Successive Injections Research Articles

Green method for glucose determination using microfluidic device with a non-enzymatic sensor based on nickel oxyhydroxide supported at activated biochar

This paper reports the use of nickel ions supported at activated biochar carbon paste electrode (NiAB-CPME) coupled in a microfluidic thread-based electroanalytical device (μTED) for non-enzymatic glucose determination. Biochar was initially prepared from castor oil cake at 400 °C and activated by HNO3 refluxing. Activation process promoted an increase of functional groups, surface area and porosity in comparison to precursor biochar. Activated biochar (AB) has shown an excellent performance to spontaneous preconcentration of Ni(II) ions. In alkaline conditions a stable voltammetric profile associated to Ni(OH)2/NiOOH redox pair was verified and a significant catalytic effect was observed in presence of glucose which was used for its monitoring. Microfluidic device was assembled at a plastic platform printed using 3D printer being easy to construction using low cost materials. Non-enzymatic amperometric glucose sensor coupled in μTED showed a good repeatability of 3.84% for successive injections of glucose (n = 10), a constant flow rate of 1.11 µL s−1 and an analytical frequency of 61 injections per hour. A linear dynamic range (LDR) from 5.0 to 100.0 µmol L−1, limit of detection (LOD) of 0.137 µmol L−1 and limit of quantification (LOQ) 0.457 µmol L−1 glucose were obtained. The proposed device was applied to glucose determination in real biological samples of human saliva and blood serum. Finally, the method was considered a green analytical procedure with Eco-Scale score of 81.

Determination of the catechin contents of bioactive plant extracts using disposable screen-printed carbon electrodes in a batch injection analysis (BIA) system

This work presents an analytical study of the determination of catechin, extracted from the Brazilian plants Rhizophora mangle, Arrabidaea brachypoda, and Lippia origanoides, using disposable screen-printed carbon electrodes (C-SPE) coupled to a batch injection analysis (BIA) system. Preliminary cyclic voltammetry experiments in acetate buffer solution (pH 4.5) containing catechin revealed reversible redox processes, with anodic and cathodic peak potentials located at ~0.16 V and ~0.10 V vs. Ag/AgCl, respectively, and an irreversible peak at ~0.49 V. Under optimized conditions, the repeatability for direct amperometric determination of catechin, performed at +0.3 V with the C-SPE in the BIA system, using successive injections of 50 μmol L−1 of catechin, was RSD = 1.03% (n = 30). The sampling throughput was 120 injections per hour. The amperometric response showed a linear range from 1 to 150 μmol L−1 (R = 0.999), with detection and quantification limits of 0.021 and 0.070 μmol L−1, respectively. Application of the proposed methodology for the determination of catechin in extracts of the medicinal plants provided quantitative results similar to those obtained by high performance liquid chromatography (HPLC), at a confidence level of ~95%.

Impact of ionic composition on modulating wetting preference of calcite surface: Implication for chemically tuned water flooding

Despite previous researches on ion-engineered waterflooding (IEWF), its underlying mechanisms are not fully understood, particularly in presence of additives, like surfactants. This paper concerned with the contribution of Ca2+, Mg2+, SO42- and Na+ into altering wettability of oil-wet carbonate minerals towards water preferred state. As a mechanistic study, an experiment workflow was conducted to probe the impact of ions' concentrations in SW, either with or without sodium dodecylbenzene sulfonate (SDBS) which is an anionic surfactant. At first, contact angle (CA) measurement was carried out to evaluate the degree of wettability reversal upon treating the oil-aged calcite slabs with desired ionic composition. Further, to evaluate dynamic response of wettability alteration, the core-flood operation was carried out by successive injection of solutions selected by static CA results.In the case of plain SW flooding, i.e., without surfactant, sulfate dominates success of IEWF, without which wettability reversal did not occur. However, at quadrupled concentration, it acts detrimentally. Ca2+ and Mg2+ both showed an increasing trend of wettability improvement versus concentration. Also, Na+ adversely affected the treating process, without which calcite surface became a neutral state. Oil recoveries observed by core-flood experiment were in accordance with primitive CA measurements. Having SDBS generally improved the wetting reversal, while with a distinct response against salinity. The synergic actions of individual ions and SDBS molecules were interpreted via three interaction modes: surface adsorption of surfactant by increasing Na+, hydrophobic interaction of SDBS's tail with adsorbed carboxylates and releasing those compounds, and reduction of monomeric surfactants by forming strong ion-pairs with divalent cations, particularly Mg2+. The effect of IFT reduction and wettability modification of SDS was distinguished via a special flooding scenario, where latter proved to be significant and kinetically controlled.

