359 research outputs found
Plant growth promoting microbial consortia mediated classical biocontrol of sunflower necrosis virus disease
ABSTRACT Biological control is gaining momentum in the management of sunflower necrosis virus disease (SNVD) as no other effective method is available. In glasshouse experiment-I, six different plant growth promoting microbes (PGPM): Streptomyces sp. PM5, Trichothecium roseum MML005, Bacillus licheniformis MML2501, Streptomyces fradiae MML1042, Pseudomonas aeruginosa MML2212 and Bacillus sp. MML2551 and 2% Morinda pubescens fruit extract applied individually (seed + foliar applications) along with sunflower necrosis virus (SNV) were evaluated in sunflower. Among the treatments, B. licheniformis (Bl), Bacillus sp. (Bsp), P. aeruginosa (Pa), S. fradiae (Sf) effectively increased the plant growth and significantly increased the reduction of virus titre, it ranging from 32.5% to 52.5%. In experiment-II, the above four effective PGPM (Bl, Bsp, Pa and Sf) were developed as consortia in all possible combination in this study and were applied along with SNV against SNVD. All the consortial treatments significantly reduced SNVD in virus titre with disease reduction and concomitant increase in growth promotion when compared to control. In experiment-III, the best PGPM consortia (PGPMC) were applied as seed + soil inoculations along with SNV to study the induction of systemic resistance enzymes. The four culture consortium significantly reduced the SNVD symptoms and virus titer with a concomitant increase in plant growth promotion and ISR enzymes compared to control. In experiment-IV, based on biocontrol efficacy and ISR against SNVD from the experiments I to III, the two more dominant PGPMC treatments were selected and evaluated against SNVD under field conditions. From these results, Bl + Bsp + Pa + Sf effectively reduced the SNVD and improved the plant growth and yield parameters with additional seed yield with income and benefit cost ratio when compared to farmer's practice. In conclusion, PGPM (Bl, Bsp, Pa and Sf) was found to be very effective against SNVD under glasshouse and field conditions
Partial Purification of Extracellular Amylase From Halotolerant Actinomycetes Streptomyces brasiliensis MML2028
Amylase is considered as an industrially important enzyme as it occupies the most important function in the food, paper, and pharmaceutical industries. The present study is concerned with the optimization, production and partial purification of halotolerant amylase from newly isolated Streptomyces brasiliensis MML2028, from Kelambakkam salt pan, Tamil Nadu, India. The primary screening was carried out by well diffusion assay to find the zone of lysis. The assay was observed for each media optimization by measuring the release of reducing sugar (RS) by the 3,5 dinitro salicylic acid (DNS) method and expressed in the international unit (UI). Ammonium sulphate precipitation was used to partially purify the enzyme and then lyophilized. SDS-PAGE was performed to identify the molecular weight. The production medium was optimized with 1% of the starch substrate, 3% of NaCl at 24˚C and pH 9, and incubation of 9 days. The total activity of the partially purified α-amylase was observed to be 1806.9U/mL. The partially purified enzyme was more active with 3% NaCl, pH 8, and 24˚C which is known to be a halotolerant alkaline α-amylase. The enzyme showed tolerance towards magnesium, manganese ions, Triton x-100, and urea. De-inking of α-amylase showed good results proving that the enzyme activity is more efficient. Hence, the alkaliphilic amylase from Halotolerant actinomycetes S. Brasiliensis MML2028 could be a better microbial source that can be used in many industries, especially in paper and textiles
Dry sliding wear behaviour of Ta/NbC filled glass-epoxy composites at elevated temperatures
In this work an attempt was made to evaluate wear loss, specific wear rate and coefficient of friction of Glass-Epoxy (G-E) composites with and without Tantalum Niobium Carbide (Ta/NbC) filler. A vacuum assisted resin transfer moulding (VARTM) technique was employed to fabricate the composite specimens. The fabricated wear specimens were tested by using pin-on-disk test rig at various temperatures viz., 30, 60, 90 and 120° C at normal applied loads of 10 N and 20 N. Sliding velocity of the disc of 1.5 m/s was maintained and test was continued for each sample up to a sliding distance of 5000 m. The wear loss in both the composites increases with increase in temperature and applied normal load. However, Ta/NbC particulate filler incorporated G-E composite exhibits lower wear rate and higher coefficient of friction as compared to unfilled G-E composite. The features of worn surfaces of the specimens were examined under scanning electron microscopy (SEM) and findings are analysed
Distinct RNA profiles in subpopulations of extracellular vesicles: apoptotic bodies, microvesicles and exosomes
