Mechanistic insights into topological network formation in free radical co-polymerization

The first part of the talk will discuss reaction kinetics and molecular architecture development during free-radical, bulk copolymerizations of a homologous series of methacrylate monomers with a series of dimethacrylate crosslinkers of varying alkyl spacer lengths. The overall objective of this work was to determine the extent to which the ester side chains of the methacrylate monomers hinder chain-end radical propagation reactions through the pendent vinyl groups of the crosslinking monomer. We have determined that this steric hindrance is quite significant and increases to the point where the sweeping radius of the pendent vinyl can be obstructed by the neighboring monomer ester side groups. The effective sweeping radius of the pendent vinyl can be equivalently expressed by various combinations of dimethacrylate and methacrylate. Please download the file below for full content

An improved protocol for efficient transformation and regeneration of diverse indica rice cultivars

<p>Abstract</p> <p>Background</p> <p>Rice genome sequencing projects have generated remarkable amount of information about genes and genome architecture having tremendous potential to be utilized in both basic and applied research. Success in transgenics is paving the way for preparing a road map of functional genomics which is expected to correlate action of a gene to a trait in cellular and organismal context. However, the lack of a simple and efficient method for transformation and regeneration is a major constraint for such studies in this important cereal crop.</p> <p>Results</p> <p>In the present study, we have developed an easy, rapid and highly efficient transformation and regeneration protocol using mature seeds as explants and found its successful applicability to a choice of elite indica rice genotypes. We have optimized various steps of transformation and standardized different components of the regeneration medium including growth hormones and the gelling agent. The modified regeneration medium triggers production of large number of shoots from smaller number of calli and promotes their faster growth, hence significantly advantageous over the existing protocols where the regeneration step requires maximum time. Using this protocol, significantly higher transformation efficiency (up to 46%) and regeneration frequency (up to 92% for the untransformed calli and 59% for the transformed calli) were achieved for the four tested cultivars. We have used this protocol to produce hundreds of independent transgenic lines of different indica rice genotypes. Upon maturity, these transgenic lines were fertile thereby indicating that faster regeneration during tissue culture did not affect their reproductive potential.</p> <p>Conclusions</p> <p>This speedy, yet less labor-intensive, protocol overcomes major limitations associated with genetic manipulation in rice. Moreover, our protocol uses mature seeds as the explant, which can easily be obtained in quantity throughout the year and kept viable for a long time. Such an easy, efficient and generalized protocol has the potential to be a major tool for crop improvement and gene-function studies on the model monocot plant rice.</p

