Retrospective study of tumor and tumor like conditions of ovary from a rural hospital in Kerala

Background: Ovarian tumor and tumor like conditions are seen in women from early childhood to post-menopausal age. The ovaries are a pair of female sex glands responsible for the germ cell maturation, storage and release; cyclically. It also plays an important role in steroidogenesis. The ovaries are a totipotential structure and hence, neoplasms from all 3 germinal layers can be seen arising from it and manifesting clinically as ovarian tumors and tumor like conditions with its occurrence more during the late reproductive life. Ovarian tumors represent about 30% of all cancers of the female genital system. They manifesting in a wide spectrum of clinical, morphological and histological features.Methods: This is retrospective observational study where analysis of all cases which were encountered surgically during the period Mar 2012 to Mar 2017. The cases diagnosed as ovarian tumors were subjected to thorough investigation by CA125, ultrasound (USG) abdomen and pelvis and Computerised Tomography (CT) scan. Emergency presentations with twisted cysts were operated in emergency setting and histopathological examination (HPE) done to identify the nature of tumor. IHC was done wherever necessary to sub classify and confirm the histological diagnosis. Surgeries were done either by conventional laparotomy or by laparoscopy.Results: We have analyzed 175 cases retrospectively after histopathological diagnosis. The commonest lesions were ovarian cysts, out of which 63 cases (36%) were simple serous cyst adenomas followed by mucinous cyst adenomas 30 cases (17.14%). Germ cell tumors with struma ovarii were 34 cases (19.42%). The interesting part of the study was that we had a very high incidence of large endometriomas diagnosed as ovarian cysts before surgery 16 cases (9.4%). Two cases (1.14%) of ovarian malignancy were detected.Conclusions: The above study has revealed a spectrum of ovarian tumors over a wide age range from adolescent to late reproductive to menopausal and late menopausal age group. The incidence of malignancy was (1.14%)

Modeling Tube-Forming of an Austenitic Stainless Steel with Exploitation of Martensite Evolution

Within the last years the industrial manufacturing of tubes has developed to an increasingly complex process. In particular, during the forming procedure of sheets made of austenitic stainless steel, the increase and the content of strain-induced martensite needs to be controlled in order to achieve the optimal structural properties of the manufactured tube with respect to very-high-cycle fatigue (VHCF). On the basis of experimental investigations this contribution deals with the numerical simulation of the forming process with special consideration of the martensite ratio as a function of temperature and deformation field. A convenient approach of modeling the martensite evolution as well as the extension of this model to polyaxial states of stress and a comparison with experimental results is presented

Nonequilibrium brittle fracture propagation: Steady state, oscillations and intermittency

A minimal model is constructed for two-dimensional fracture propagation. The heterogeneous process zone is presumed to suppress stress relaxation rate, leading to non-quasistatic behavior. Using the Yoffe solution, I construct and solve a dynamical equation for the tip stress. I discuss a generic tip velocity response to local stress and find that noise-free propagation is either at steady state or oscillatory, depending only on one material parameter. Noise gives rise to intermittency and quasi-periodicity. The theory explains the velocity oscillations and the complicated behavior seen in polymeric and amorphous brittle materials. I suggest experimental verifications and new connections between velocity measurements and material properties.Comment: To appear in Phys. Rev. Lett., 6 pages, self-contained TeX file, 3 postscript figures upon request from author at [email protected] or [email protected], http://cnls-www.lanl.gov/homepages/rafi/rafindex.htm

Electromagnetic Meson Form Factors in the Salpeter Model

We present a covariant scheme to calculate mesonic transitions in the framework of the Salpeter equation for $q\bar{q}$-states. The full Bethe Salpeter amplitudes are reconstructed from equal time amplitudes which were obtained in a previous paper\cite{Mue} by solving the Salpeter equation for a confining plus an instanton induced interaction. This method is applied to calculate electromagnetic form factors and decay widths of low lying pseudoscalar and vector mesons including predictions for CEBAF experiments. We also describe the momentum transfer dependence for the processes $\pi^0,\eta,\eta'\rightarrow\gamma\gamma^*$.Comment: 22 pages including 10 figure