Introduction: In recent years, there has been an exponential increase in the number of studies aiming to understand the biology of exosomes, as well as other extracellular vesicles. However, classification of membrane vesicles and the appropriate protocols for their isolation are still under intense discussion and investigation. When isolating vesicles, it is crucial to use systems that are able to separate them, to avoid cross-contamination. Method: EVs released from three different kinds of cell lines: HMC-1, TF-1 and BV-2 were isolated using two centrifugation-based protocols. In protocol 1, apoptotic bodies were collected at 2,000×g, followed by filtering the supernatant through 0.8 µm pores and pelleting of microvesicles at 12,200×g. In protocol 2, apoptotic bodies and microvesicles were collected together at 16,500×g, followed by filtering of the supernatant through 0.2 µm pores and pelleting of exosomes at 120,000×g. Extracellular vesicles were analyzed by transmission electron microscopy, flow cytometry and the RNA profiles were investigated using a Bioanalyzer®. Results: RNA profiles showed that ribosomal RNA was primary detectable in apoptotic bodies and smaller RNAs without prominent ribosomal RNA peaks in exosomes. In contrast, microvesicles contained little or no RNA except for microvesicles collected from TF-1 cell cultures. The different vesicle pellets showed highly different distribution of size, shape and electron density with typical apoptotic body, microvesicle and exosome characteristics when analyzed by transmission electron microscopy. Flow cytometry revealed the presence of CD63 and CD81 in all vesicles investigated, as well as CD9 except in the TF-1-derived vesicles, as these cells do not express CD9. Conclusions: Our results demonstrate that centrifugation-based protocols are simple and fast systems to distinguish subpopulations of extracellular vesicles. Different vesicles show different RNA profiles and morphological characteristics, but they are indistinguishable using CD63-coated beads for flow cytometry analysis
NCBI Peptidome: a new repository for mass spectrometry proteomics data
Peptidome is a public repository that archives and freely distributes tandem mass spectrometry peptide and protein identification data generated by the scientific community. Data from all stages of a mass spectrometry experiment are captured, including original mass spectra files, experimental metadata and conclusion-level results. The submission process is facilitated through acceptance of data in commonly used open formats, and all submissions undergo syntactic validation and curation in an effort to uphold data integrity and quality. Peptidome is not restricted to specific organisms, instruments or experiment types; data from any tandem mass spectrometry experiment from any species are accepted. In addition to data storage, web-based interfaces are available to help users query, browse and explore individual peptides, proteins or entire Samples and Studies. Results are integrated and linked with other NCBI resources to ensure dissemination of the information beyond the mass spectroscopy proteomics community. Peptidome is freely accessible at http://www.ncbi.nlm.nih.gov/peptidome
Microparticle-mediated transfer of the viral receptors CAR and CD46, and the CFTR channel in a CHO cell model confers new functions to target cells
Cell microparticles (MPs) released in the extracellular milieu can embark plasma membrane and intracellular components which are specific of their cellular origin, and transfer them to target cells. The MP-mediated, cell-to-cell transfer of three human membrane glycoproteins of different degrees of complexity was investigated in the present study, using a CHO cell model system. We first tested the delivery of CAR and CD46, two monospanins which act as adenovirus receptors, to target CHO cells. CHO cells lack CAR and CD46, high affinity receptors for human adenovirus serotype 5 (HAdV5), and serotype 35 (HAdV35), respectively. We found that MPs derived from CHO cells (MP-donor cells) constitutively expressing CAR (MP-CAR) or CD46 (MP-CD46) were able to transfer CAR and CD46 to target CHO cells, and conferred selective permissiveness to HAdV5 and HAdV35. In addition, target CHO cells incubated with MP-CD46 acquired the CD46-associated function in complement regulation. We also explored the MP-mediated delivery of a dodecaspanin membrane glycoprotein, the CFTR to target CHO cells. CFTR functions as a chloride channel in human cells and is implicated in the genetic disease cystic fibrosis. Target CHO cells incubated with MPs produced by CHO cells constitutively expressing GFP-tagged CFTR (MP-GFP-CFTR) were found to gain a new cellular function, the chloride channel activity associated to CFTR. Time-course analysis of the appearance of GFP-CFTR in target cells suggested that MPs could achieve the delivery of CFTR to target cells via two mechanisms: the transfer of mature, membrane-inserted CFTR glycoprotein, and the transfer of CFTR-encoding mRNA. These results confirmed that cell-derived MPs represent a new class of promising therapeutic vehicles for the delivery of bioactive macromolecules, proteins or mRNAs, the latter exerting the desired therapeutic effect in target cells via de novo synthesis of their encoded proteins
