Electrodegradation of tetracycline on BDD anode Brinzila, C.I.; Pacheco, M.J.; Ciríaco, L. ...
Chemical engineering journal (Lausanne, Switzerland : 1996),
10/2012, Letnik:
209
Journal Article
Recenzirano
► High degree of mineralization can be achieved in the electrooxidation of tetracycline at a BDD anode. ► During the anodic oxidation of tetracycline organic nitrogen is mainly converted to ammonium, ...nitrate and nitrite. ► Average mass transfer coefficients increase with recirculation flow rate.
The anodic oxidation of tetracycline was performed in an up-flow reactor, operating in batch mode with recirculation, using as anode a boron-doped diamond electrode. The influence on the degradation rate of tetracycline initial concentration and recirculation flow rate were investigated. Assays were performed at constant current density, 300Am−2, using as electrolyte a sodium sulfate aqueous solution, 5gL−1. At the experimental conditions tested, HPLC results have shown an almost complete removal of tetracycline after 2h assay. The removals of the organic load, measured as chemical oxygen demand (COD) and total organic carbon (TOC), increased with tetracycline initial concentration and recirculation flow rate. At the highest recirculation flow rate tested, 100Lh−1, with an initial tetracycline concentration of 150mgL−1, after 4h assay, the removals of COD, TOC and absorbance (measured at 276.5 and 360.0nm) were 93%, 87%, 99% and 100%, respectively. Regarding the total Kjeldahl nitrogen elimination, it takes place mainly via transformation of organic nitrogen into ammonium, nitrate and nitrite. The total nitrogen removal increased with initial tetracycline concentration and showed also a tendency to increase with recirculation flow rate.
The paper presents an experimental study that has as main objective the evaluation of the integration capacity of the spur gears obtained by FDM in high precision mechanisms. The development of ...precision mechanical systems required the use of the additive layer manufacturing technology in order to manufacture the gears that have specific particularities for the applications in which gears are integrated. Take these aspects into consideration, the paper presents the results achieved by testing on a ZWP-06 machine the gears obtained by fused deposition modeling technology. Gears were obtained on an Anet A2, semiprofessional 3D printer. To obtain a superior quality of toothed wheels, both process parameters: the material properties, and the features of the 3D printer were taken into account. The results, obtained from the test, revealed the level of influence of the execution parameters of the toothed wheels by FDM on their quality. The correlation of the process parameters remains the most important aspect for obtaining components with a high accuracy class, which complies with the resistance standards under the conditions of a shorter execution time.
The authors developed a research for studying the behaviour of 3D printed machine elements such as: clutches, springs, bellows, screws, nuts, gears, differential and planetary mechanisms. There are ...different applications where metallic springs cannot be used: corrosive, explosive, magnetic field, electromagnetic radiation, nuclear techniques and other applications or environments that require light spring masses.
Minor and trace elements can substitute into the crystal lattice of galena at various concentrations. In situ LA-ICP-MS analysis and trace element mapping of a range of galena specimens from ...different deposit types are used to obtain minor/trace element data, aimed at achieving insight into factors that control minor/trace element partitioning. The previously recognized coupled substitution Ag++(Bi,Sb)3+ ⇌ 2Pb2+ is confirmed. However, the poorer correlation between Ag and (Bi+Sb) when the latter elements are present at high concentrations (∼>2000 ppm), suggests that site vacancies may come into play: 2(Bi,Sb)3++∎ ⇌ 3Pb2+. Galena is the primary host of Tl in all mapped mineral assemblages. Along with Cu, Tl is likely incorporated into galena via the coupled substitution: (Ag,Cu,Tl)++(Bi,Sb)3+ ⇌ 2Pb2+. Tin can reach significant concentrations in galena (>500 ppm). Cd and minor Hg can be incorporated into galena; the simple isovalent substitution (Cd,Hg)2+ ⇌ Pb2+ is inferred. This paper shows for the first time, oscillatory and sector compositional zoning of minor/trace elements (Ag, Sb, Bi, Se, Te, Tl) in galena from two epithermal ores. Zoning is attributed to slow crystal growth into open spaces within the vein at relatively low temperatures.The present data show that galena can host a broader range of elements than previously recognized. For many measured elements, the data sets generated display predictable partitioning patterns between galena and coexisting minerals, which may be dependent on temperature or other factors. Trace element concentrations in galena and their grain-scale distributions may also have potential in the identification of spatial and/or temporal trends within individual metallogenic belts, and as markers of ore formation processes in deposits that have undergone superimposed metamorphism and deformation. Galena trace element geochemistry may also display potential to be used as a trace/minor element vector approach in mineral exploration, notably for recognition of proximal-to-distal trends within a given ore system.
We report the observation of single top-quark production using 3.2 fb(-1) of ppover collision data with sqrts=1.96 TeV collected by the Collider Detector at Fermilab. The significance of the ...observed data is 5.0 standard deviations, and the expected sensitivity for standard model production and decay is in excess of 5.9 standard deviations. Assuming m(t) = 175 GeV/c(2), we measure a cross section of 2.3(-0.5);(+0.6)(stat + syst) pb, extract the CKM matrix-element value |V(tb)| = 0.91 + or - 0.11(stat + syst) + or - 0.07(theory), and set the limit |V(tb)| > 0.71 at the 95% C.L.
