1,298 research outputs found
Production of a potential liquid plant bio-stimulant by immobilized Piriformospora indica in repeated-batch fermentation process
Piriformospora indica, a mycorrhizal-like fungus able to establish associations with roots of a wide range of plants, supporting plant nutrition and increasing plant resistance and tolerance to stress, was shown to solubilise phosphate applied in the form of animal bone char (HABO) in fermentation systems. The process of P solubilisation was caused most likely by proton extrusion and medium pH lowering. The fungal mycelium was successfully immobilized/retained in a polyurethane foam carrier. Further employment of the immobilized mycelium in repeated-batch fermentation process resulted in at least 5 cycles of P solubilization. The concentration of soluble P increased during the experiment with 1.0 and 3.0 g HABO lâ1 and at the end of the 5th batch cycle reached 40.8 and 120 mg lâ1, respectively. The resulting final liquid product, without or with solubilized phosphate, was found to significantly increase plant growth and P plant uptake. It can be used as a biostimulant containing microbial plant growth-promoting substances and soluble P derived from renewable sources (HABO) thus supporting the development of sustainable agro-ecosystems.This work was supported by Project CTM2014-53186-R, Ministerio de Economia y Competitividad-ES/EC FEDER Fund and the sabbatical Grant PRX16/00277 to NV
Glutathione accelerates sodium channel inactivation in excised rat axonal membrane patches
The effects of glutathione were studied on the gating behaviour of sodium channels in membrane patches of rat axons. Depolarizing pulses from â120 to â40 mV elicited sodium currents of up to 500 pA, indicating the simultaneous activation of up to 250 sodium channels. Inactivation of these channels in the excised, inside-out configuration was fitted by two time constants ( h1=0.81 ms; h2= 5.03 ms) and open time histograms at 0 mV revealed a biexponential distribution of channel openings ( short=0.28 ms; long=3.68 ms). Both, the slow time constant of inactivation and the long lasting single channel openings disappeared after addition of the reducing agent glutathione (2â5 mM) to the bathing solution. Sodium channels of excised patches with glutathione present on the cytoplasmatic face of the membrane had inactivation kinetics similar to channels recorded in the cell-attached configuration. These observations indicate that redox processes may contribute to the gating of axonal sodium channels
Mortality of patients with multiple sclerosis: a cohort study in UK primary care
We aimed to estimate rates, causes and risk factors of all-cause mortality in a large population-based cohort of multiple sclerosis (MS) patients compared with patients without MS. Using data from the UK General Practice Research Database, we identified MS cases diagnosed during 2001â2006 and validated using patientsâ original records where possible. We also included MS cases during 1993â2000 identified and validated in an earlier study. Cases were matched to up to ten referents without MS by age, sex, index date (date of first MS diagnosis for cases and equivalent reference date for controls), general practice and length of medical history before first MS diagnosis. Patients were followed up to identify deaths; hazard ratios (HRs) and 95 % confidence intervals (CIs) were estimated using Cox-proportional regression. MS patients (N = 1,822) had a significantly increased risk of all-cause mortality compared with referents (N = 18,211); adjusted HR 1.7 (95 % CI 1.4â2.1). Compared with referents, female MS patients had a higher but not significantly different HR for death than males; adjusted HR 1.86 (95 % CI 1.46â2.38) vs. HR 1.31 (95 % CI 0.93â1.84), respectively. The most commonly recorded cause of death in MS patients was âMSâ (41 %), with a higher proportion recorded among younger patients. A significantly higher proportion of referents than MS patients had cancer recorded as cause of death (40 vs. 19 %). Patients with MS have a significant 1.7-fold increased risk of all-cause mortality compared with the general population. MS is the most commonly recorded cause of death among MS patients. Electronic supplementary material The online version of this article (doi:10.1007/s00415-014-7370-3) contains supplementary material, which is available to authorized users
âGreenâ Synthesis of Sucrose Octaacetate and Characterization of Its Physicochemical Properties and Antimicrobial Activity
Sucrose octaacetate (octa-O-acetylsucrose) has been synthesized by esterification of sucrose with acetic anhydride using ultrasound-assisted irradiation. This sucrose ester is a white, water-insoluble substance with a bitter taste. The FT-IR and NMR spectra confirmed
acetylation and revealed the hydrophobic incorporation in sucrose molecule. Furthermore, the foamability, foam stability, emulsification and antimicrobial properties of octa-O-acetylsucrose were evaluated. Foams and 50 % (oil/water) model emulsions were prepared with 2 % (w/w) octa-O-acetylsucrose. The obtained results demonstrate the
formation of emulsions and foams with high stability (50â70 %). The antimicrobial activity of octa-O-acetylsucrose was evaluated against seventeen microorganisms (Gram-positive and Gram-negative bacteria, yeasts, and fungi). Octa-O-acetylsucrose inhibited
the growth of fungi Penicillium sp., Rhizopus sp. and Fusarium moniliforme at 5 mg cmâ3, and yeasts Candida albicans at 1 mg cmâ3. Inhibition against Gram-positive and Gram-negative bacteria was not observed. The obtained results demonstrate the potential
applications of octa-O-acetylsucrose as a foaming agent, oil-in-water emulsion stabilizer, and antifungal substance in pharmaceutical and cosmetic preparations.