Curcumin ameliorates glyoxylate-induced calcium oxalate deposition and renal injuries in mice

BackgroundNephrolithiasis is one of the most common and frequent urologic diseases worldwide. Several pathophysiological mechanisms are involved in stone formation, including oxidative stress, inflammation, apoptosis, fibrosis and autophagy. Curcumin, the predominant active component of turmeric, has been shown to have pleiotropic biological and pharmacological properties, such as antioxidant, anti-inflammatory and antifibrotic effects. PurposeThe current study proposed to systematically investigate the protective effects and the underlying mechanisms of curcumin in a calcium oxalate (CaOx) nephrolithiasis mouse model. MethodsThe animal model was established in male C57BL/6 mice by successive intraperitoneal injection of glyoxylate (100 mg/kg) for 1 week. Curcumin was orally given to mice 7 days before the injection of glyoxylate and for a total of 14 days at 50 mg/kg or 100 mg/kg. Bilateral renal tissue was harvested and processed for oxidative stress index detection, histopathological examinations and other analyses. ResultsCoadministration of curcumin could significantly reduce glyoxylate-induced CaOx deposition and simultaneous tissue injury in mouse kidneys. Meanwhile, curcumin alleviated the oxidative stress response via reducing MDA content and increasing SOD, CAT, GPx, GR and GSH levels in this animal model. Moreover, treatment with curcumin significantly inhibited apoptosis and autophagy induced by hyperoxaluria. Curcumin also attenuated the high expression of IL-6, MCP-1, OPN, CD44, α-SMA, Collagen I and collagen fibril deposition, which were elevated by hyperoxaluria. Furthermore, the results revealed that both the total expression and nuclear accumulation of Nrf2, as well as its main downstream products such as HO-1, NQO1 and UGT, were decreased in the kidneys of mice in the crystal group, while treatment with curcumin could rescue this deterioration. ConclusionCurcumin could significantly alleviate CaOx crystal deposition in the mouse kidney and the concurrent renal tissue injury. The underlying mechanism involved the combination of antioxidant, anti-apoptotic, inhibiting autophagy, anti-inflammatory, and antifibrotic activity and the ability to decrease expression of OPN and CD44 through the Nrf2 signaling pathway. The pleiotropic antilithic properties, combined with the minimal side effects, make curcumin a good potential choice to prevent and treat new or recurrent nephrolithiasis.

Quantifying and Reducing Retained Botulinum Toxin Postinjection.

Retained botulinum toxin solution may be visible in vials and syringe tips after mixing and presumed complete injections, leaving patients without the full prescribed dose. To quantify the mean amount of retained toxin within vials, syringes, and needles following spasticity injections (phase 1) and to design/test a targeted intervention for reduced retained toxin (phase 2). Prospective cohort quality assurance study. Outpatient spasticity program in a rehabilitation facility. Nine physicians specializing in physical medicine and rehabilitation, performing successive mixing and injections for spasticity with onabotulinumtoxinA or incobotulinumtoxinA. After initial review (phase 1), recommendations were made (phase 2) including not inverting the vial to withdraw medication unless needed, favoring 2-mL dilutions when possible, and decapping of vials for more complete medication withdrawal. Retained volume of toxin solution that was not injected and estimated retained units oftoxin. A total of 157 vials of botulinum toxin A were tested. Of the 82 initial, phase 1, preintervention vials (8200 units), 5.5% (∼452 units) of toxin solution was retained following mixing and injections. One and 3-mL syringe tips contained a mean of 3.32 and 1.44 units of toxin respectively. Within vials, saline dilutions with 2 mL contained less mean retained toxin (1.89 vs 3.31 units) relative to 1-mL dilution. Awareness of monitoring significantly decreased retained solution in vials (0.035 mL vs 0.069 mL for naïve group, P = .002). Phase 2, postintervention testing of 75 vials demonstrated that withdrawing toxin from the inferior edge from a non-inverted vial reduced the retained toxin by 32.8% (P < .001). Decapping the vial further reduced the mean retained toxin to 0.42 units per vial (81.9% reduction, P < .001). A potentially clinically significant amount of botulinum toxin solution is retained following mixing and injections. Implementation of guidelines significantly decreased wasted botulinum toxin. III.

