Modeling and analysis of temperature modulated differential scanning calorimetry (TMDSC)

Ph.DDOCTOR OF PHILOSOPH

Biological and genomic analysis of a symbiotic nitrogen fixation defective mutant in Medicago truncatula

Medicago truncatula has been selected as one of the model legume species for gene functional studies. To elucidate the functions of the very large number of genes present in plant genomes, genetic mutant resources are very useful and necessary tools. Fast Neutron (FN) mutagenesis is effective in inducing deletion mutations in genomes of diverse species. Through this method, we have generated a large mutant resource in M. truncatula. This mutant resources have been used to screen for different mutant using a forward genetics methods. We have isolated and identified a large amount of symbiotic nitrogen fixation (SNF) deficiency mutants. Here, we describe the detail procedures that are being used to characterize symbiotic mutants in M. truncatula. In recent years, whole genome sequencing has been used to speed up and scale up the deletion identification in the mutant. Using this method, we have successfully isolated a SNF defective mutant FN007 and identified that it has a large segment deletion on chromosome 3. The causal deletion in the mutant was confirmed by tail PCR amplication and sequencing. Our results illustrate the utility of whole genome sequencing analysis in the characterization of FN induced deletion mutants for gene discovery and functional studies in the M. truncatula. It is expected to improve our understanding of molecular mechanisms underlying symbiotic nitrogen fixation in legume plants to a great extent

Preparation of the Essential Oil from Artemisia Argyi Grown in Qichun, China and its application in Antibacterial effection

To evaluate the antibacterial activity and chemical constituents of the essential oil from the artemisia argyi grown in Qichun (China). METHODS: Steam distillation method was used to extract volatile oil from Artemisia argyi. The antibacterial effect of the volatile oil was investigated by the plate coating method and the double gradient liquid dilution method. Gas chromatography-mass spectrometry(GC-MS) was applied for the identification of chemical constituents in volatile oil from Artemisia argyi and the relative percentage of each component was calculated by area normalization. RESULTS: The essential oil from artemisia argyi grown in Qichun (China) has significant antibacterial activity against staphylococcus aureus, pseudomonas aeruginosa, salmonella, candida albicans, aspergillus niger and aspergillus flavus. And fifty chemical components were detected in the essential oil, and twenty compounds were identified, accounting for 95.95% of total essential oil. And the artemisol in artemisia argyi grown in Qichun (China) was found to be the highest compared with the same species from other producing areas. CONCLUSION: The essential oil from artemisia argyi grown in Qichun (China) was a potent antibacterial plant extract with potential applications as an antibacterial drugs or food preservative

Minimization of cross-talk in a piezo inkjet printhead based on system identification and feedforward control

The printing quality delivered by a drop-on-demand inkjet printhead is severely affected by the residual oscillations in an ink channel and the cross-talk between neighboring ink channels. For a single ink channel, our earlier contribution shows that the actuation pulse can be designed, using a physical model, to effectively damp the residual oscillations. It is not always possible to obtain a good physical model for a single ink channel. A physical model for a multi-input multi-output (MIMO) inkjet printhead is made even more sophisticated by the presence of the cross-talk effect. This paper proposes a system identification-based approach to build a MIMO model for an inkjet printhead. Additionally, the identified MIMO model is used to design new actuation pulses to effectively minimize the residual oscillations and the cross-talk. Using simulation and experimental results, we demonstrate the efficacy of the proposed method

Minimization of cross-talk in a piezo inkjet printhead based on system identification and feedforward control

\u3cp\u3eThe printing quality delivered by a drop-on-demand inkjet printhead is severely affected by the residual oscillations in an ink channel and the cross-talk between neighboring ink channels. For a single ink channel, our earlier contribution shows that the actuation pulse can be designed, using a physical model, to effectively damp the residual oscillations. It is not always possible to obtain a good physical model for a single ink channel. A physical model for a multi-input multi-output (MIMO) inkjet printhead is made even more sophisticated by the presence of the cross-talk effect. This paper proposes a system identification-based approach to build a MIMO model for an inkjet printhead. Additionally, the identified MIMO model is used to design new actuation pulses to effectively minimize the residual oscillations and the cross-talk. Using simulation and experimental results, we demonstrate the efficacy of the proposed method.\u3c/p\u3

Cytotoxic Cleistanthane and Cassane Diterpenoids from the Entomogenous Fungus <i>Paraconiothyrium hawaiiense</i>

Hawaiinolides A–D (<b>1</b>–<b>4</b>), four new secondary metabolites including three cleistanthane (<b>1</b>, <b>3</b>, and <b>4</b>) and one cassane (<b>2</b>) type of diterpene lactones, were isolated from the crude extract of <i>Paraconiothyrium hawaiiense</i>, a fungus entomogenous to the <i>Septobasidium</i>-infected insect <i>Diaspidiotus</i> sp. The structures of <b>1</b>–<b>4</b> were elucidated by nuclear magnetic resonance experiments, and <b>1</b> and <b>3</b> were further confirmed by X-ray crystallography. The absolute configuration of <b>1</b> was assigned via single-crystal X-ray diffraction analysis using Cu Kα radiation, whereas that of <b>2</b>–<b>4</b> was deduced via the circular dichroism data. Compound <b>1</b> showed significant cytotoxicity against a small panel of five human tumor cell lines, A549, T24, HeLa, HCT116, and MCF-7

Dioxatricyclic and Oxabicyclic Polyketides from <i>Trichocladium opacum</i>

Five new polyketides, trichocladinols D–H (<b>1</b>–<b>5</b>) with dioxatricyclic (<b>1</b>–<b>3</b>) and oxabicyclic (<b>4</b> and <b>5</b>) skeletons, and the known massarilactone C (<b>6</b>) were isolated from the solid-substrate fermentation cultures of the ascomycete fungus <i>Trichocladium opacum</i>. The structures of <b>1</b>–<b>5</b> were determined mainly by NMR experiments, and <b>1</b>, <b>3</b>, and <b>4</b> were confirmed by X-ray crystallography. The absolute configurations of <b>1</b> and <b>3</b> were assigned by X-ray crystallography using Cu Kα radiation, whereas that of C-5 in <b>2</b> and <b>4</b> was deduced via the circular dichroism (CD) data. Compounds <b>2</b>–<b>4</b> showed weak cytotoxicity against the human tumor cell lines A549, HCT116, and SW480