Self Injection length in La0.7 Ca0.3 Mno3-YBa 2Cu3O7-d ferromagnet- superconductor multi layer thin films

We have carried out extensive studies on the self-injection problem in barrierless heterojunctions between La0.7Ca0.3MnO3 (LCMO) and YBa2Cu3O7-d (YBCO). The heterojunctions were grown in situ by sequentially growing LCMO and YBCO films on LaAlO3 (LAO) substrate using a pulsed laser deposition (PLD) system. YBCO micro-bridges with 64 microns width were patterned both on the LAO (control) and LCMO side of the substrate. Critical current, Ic, was measured at 77K on both the control side as well as the LCMO side for different YBCO film thickness. It was observed that while the control side showed a Jc of ~2 x 10E6 A/ cm2 the LCMO side showed about half the value for the same thickness (1800 A). The difference in Jc indicates that a certain thickness of YBCO has become 'effectively' normal due to self-injection. From the measurement of Jc at two different thickness' (1800 A and 1500 A) of YBCO both on the LAO as well as the LCMO side, the value of self-injection length (at 77K) was estimated to be ~900 A self-injection length has been quantified. A control experiment carried out with LaNiO3 deposited by PLD on YBCO did not show any evidence of self-injection.Comment: 6 pages, one figure in .ps forma

Skeletal muscle glycoprotein 130\u27s role in Lewis lung carcinoma-induced cachexia

Chronic inflammation is associated with cachexia-induced skeletal muscle mass loss in cancer. Levels of IL-6 cytokine family members are increased during cancer-related cachexia and induce intracellular signaling through glycoprotein130 (gp130). Although muscle STAT3 and circulating IL-6 are implicated in cancer-induced muscle wasting, there is limited understanding of muscle gp130\u27s role in this process. Therefore, we investigated the role of skeletal muscle gp130 (skm-gp130) in cancer-induced alterations in the regulation of muscle protein turnover. Lewis lung carcinoma (LLC) cells were injected into 8-wk-old skmgp130- knockout (KO) mice or wild-type mice. Skeletal muscle loss was attenuated by 16% in gp130-KO mice, which coincided with attenuated LLC-induced phosphorylation of muscle STAT3, p38, and FOXO3. gp130 KO did not restore mTOR inhibition or alter AMPactivated protein kinase (AMPK) expression. The induction of atrogin expression and p38 phosphorylation in C2C12 myotubes exposed to LLC-treated medium was attenuated by gp130 inhibition, but mTOR inhibition was not restored. STAT signaling inhibition in LLC-treated myotubes did not attenuate the induction of p38 or AMPK phosphorylation. We concluded that, during LLC-induced cachexia, skm-gp130 regulates muscle mass signaling through STAT3 and p38 for the activation of FOXO3 and atrogin, but does not directly regulate the suppression of mTOR. © FASEB

Characterization of the male ApcMin/+ mouse as a hypogonadism model related to cancer cachexia

Summary Cancer cachexia, the unintentional loss of lean body mass, is associated with decreased quality of life and poor patient survival. Hypogonadism, involving a reduction in circulating testosterone, is associated with the cachectic condition. At this time there is a very limited understanding of the role of hypogonadism in cancer cachexia progression. This gap in our knowledge is related to a lack of functional hypogonadal models associated with cancer cachexia. The ApcMin/+ mouse is an established colorectal cancer model that develops an IL-6 dependent cachexia which is physiologically related to human disease due to the gradual progression of tumor development and cachexia. The purpose of this study was to assess the utility of the ApcMin/+ mouse for the examination of hypogonadism during cancer cachexia and to investigate if IL-6 has a role in this process. We report that ApcMin/+ mice that are weight stable have comparable testosterone levels and gonad size compared to wild type mice. Cachectic ApcMin/+ mice exhibit a reduction in circulating testosterone and gonad size, which has a significant association with the degree of muscle mass and functional strength loss. Circulating testosterone levels were also significantly associated with the suppression of myofibrillar protein synthesis. Skeletal muscle and testes androgen receptor expression were decreased with severe cachexia. Although testes STAT3 phosphorylation increased with severe cachexia, systemic IL-6 over-expression for 2 weeks was not sufficient to reduce either testes weight or circulating testosterone. Inhibition of systemic IL-6 signaling by an IL-6 receptor antibody to ApcMin/+ mice that had already initiated weight loss was sufficient to attenuate a reduction in testes size and circulating testosterone. In summary, the ApcMin/+ mouse becomes hypogonadal with the progression of cachexia severity and elevated circulating IL-6 levels may have a role in the development of hypogonadism during cancer cachexia

