Studies towards the total synthesis of tagetitoxin

Tagetitoxin is a phytotoxin produced by the bacterium Pseudomonas syringae pv. tagetis. It is a selective inhibitor of RNA polymerase III in eukaryotic cells and RNA polymerase in bacteria. To date, no total synthesis of the proposed structure of tagetitoxin has been reported. While there is some ambiguity surrounding the structure of tagetitoxin, the most likely structure incorporates a unique 9-oxa-thiabicyclo[3.3.1]nonane core, with six stereogenic centres and a range of functional groups. This thesis describes the development of a novel synthetic route towards tagetitoxin. The first task was the introduction, at C-5 of D-glucose, of a carbon substituent which could later be transformed to the carboxylic acid moiety of tagetitoxin. Initial studies showed that, while incorporation of a hydroxymethyl substituent was straightforward, problems arose in attempts to selectively functionalise one of the two primary hydroxyl groups in the resulting molecule. Alternatively, incorporation of a vinyl moiety at C-5 of D-glucose was achieved using a procedure described by Rama Rao et al. This led to the formation of 1,6-anhydro-5-C-vinyl- D-glucose, which was successfully functionalised at C-1 via incorporation of a TMS acetylene group following a method described by Vasella and co-workers. The next task was to introduce a nitrogen substituent at C-3 of the sugar while inverting the configurations at both C-2 and C-3; for this purpose, conversion to a 2,3-β-epoxide was achieved in six steps. Unfortunately, attempted ring opening of the epoxide with various azide sources failed to give the desired product. A modified route was thus investigated in which the vinyl group at C-5 was converted to a less sterically demanding nitrile group. In this case, the 2,3-β- epoxide, when subjected to treatment with sodium azide in the presence of lithium perchlorate, furnished the desired azido compound with inversion of configuration at C-3. While time constraints did not allow further progress to be made towards tagetitoxin, the remaining tasks are to further introduce a thiol group at C-6, a phosphate at O-4 and oxidation of the acetylene moiety to a methyl ketoester which upon cyclisation should give the desired tagetitoxin molecule.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Diversity of Soil Nematodes in Agricultural Fields with Different Crops

Agriculture has been significant part of the Indian livelihood since ages. As agriculture rely upon the various aspects such as quality of soil, soil minerals and nematodes present in soil. In the present project of soil nematode diversity is successfully estimated by using nematode extraction method given by Cobb (1918). The experiments were performed on soil sample which were collected from four different sites during the study. These four sites were agricultural fields located in Sri Anandpur Sahib (India) with different crops viz; Site 1: Agricultural field with vegetable crops, Site 2: Agricultural field with oilseed crops, Site 3: Agricultural field with wheat crops, Site 4: Agricultural field with Maize crop. The estimation part of the study was performed at PG Zoology Laboratory of PG Department of Zoology, Sri Guru Teg Bahadur Khalsa College, Sri Anandpur Sahib, Punjab, India. The six nematode species were recorded with 100% frequency along with sixteen species of nematodes with 90% frequency of occurrence in all agricultural sites selected during present study. Additionally, eighteen nematode species were recorded with 80% frequency of occurrence in all sites. Apart from this, the nematode species H. indicus and T. hynchus spp. were recorded with 70% frequency of occurrence. It can be deduced from the present experimental program that the beneficial nematodes were present abundantly in all the soil samples of selected sites. Thus, it can be stated that, to improve the soil fertility the eco-friendly agricultural practices would be an efficient approach as it foster the soil nematode diversity.&nbsp

Observational study for the functional outcome of humerus shaft fractures treated with plating versus nailing

Background: Fractures of the humerus diaphysis comprise approximately 3% of all fractures. It’s treatment has mainly been conservative in the past but is not well tolerated by the patient now a days. Also, all humerus shaft fractures are not amenable to conservative methods. Operative interventions like dynamic compression plating and intramedullary nailing are associated with better functional outcome. There has been a lot of debate on which of the above two surgical methods is better for management of humeral shaft fractures to ensure better functional outcome and lesser complication rate. Objective were to compare the results of the plating and nailing in the treatment of humerus shaft with reference to A) functional outcome and B) complications and their management.Methods: All patients with fracture of humeral shaft presenting to the department of orthopaedics, MMIMSR, during the study period and that met our criteria were included in the study. Out of total 30 patients, 15 were randomly selected for intramedullary nailing and 15 for plating. Postoperatively, these patients were followed up for 6 months and relevant data was collected. Time taken for union, post operative complications rate and final functional outcome were then compared in the two groups. Study design was observational study.Results: It was observed that most of the patient that sustained humeral shaft fractures were 18-40 years of age. Post-operatively, fractures treated by plating united earlier, had lesser complications and significantly better functional outcome compared to nailing.Conclusions: We concluded that plating is a better method and more acceptable to patients as compare to intramedullary nailing for the treatment of fractures shaft humerus, as it is associated with better functional outcome, earlier union of fracture and lesser complication rate

Evaluation of the immunohistochemical expression of HER2/NEU in urinary bladder neoplasms in a tertiary care hospital