How do metals escape from magmas to form porphyry-type ore deposits?

Many precious and base metals (Cu, Au, Ag, Mo, W, Sn) in porphyry-type deposits are extracted from a granitic to granodioritic silicate melt and transported by magmatic-hydrothermal fluids to the site of ore deposition. Metals abundance increases from some ppb in the melt to % in ore bodies. Assuming a unique magmatic source for metals, it implies an exceptional combination of enrichment process acting over up to 4 orders of magnitude. Previous models of magma differentiation and hydrothermal circulations omitted to consider the role of metal segregation during magma chamber evolution. Models for the formation and evolution of intrusions have recently shifted from the so-called melting-storage-assimilation-homogenization (MASH) paradigm, basically steady state, to the mantle-melting-segregation-ascent-emplacement (m(M-SAE)) paradigm, dynamic and discontinuous in time. Successive magma injections of variable compositions progressively build the magma chamber. This is supported by field relations (e.g. cross-cutting dykes and stocks), textures (e.g. partially resorbed enclaves, or mineral fabrics), geochemistry (e.g. hybridization signatures), and age dating aswell as istopic studies. As melt crystallizes and forms a mush (>50% crystals), volatiles also exsolve forming a magmatic volatile phase (MVP) while melt motion slows down. Metals partition between the three phases: melt; crystals; and MVP. They generally prefer the MVP owing to more favorable partition coefficients. This is indicated by metal content in coeval melt and fluid inclusions with homogenization temperatures above 600 °C, or in volcanic fumaroles. Here, by simulating the physical interactions between the three phases we suggest a model of fluid sparging, during which metals segregate towards the MVP by diffusion and are further transported by advection as metal complexes. The model also provides estimates of metal enrichment. An undimensional Péclet number rules the competition between diffusion and advection, basically scaling with respect to the inverse of the product of melt viscosity (η) by metal diffusivity (D). The threshold value of the Péclet number between diffusion and advection is roughly 10−9. Fast diffusive metals (Au, Cu, Ag, W) readily diffuse from silicate melt and towards bubbles of the MVP. To escape the mush through tubular structures, the MVP must overcome a critical gas saturation level (about 20% vol.) usually reached after several magma injections. Advection then takes over and transports the metal-enriched MVP towards the top of the magma chamber. This leads to nearly coeval (1) separation between a high salinity-liquid phase and a low-salinity vapor phase, (2) fluid-rock interactions resulting in potassic, advanced argillic and phyllic alterations and (3) metal deposition. The metal enrichment scales as the ratio between partition coefficient (i.e. related to the gradient in chemical potential), diffusivity (i.e. related to the gradient of concentration), and melt viscosity (i.e. related to the gradient of momentum). The rates at which all such gradients relax determe metals enrichment, inducing chemical and physical instabilities, leading to a cyclic process. The whole cycle also encompasses the case of a partial, non-completed, full enrichment yielding to barren intrusions. A tentative model generalizes the sparging fluid model to other metal deposits linked to an intrusion. Such generalization should be interpreted as predicting metal enrichment by 3–4 orders of magnitude, rather than predicting an exact value.

Effect of Al 6061 Alloy Compositions on Mechanical Properties of the Automotive Steering Knuckle Made by Novel Casting Process

This study demonstrates the feasibility of a novel casting process called tailored additive casting (TAC). The TAC process involves injecting the melt several times to fabricate a single component, with a few seconds of holding between successive injections. Using TAC, we can successfully produce commercial-grade automotive steering knuckles with a tensile strength of 383 ± 3 MPa and an elongation percentage of 10.7 ± 1.1%, from Al 6061 alloys. To produce steering knuckles with sufficient mechanical strength, the composition of an Al 6061 alloy is optimized with the addition of Zr, Zn, and Cu as minor elements. These minor elements influence the thermal properties of the melt and alloy, such as their thermal stress, strain rate, shrinkage volume, and porosity. Optimal conditions for heat treatment before and after forging further improve the mechanical strength of the steering knuckles produced by TAC followed by forging.

Activation of adiponectin receptors has negative impact on muscle mass in C2C12 myotubes and fast-type mouse skeletal muscle.