Design of microprocessor controlled RTA system for processing of ion implanted semiconductor materials

543-551<span style="font-size:14.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Rapid thermal annealing (RTA) is one of the important techniques used for removal of radiation induced defects in ion implanted semiconductor materials. A complete stand-alone microprocessor controlled RTA system has been designed and fabricated. It uses a 12 kW halogen lamp bank for rapid radiative heating of the sample and provides good temperature ramp-up rate of > 120°C/s up to a temperature of 700°C. A gas line assembly has been provided to carry out the annealing in hydrogen, nitrogen, argon and oxygen gas ambient. The system temperature is programmable in the step of 1°C each up to the maximum attainable temperature of 1080oC. The soak time can be programmed from a minimum of 1 s up to a maximum of 15 min per set temperature. The system has been used for annealing of single crystal GaAs substrates implanted with 70 MeV 56Fe ions with a dose of 1×1014 ions/cm2, in the temperature range 100-600oC. The implanted samples have been investigated by optical transmission measurements over photon energy range 0.1-1.4 eV, after each annealing stage. The mid-gap defect states are annealed out more rapidly than the near-band edge defect states during annealing up to 350°C whereas, the near-band edge defect states are annealed out more rapidly than the mid-gap defect states during annealing between 350-600oC.</span

Annealing behaviour of GaAs implanted with 70 MeV 120Sn ions

170-174Single crystal GaAs substrates implanted with 70 MeV 120Sn have been investigated by X-ray diffraction (XRD) and electrical resistance measurements after annealing in the temperature range 373-823 K. XRD measurements for the samples annealed up to 723 K show two peaks, one due to the substrate and another due to the implant damaged layer. The strain parameter from the measured separation between the substrate and layer peaks of several symmetric and asymmetric reflections after each annealing step has been calculated. Strain recovery occurs in two predominant annealing stages, one at about 500 K and the other at about 700 K. Temperature dependence (100-300 K) of resistance of these samples indicates that electrical conduction in the samples annealed up to 723 K, is dominated by variable range hopping. Localized states density at the Fermi level N(EF), estimated from temperature dependence of sample resistance after each annealing step, shows two annealing stages similar to those observed from XRD measurements. Isothermal annealing carried out at two different annealing temperatures (523 and 573 K) indicates the activation energy Ea = 0.16 eV for the first annealing stage

<link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> Self-injection length of polarized spins in La_0.7Ca_0.3MnO₃ -YBa₂Cu₃O_7-_d ferromagnet-superconductor heterostructures

764-770 Studies on the self-injection length of polarized spins in La0.7Ca0.3MnO3 (LCMO)-YBa2Cu3O7-d (YBCO) heterostructures on LaAlO3 (LAO) substrates fabricated in situ with pulsed laser deposition have been carried out. The measured critical current density, Jc of YBCO microbridges on LAO (control) arm was found to be larger than that of the microbridges on the LCMO arm. The difference in Jc in the two arms indicates that a certain thickness of YBCO has become effectively normal due to self-injection of spin-polarized carriers. Further, by measuring transition temperature Tc of YBCO layers with ac susceptibility, it has been found that the thickness of the non-superconducting YBCO layer, due to self-injection at the interface, depends upon the LCMO thickness. Both the above experiments led us to estimate the maximum thickness of the non-superconducting YBCO layer at the interface due to self-injection of spin polarized quasi-particles from YBCO into LCMO; this thickness is found to be in the range 650-850 Å for LCMO thickness ≥ 1000 Å. A control experiment performed on YBCO-LNO (LaNiO3) heterostructure did not show any evidence of self-injection

Auger electron spectroscopy and x-ray diffraction studies of Ti-Si layers synthesised by ion implantation

Ion implantation of (48Ti)+ ions into silicon substrates at 30 keV has been done and the resulting layers are investigated by Auger Electron Spectroscopy and Seeman-Bohlin x-ray diffraction