This work is licensed under a Creative Commons Attribution 4.0 International License
Cylindrical equilibrium shapes of fluid membranes
Within the framework of the well-known curvature models, a fluid lipid
bilayer membrane is regarded as a surface embedded in the three-dimensional
Euclidean space whose equilibrium shapes are described in terms of its mean and
Gaussian curvatures by the so-called membrane shape equation. In the present
paper, all solutions to this equation determining cylindrical membrane shapes
are found and presented, together with the expressions for the corresponding
position vectors, in explicit analytic form. The necessary and sufficient
conditions for such a surface to be closed are derived and several sufficient
conditions for its directrix to be simple or self-intersecting are given.Comment: 17 pages, 4 figures. Published in J. Phys. A: Math. Theore
New distinguished classes of spectral spaces: a survey
In the present survey paper, we present several new classes of Hochster's
spectral spaces "occurring in nature", actually in multiplicative ideal theory,
and not linked to or realized in an explicit way by prime spectra of rings. The
general setting is the space of the semistar operations (of finite type),
endowed with a Zariski-like topology, which turns out to be a natural
topological extension of the space of the overrings of an integral domain,
endowed with a topology introduced by Zariski. One of the key tool is a recent
characterization of spectral spaces, based on the ultrafilter topology, given
in a paper by C. Finocchiaro in Comm. Algebra 2014. Several applications are
also discussed
Risk assessment of non-native fishes in the Balkans Region using FISK, the invasiveness screening tool for non-native freshwater fishes
A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK) providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, indicating concordance amongst assessors
Detection of interstellar hydrogen peroxide
The molecular species hydrogen peroxide, HOOH, is likely to be a key
ingredient in the oxygen and water chemistry in the interstellar medium. Our
aim with this investigation is to determine how abundant HOOH is in the cloud
core {\rho} Oph A. By observing several transitions of HOOH in the
(sub)millimeter regime we seek to identify the molecule and also to determine
the excitation conditions through a multilevel excitation analysis. We have
detected three spectral lines toward the SM1 position of {\rho} Oph A at
velocity-corrected frequencies that coincide very closely with those measured
from laboratory spectroscopy of HOOH. A fourth line was detected at the
4{\sigma} level. We also found through mapping observations that the HOOH
emission extends (about 0.05 pc) over the densest part of the {\rho} Oph A
cloud core. We derive an abundance of HOOH relative to that of H_2 in the SM1
core of about 1\times10^(-10). To our knowledge, this is the first reported
detection of HOOH in the interstellar medium.Comment: 5 pages, 4 figures, accepted for publication in Astronomy &
Astrophysics, new version corrects a typo in Table 1 (and consequently in Fig
4
Multiphysics simulation tools for designing motors for traction applications in hybrid and electric vehicles
Motor manufacturers are facing a difficult challenge in designing traction motors for the latest generation of hybrid and all-electric vehicles. The efficiency with which these motors can perform is critical, as it impacts on the vehicle range and battery life. Many of the issues involved in the motor design have a complex nature which requires multiple fields of physics such as electromagnetics (EM), mechanics and thermal analysis. All these physics are usually interdependent and have to be considered collectively in order to obtain optimal performance for a particular scenario. This paper presents a multiphysics simulation tool that was implemented to address this situation. The Opera FEA software suite [1] was developed to include a multiphysics analysis that can link several EM, thermal and stress analyses. Operaâs Machines Environment (parameterised template software for designing motors and generators) has been extended to allow easy setup of coupled multiphysics analyses such as EM to thermal and EM to stress. In order to further facilitate the coupling of different analyses, a link to the Python programming language was embedded in Opera FEA software. The embedded Python facility offers options to perform certain post-processing operations during the solving stage and hence allow data transfer between different stages of the multiphysics analysis. It also extends Operaâs capabilities to interact with other FEA software
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