This study investigated the effects of AdipoRon, which is an agonist for adiponectin receptor 1 (AdipoR1) and AdipoR2, on the protein content, myotube diameter, and number of nuclei per myotube of C2C12 cells and skeletal muscle mass in C57BL/6J mice. AdipoRon suppressed the protein content, myotube diameter, and number of nuclei per myotube of C2C12 cells of C2C12 myotubes in a dose-dependent manner. Adiponectin-associated decline of protein content, diameter, and number of nuclei per myotube in C2C12 myotubes was partially rescued by knockdown of AdipoR1 and/or AdipoR2. Phosphorylation level of AMPK showed a trend to be increased by AdipoRon. A significant increase in phosphorylation level of AMPK was observed at 20 μM AdipoRon. Knockdown of AdipoR1 and/or AdipoR2 rescued AdipoRon-associated decrease in protein content of C2C12 myotubes. AdipoRon-associated increase in phosphorylation level of AMPK in C2C12 myotubes was suppressed by knockdown of AdipoR1 and/or AdipoR2. Successive intravenous injections of AdipoRon into mice caused a decrease in the wet weight of plantaris muscle (PLA), but not in soleus muscle (SOL). Mean fiber cross-sectional area of PLA, but not of SOL, was significantly decreased by AdipoRon administration. On the one hand, the expression level of phosphorylated AMPK and ubiquitinated protein in SOL and PLA muscles was upregulated by AdipoRon administration. On the other hand, AdipoRon administration induced no changes in the expression level of puromycin-labeled proteins in both SOL and PLA muscles. Expression level of adiponectin in extensor digitorum longus (EDL) muscle was increased by aging, but not in SOL muscle. Aging had no effect on the expression level of AdipoR1 and AdipoR2 in both muscles. Phosphorylation level of AMPK in EDL was increased by aging, but not SOL muscle. Results from this study suggest that high level of circulating adiponectin may induce skeletal muscle atrophy, especially fast-type muscle.

Thermal model of successive dike injections and implications for the development of intraplate volcanoes

Temperatures in the root zones of volcanoes play a critical role in the development and persistence of shallow-level magmatic reservoirs in the crust. Here, we present a 1D thermal model allowing evaluation of the thermal impact of magma travelling in conduits to the surface on the root zone of a volcano. This thermal model has been developed to better understand the formation of a vertical intrusion located in the root zone of a dismembered Miocene volcano on Fuerteventura, Canary Archipelago. This intrusion, named PX1, constitutes an almost pure amalgamation of dikes of either clinopyroxenitic or gabbroic composition. Both types of dikes display cumulate textures and are interpreted as resulting from the protracted crystallization of a mafic magma. The formation of clinopyroxenitic, in contrast to gabbroic dikes, requires that the residual melt was extracted at high temperature (>1050°) to avoid plagioclase crystallization.Simulations of multiple dike injections show that the temperature in the root zone increases significantly with the addition of dikes, but the maximum temperature reached in the system depends on the duration of magma flow in the conduits and the time interval between dike injections (i.e., repose period). Active flow is the critical parameter that distinguishes instantaneous dike injection from a magmatic conduit. Without significant magma flow (>1 month), high-temperature conditions (>1000 °C) cannot be maintained in the pluton unless dikes are very thick and the repose period is extremely small. On the other hand, magma flow times of one to several months, combined with short time intervals between dike injections (<25 years), which are conditions comparable to those recorded for historical eruptions of oceanic island volcanoes, allow the production and preservation of temperatures above the plagioclase liquidus for significant durations, as required to generate clinopyroxenitic dikes such as those observed in the PX1 pluton.Persistent high temperature in the vicinity of magma conduits limits the differentiation of melts in transit to the surface, providing a potential explanation for why lavas of mafic to intermediate composition predominate in intraplate volcanoes such as Fuerteventura or Fogo Island (Cape Verde Archipelago). In extreme cases, when temperatures over 1000–1050 °C in the central part of the feeding zone are maintained for years, the remaining magma in the conduit does not solidify but is preserved in a mushy state. New pulses of magma would not be able to cross this zone but would rather amalgamate in the incipient magma reservoir. The present model differs from previous models of sill intrusion in that magmas do not need to pond at depth to create a reservoir but merely supply heat while travelling to the surface. Depending on the time interval between dike injections and the duration of magma flow through the crust, magma rising in vertical conduits could directly feed the volcanic edifice or could lead to the formation of magma reservoirs. This process may explain why some volcanoes erupt mafic or differentiated magmas during distinct periods of activity.

