Search results for "Biochemical"
showing 10 items of 870 documents
Biodegradability Prediction of Fragrant Molecules by Molecular Topology
2016
Biodegradability is a key property in the development of safer fragrances. In this work we present a green methodology for its preliminary assessment. The structure of various fragrant molecules is characterized by computing a large set of topological indices. Those relevant to biodegradability are selected by means of a hybrid stepwise selection method to build a linear classifier. This model is compared with a more complex artificial neural network trained with the indices previously found. After validation, the models show promise for time and cost reduction in the development of new, safer fragrances. The methodology presented could easily be adapted to many quasi-big data problems in R…
A new system for animal products traceability and authentication: Use of DNA analysis of natural tracers and example of application to dry cured hams
2010
A few DNA based approaches have been developed to trace animal products from the farm to the consumer “fork”. These approaches make use of the animal DNA that can be recovered during all steps of t...
Sexual dimorphism in immune function: The role of sex steroid hormones
2018
There is evidence of the relation of sex steroid hormones and sexual dimorphism in immune system response to infectious diseases. The aim of this review was to identify the role of sex hormones in immune function and sexual dimorphism of immune reactions. Gonadal hormones together with the immune system play an important role in process of immune responses to the disease [1]. Estrogens, progesterone and testosterone have different impacts on immune cells and different gonadal hormones are of high importance for responses of innate and adaptive immunity [1, 2]. Estrogens mainly enhance immune function while testosterone has a suppressive role. Higher progesterone during pregnancy leads to au…
Enterococcal meningitis caused by Enterococcus casseliflavus. First case report
2005
Abstract Background Enterococcal meningitis is an uncommon disease usually caused by Enterococcus faecalis and Enterococcus faecium and is associated with a high mortality rate. Enterococcus casseliflavus has been implicated in a wide variety of infections in humans, but never in meningitis. Case presentation A 77-year-old Italian female presented for evaluation of fever, stupor, diarrhea and vomiting of 3 days duration. There was no history of head injury nor of previous surgical procedures. She had been suffering from rheumatoid arthritis for 30 years, for which she was being treated with steroids and methotrexate. On admission, she was febrile, alert but not oriented to time and place. H…
The structure and biosynthesis of heinamides A1-A3 and B1-B5, antifungal members of the laxaphycin lipopeptide family.
2021
Laxaphycins are a family of cyclic lipopeptides with synergistic antifungal and antiproliferative activities. They are produced by multiple cyanobacterial genera and comprise two sets of structurally unrelated 11- and 12-residue macrocyclic lipopeptides. Here, we report the discovery of new antifungal laxaphycins from Nostoc sp. UHCC 0702, which we name heinamides, through antimicrobial bioactivity screening. We characterized the chemical structures of eight heinamide structural variants A1-A3 and B1-B5. These variants contain the rare non-proteinogenic amino acids 3-hydroxy-4-methylproline, 4-hydroxyproline, 3-hydroxy-d-leucine, dehydrobutyrine, 5-hydroxyl beta-amino octanoic acid, and O-c…
Amino polyphosphonates - chemical features and practical uses, environmental durability and biodegradation
2012
Growing concerns about the quality of the environment led to the introduction of complex system of safety assessment of synthetically manufactured and commonly applied chemicals. Sometimes, however, our knowledge of consequences that result from the usage of these substances, appears far later, than at the beginning of their application. Such situation is observed in the case of aminopolyphosphonates being an important subgroup of organophosphorus compounds. The increasing industrial and household applications, led to introduce thousand tons of polyphosphonates every year into the environment. These substances are difficult to determine in environmental samples because of lack of appropriat…
Purification and analysis of polyhistidine-tagged human parvovirus B19 VP1 and VP2 expressed in insect cells
2008
Human parvovirus B19 is an autonomously replicating human pathogen with a specific tropism for human erythroid progenitor cells. There is an interest in producing empty nucleocapsids of B19 as they can be used as tools in molecular biology and diagnostics. Native B19 virus particles are formed from two structural viral proteins, VP1 and VP2. The VP2 protein alone is able to self assemble and consequently form virus-like particles (VLPs) in heterologous expression systems. Purification of recombinant VLPs has been conducted using various traditional methods. These include laborious and time-consuming, e.g. cesium chloride or sucrose gradient ultracentrifugation steps, allowing limited workin…
Recent advances on development of portable biosensors for monitoring of biological contaminants in foods
2021
Abstract Background There is a demand for easy, rapid and affordable analysis of biological contaminants in foods to guarantee their safety and quality. Most analysis of food contaminants is commonly performed in a limited number of samples in centralized laboratories by an expert technician. Therefore, developing of alternative techniques such as portable biosensors is of great significance. Scope and approach This review aims to discuss the recent advances in designing and applying of portable biosensors for the detection of biological food contaminants including bacteria, fungi and the related toxins. Also, the review deals briefly the basic knowledge of various portable biosensors which…
Enzyme and lateral flow monoclonal antibody-based immunoassays to simultaneously determine spirotetramat and spirotetramat-enol in foodstuffs.
2021
Spirotetramat is employed worldwide to fight insect pests due to its high efficiency. This chemical is quickly metabolized by plants into spirotetramat-enol, so current regulations establish that both compounds must be determined in foodstuffs for monitoring purposes. Nowadays, immunochemical methods constitute rapid and cost-effective strategies for chemical contaminant analysis at trace levels. However, high-affinity binders and suitable bioconjugates are required. In this study, haptens with opposite functionalisation sites were synthesized in order to generate high-affinity monoclonal antibodies. A direct competitive enzyme-linked immunosorbent assay with an IC50 value for the sum of sp…
Biocatalysis and biorecognition in nonaqueous media. Some perspectives in analytical biochemistry
1995
Biocatalysis and, to a lesser extent, biorecognition in non-aqueous media (including organic solvents as well as supercritical fluids and gases) constitute at present an exciting research area which has already demonstrated its biotechnological potential in numerous, varied applications. Less attention, however, has been paid to its analytical possibilities, even though many advantages have been postulated and a wide range of poorly water-soluble analytes are present in samples (or waste materials) from food and drink, petrochemical, pharmaceutical, military and other industries. The main approaches, developed in recent years to exploit the use of enzymes, antibodies or antibody mimics in w…