used. Questionnaires including all possible theoretical slip scenarios were sent online to 14 participants, experienced in the field of children's orthopedics and in the treatment of hip disorders in children. Results:In-situ fixation was considered to be the first treatment choice in all types of mild slip scenarios and in moderate, stable ones. Performing in-situ fixation was not favored in moderate, unstable, and in all severe slip scenarios. In moderate to severe, unstable slip scenarios, there was consensus on the use of gentle closed or open reduction and internal fixation. Any consensus was not established in the optimal treatment of severe, stable slips. There was also consensus on the use of prophylactic screw fixation of the contralateral side in case of co-existing endocrine disorder and younger age. Conclusions:The establishment of consensus on the treatment of all types of slipped capital femoral epiphysis even among the experienced surgeons does not seem to be possible. The severity of the slip and stability of the slip are the primary and secondary determinants of the surgeons' treatment choices, respectively. In-situ fixation is still the preferred treatment option in several slip types. Gentle capital realignment by closed or open means is recommended in displaced, unstable slips. Prophylactic screw fixation of the contralateral side is indicated under certain circumstances

Lightlike Submanifolds of Metallic Semi-Riemannian Manifolds

WOS:000603450300003Our aim in this paper is to investigate some special types of lightlike submanifolds in metallic semi-Riemannian manifolds. We study invariant lightlike submanifolds and screen semi-invariant lightlike hypersurfaces of metallic semi-Riemannian manifolds and give examples. We obtain some conditions for the induced connection to be a metric connection and present integrability conditions for the distributions involved in the definitions of such types