Ushuaia pluton: Magma diversification, emplacement and relation with regional tectonics in the southernmost Andes

The Ushuaia pluton (UP) and the Ushuaia Peninsula Andesites (UPA) are intrusive units of a Late Cretaceous rear-arc in the Southernmost Andes. We report new LA-ICP-MS zircon ages from ∼71 to 75 Ma for the UP, and of ∼84 Ma for the UPA, which allow to differentiate these two magmatic events; consistent with their distinct petrography and geochemistry. The UP is a composite, incrementally assembled pluton in upper crustal levels. Successive injections of magma batches define two main sections, each in turn constructed by several smaller pulses: an early ultramafic-mafic section consists mainly of hornblende pyroxenite, hornblendite and gabbro/diorite with reverse concentric zonation, and a later intermediate section built up mainly by monzodiorite. Mingling and layering between mafic and intermediate facies along the contact point to simultaneous emplacement at the end of one main pulse and the beginning of the other. Mineralogy and geochemistry suggest the rock sequence in the UP is cogenetic. In part it resulted by in-situ magmatic processes that included crystal-melt fractionation during injection of magma mushes, mingling, local melt segregation and mixing with crustal partial melts. The country rock is affected by penetrative ductile deformation and regional metamorphism developed during mid-Cretaceous Andean main orogenic phase. It also shows an overimposed pluton-margin parallel foliation and a post-kinematic contact metamorphic aureole. On the other hand, the UP has a concentric igneous foliation parallel to pluton margins interpreted as a primary magmatic feature. The above evidences, along with absence of subsolidus fabrics and metamorphism, indicate the pluton post-date peak regional metamorphism and ductile structures in the country rock. The new zircon ages constrain the top age of early Andean deformation, as well as the magmatic gap registered for the end of the Cretaceous, and confirm an emplacement during a recorded compressive regime that transmitted shortening to the foreland.

CTA 102 in exceptionally high state during 2016–2017

Blazars in outburst provide a unique opportunity to study their spectral behavior, correlated variations at different frequencies, and jet structure. An unprecedented flaring activity in FSRQ CTA 102, occuring from 2016 November to 2017 January, is used here for a detailed study to understand flaring mechanisms at short and long timescales, spectral behavior in different energy regimes, and to estimate sizes and location of the high-energy emitting region in the jet. Multiwavelength (MW) data for CTA 102 during its outburst period, were obtained from Fermi-LAT, Swift-XRT/UVOT, Steward Observatory, Mt Abu Infrared Observatory, and OVRO. These were analyzed to construct MW light curves, extract the spectral information, and to perform the correlated variability studies. Our study shows that CTA 102 attained the highest ever flux levels across the electromagnetic spectrum (EMS) while flaring and otherwise, with rapid and prolonged activities at all the frequencies. A number of short-term (three to eight days) and long-term (more than a month) variability events are noticed across the EMS. We infer a redder when brighter trend in faint state and a bluer when brighter trend during a few optical flares. Based on the flux doubling timescale, the size of γ-ray emitting region is estimated as ≈8.76 × 1015 cm, located at a distance of about 5.58 × 1016 cm from the central engine. CTA 102 was in extremely bright phase during 2016–2017, possibly due to, successive high energy particle injections into the jet, creating shocks traveling down the jet which lead to the overall flux enhancement across the EMS. Alternatively, a decreasing viewing angle could also lead to such flux enhancement. The study reveals correlated variations in all the energy bands, with lags within time bins, indicating co-spatial origin of the emissions. During the flaring event, a bluer-when-brighter color in the optical and harder when brighter trend in the X-ray and γ-ray spectra are noticed. During some flares softer γ-ray spectra are observed.

AB084. intracavernous administration of embryonic stem cell-derived exosome restores erectile function through penile neurovascular regeneration in the streptozotocin-induced diabetic mouse