Background: HER2/NEU expression in urothelial neoplasms has been reported to range from 9% to 80% on immunohistochemistry. We studied the expression of HER2/NEU in urothelial neoplasms and its variability according to histological grade along with the prognostic value. Methods: The present study was conducted on 60 formalin-fixed, paraffin-embedded specimens of urinary bladder neoplasms, which comprised 45 cases of high-grade urothelial carcinoma followed by 13 cases of low-grade and 2 cases of PUNLMP. These were then subjected to IHC by HER2/NEU. Membrane positivity for HER2/NEU was noted. Results: A total of 65% of cases showed positive membranous HER2/NEU expression. HER2/NEU expression was noted in 82.6% of cases of high grade while 8.4% of cases of low grade were positive for HER2/NEU expression. Conclusions: The majority of high grade invasive urothelial carcinomas showed positive HER2/NEU expression with a significant p-value <0.001. Thus patients with high grade urothelial carcinoma may benefit from HER2/NEU targeted therapy

Diagnosing the First Democratic Regime in Afghanistan: Human Rights Perspective

The constant presence of undemocratic regimes, insurgencies and political instability in Afghanistan has continuously resulted into the miserable status of civil and political human rights. Furthermore, the heterogeneous nature of Afghan society and economic under development have deprived the people of social, cultural and economic rights. In 2004, democratic government had been established in Afghanistan under the presidentship of Hamid Karzai. Very obviously, the people at domestic level as well as the international community expected from the democratically elected regime to take concrete initiatives for the promotion and protection of human rights. The study observes that the pioneer democratically elected government of Afghanistan had taken all constitutional measures and legal provisions for the promotion and protection of human rights in Afghanistan which can be expected from a democratic nation. But several political, socio-ethnic and socio-economic circumstances such as frequent violence due to insurgency and counter-insurgency operations, dearth of popular legitimacy to the regime, challenges to political instability along with the orthodox and heterogeneous society, facing acute economic underdevelopment have hampered the actual process of the promotion and protection of human rights in Afghanistan

Light charged particle emission from Pb isotopes formed in n-induced channel and related structural analysis

The Dynamical Cluster-decay Model (DCM) has been employed to analyze the charge particle emission from $$^{207, 209}$$Pb$$^*$$ isotopes formed in highly asymmetric n-induced channel. The experimental data for $$\alpha$$-emission from $$^{207, 209}$$Pb$$^*$$ and p-emission from $$^{209}$$Pb$$^*$$ is addressed nicely by optimizing the neck-length parameter$$\varDelta$$R over an energy spread of 14-20 MeV. The comparative analysis of the decay profiles of $$^{207, 209}$$Pb$$^*$$ is carried out at common excitation energy, by analyzing the fragmentation structure at extreme angular momentum values. The relevance of sticking and non-sticking moment of inertia has also been analyzed for the light particle (LP) emission (asymmetric decay mode) and fission decay channel (symmetric decay mode). Besides this, the effect of mass of target nucleus on the reaction dynamics is explored by investigating the decay profiles of a lighter compound system $$^{113}Sn^*$$ formed under similar reaction conditions and the comparative analysis of the fragmentation behavior is carried out at common beam energy. The product $$Z_1Z_2$$ is minimum for the p-emission from any excited parent nucleus, hence, it would be interesting to explore the charge distribution of the decaying fragments. This aspect is explored by employing charge dependent radius expression within the framework of DCM

Impact of Green Manures in Mitigating Heavy Metal Toxicity: A Review

The contamination of soil with heavy metals poses a serious threat to both ecology and public health. Human activity, such as mining, excessive fertilizer application, and industrial processes, are among the various sources of heavy metal pollution. There are various green manure plant species used as potential for mitigating heavy metal toxicity, certain legume plants like Albizia leibbeck L., Bauhinia purpurea L., Dalbergia sissoo, Millettia peguensis Ali, and Pongamia pinnata are being looked for applications in phytoremediation. Various techniques such as bioremediation, phytoextraction, phytofiltration, phytovolatilization, rhizofiltration, phytodegradation, and phyto desalinization are employed to address environmental pollution. Phytoremediation, in particular, aims to collect pollutants from the environment and convert them into forms that can be easily extracted from plant tissues. Contamination by heavy metals is a severe environmental matter. However, there are various contemporary methods that offer potential solutions to address this issue. One such approach involves the use of biochar to decrease the bioavailability of heavy metals in soil. By binding to them reducing their availability for plant absorption and entry into the food chain. Genetic engineering permits researchers to insert genes into plants that improve their acceptance of heavy metals or increase their ability to accumulate them (phytoextraction). Consequently, the utilization of these conventional methods in phytoremediation has demonstrated the most favourable and sustainable outcomes, ensuring an eco-friendly approach for the ecosystem

Multi-omics assisted breeding for biotic stress resistance in soybean

Biotic stress is a critical factor limiting soybean growth and development. Soybean responses to biotic stresses such as insects, nematodes, fungal, bacterial, and viral pathogens are governed by complex regulatory and defense mechanisms. Next-generation sequencing has availed research techniques and strategies in genomics and post-genomics. This review summarizes the available information on marker resources, quantitative trait loci, and marker-trait associations involved in regulating biotic stress responses in soybean. We discuss the differential expression of related genes and proteins reported in different transcriptomics and proteomics studies and the role of signaling pathways and metabolites reported in metabolomic studies. Recent advances in omics technologies offer opportunities to reshape and improve biotic stress resistance in soybean by altering gene regulation and/or other regulatory networks. We suggest using ‘integrated omics’ to precisely understand how soybean responds to different biotic stresses. We also discuss the potential challenges of integrating multi-omics for the functional analysis of genes and their regulatory networks and the development of biotic stress-resistant cultivars. This review will help direct soybean breeding programs to develop resistance against different biotic stresses