Annexin A2 expression in prostate cancer cells

Background: Metastasis is a major cause of morbidity in prostate cancer patients, the primary mortality in this disease is metastasis to the bone tissue. Despite substantial efforts to understand prostate cancer metastasis, the mechanisms that are involved in preparing the metastatic niche for colonizing the prostate cancer cells are still not known. Therefore, there is an urgent need to identify essential regulators of bone metastasis in prostate cancer for therapeutic targets.Purpose: Annexin A2 (AnxA2), a calcium-dependent phospholipid binding protein, is overexpressed in the poorly differentiated high-grade adenocarcinomas of prostate cancer. AnxA2 exists as a monomer in the cytosol and as a heterotetrameric complex with S100A10 [(AnxA2)2-(S100A10)2] at the cell surface. Phosphorylation of AnxA2 at tyrosine 23 (pAnxA2-Y23) is an important event for the localization of AnxA2 to the cell surface. At the cell surface, AnxA2 heterotetramer complex provides binding site for tissue plasminogen activator (tPA) and converts plasminogen into plasmin, which plays an important role in invasion and metastasis of cancer. The cell surface AnxA2 also plays an important role in hematopoietic stem cell localization to the marrow niche and regulates osteogenic differentiation. However, the cell surface expression of AnxA2 in prostate cancer is unknown. Therefore, in the present study, we have demonstrated the cell surface expression of AnxA2 in prostate cancer cells to delineate the mechanism of bone metastasis.Methods: Prostate cancer cell lines, PC3 and DU145 were grown in RPMI-1640 medium containing 10% fetal bovine serum, in a humidified incubator at 37ºC with 5% CO2. The RWPE1, and PWR-1E cells were cultured in keratinocyte growth medium supplemented with 5 ng/ml human recombinant epidermal growth factor and 0.05 mg/ml bovine pituitary extract (Invitrogen, Carlsbad, CA) and maintained in an incubator under the conditions described above. Immunoblotting was used to detect the expression of pAnxA2-Y23 and AnxA2 proteins in cells.Results: Our results demonstrated that the expression of pAnxA2-Y23 is very high in prostate cancer cells (PC3 and DU145 cells) compared to normal prostate epithelial (PWR1E, and RWPE1 cells). However, the expression of total AnxA2 in both prostate normal and cancer cell lines is comparable. In addition, our membrane wash experiment showed that a large amount of AnxA2 is present at the cell surface of the PC3 and DU145 cell lines. In normal prostate epithelial cells, even though the expression of total AnxA2 is comparable to PC3 and DU145 prostate cancer cells, membrane localization of AnxA2 is very low.Conclusion: Our results clearly suggest that the cell surface expression of AnxA2 is high in prostate cancer cells due to increased phosphorylation of AnxA2 at tyrosine 23.Oklahoma Louis Stokes Alliance for Minority Participation ProgramMicrobiology, Immunology and GeneticsBiolog

Coronavirus Disease 2019 (COVID-19): Origin, Impact, and Drug Development

At the end of December 2019, in Wuhan, China, a rapidly spreading unknown virus was reported to have caused coronavirus disease of 2019 (COVID-19). Origin linked to Wuhan’s wholesale food market where live animals are sold. This disease is caused by SARS Coronavirus-2 (SARS-CoV-2), which is closely related to the Severe Acute Respiratory Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). This virus shares a high sequence identity with bat-derived SARS-like Coronavirus, which indicating its zoonotic origin. The virus spread globally, provoking widespread attention and panic. This Coronavirus is highly pathogenic and causes mild to severe respiratory disorders. Later, it was declared a global pandemic by the World Health Organization (WHO) due to its highly infectious nature and worldwide mortality rate. This virus is a single-stranded, positive-sense RNA genome, and its genome length about 26 to 32 kb that infects a broad range of vertebrates. The researchers worldwide focus on establishing treatment strategies on drug and vaccine development to prevent this COVID-19 pandemic. A drug repurposing approach has been used to identify a rapid treatment for the people affected by COVID-19, which could be cost-effective and bypass some Food and Drug Association (FDA) regulations to move quickly in phase-3 trials. However, there is no promising therapeutic option available yet. This book chapter addresses current information about the COVID-19 disease, including its origins, impacts, and the novel potential drug candidates that can help treat the COVID-19

Antioxidant Capacity and Radical Scavenging Effect of Polyphenol Rich Mallotus philippenensis

Mallotus philippinensis is an important source of molecules with strong antioxidant activity widely used medicinal plant. Previous studies have highlighted their anticestodal, antibacterial, wound healing activities, and so forth. So, present investigation was designed to evaluate the total antioxidant activity and radical scavenging effect of 50% ethanol fruit glandular hair extract (MPE) and its role on Human Erythrocytes. MPE was tested for phytochemical test followed by its HPLC analysis. Standard antioxidant assays like DPPH, ABTS, hydroxyl, superoxide radical, nitric oxide, and lipid peroxidation assay were determined along with total phenolic and flavonoids content. Results showed that MPE contains the presence of various phytochemicals, with high total phenolic and flavonoid content. HPLC analysis showed the presence of rottlerin, a polyphenolic compound in a very rich quantity. MPE exhibits significant strong scavenging activity on DPPH and ABTS assay. Reducing power showed dose dependent increase in concentration absorption compared to standard, Quercetin. Superoxide, hydroxyl radical, lipid peroxidation, nitric oxide assay showed a comparable scavenging activity compared to its standard. Our finding further provides evidence that Mallotus fruit extract is a potential natural source of antioxidants which have a protective role on human Erythrocytes exhibiting minimum hemolytic activity and this justified its uses in folklore medicines