BackgroundExosome contains a variety of protein, mRNA, and miRNA and is known to play an important role in intercellular communication as a bio-nanoparticle with a diameter of 40 to 100 nm. Recent studies have demonstrated the therapeutic potential of exosome in a variety of animal models for cardiovascular diseases and neuropathies. The aim of this study was to investigate effectiveness of embryonic stem cell (ESC)-derived exosome in restoring erectile function in diabetic mice.MethodsDiabetes was induced by intraperitoneal injection of streptozotocin into 8-week-old C57BL/6 male mice. At 8 weeks after the induction of diabetes, the animals were distributed into 3 groups: control nondiabetic mice and diabetic mice receiving two successive intracavernous injections of phosphate buffered saline (PBS) (days −3 and 0; 20 µL) or ESC-derived exosome (days −3 and 0; 1 µg in 20 µL of PBS). Two weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested and stained with antibodies to PECAM-1, smooth muscle α-actin, NG2, and βIII tubulin. We also determined angiogenic potential of ESC-derived exosome in an ex vivo aortic ring assay and in primary cultured mouse cavernous endothelial cell (MCEC) and pericyte (MCP) mono-culture or co-culture system in vitro.ResultsIntracavernous injections of ESC-derived exosome significantly improved erectile function in diabetic mice, which reached up to 90% of control values. ESC-derived exosome induced significant restoration of cavernous contents of endothelial cells, smooth muscle cells, pericytes, and neuronal cells in diabetic condition. Moreover, ESC-derived exosome promoted microvascular sprouting from aortic ring and accelerated tube formation in primary cultured MCEC and MCP mono-culture or co-culture system in vitro.ConclusionsESC-derived exosome successfully restored erectile function through enhanced cavernous angiogenesis and neural regeneration in diabetic mice. Further studies are needed to clarify mechanism by which ESC-derived exosome induces neurovascular repair.

Projection of Long-Term Visual Acuity Outcomes Based on Initial Treatment Response in Neovascular Age-Related Macular Degeneration

To explore various methods for assessing the early response to vascular endothelial growth factor (VEGF) inhibitors for neovascular age-related macular degeneration and investigate their association with 3-year visual acuity (VA) outcomes. Database study, prospectively designed. Treatment-naïve eyes in the Fight Retinal Blindness! registry that commenced anti-VEGF therapy between January 1, 2007, and March 1, 2014, that received 3 anti-VEGF injections within the first 3 months. The early response was defined as occurring up until the fourth injection. Various early response metrics were explored: (1) achieving good VA (≥70 letters; Snellen equivalent, 20/40), (2) absolute change in VA from baseline, (3) time to first grading of the choroidal neovascular lesion as inactive, and (4) maximum rate of VA change between successive injections. Proportion of eyes achieving ≥70 letters 3 years. This study included 2051 treatment-naïve eyes from 1828 patients. Achieving good vision at 3 years was associated significantly with (1) having good vision by the fourth injection (VA ≥70 vs. VA <70 letters: odds ratio [OR], 9.8; 95% confidence interval [CI], 6.5-14.7), (2) small (1-5 letters) or large (>5 letters) early VA gains (vs. early VA loss: OR, 1.8; 95% CI, 1.2-2.6; P= 0.002; and OR, 1.8; 95% CI, 1.3-2.5; P < 0.001), (3) fewer injections until first grading of lesion inactivity (≤3 vs. >3 injections: OR, 1.6; 95% CI, 1.2-2.1; P < 0.001), (4) gradual change (between -4 and 4 letters) or rapid gains (≥5 letters) between successive injections (vs. rapid loss: OR, 1.7; 95% CI, 1.1-2.6; P= 0.015; and OR, 1.6; 95% CI, 1.1-2.3; P= 0.018). Eyes that achieved small or large early gains had similar vision at 3 years (65.0 and 64.7 letters, respectively) and had better vision than eyes with early VA loss (57.2 letters). Attainment of good vision by the fourth injection was associated strongly with 3-year visual outcomes, whereas other early response parameters showed a moderate association. The early response during theinitial 3 monthly injections can be a useful guide for subsequent treatment decisions.

Effect of two-stage injection dwell angle on engine combustion and performance characteristics of a common-rail diesel engine fueled with coconut oil methyl esters-diesel fuel blends

Diesel engine is widely used as prime mover due to its high thermal efficiency. Usage of renewable biodiesel in diesel engine is also widely studied due to its potential in reducing emission and as a replacement of conventional diesel. Biodiesel performance could be improved by blending it with petroleum diesel besides introducing appropriate injection strategies. In this experiment, the effect of percentage of biodiesel blends and injection strategies such as variations in start of injection (SOI) timing and dwell angle on diesel engine performance were investigated. The test engine used is four-stroke turbocharged direct injection diesel engine. Results show that exhaust emissions, engine performance and combustion characteristics are substantially affected by biodiesel blending ratio and SOI timing but slightly influenced by two-stage injection dwell angle. Biodiesel blends percentage could be raised to improve NOx and smoke emissions. Even though SOI performed at a later timing could reduce NOx emission, smoke emission increased. Dwell angle between two successive injections could be prolonged to lower the effect of the increase in smoke emission. It could also be inferred that by setting a proper SOI timing and dwell angle under two-stage injection scheme when suitable biodiesel blend is used, the engine performance could be optimized.

