Sodium dodecyl sulfate, a biological membrane mimetic, can be used to study the conversion of globular proteins into amyloid fibrils in vitro. Using multiple approaches, the effect of SDS was examined on stem bromelain (SB), a widely recognized therapeutic protein. SB is known to exist as a partially folded intermediate at pH 2.0, situation also encountered in the gastrointestinal tract (its site of absorption). In the presence of sub-micellar SDS concentration (500-1000 μM), this intermediate was found to exhibit great propensity to form large-sized β-sheeted aggregates with fibrillar morphology, the hall marks of amyloid structure. We also observed inhibition of fibrillation by two naphthalene-based compounds, ANS and bis-ANS. While bis-ANS significantly inhibited fibril formation at 50 μM, ANS did so at relatively higher concentration (400 μM). Alcohols, but not salts, were found to weaken the inhibitory action of these compounds suggesting the possible involvement of hydrophobic interactions in their binding to protein. Besides, isothermal titration calorimetry and molecular docking studies suggested that inhibition of fibrillation by these naphthalene derivatives is mediated not just through hydrophobic forces, but also by disruption of π-π interactions between the aromatic residues together with the inter-polypeptide chain repulsion among negatively charged ANS/bis-ANS bound SB.

The effect of sintering temperature on ZnO varistor properties is investigated in the range of 700–1400 1C. The
increase of sintering temperature does not influence the well-known peaks related to hexagonal wurtzite
structure of ZnO ceramics, whereas the average grain size is increased from (1.08 to 2.1 mm).With increasing
sintering temperature up to 1200 1C, the nonlinear region is clearly observed in the I–V characteristics,
whereas this region is completely absent only for the sample sintered at 1400 1C. As the sintering
temperature increased, the breakdown field decreased over a wide range from 2838.7 to 6.41 V/cm,
while the nonlinear coefficient is increased in the range of (23.86–47.76). Furthermore, the barrier height
decreased from 1.76 to 0.974 eV, whereas electrical conductivity is improved. On the other hand, the optical
band gap is gradually decreased in the range of 3.08–2.70 eV with increasing sintering temperature. These
results showed a strong correlation between sintering temperature and the properties of ZnO ceramic
varistor.

We report here structural, surface morphology, mechanical, and current–voltage characteristics of Zn1

Structural,mechanicalandsuperconductingpropertiesofBi2Sr2Ca1xYxCu2Oy superconductorswith
various x values(0.00rxr0.50) areinvestigatedbyX-raydiffraction,scanningelectronmicroscopy,
Vickershardnessandresistivitymeasurements.ItisfoundthatthereplacementofCa2þ by Y3þ does
not influencethephasepurityofBi:2212whilelatticeparameters,orthorhombicdistortion,surface
morphology,oxygencontentandholecarrierperCuion(P)areaffected.Furthermore,thecritical
temperatures Tc are increasedbyincreasing Y contentupto0.30,followedbyadecreasewithfurther
increaseof Y contentupto0.50.Thevaluesof Tc are 88,94,101,104and501 K for x¼0.00,0.075,0.15,
0.30 and0.50,respectively.Similarbehaviorisobtainedfortheabsolutevaluesoftruehardness Ht and
surface energy g against Y contentwhiletheoppositebehaviorisrecordedfortheholecarrierperCu
ion (P),deducedfrom Tc values,against Y content.Similarbehaviorisobtainedfortheabsolutevalues
of truehardness Ht and surfaceenergy g against Y content.Theseresultsarediscussedintermsof
possiblereasonsforsuppressionofsuperconductivityby Y substitutionattheCasiteintheBi:2212
superconductingsystem.

Mechanical and magnetic properties of the ZnO/Fe2O3 ceramic
varistors have been examined by using mechanical analyzer, digital
microhardness tester and vibrating sample magnetometer. The
initial stress–strain behavior is found to be linear (elastic) then
becomes nonlinear (plastic deformation) without reaching the failure
limit up to the maximum available stress (0.07 MPa). The compressive
elastic modulus varies between 0.2 and 0.8 MPa with Fe
addition up to 0.50. Furthermore, an approximately monotonically
linear decrease in VHN with increasing Fe content up to 50% has
been observed for all applied loads, which closely resembles the
behavior of the true hardness and the surface energy. The magnetic
measurements revealed an antiferromagnetic to paramagnetic to
transition for all Fe doped samples. The Fe free sample showed
paramagnetic behavior down to 2 K. The Neel temperature moderately
increased from 18 K at 0.05% Fe to 25 K at 0.5% Fe. The magnetization
(M) versus applied magnetic field (H) did not reach
saturation for all samples up to 9 Tesla. The saturated magnetization
(per Fe contents) is low and found to decreases linearly at a
rate of (35 emu/g-Fe) in a clear manifestation of the strengthening
of the antiferromagnetic exchange interaction with increasing
Fe contents.

