Qualitative and quantitative analysis of petitgrain Eureka lemon essential oil by fused silica capillary column gas chromatography mass spectrometry

The identification of Algerian petitgrain Eureka lemon essential oil was carried out by gas liquid chromatography-mass spectrometry in electronic impact mode using a fused silica capillary column (FFAP). The results enabled a previous study on this oil to be completed where the relative retention data and chemical derivation reactions had been performed. A preparative gas chromatography was applied to give a better g.c.-m.s.analysis of minor compounds; thus, two new products (citronellyl n-propionate and cedrol) were revealed by this method. Only 80 compounds were identified after indexation of 137 mass spectra and after comparison with those in the literature because most mass spectra data banks are not well adapted for the identification of essential oils. A global comparison of the percentage composition of the major compounds of this oil with those in other petitgrain lemon essential oils has revealed distinct differences. From the mass spectra of nine monoterpenic hydrocarbons, it was shown that comparison of the intensity ratio of the characteristic fragment ions in EI mode, which has been suggested by some authors as a general method of identification of compounds with similar mass spectra, is not reliable.     

The effect of boron nitride on electrical conductivity of nanocarbon-polymer composites

The electrical conductivity concentration and temperature dependences of polymer composite materials (CMs) with nanocarbon fillers [graphite nanoplatelets and multi-walled carbon nanotubes (MWCNTs)] were investigated. Epoxy resin modified with organosilicon compound was used as polymer matrix. The content of nanocarbon filler in varied from 1 to 10 wt%. To study of the synergetic properties the additional dispersed dielectric filler—boron nitride (BN) was added to given systems in content of 27 wt%. The electrical resistivity of CMs was investigated in the temperature range of 77–300 K. In the studied CMs the percolation transition at sufficient low filler content (0.01–0.022 vol. fr.) was observed. The values of critical index varied from 3.0 to 5.2. The electrical conductivity of investigated CMs was analyzed in the framework of proposed model that takes into consideration the morphology of filler particles. It was shown that the increase of electrical conductivity of GNP-polymer CM in the presence of BN is attributed to the decrease of contact resistance between filler particles, while for MWCNT-polymer CM is due to the increase of the number of conductive chains in this particular system.     

Protective Effect of Water-Soluble C60 Fullerene Nanoparticles on the Ischemia-Reperfusion Injury of the Muscle Soleus in Rats

The biomechanical parameters of muscle soleus contraction in rats and their blood biochemical indicators after the intramuscular administration of water-soluble C₆₀ fullerene at doses of 0.5, 1, and 2 mg/kg 1 h before the onset of muscle ischemia were investigated. In particular, changes in the contraction force of the ischemic muscle soleus, the integrated power of the muscle, the time to achieve the maximum force response, the dynamics of fatigue processes, and the parameters of the transition from dentate to smooth tetanus, levels of creatinine, creatine kinase, lactate and lactate dehydrogenase, and parameters of prooxidant–antioxidant balance (thiobarbituric acid reactive substances, hydrogen peroxide, and reduced glutathione and catalase) were analyzed. The positive therapeutic changes in the studied biomechanical and biochemical markers were revealed, which indicate the possibility of using water-soluble C₆₀ fullerenes as effective prophylactic nanoagents to reduce the severity of pathological conditions of the muscular system caused by ischemic damage to skeletal muscles.     

Characterization of a cell cycle mutant derived from hamster fibroblast: reversion analysis

K12 is a temperature-sensitive (ts) mutant cell line derived from Chinese hamster fibroblasts. When incubated at the nonpermissive temperature, K12 cells exhibit the following properties: (a) the cells cannot initiate DNA synthesis;o (b) the synthesis of cytosol thymidine kinase is suppressed; and (c) the synthesis of three cellular proteins of molecular weights 94, 78, and 58 kdaltons is greatly enhanced. Here we characterize a spontaneous revertant clone, R12, derived from the K12 cells. We selected the revertant clone for its ability to grow at the nonpermissive temperature. Our results indicate that all the traits which constitute the K12 mutant phenotype are simultaneously reverted to the wild type in the revertant cell line, suggesting that the ts mutation of the K12 cells is of regulatory nature and exerts multiple effects on the expressed phenotypes.     