Mycobacterium tuberculosis nucleoid-associated DNA-binding protein H-NS binds with high-affinity to the Holliday junction and inhibits strand exchange promoted by RecA protein

A number of studies have shown that the structure and composition of bacterial nucleoid influences many a processes related to DNA metabolism. The nucleoid-associated proteins modulate not only the DNA conformation but also regulate the DNA metabolic processes such as replication, recombination, repair and transcription. Understanding of how these processes occur in the context of Mycobacterium tuberculosis nucleoid is of considerable medical importance because the nucleoid structure may be constantly remodeled in response to environmental signals and/or growth conditions. Many studies have concluded that Escherichia coli H-NS binds to DNA in a sequence-independent manner, with a preference for A-/T-rich tracts in curved DNA; however, recent studies have identified the existence of medium- and low-affinity binding sites in the vicinity of the curved DNA. Here, we show that the M. tuberculosis H-NS protein binds in a more structure-specific manner to DNA replication and repair intermediates, but displays lower affinity for double-stranded DNA with relatively higher GC content. Notably, M. tuberculosis H-NS was able to bind Holliday junction (HJ), the central recombination intermediate, with substantially higher affinity and inhibited the three-strand exchange promoted by its cognate RecA. Likewise, E. coli H-NS was able to bind the HJ and suppress DNA strand exchange promoted by E. coli RecA, although much less efficiently compared to M. tuberculosis H-NS. Our results provide new insights into a previously unrecognized function of H-NS protein, with implications for blocking the genome integration of horizontally transferred genes by homologous and/or homeologous recombination

Morpho-biochemical characterization of a RIL population for seed parameters and identification of candidate genes regulating seed size trait in lentil (Lens culinaris Medik.)

The seed size and shape in lentil (Lens culinaris Medik.) are important quality traits as these influences the milled grain yield, cooking time, and market class of the grains. Linkage analysis was done for seed size in a RIL (F5:6) population derived by crossing L830 (20.9 g/1000 seeds) with L4602 (42.13 g/1000 seeds) which consisted of 188 lines (15.0 to 40.5 g/1000 seeds). Parental polymorphism survey using 394 SSRs identified 31 polymorphic primers, which were used for the bulked segregant analysis (BSA). Marker PBALC449 differentiated the parents and small seed size bulk only, whereas large seeded bulk or the individual plants constituting the large-seeded bulk could not be differentiated. Single plant analysis identified only six recombinant and 13 heterozygotes, of 93 small-seeded RILs (<24.0 g/1000 seed). This clearly showed that the small seed size trait is very strongly regulated by the locus near PBLAC449; whereas, large seed size trait seems governed by more than one locus. The PCR amplified products from the PBLAC449 marker (149bp from L4602 and 131bp from L830) were cloned, sequenced and BLAST searched using the lentil reference genome and was found amplified from chromosome 03. Afterward, the nearby region on chromosome 3 was searched, and a few candidate genes like ubiquitin carboxyl-terminal hydrolase, E3 ubiquitin ligase, TIFY-like protein, and hexosyltransferase having a role in seed size determination were identified. Validation study in another RIL mapping population which is differing for seed size, showed a number of SNPs and InDels among these genes when studied using whole genome resequencing (WGRS) approach. Biochemical parameters like cellulose, lignin, and xylose content showed no significant differences between parents and the extreme RILs, at maturity. Various seed morphological traits like area, length, width, compactness, volume, perimeter, etc., when measured using VideometerLab 4.0 showed significant differences for the parents and RILs. The results have ultimately helped in better understanding the region regulating the seed size trait in genomically less explored crops like lentils

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure