10,844 research outputs found
Effect of Different Carbon Concentration on Yield of Extracellular Polymeric Substances (EPS) Produced by Pseudomonas Putida ATCC 11172
The extracellular polymeric substances (EPS) extracted from Pseudomonas putida ATCC 11172 at different carbon concentration, where Luria broth used as medium growth with and without addition of 0.5% w/v (LBG 0.5%) and 1.0% w/v (LBG 1%) glucose. The Bound EPS were extracted by ethylene diamine tetra acetic acid (EDTA) methods and precipitated by cold ethanol 3:1; while free EPS extracted only by precipitate by cold ethanol 3:1. The study shows the clear effect of carbon concentration on the production of EPS. The amount of free EPS found 120.39±2.20, 111.16±1.75 and 100.38±2.0 mg g-1 dry cell for LB, LBG 0.5 and LBG 1 respectively. Where the yield of bound EPS shows fewer amounts from free EPS, the amount of bound EPS was 29.22±1.40, 21.18±0.90 and 17.10±1.10 mg g-1 dry cell for LB, LBG 0.5 and LBG 1 respectively
Recommended from our members
Damages caused by cotton rat, Sigmodon hispidus zanjonensis, on sugar cane in San Pedrosula, Honduras
Technical assistance was given to CompañĂa Azucarera Hondureña, S.A. (Agro-Industrial Co.), Honduras, Central America, to determine if a campaign against noxious rodents to agriculture crops was needed. Several trappings were carried out at different places using snap traps to determine the population structure of rodents associated with the crop, and live traps to determine the index or density of the Sigmodon hispidus rat population, which was identified as being responsible for the damage to sugarcane. Results were 43.24% adult males, 14.86% young males, 31.41% adult females, and 10.47% young females. Of the adult females captured, 54.83% were pregnant with an average of 3 to 4 embryos per rat. A control demonstration combat was carried out at one of the experimental stations with a bait prepared with 2% zinc phosphide in a place where it had been previously determined there was a population of 39 rats per hectare. After such control, the population was reduced to 18 rats per hectare, which represents an efficiency of 53.85%. An evaluation of damages was also measured at different places to determine the degree of loss caused by the rats, which proved to be 22.79% damage. The size of the sample was estimated in 3 samples per hectare, with a level of confidence of 95%
Microsolvation of Mg2+, Ca2+: Strong influence of formal charges in hydrogen bond networks
A stochastic exploration of the quantum conformational spaces in the microsolvation of divalent cations with explicit consideration of up to six solvent molecules [Mg (H 2 O) n )]2+, (n = 3, 4, 5, 6) at the B3LYP, MP2, CCSD(T) levels is presented. We find several cases in which the formal charge in Mg2+ causes dissociation of water molecules in the first solvation shell, leaving a hydroxide ion available to interact with the central cation, the released proton being transferred to outer solvation shells in a Grotthus type mechanism; this particular finding sheds light on the capacity of Mg2+ to promote formation of hydroxide anions, a process necessary to regulate proton transfer in enzymes with exonuclease activity. Two distinct types of hydrogen bonds, scattered over a wide range of distances (1.35–2.15 Å) were identified. We find that in inner solvation shells, where hydrogen bond networks are severely disturbed, most of the interaction energies come from electrostatic and polarization+charge transfer, while in outer solvation shells the situation approximates that of pure water clusters
INDUCED-PLURIPOTENT STEM-DERIVED NEURONAL PROGENITOR CELLS AS A NOVEL TREATMENT FOR NEURODEGENERATIVE DISEASES
Cellular therapies, as neuronal progenitor (NP) cells grafting, are promising therapies for patients affected with neurodegenerative diseases like Creutzfeldt-Jakob Disease (CJD). At this time there is no effective treatment or cure for CJD. The disease is inevitably fatal and affected people usually die within months of the appearance of the first clinical symptoms. Compelling evidence indicate that the hallmark event in the disease is the conversion of the normal prion protein (termed PrPC) into the disease-associated, misfolded form (called PrPSc). Thus, a reasonable therapeutic target would be to prevent PrP misfolding and prion replication. This strategy has been applied with poor results since at the time of clinical intervention substantial brain damage has been done. It seems that a more effective treatment aimed at patients with established symptoms of CJD would need to stop further brain degeneration or even recover some of the previously lost brain tissue. The most promising possibility to recover brain tissue is the use of NPs that have the potential to replenish the nerve cells lost during the early stages of the disease.
Advanced cellular therapies, beside their potential for cell replacement, might be used as biomaterials for drug delivery in order to stimulate cell survival or the resolution the disease. Also, implanted cells can be genetically manipulated to correct abnormalities causing disease or to make them more resistant to the toxic microenvironments present in damaged tissue.