C60 fullerene enhances cisplatin anticancer activity and overcomes tumor cell drug resistance

We formulated and analyzed a novel nanoformulation of the anticancer drug cisplatin (Cis) with C60 fullerene (C60+Cis complex) and showed its higher toxicity toward tumor cell lines in vitro when compared to Cis alone.The highest toxicity of the complex was observed in HL-60/adr and HL-60/vinc chemotherapyresistant human leukemia cell sublines (resistant to Adriamycin and Vinculin,respectively).We discovered that the action of the C60+Cis complex is associated with overcoming the drug resistance of the tumor cell lines through observing an increased number of apoptotic cells in the Annexin V/PI assay.Moreover,in vivo assays with Lewis lung carcinoma (LLC) C57BL/6J male mice showed that the C60+Cis complex increases tumor growth inhibition,when compared to Cis or C60 fullerenes alone.Simultaneous1y,we conducted a molecular docking study and performed an Ames test.Molecular docking specifies the capability of a C60 fullerene to form van der Waals interactions with potential binding sites on P-glycoprotein (P-gp),multidrug resistance protein 1 (MRP-1),and multidrug resistance protein 2 (MRP-2) molecules.The observed phenomenon revealed a possible mechanism to bypass tumor cell drug resistance by the C,o+Cis complex.Additionally,the results of the Ames test show that the formation of such a complex diminishes the Cis mutagenic activity and may reduce the probability of secondary neoplasm formation.In conclusion,the C60+Cis complex effectively induced tumor cell death in vitro and inhibited tumor growth in vivo,overcoming drug resistance likely by the potential of the C60 fullerene to interact with P-gp,MRP-1,and MRP-2 molecules.Thus,the C60+Cis complex might be a potential novel chemotherapy modification.     

Radiation damage to multi-walled carbon nanotubes and their Raman vibrational modes

The influence of the radiation damage to multi-walled carbon nanotubes (MWCNT) during the high-energy electron irradiation (E_e = 1.8 MeV) with different doses of absorption (D_n = 0.5; 1.0; 1.5 and 2.0 MGy) on their Raman vibrational spectra is studied in detail. The modification of both radial and tangential optical vibrations is observed depending on radiation dose. This is manifested both in the frequency shifts of the vibrational modes and in a change in the intensity of the Raman scattering, which corresponds to different optical vibrations. This behavior of Raman spectrum is explained by appearance and increase in the concentration of radiation defects and by seams of separate layers of nanotubes.     

Economic burden from health losses due to foodborne illness in the United States

The Centers for Disease Control and Prevention (CDC) recently revised their estimates for the annual number of foodborne illnesses; 48 million Americans suffer from domestically acquired foodborne illness associated with 31 identified pathogens and a broad category of unspecified agents. Consequently, economic studies based on the previous estimates are now obsolete. This study was conducted to provide improved and updated estimates of the cost of foodborne illness by adding a replication of the 2011 CDC model to existing cost-of-illness models. The basic cost-of-illness model includes economic estimates for medical costs, productivity losses, and illness-related mortality (based on hedonic value-of-statistical-life studies). The enhanced cost-of-illness model replaces the productivity loss estimates with a more inclusive pain, suffering, and functional disability measure based on monetized quality-adjusted life year estimates. Costs are estimated for each pathogen and a broader class of unknown pathogens. The addition of updated cost data and improvements to methodology enhanced the performance of each existing economic model. Uncertainty in these models was characterized using Monte Carlo simulations in @Risk version 5.5. With this model, the average cost per case of foodborne illness was $1,626 (90% credible interval [CI], $607 to $3,073) for the enhanced cost-of-illness model and $1,068 (90% CI, $683 to $1,646) for the basic model. The resulting aggregated annual cost of illness was $77.7 billion (90% CI, $28.6 to $144.6 billion) and $51.0 billion (90% CI, $31.2 to $76.1 billion) for the enhanced and basic models, respectively.