Pion and Kaon Vector Form Factors

We develop a unitarity approach to consider the final state interaction corrections to the tree level graphs calculated from Chiral Perturbation Theory ($\chi PT$) allowing the inclusion of explicit resonance fields. The method is discussed considering the coupled channel pion and kaon vector form factors. These form factors are then matched with the one loop $\chi PT$ results. A very good description of experimental data is accomplished for the vector form factors and for the $\pi\pi$ P-wave phase shifts up to $\sqrt{s}\lesssim 1.2$ GeV, beyond which multiparticle states play a non negligible role. In particular the low and resonance energy regions are discussed in detail and for the former a comparison with one and two loop $\chi PT$ is made showing a remarkable coincidence with the two loop $\chi PT$ results.Comment: 20 pages, 7 figs, to appear in Phys. Rev.

Light-cone QCD Sum Rules for the Λ\Lambda Baryon Electromagnetic Form Factors and its magnetic moment

We present the light-cone QCD sum rules up to twist 6 for the electromagnetic form factors of the $\Lambda$ baryon. To estimate the magnetic moment of the baryon, the magnetic form factor is fitted by the dipole formula. The numerical value of our estimation is $\mu_\Lambda=-(0.64\pm0.04)\mu_N$, which is in accordance with the experimental data and the existing theoretical results. We find that it is twist 4 but not the leading twist distribution amplitudes that dominate the results.Comment: 13 page, 7 figures, accepted for publication in Euro. Phys. J.

The π\pi, K+K^+, and K0K^0 electromagnetic form factors

The rainbow truncation of the quark Dyson-Schwinger equation is combined with the ladder Bethe-Salpeter equation for the meson amplitudes and the dressed quark-photon vertex in a self-consistent Poincar\'e-invariant study of the pion and kaon electromagnetic form factors in impulse approximation. We demonstrate explicitly that the current is conserved in this approach and that the obtained results are independent of the momentum partitioning in the Bethe-Salpeter amplitudes. With model gluon parameters previously fixed by the condensate, the pion mass and decay constant, and the kaon mass, the charge radii and spacelike form factors are found to be in good agreement with the experimental data.Comment: 8 pages, 6 figures, Revte

A consistent treatment for pion form factors in space-like and time-like regions

We write down some relevant matrix elements for the scattering and decay processes of the pion by considering a quark-meson vertex function. The pion charge and transition form factors $F_\pi$, $F_{\pi\gamma}$, and $F_{\pi\gamma^*}$ are extracted from these matrix elements using a relativistic quark model on the light-front. We found that, the form factors $F_\pi$ and $F_{\pi\gamma}$ in the space-like region agree well with experiment. Furthermore, the branching ratios of all observed decay modes of the neutral pion, that are related to the form factors $F_{\pi\gamma}$ and $F_{\pi\gamma^*}$ in the time-like region, are all consistent with the data as well. Additionally, $F_\pi$ in the time-like region, which deals with the nonvalence contribution, is also discussed.Comment: 24 pages, 6 figures, to appear in Phys. Rev.

Orbital character of the spin-reorientation transition in TbMn6_6Sn6_6

Ferromagnetic (FM) order in a two-dimensional kagome layer is predicted to generate a topological Chern insulator without an applied magnetic field. The Chern gap is largest when spin moments point perpendicular to the kagome layer, enabling the capability to switch topological transport properties, such as the quantum anomalous Hall effect, by controlling the spin orientation. In TbMn$_{6}$Sn$_{6}$, the uniaxial magnetic anisotropy of the Tb$^{3+}$ ion is effective at generating the Chern state within the FM Mn kagome layers while a spin-reorientation (SR) transition to easy-plane order above $T_{SR}=310$ K provides a mechanism for switching. Here, we use inelastic neutron scattering to provide key insights into the fundamental nature of the SR transition. The observation of two Tb excitations, which are split by the magnetic anisotropy energy, indicates an effective two-state orbital character for the Tb ion, with a uniaxial ground state and an isotropic excited state. The simultaneous observation of both modes below $T_{SR}$ confirms that orbital fluctuations are slow on magnetic and electronic time scales $<$ ps and act as a spatially-random orbital alloy. A thermally-driven critical concentration of isotropic Tb ions triggers the SR transition.Comment: 21 page