In recent years cell engineering has been within the scope of the scientific and general community after the development of technologies able to “de-differentiate” somatic cells into induced-pluripotent stem (IPS) cells. This new tool permits the use of easy-to-reach cells like skin or blood cells as a primary material to obtain embryonic stem-like cells for cellular therapies, evading all ethical issues regarding the use of human embryos as a source of embryonic stem cells.
The complete work proposes to implant IPS-derived NP cells into the brain of prion-infected animals to evaluate their therapeutic potential. Since it is well known that the expression of prion protein in the cell membrane is necessary for PrPSc mediated toxicity, we also want to determine if NPs lacking the prion protein have better survival rates once implanted into sick animals.
The main objective of this work is to develop implantable neural precursor from IPS coming from animals lacking the prion protein.
Specific aim 1: To develop and characterize cellular cultures of IPS cells from prp-/- mice. Fibroblasts from prp-/- animals will be reprogrammed using the four Yamanaka factors. IPS colonies will be selected and characterized by immunohistochemistry for markers of pluripotency. Their developmental capabilities will be evaluated by teratoma and embryoid body formation assays.
Specific aim 2: To differentiate IPS cells to a neuronal lineage. IPS cells will be differentiated to a NP stage by the use of defined media culture conditions. NP cells will be characterized by their immunohistochemical profile as well as by their ability to differentiate into neuronal cells.
Specific aim 3: Cellular labeling of neuronal progenitors cells for in vitro traceability. In order to track the cells once implanted in the host brain, they will be tagged with different methods such as lipophilic fluorescent tracers and transduction with GFP protein expression
A novel and chemoselective process of N-alkylation of aromatic nitrogen compounds using quaternary ammonium salts as starting material
ArtĂculo Internacional Open AccesThe process of N-alkylation of several pyrroles, indoles, and derivative heterocycles is herein described, using quaternary ammonium salts as the source of an alkylating agent. These reactions were carried out on several heterocyclic rings with triethylbenzylammonium chloride or tetradecyltrimethyl ammonium bromide and an NaOH solution at 50%, leading to a chemoselective N-alkylated product and an average yield of 73%. This is an alternative process to the traditional benzylation and methylation of N-heterocycles with direct handling of alkyl halides.CONACYT, SecretarĂa de InvestigaciĂłn y Estudios Avanzados de la UAE
Influence of alternating air injection on the color and <em>“alambrado”</em> of natural black olives cv. Arauco, as compared with the traditional Argentine method
Ripe black olives cv. Arauco were processed under different conditions to evaluate the effects of alternating air injection (AI) on the color of olives and on spoilage known as “<em>alambrado</em>”, using a system based on the one patented by the “Instituto de la Grasa” (Sevilla, Spain), as compared with the traditional Argentine processing method, which consists of drying the olives in natural air (“<em>extendido</em>”) for 24 hours at 7, 14 and 21 days of fermentation. Four types of fermentation were used: brine at 2% NaCl plus AI; brine at 2% NaCl plus three “<em>extendidos</em>”; brine at 9% NaCl plus three “<em>extendido</em>s”; and brine at 9% NaCl plus AI and one “<em>extendido</em>”. As previously observed in other varieties by other authors, we noticed that lower pH values were achieved in 2% NaCl fermentations vs. 9% NaCl fermentations. AI prevented the “<em>alambrado</em>” whereas brine at 2% NaCl reduced this spoilage as compared with brine at 9% NaCl. The darkest color of olives was obtained with three “<em>extendido</em>s”, but 83% of brightness reduction was achieved with only one “<em>extendido</em>”. The “<em>extendido</em>” process decreased the texture. We conclude that the combination of AI and “<em>extendido</em>” can add benefits to natural black olives of the Arauco variety.<br><br>Se elaboraron aceitunas negras maduras variedad Arauco en distintas condiciones para evaluar la inyecciĂłn alternante de aire (IA) con un sistema basado en el patentado por el Instituto de la Grasa, en comparaciĂłn con la elaboraciĂłn tradicional argentina donde se realiza exposiciĂłn al aire en seco (“extendido”) de los frutos durante 24 h, en tres momentos de la fermentaciĂłn (despuĂ©s de 7, 14 y 21 dĂas). Se hicieron cuatro tipos de fermentaciones: en salmuera al 2% con IA; en salmuera al 2% y 9% con tres “extendidos” y salmuera 9% con IA y un “extendido”. Se alcanzaron los valores mas bajos de pH en fermentaciones con el 2% de NaCl versus las de 9%. La IA evita el defecto de “alambrado” y lo reduce la concentraciĂłn de 2% versus la de 9%. El color más oscuro se obtiene aplicando el “extendido” en tres oportunidades, pero con una aplicaciĂłn se alcanza el 83% de la reducciĂłn de luminosidad alcanzada por las tres aplicaciones. La textura se ve disminuida por el proceso de “extendido”. La combinaciĂłn de la IA y el “extendido” reducen el defecto de “alambrado” y oscurecen las aceitunas negras al natural de la variedad Arauco
- …