Rapid 18F-FDG Uptake in Brain of Awake, Behaving Rat and Anesthetized Chicken has Implications for Behavioral PET Studies in Species With High Metabolisms.

Brain-behavior studies using 18F-FDG PET aim to reveal brain regions that become active during behavior. In standard protocols, 18F-FDG is injected, the behavior is executed during 30–60 min of tracer uptake, and then the animal is anesthetized and scanned. Hence, the uptake of 18F-FDG is not itself observed and could, in fact, be complete in very little time. This has implications for behavioral studies because uptake is assumed to reflect concurrent behavior. Here, we utilized a new, miniature PET scanner termed RatCAP to measure uptake simultaneously with behavior. We employed a novel injection protocol in which we administered 18F-FDG (i.v.) four times over two 2 h to allow for repeated measurements and the correlation of changes in uptake and behavioral activity. Furthermore, using standard PET methods, we explored the effects of injection route on uptake time in chickens, a model for avians, for which PET studies are just beginning. We found that in the awake, behaving rat most of the 18F-FDG uptake occurred within minutes and overlapped to a large extent with 18F-FDG data taken from longer uptake periods. By contrast, behavior which occurred within minutes of the 18F-FDG infusion differed markedly from the behavior that occurred during later uptake periods. Accordingly, we found that changes in 18F-FDG uptake in the striatum, motor cortex and cerebellum relative to different reference regions significantly predicted changes in behavioral activity during the scan, if the time bins used for correlation were near the injection times of 18F-FDG. However, when morphine was also injected during the scan, which completely abolished behavioral activity for over 50 min, a large proportion of the variance in behavioral activity was also explained by the uptake data from the entire scan. In anesthetized chickens, tracer uptake was complete in about 80 min with s.c. injection, but 8 min with i.v. injection. In conclusion, uptake time needs to be taken into account to more accurately correlate PET and behavioral data in mammals and avians. Additionally, RatCAP together with multiple, successive injections of 18F-FDG may be useful to explore changes in uptake over time in relation to changes in behavior.

Geochemistry of basaltic flows from a basalt ring structure of the Serra Geral formation at Água Vermelha dam, Triângulo Mineiro, Brazil: implications for the magmatic evolution of the Paraná-Etendeka Province

The Serra Geral Formation belongs to the Parana-Etendeka Magmatic Province (PEMP) and its geochemical and petrographic characteristics are not homogeneous. Many studies segment this group into six basaltic and two rhyolitic magma-types. It is believed that its extrusion occurred through crustal fissures in the Cretaceous, but some authors described the presence of conduits in the shape of basaltic ring structures (BRS) in the Agua Vermelha region in the North of the province. The BRS rocks, based on textures and structures, were divided into four groups—central flow, basal flow, main ring dyke and lava flow—with a very similar petrography, composed of plagioclase (labradorite-bytownite), clinopyroxene (augite) and oxide (titanomagnetite) with intergranular texture. The whole-rock analyses of the basal and lava flows allow classifying them as tholeiitic basalts of the Paranapanema magma-type. Geochemical data interpretation suggests an enriched magma source, with low degree of partial melting, high depth of melt generation and without significant crustal contamination. The BRS experienced fractional crystallization on shallow magma chamber, influenced by successive new injections from different parental magmas which would be responsible for the pulses of effusion and explosion. Thus, the singularities of the BRS of Agua Vermelha are important to comprehend the evolution of the PEMP.

Two plutonic complexes of the Sanandaj-Sirjan magmatic-metamorphic belt record Jurassic to Early Cretaceous subduction of an old Neotethys beneath the Iran microplate