Introduction
Despite the rapid increase in disability and death due to Parkinson’s disease and associated psychiatric comorbidities (psychosis, depression, cognitive impairment, anxiety), the quest ...for a clear pathophysiological mechanism and treatment remains elusive. Numerous studies aim to identify a metabolomic fingerprint for PD and new, promising biomarkers are discovered with implications beyond neurodegenerative diseases, such as novel markers as predictors of bipolar type in depressed patients.Changes in neuronal microenvironment employ electrochemical techniques, such as cyclic voltammetry, used in both animal and human models of PD to monitor dopamine (DA) alterations in vivo, with high spatial and temporal resolution.
Objectives
Our aim is to investigate the latest scientific literature on PD and associated neuropsychiatric disorders and review the applications cyclic voltammetry has in recent technological advances in the field.
Methods
To gain a broad understanding of the subject, we have consulted multiple scientific literature databases (PubMed, Google Academic, Science Direct) using the keywords “cyclic voltammetry, Parkinson’s disease, psychiatric disorders, dopamine” and included original research articles published in the last 10 years
Results
The first
in situ
measurement of DA release in the human brain has been demonstrated in a sequential investment task, with implications for future research in decision-making behavior.
One study combines cyclic voltammetry and wireless telemetry for in vivo recording of changes in extracellular levels of DA, with high temporal and spatial resolution.
Disulfide nanorod-graphene-β-cyclodextrin nanocomposites biosensors have been succesfully used in detecting DA in rodent brain and human blood serum samples, with implications for minimally invasive measuring techniques.
Animal studies use cyclic voltammetry to monitor changes in DA levels in cerebrospinal fluid and plasma of mouse models of PD and investigate DA metabolism, release, uptake and receptor sensitivity in Knock-out mice, with implications for the diurnal variation of extracellular DA tone and release.Furthermore, a human alpha-synuclein-expressing mouse model of PD exhibited increased extracellular DA concentrations, decreased DA uptake and relieved paired-stimulus depression.
Conclusions
Cyclic voltammetry is a powerful tool in the expansion to humans of electrochemical recording techniques in PD. The final aim is to investigate DA neuron physiology before neurodegeneration onset and to measure neurotransmitter release in real time.
Disclosure of Interest
None Declared
Introduction
The use of electroconvulsive therapy (ECT) as a treatment for psychotic disorders is well-documented and effective. Despite the fact that ECT is often used, the precise neurobiological ...mechanisms supporting its effectiveness are still incompletely understood. Over the pastyears, extensive research on primates, rodents, and humans has begun to clarify the effects of electroconvulsive seizures (ECS) and ECT on neurotransmission systems such the dopaminergic system.
Objectives
The aim of this paper is to search evidence in the literature regarding the effects of ECT on the dopamine system.
Methods
In order to write this article, we searched for information in the most important scientific articles from the Google Scholar and Pubmed databases regarding the effects of ECT on the dopaminergic system.
Results
ECT and electroconvulsive shock are linked to enhanced dopamine release and dopamine receptor modification. Human studies show that ECT activates the dopamine system. In a study by Rudorfer et al., it was discovered that ECT increased the amount of homovanillic acid (HVA), a marker of dopamine turnover, in the cerebrospinal fluid (CRF). One important study indicates that monkeys given a brief clinical course of ECT (six sessions only) exhibit significant changes in dopaminergic presynaptic neurotransmission, with baseline function returning to quadratic (‘inverted U’ shape) by six weeks of the last ECT treatment. According to single-unit electrophysiological methods, repeated electroconvulsive shock to rats causes a subsensitivity of dopamine autoreceptors in the substantia nigra. Since effects identical to those reported with repeated treatment were also detected when a single electroconvulsive shock was followed by an acceptable treatment-free interval, this decreased sensitivity is time-dependent.
Conclusions
The results support the idea that ECT boosts the dopamine system and can be an effective strategy in the management of psychotic disorders.
Disclosure of Interest
None Declared
Research in the area of the pale, soft and exudative (PSE) pork and poultry meat is reviewed in this article with an emphasis on genetic, biochemical and metabolic factors contributing to the ...problem. Over the past five decades, there has been much more work in the pork meat area where a few genetic markers have been identified, and are currently used to remove susceptible animals from the herd. Some of the markers are linked to aberrant calcium regulation in the early postmortem muscle. The poultry industry is still not at the point of using genetic marker(s); however, some recent work has revealed several potential markers. The review also discusses environmental factors such as antemortem stress and early postmortem processing practices (e.g. chilling rate) that can influence the development and severity of the PSE phenomenon. Some of these factors are known to cause protein denaturation at the early stage of postmortem and directly contribute to poor water-holding capacity and inferior texture in fresh meat and later in processed products. A newer hypothesis suggesting that variation in protein oxidation, in response to antemortem stress and early postmortem tissue environment, can contribute to development of PSE pork is also discussed. Finally, a few recommendations for future work are proposed.
We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb(-1) collected in ppover collisions at sqrts=1.96 TeV by the CDF II detector ...at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 95% confidence level upper limits on sigmaBR(pp-->X-->micromicro), where X is a boson with spin-0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, Z' bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.
Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and ...release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery.
•Thirty parvocellular oxytocin neurons (ParvOT) alleviate acute pain•ParvOT project to WDR sensory neurons in spinal cord (SC)•ParvOT activate OT release from magnocellular OT neurons (magnOT)•Dual pain suppression by peripheral magnOT and central SC OT
Eliava, Melchior, Knobloch-Bollmann, Wahis et al. demonstrate that thirty specialized oxytocin neurons in the rat hypothalamus coordinate activity of oxytocin neurons and deep dorsal horn spinal processing, as revealed by the repression of nociceptive messages and the promotion of analgesia.
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