Improved model for the analysis of the Heat Release Rate (HRR) in Compression Ignition (CI) engines
The accuracy of the Heat Release Rate (HRR) model of Internal Combustion Engines (ICEs) is highly depended on the ratio of specific heats, gamma (γ). Previous γ models were largely expressed as functions of temperature only. The effects of the excess air ratio (λ) and the Exhaust Gas Recirculation (EGR) rate on γ were neglected in most of the existing γ functions. Furthermore, previous HRR models were developed for stoichiometric or near – stoichiometric air - fuel mixtures in an engine condition. However, Compression Ignition (CI) engines operate over a wide range of λ. No work has been done to model the HRR of CI engines under non – stoichiometric conditions. Also, no work has been done to investigate the accuracy of existing γ functions specifically with respect to the modelling of the HRR of CI engines for non – stoichiometric conditions. The aim of this work was to develop an improved HRR model for the analysis of the HRR of CI engines for non – stoichiometric conditions (λ>1). In this work, a modified γ(T,λ), was used to model the HRR of a 96 kW, multiple fuel injection, Euro V, Direct Injection (DI) engine. The modified HRR model (Leeds HRR model) predicted the fuel consumption of the engine with an average error of 1.41% confirming that the accuracy of the HRR model of CI engines is improved by using γ(T,λ). The typical average error in the prediction of the other models was 16%. The much improved HRR model leads to more accurate prediction of fuel consumption, which enables the development of and enhances better fuel consumption management strategies for engines and fuels. It was also ascertained in this work that EGR has insignificant effect on the HRR of CI engines at low and medium loads
Rule-based modeling of biochemical systems with BioNetGen
Totowa, NJ. Please cite this article when referencing BioNetGen in future publications. Rule-based modeling involves the representation of molecules as structured objects and molecular interactions as rules for transforming the attributes of these objects. The approach is notable in that it allows one to systematically incorporate site-specific details about proteinprotein interactions into a model for the dynamics of a signal-transduction system, but the method has other applications as well, such as following the fates of individual carbon atoms in metabolic reactions. The consequences of protein-protein interactions are difficult to specify and track with a conventional modeling approach because of the large number of protein phosphoforms and protein complexes that these interactions potentially generate. Here, we focus on how a rule-based model is specified in the BioNetGen language (BNGL) and how a model specification is analyzed using the BioNetGen software tool. We also discuss new developments in rule-based modeling that should enable the construction and analyses of comprehensive models for signal transduction pathways and similarly large-scale models for other biochemical systems. Key Words: Computational systems biology; mathematical modeling; combinatorial complexity; software; formal languages; stochastic simulation; ordinary differential equations; protein-protein interactions; signal transduction; metabolic networks. 1
A Compendium of Potential Biomarkers of Pancreatic Cancer
Akhilesh Pandey and colleagues describe a compendium of potential biomarkers that can be systematically validated by the pancreatic cancer community
A dual specificity kinase, DYRK1A, as a potential therapeutic target for head and neck squamous cell carcinoma
Despite advances in clinical management, 5-year survival rate in patients with late-stage head and neck squamous cell carcinoma (HNSCC) has not improved significantly over the past decade. Targeted therapies have emerged as one of the most promising approaches to treat several malignancies. Though tyrosine phosphorylation accounts for a minority of total phosphorylation, it is critical for activation of signaling pathways and plays a significant role in driving cancers. To identify activated tyrosine kinase signaling pathways in HNSCC, we compared the phosphotyrosine profiles of a panel of HNSCC cell lines to a normal oral keratinocyte cell line. Dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) was one of the kinases hyperphosphorylated at Tyr-321 in all HNSCC cell lines. Inhibition of DYRK1A resulted in an increased apoptosis and decrease in invasion and colony formation ability of HNSCC cell lines. Further, administration of the small molecular inhibitor against DYRK1A in mice bearing HNSCC xenograft tumors induced regression of tumor growth. Immunohistochemical labeling of DYRK1A in primary tumor tissues using tissue microarrays revealed strong to moderate staining of DYRK1A in 97.5% (39/40) of HNSCC tissues analyzed. Taken together our results suggest that DYRK1A could be a novel therapeutic target in HNSCC
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