Unfolding the Sulcus

Sulci are localized furrows on the surface of soft materials that form by a compression-induced instability. We unfold this instability by breaking its natural scale and translation invariance, and compute a limiting bifurcation diagram for sulcfication showing that it is a scale-free, sub-critical {\em nonlinear} instability. In contrast with classical nucleation, sulcification is {\em continuous}, occurs in purely elastic continua and is structurally stable in the limit of vanishing surface energy. During loading, a sulcus nucleates at a point with an upper critical strain and an essential singularity in the linearized spectrum. On unloading, it quasi-statically shrinks to a point with a lower critical strain, explained by breaking of scale symmetry. At intermediate strains the system is linearly stable but nonlinearly unstable with {\em no} energy barrier. Simple experiments confirm the existence of these two critical strains.Comment: Main text with supporting appendix. Revised to agree with published version. New result in the Supplementary Informatio

Systematic Topology Analysis and Generation Using Degree Correlations

We present a new, systematic approach for analyzing network topologies. We first introduce the dK-series of probability distributions specifying all degree correlations within d-sized subgraphs of a given graph G. Increasing values of d capture progressively more properties of G at the cost of more complex representation of the probability distribution. Using this series, we can quantitatively measure the distance between two graphs and construct random graphs that accurately reproduce virtually all metrics proposed in the literature. The nature of the dK-series implies that it will also capture any future metrics that may be proposed. Using our approach, we construct graphs for d=0,1,2,3 and demonstrate that these graphs reproduce, with increasing accuracy, important properties of measured and modeled Internet topologies. We find that the d=2 case is sufficient for most practical purposes, while d=3 essentially reconstructs the Internet AS- and router-level topologies exactly. We hope that a systematic method to analyze and synthesize topologies offers a significant improvement to the set of tools available to network topology and protocol researchers.Comment: Final versio

Low-Temperature Spin Dynamics of Doped Manganites: roles of Mn-t2g and eg and O-2p states

The low-temperature spin dynamics of doped manganites have been analyzed within a tight-binding model, the parameters of which are estimated by mapping the results of ab initio density functional calculations onto the model. This approach is found to provide a good description of the spin dynamics of the doped manganites, observed earlier within the ab initio calculations. Our analysis not only provides some insight into the roles of the eg and the t2g states but also indicates that the oxygen p states play an important role in the spin dynamics. This may cast doubt on the adaptability of the conventional model Hamiltonian approaches to the analysis of spin dynamics of doped manganites.Comment: 12 pages; Includes 5 figure

An indomethacin sensitive suppressor factor released by macrophages of leprosy patients

Reduction in Fc receptor expression as assayed by 'erythrocyte' rosetting of macrophage cultures from long term treated lepromatous leprosy patients (bactereologically negative) was seen in the presence of viable Mycobacterium leprae. Macrophages with and without intracellular bacilli demonstrated this reduction. On the basis of this observation the conditioned medium of Mycobacterium leprae infected macrophage cultures of lepromatous patients, were tested on macrophages from normal individuals for [3H]-leucine incorporation and antigen specific physical interaction with lymphocytes. Both these parameters showed decreased values as compared to the controls which were not exposed to this conditioned medium. Lymphocyte transformation to Mycobacterium leprae in leucocyte cultures of normal individuals was also reduced in the presence of the conditioned medium from lepromatous patients' macrophages. The indication that this factor may be a prostaglandin was suggested by the observation that its synthesis was inhibited by indomethacin. Its importance in the non-specific depression in cell-mediated immunity seen in lepromatous patients is discussed

SYNTHESIS, IN VITRO ANTIBACTERIAL, TOXICITY AND MOLECULAR DOCKING ANTICANCER ACTIVITY OF NOVEL N-[(2-CHLOROQUINOLIN-3-YL) METHYLIDENE]-2-ANILINE SCHIFF'S BASES

Objective: Synthesis of N-[(2-chloroquinolin-3-yl) methylidene]-2-aniline schiff bases (3a-j) and to study their in vitro antibacterial activity and in silico study towards cancer and malarial proteins. Methods: Various N-[(2-chloroquinolin-3-yl) methylidene]-2-aniline schiff bases (3a-j) were synthesized by using 2-chloro-3-formyl quinoline and different anilines in presence of acetic acid as catalyst. All the new compounds were characterized by 1H-NMR, [13]C-NMR and LCMS analysis. The compounds 3a-j was subjected to antibacterial activity. In silico molecular properties were predicted using various online cheminformatic tools, the binding interactions with Human DNA topoisomerase I and Plasmodium falciparum lactate dehydrogenase proteins was studied through molecular docking and Irinotecan and mefloquine were used as reference drugs. Results: Fairly good yield of N-[(2-chloroquinolin-3-yl) methylidene]-2-aniline schiff bases (3a-j) were synthesized by convenient and economical procedure. The preliminary in silico pharmacokinetics study reveals that the compounds 3a-j shows excellent drug like property. The toxicity profile of compounds 3a-h was found safe. The compounds 3a-j was exhibited promising MIC values against the both S. aureus and E. coli. Similarly the docking results predict that the compound 3d shown highest interaction by forming two hydrogen bonds against the cancer protein with the interaction energy-20.696 kcal/mol. Compound 3c exhibits highest dock score of-45.703 kcal/mol with two hydrogen bonds against malarial protein. Conclusion: From the results of docking studies of N-[(2-chloroquinolin-3-yl) methylidene]-2-aniline schiff bases (3a-j), it has been concluded that the compounds were found to exhibit multifunctional lead property, hence these compounds are worth to be considered as potential lead molecules for further study