The Neotethyan tectonics of the Zagros orogenic belt, SW Iran remains still hotly debated in comparing with its western counterparts. One major issue concerns the timing and nature of the Sanandaj-Sirjan magmatic-metamorphic belt (SSMB), which is made predominantly of metamorphic rocks and Jurassic to Early Cretaceous large plutonic complexes. The Alvand and Qory are two largest plutonic complexes locating in north-central and southern segments, respectively, of the SSMB. Careful LA-ICP-MS U/Pb analyses of the magmatic zircons from the Alvand plutonic complex reveal a smooth spectra, along which the concordant age increase gradually from 120 to 190 Ma; while that of Qory is step-like consisting of two stages, a Jurassic and a late Early Cretaceous ones, respectively. New geochemical data, combined with zircon Lu/Hf results suggest that (1) the Alvand granitoids mostly resulted from a long-lived, successive injection of juvenile-crust-sourced magma batches without obvious fractionation crystallization (FC); but (2) the two stages granitoids of the Qory complex both generated by FC of juvenile-crust-sourced magmas; and (3) the gabbros of the Alvand complex are geochemically of E-MORB-affinity while those of the Qory complex are typical continental arc mafic rocks. Previously published petrological and 40Ar/39Ar data have identified a broken, Jurassic to Early Cretaceous high-pressure metamorphic belt to the southwest of the SSMB, which likely represents the closed, southeastern equivalent of the northern Neotethyan Ocean, north of the Taurides-Anatolia-Armenia block. Thus, the SSMB in Iran, the Kapan belt in Caucasus, and the Serbo-Macedonian belt in northern Turkey form a huge Jurassic to Early Cretaceous continental margin arc system recording northeastwards subduction of the older Northern Neotethyan Ocean beneath Eurasia. The Albian-Cenomanian ophiolites such as Koy, Kermanshah, and Neyriz in Iran represent the eastern counterpart of the younger Southern Neotethyan Ocean, south of the Taurides-Anatolia-Armenia block. During the subduction of the Old Neotethys, an intraplate transform fault likely opened and generated a slab-window beneath the Alvand region, which provided a constant energy source to steadily heat the low crust. This model satisfactorily interprets the unusual geochronological framework and geochemistry of the Alvand complex.

Successive injection in microstructured-capillary electrophoresis for rapid pairwise comparisons. Application to questioned documents

Herein we propose a successive double injection in microstructured-capillary electrophoresis for a fast, simple and easy-to-interpret comparison of samples. First, injection was optimized through three capillaries (conventional capillary of 28.5μm id, microstructured capillary (MSC) of 6 holes of 32.8μm each, and MSC of 61 holes of 8.9μm each). The 6-hole MSC was selected, as it provided reproducible results, and higher volume capacity, which allowed larger injection volumes. Then, the method was applied to the analysis of different types of inks present in questioned documents. After the criterion to establish a MATCH or No match between two successive samples, a blind test with 20 pairwise comparisons between questioned signatures was finally made to demonstrate the potential of the method. The method proved to be useful in pairwise comparison analyses, as it: i) provides a fast and practical analysis; ii) maintains the same CE conditions for both samples; iii) uses simple data treatment which puts on easy interpretation on the results, interesting in court.

Optimization of the Electrochemically Generated Luminescence of Polyfluorene Films

Electrochemically generated chemiluminescence (ECL) from solid-state poly(9,9′-octylfluorene) films was obtained by the successive electrochemical injection of polarons with opposite sign (annihilation ECL) in double potential steps. The processes involved in the recombination of polarons, the quenching of the electrochemically generated excitons, and the emission stability have been also analyzed. A systematic study at various electrochemical potentials has been carried out to determine optimal conditions to obtain a maximum ECL intensity, particularly with potentials of 0.4 V beyond the doping onsets (for both p- and n-doping). Results show that while the ECL emission is slightly affected by the potential of the emission, it is strongly dependent on the charging potential. Under large charging potential, the electrochemically generated excitons formed in the emission step get quenched by an excess of polarons and bipolarons that are detrimental to ECL. The maximum emission is obtained when the applied p...

Experimental Investigation of Low-Salinity Water Flooding in a Low-Permeability Oil Reservoir

Low-salinity water (LSW) flooding has become a quite simple, effective, and economically feasible enhanced oil recovery (EOR) technology under the background of low oil price. The B425 block with a low permeability in Shengli oilfield, China, has achieved an excellent LSW flooding performance, but the main EOR mechanisms in the block are still not clear. Therefore, in order to investigate the LSW flooding mechanisms in the B425 block, a set of core-flooding experiments were conducted. The water contact angle on core slice and the zeta potential of rock particle were also measured. Then the main EOR mechanisms of LSW flooding in the block were discussed. The experimental results show that the LSW injection can indeed enhance the oil recovery in the low-permeability oil reservoir. Compared with the direct high salinity water (HSW) injection, direct LSW injection and HSW–MSW (medium salinity water)–LSW successive injection can increase the oil recovery factor by 10% and 29.52%, respectively (when the core pe...