Integrins are heterodimeric cell-surface molecules, which act as the principle mediators of molecular dialog between a cell and its extracellular matrix environment. In addition to their structural functions, integrins mediate signaling from the extracellular space into the cell through integrin-associated signaling and adaptor molecules such as FAK (focal adhesion kinase), ILK (integrin-linked kinase), PINCH (particularly interesting new cysteine-histidine rich protein) and Nck2 (non-catalytic (region of) tyrosine kinase adaptor protein-2). Via these molecules, integrin signaling tightly and cooperatively interacts with receptor tyrosine kinases (RTKs) signaling to regulate survival, proliferation and cell shape as well as polarity, adhesion, migration and differentiation. In the heart and blood vessels, the function and regulation of these molecules can be partially disturbed and thus contribute to cardiovascular diseases such as cardiac hypertrophy and atherosclerosis. In this review, we discuss the primary mechanisms of action and signaling of integrins in the cardiac and vascular system in normal and pathological states, as well as therapeutic strategies for targeting these systems (1).
Over the years central research of spintronics has focused on generating spin-current to manipulate nano-magnets by spin torque. So far electrically 1-9 and thermally driven spin-torques [10][11][12] have been experimentally demonstrated. These torques can be attributed to either Slonczewski's spin-transfer torque (STT) 13 or field-like torque (FLT) 3,8,14 . STT arises when ferromagnet absorbs spin current generated by many ways like spin-Hall effect (SHE) 15,16 , spin-pumping 17 , spin-Nernst effect 18 , spin-(dependent) Seebeck effect 19-21 etc. Field-like torque is generally observed in asymmetric magnetic tunnel junctions (MTJ) with current perpendicular to the plane (CPP) geometry 3,14,22 and ferromagnet/heavy metal bilayer where Rashba 8 or Dressulhous 7 spin orbit interaction is present. Control of magnetization dynamics is not only interesting from physics perspective but also useful in technological applications 23,24 . We have experimentally observed a new form of spin torque which is completely different from conventional STT and FLT. This unconventional spin torque is exerted by a fixed magnet on a free magnet in spin valve structure with current in-plane (CIP) geometry. The observed spin torque originates from an out of plane effective magnetic field with symmetry of (M× J), where M denotes the magnetization direction of fixed FM and J denotes current density. This torque could be potentially useful for switching out-of-plane magnets in high density MRAM.Spin-orbit torque 4,7,8,25 has evolved in a promising way to manipulate spins since last few years. Heavy metals like Pt 26 , anti-ferromagnets 27,28 , two dimensional materials 29,30 and semiconductor systems 7 have been recently studied as candidates for generating spin torques. However ferromagnetic metal (FM) itself has its own spin-orbit coupling which is responsible for various effects like: anisotropic magneto resistance (AMR), planar Hall effect (PHE) and anomalous Hall effect (AHE). AHE is analogous to SHE in heavy metal which can induce spin current in neighbouring metal and cause spin orbit torque (Fig. 1b). Previous studies show that spin Hall angle of FM 31,32 is quite comparable to Pt. Hence FM can be considered as good candidate for SOT [33][34] . To study spin orbit torque by FM we need FM(free)/Cu/FM(fixed) heterostructure where fixed layer will be source of spin current which will exert torque on another FM separated by Cu spacer. Based on this principle we carried out spin-torque ferromagnetic resonance (ST-FMR) 3,7,26 measurement of current in-plane giant-magnetoresistive (GMR) stack consisting of Ta(5 nm)/Ru(5 nm)/IrMn(7 nm)/CoFe(2 nm)/Cu(5 nm)/CoFe(2 nm)/Cu(5 nm). However we surprisingly observe the existence of a new kind of torque which is completely different from standard spin-orbit torque by FM (owing to its AHE) which we initially expected. This unconventional spin-torque depends on the mutual orientation of fixed layer magnetization direction (M) and direction of in-plane current flow (J) and manifests itself as an effect...
A B S T R A C T The effects of calcium on the renal actions of parathyroid hormone (PTH) were studied in vivo and in vitro. In parathyroidectomized rats, variable levels of blood calcium concentration were induced by intravenous infusion of calcium. The renal responses to the injected PTH, i.e. phosphate and cyclic AMP excretion, were compared in these animals. After PTH injection, the increases of both phosphate and cyclic AMP excretion were less in the calcium-infused animals than in the control group without calcium infusion. There was an inverse correlation between the renal responses to PTH and plasma calcium concentration of 4.2-13.5 mg/100 ml. But calcium had no effect on phosphate excretion induced by infusion of dibutyryl cyclic AMP. In the in vitro experiments, the increase of cyclic AMP concentration in response to PTH was less in renal cortical slices taken from the calcium-infused animals than in ones from the control group without calcium infusion. Calcium also inhibited the activation of renal cortical adenylate cyclase in response to PTH, but calcium had no effect on phosphodiesterase. The data indicate that calcium directly inhibits renal actions of PTH both in vivo and in vitro. Such inhibitory mechanism is probably at or before the step of PTHdependent cyclic AMP generation in the kidney. INTRODUCTIONParathyroid hormone (PTH) 1 plays a major role in the regulation of the concentrations of calcium and phosphate in plasma. This appears to be accomplished primarily by a reciprocal relationship between the concentration of ionized calcium in plasma and the rate of
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