MELK-a conserved kinase: functions, signaling, cancer, and controversy.

Maternal embryonic leucine zipper kinase (MELK) is a highly conserved serine/threonine kinase initially found to be expressed in a wide range of early embryonic cellular stages, and as a result has been implicated in embryogenesis and cell cycle control. Recent evidence has identified a broader spectrum of tissue expression pattern for this kinase than previously appreciated. MELK is expressed in several human cancers and stem cell populations. Unique spatial and temporal patterns of expression within these tissues suggest that MELK plays a prominent role in cell cycle control, cell proliferation, apoptosis, cell migration, cell renewal, embryogenesis, oncogenesis, and cancer treatment resistance and recurrence. These findings have important implications for our understanding of development, disease, and cancer therapeutics. Furthermore understanding MELK signaling may elucidate an added dimension of stem cell control

Tunable polarization components and electric field induced crystallization in polyvinylidenefluoride (PVDF); a piezo polymer

Polyvinylidenefluoride (PVDF) a semicrystalline pieozoelectric polymer was synthesized with varying process conditions and its ferroelectric domain orientations were studied using piezoresponse force microscope (PFM). PVDF thin films fabricated using tape casting technique with precursor solutions of varying viscosities reveal that the polarization components transform from a dominant planar component to an out-of-plane polarization components with increase in viscosity. Interestingly the planar components possessed a head to head or tail to tail kind of paired domains separated by a distance of ~ 380-400nm. The electrostatic energies computed by numerically solving the electrostatic equilibrium equation for the electrically inhomogeneous system are in good correlation with the experiments. On increment of electric field, the domains were observed to grow in size and shape which indicates amorphous to crystalline transformation in the case of PVDF. Such transformation was evident from x-ray diffraction studies performed in-situ in the presence of an applied electric field

Tunable polarization components and electric field induced crystallization in polyvinylidenefluoride: A piezo polymer

Polyvinylidenefluoride (PVDF) a semicrystalline pieozoelectric polymer was synthesized with varying process conditions and its ferroelectric domain orientations were studied using piezoresponse force microscope (PFM). PVDF thin films fabricated using tape casting technique with precursor solutions of varying viscosities reveal that the polarization components transform from a dominant planar to an out‐of‐plane configuration with increase in viscosity. Interestingly the planar components possessed a head to head or tail to tail kind of paired domains separated by a distance of ~ 380‐400 nm. Electrostatic energy minimization of an electrically inhomogeneous system containing similar domain arrangements as the experiments shows that the head to head and tail to tail arrangements with a minimum separation distance are more favorable than head to tail arrangements of domains. With increment of applied field, the domains grew in size and shape indicating amorphous to crystalline transformation of PVDF films. Such transformation was evident from X‐ray diffraction studies performed in‐situ in the presence of an applied electric field

EXTRUSION TECHNIQUE IN FOOD PROCESSING AND A REVIEW ON ITS VARIOUS TECHNOLOGICAL PARAMETERS

*Author for Correspondence Extrusion technique is a process in food processing technology which combines several unit operations including mixing, cooking, kneading, shearing, shaping and forming. Food extrusion is a form of extrusion used in food processing. It is a process by which a set of mixed ingredients are forced through an opening in a perforated plate or die with a design specific to the food, and is then cut to a specified size by blades. The machine which forces the mix through the die is an extruder, and the mix is known as the extrudate. The extruder consists of a large, rotating screw tightly fitting within a stationary barrel, at the end of which is the die. Key Words: Extrudate, Extrusion and Food Processin

Dielectric switching studies of polyvinylidene fluoride thin films with dominant planar ferroelectric domain configuration for flexible electronic devices

Electrical switching characteristics of the polymer chains of polyvinylidene fluoride (PVDF) thin films with dominant planar domain configuration were investigated in this work. PVDF a semi-crystalline piezoelectric polymer is known to undergo structural transformation when subjected to electric field. In this study, the I-V characteristics of PVDF was analyzed by varying the delay time from 0.1 to 0.001 seconds in order to understand the response of switching behavior; a promising attribute that governs the operational speed of the device. A hysteretic behavior in the I-V characteristics was observed at different drive voltages. The ferroelectric polarization domains responds at different voltages and give rise to polarization switching currents. In addition to this, at relatively larger voltages (> 10 V) the amorphous intermediate regions of PVDF is expected to undergo an amorphous to crystalline transformation. Hence, the switching characteristics of the ferroelectric domains in the form of switching currents and the dipolar re-orientation arising due to the amorphous to crystalline transformation by rotation of polymer chains are captured at different voltages. Furthermore, a longer delay time (0.1 seconds) is employed to capture the current arising from a reversible amorphous to crystalline transformation. The dielectric relaxation time for the rotation of polymer chains in PVDF was inferred from independent studies and observed to be between 100 to 500 μS

MELK—a conserved kinase: functions, signaling, cancer, and controversy

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Maternal Embryonic Leucine Zipper Kinase: Key Kinase for Stem Cell Phenotype in Glioma and Other Cancers

Maternal embryonic leucine zipper kinase (MELK) is a member of the snf1/AMPK family of protein Serine/Threonine kinases that has recently gained significant attention in the stem cell and cancer biology field. Recent studies suggest that activation of this kinase is tightly associated with extended survival and accelerated proliferation of cancer stem cells (CSCs) in various organs. Overexpression of MELK has been noted in various cancers, including colon, breast, ovaries, pancreas, prostate, and brain, making the inhibition of MELK an attractive therapeutic strategy for a variety of cancers. In the experimental cancer models, depletion of MELK by RNA interference or small molecule inhibitors induces apoptotic cell death of cancer stem cells derived from glioblastoma and breast cancer, both in vitro and in vivo. Mechanism of action of MELK includes, yet may not be restricted to, direct binding and activation of the oncogenic transcription factors c-JUN and FOXM1 in cancer cells but not in the normal counterparts. Following these pre-clinical studies, the Phase I clinical trial for advanced cancers with OTS167 started in 2013, as the first-in-class MELK inhibitor. This review summarizes the current molecular understanding of MELK and the recent pre-clinical studies about MELK as a cancer therapeutic target