In this paper, the Kelvin-Helmholtz instability of viscous incompressible magnetic fluid fully
saturated porous media is achieved through the viscous potential theory. The flow is considered to
be through semi-permeable boundaries above and below the fluids through which the fluid may
either be blown in or sucked out, in a direction normal to the main streaming direction of the fluid
flow. An oblique magnetic field, mass, heat transfer, and surface tension are present across the
interface. Through the linear stability analysis, a general dispersion relation is derived and the
natural curves are plotted. Therefore, the linear stability condition is discussed in some depth. In
view of the multiple time scale technique, the Ginzburg–Landau equation, which describes the
behavior of the system in the nonlinear approach, is obtained. The effects of the orientation of
the magnetic fields on the stability configuration in linear, as well as nonlinear approaches, are
discussed. It is found that the Darcy’s coefficient for the porous layers plays a stabilizing role. The
injection of the fluids at both boundaries has a stabilizing effect, in contrast with the suction at both

The cleavage of F!CN bond in the presence of Fe(II)
silyl complex, [Cp(CO)FeSiMe3], was studied using density
functional theory calculations and compared with the mechanisms
for E!CN (E = C, N, and O) bond cleavages, which
have previously been clarified to be a silyl-migration-induced
reaction.

Using hybrid density functional theory calculations
with the B3LYP functional, the reaction mechanisms
for cleavage of R2N−CN (R  H, Me) and MeO−CN bonds
in the presence of an unsaturated iron(II) silyl complex,
CpFe(CO)SiMe3, were studied. The following sequence of
reactions was shown to be favorable: (i) coordination of a
nitrile through the lone pair of electrons on the nitrile N atom (NCN) to form an end-on complex, (ii) isomerization of the endon
complex to a side-on complex, (iii) migration of the silyl group to NCN facilitated by the hypervalent character of the Si atom
and its electrostatic attraction with NCN to form a stable Fe−C−NCN three-membered-ring intermediate with an Fe−NCN dative
bond, (iv) dissociation of the NCN atom from Fe and coordination of an amino N atom (NNR2) or methoxy O atom to Fe leading
to an Fe−C−NNR2 or Fe−C−O three-membered-ring intermediate, and (v) cleavage of the R2N−C or MeO−C bond to form a
silyl isocyanide ligand. Step iv possesses the largest activation energy in the sequence of reactions. The activation energies for the
reactions of H2NCN, Me2NCN, and MeOCN were calculated to be 29.9, 28.0, and 19.1 kcal/mol, respectively, on the basis of
potential energies with zero-point energy correction. This accounts for the experimental observation that the intermediates
formed by silyl group migration can be isolated. The effects of the amino and methoxy groups are discussed by comparing their
reaction profiles with that for the reaction of acetonitrile. Localized orbital analysis showed that in the three-membered-ring
intermediates formed in step iv, the R2N−C and MeO−C bonds are activated by ring strain, whereas the Me−CN bond is
activated by interaction of the Me−C bond with the vacant coordination site that is produced in the dissociation of NCN.

O−CN bond cleavage of cyanates (ROCN) has been achieved at room
temperature in the reaction of ROCN with a methyl Fe, Mo, or W complex. A mechanistic
investigation involving DFT calculations revealed that silyl migration from Mo to the CN
nitrogen gave an N-silylated η2-imidato Mo complex. This intermediate analogue was isolated
and characterized by X-ray analysis. Catalytic O−CN bond cleavage was achieved using
Cp(CO)3MoMe under thermal conditions.

In this work, a viscous potential flow analysis is used to investigate capillary surface waves between two horizontal finite fluid layers. The two layers have finite conductivities and admit mass and heat transfer. A general dispersion relation is derived. The presence of finite conductivities together with the dielectric permeabilities makes the horizontal electric field play a dual role in the stability criterion. The phenomenon of negative viscosity is observed. A new growth rate parameter, depending on the kinematical viscosity of the lower fluid layer, is found and has a stabilizing effect on the unstable modes. The growth rates and neutral stability curve are given and applied to air-water interface. The effects of various parameters are discussed for the Kelvin-Helmholtz and the Rayleigh-Taylor instabilities.