Growth and characterization of benzil single crystals using nanotranslation by the modified vertical Bridgman technique

Benzil single crystals have been grown by the modified vertical Bridgman technique using the double wall ampoule with nanotranslation for the first time. The characterization studies of benzil crystals grown by both single and double wall ampoules were analyzed. The grown benzil crystal was confirmed by single crystal and powder X-ray diffraction analyses. Fourier transform infrared analysis confirms the functional groups of the grown benzil. High resolution X-ray diffraction analysis indicates the crystalline perfection of the grown crystals. The UV-Vis-NIR studies show that the grown benzil crystals cutoff wavelength is around 434 nm. The green emission of the grown benzil was identified by photoluminescence studies. The thermal property of the grown benzil was studied by thermogravimetric and differential thermal analyses. The dielectric measurements of benzil crystals were carried out with different frequencies and temperatures and the results indicate an increase in dielectric and conductivity parameters with the increase of temperature at all frequencies. The second harmonic conversion efficiency of the grown benzil was determined

SYNTHESIS AND MOLECULAR DOCKING STUDY OF 2-ARYL/HETEROARYL-6-CHLOROQUINOLINE-4-CARBOXYLIC ACIDS WITH PLASMODIUM LDH RECEPTOR PROTEIN

Objective: Synthesis and in silico molecular docking studies of 2-aryl/heteroaryl-quinoline-4-carboxylic acid derivatives (3a-j) with plasmodium LDH receptor protein.Methods: The 2-aryl/heteroaryl-quinoline-4-carboxylic acids (3a-j) were obtained by Pfitzinger reaction. Ligands (3a-j) interaction with plasmodium LDH receptor protein was studied through molecular docking method.Results: Good yields of 2-aryl/heteroaryl-quinoline-4-carboxylic acid derivatives (3a-j) were obtained by convenient and economical procedure. Their structures were confirmed by 1H NMR, 13C NMR, and MS spectral analysis. The binding site analysis of the synthesized compounds (3a-j) with plasmodium LDH receptor that are responsible for malaria parasite response was evaluated through molecular docking study. The results reveal that the ligand 3d shows maximum of five hydrogen bonding interactions with binding energy -9.05 kcal/mol, shown to be a promising lead molecule to inhibit Plasmodium LDH receptor.Conclusion: The docking studies of newly synthesized 2-aryl/heteroaryl-quinoline-4-carboxylic acids were found to be very useful ligands for antimalarial therapy particularly on Plasmodium LDH protein. However the installation of still many appropriate substitutions on quinoline moiety would lead to identification of novel antimalarial compounds that ascertained via molecular docking is underway in our lab

Electromigration-Induced Propagation of Nonlinear Surface Waves

Due to the effects of surface electromigration, waves can propagate over the free surface of a current-carrying metallic or semiconducting film of thickness h_0. In this paper, waves of finite amplitude, and slow modulations of these waves, are studied. Periodic wave trains of finite amplitude are found, as well as their dispersion relation. If the film material is isotropic, a wave train with wavelength lambda is unstable if lambda/h_0 < 3.9027..., and is otherwise marginally stable. The equation of motion for slow modulations of a finite amplitude, periodic wave train is shown to be the nonlinear Schrodinger equation. As a result, envelope solitons can travel over the film's surface.Comment: 13 pages, 2 figures. To appear in Phys. Rev.

Model for coiling and meandering instability of viscous threads

A numerical model is presented to describe both the transient and steady-state dynamics of viscous threads falling onto a plane. The steady-state coiling frequency w is calculated as a function of fall height H. In the case of weak gravity, w ~ H^{-1} and w ~ H are obtained for lower and higher fall heights respectively. When the effect of gravity is significant, the relation w ~ H^2 is observed. These results agree with the scaling laws previously predicted. The critical Reynolds number for coil-uncoil transition is discussed. When the gravity is weak, the transition occurs with hysteresis effects. If the plane moves horizontally at a constant speed, a variety of meandering oscillation modes can be observed experimentally. The present model also can describe this phenomenon. The numerically obtained state diagram for the meandering modes qualitatively agrees with the experiment.Comment: 12 pages, 10 figure