Bioactive Compounds From Torbangun [Plectranthus Amboinicus (Lour.) Spreng] Chloroform Fraction Induce Apoptosis in Breast Cancer (Mcf-7 Cells) in Vitro

Torbangun (Plectranthus amboinicus (Lour.) Spreng) is a medicinal plant that has been traditionally used in tropical countries to cure various illnesses. The objective of this study was to identify the active compounds in the chloroform fraction which have effect on the apoptosis-related genes expression of breast cancer MCF-7 cells. Apoptosis was observed morphologically using Hoechst nuclear staining. Expression of the genes was analyzed using Real-Time PCR. Chemical compounds of the plant fractions were determined using LC-MS. Result of cell morphology observation clearly indicated apoptosis after the treatment of the plant fraction. Increased expression of anti-apoptotic gene Bcl-2 could not prevent the cells from apoptosis. Expressions of p53 and p21 genes were increased significantly. The expressions of caspase 9, caspase 7 and caspase 1 were increased at concentration-dependent manner. Most of the compounds in the chloroform fraction are identified as diterpenoids which may contribute to the apoptosis inducing activity of the fraction

How does Cross-Linking Effect the Thermal Stability of Polyisoprene

Polyisoprene can be cross-linked by an initial lithiation followed by reaction with both monochloro compounds and dichloro compounds. The monochloro compounds effect crosslinking through a lithium-chlorine exchange route while the use of dichloro compounds links the PIP chains with the spacer between the two chlorine atoms. A significant amount of char is produced from compounds which have been cross-linked with aromatic dihalides while aliphatic dihalides do not produce significant char

Physical properties of Thallium-Tellurium based thermoelectric compounds using first-principles simulations

We present a study of the thermodynamic and physical properties of Tl5Te3, BiTl9Te6 and SbTl9Te6 compounds by means of density functional theory based calculations. The optimized lattice constants of the compounds are in good agreement with the experimental data. The electronic density of states and band structures are calculated to understand the bonding mechanism in the three compounds. The indirect band gap of BiTl9Te6 and SbTl9Te6 compounds are found to be equal to 0.256 eV and 0.374 eV, respectively. The spin-orbit coupling has important effects on the electronic structure of the two semiconducting compounds and should therefore be included for a good numerical description of these materials. The elastic constants of the three compounds have been calculated, and the bulk modulus, shear modulus, and young's modulus have been determined. The change from ductile to brittle behavior after Sb or Bi alloying is related to the change of the electronic properties. Finally, the Debye temperature, longitudinal, transverse and average sound velocities have been obtained

Qualitative and quantitative analysis of mixtures of compounds containing both hydrogen and deuterium

Method allows qualitative and quantitative analysis of mixtures of partially deuterated compounds. Nuclear magnetic resonance spectroscopy determines location and amount of deuterium in organic compounds but not fully deuterated compounds. Mass spectroscopy can detect fully deuterated species but not the location

Topological insulators in filled skutterudites

We propose new topological insulators in cerium filled skutterudite (FS) compounds based on ab initio calculations. We find that two compounds CeOs4As12 and CeOs4Sb12 are zero gap materials with band inversion between Os-d and Ce-f orbitals, which are thus parent compounds of two and three-dimensional topological insulators just like bulk HgTe. At low temperature, both compounds become topological Kondo insulators, which are Kondo insulators in the bulk, but have robust Dirac surface states on the boundary. This new family of topological insulators has two advantages compared to previous ones. First, they can have good proximity effect with other superconducting FS compounds to realize Majarona fermions. Second, the antiferromagnetism of CeOs4Sb12 at low temperature provides a way to realize the massive Dirac fermion with novel topological phenomena.Comment: 4 page, 3 figure

Effect of doping on the thermoelectric properties of thallium tellurides using first principles calculations

We present a study of the electronic properties of Tl5Te3, BiTl9Te6 and SbTl9Te6 compounds by means of density functional theory based calculations. The optimized lattice constants of the compounds are in good agreement with the experimental data. The band gap of BiTl9Te6 and SbTl9Te6 compounds are found to be equal to 0.589 eV and 0.538 eV, respectively and are in agreement with the available experimental data. To compare the thermoelectric properties of the different compounds we calculate their thermopower using Mott's law and show, as expected experimentally, that the substituted tellurides have much better thermoelectric properties compared to the pure compound.Comment: PTM2010 Conferenc