Myoglobin-biomimetic electroactive materials made by surface molecular imprinting on silica beads and their use as ionophores in polymeric membranes for potentiometric transduction

Myoglobin (Mb) is among the cardiac biomarkers playing a major role in urgent diagnosis of cardiovascular diseases. Its monitoring in point-of-care is therefore fundamental. Pursuing this goal, a novel biomimetic ionophore for the potentiometric transduction of Mb is presented. It was synthesized by surface molecular imprinting (SMI) with the purpose of developing highly efficient sensor layers for near-stereochemical recognition of Mb. The template (Mb) was imprinted on a silane surface that was covalently attached to silica beads by means of self-assembled monolayers. First the silica was modified with an external layer of aldehyde groups. Then, Mb was attached by reaction with its amine groups (on the external surface) and subsequent formation of imine bonds. The vacant places surrounding Mb were filled by polymerization of the silane monomers 3-aminopropyltrimethoxysilane (APTMS) and propyltrimethoxysilane (PTMS). Finally, the template was removed by imine cleavage after treatment with oxalic acid. The results materials were finely dispersed in plasticized PVC selective membranes and used as ionophores in potentiometric transduction. The best analytical features were found in HEPES buffer of pH 4. Under this condition, the limits of detection were of 1.3 × 10(-6)mol/L for a linear response after 8.0 × 10(-7) mol/L with an anionic slope of -65.9 mV/decade. The imprinting effect was tested by preparing non-imprinted (NI) particles and employing these materials as ionophores. The resulting membranes showed no ability to detect Mb. Good selectivity was observed towards creatinine, sacarose, fructose, galactose, sodium glutamate, and alanine. The analytical application was conducted successfully and showed accurate and precise results.     

Screening Perennial Warm-Season Bioenergy Crops as an Alternative for Phytoremediation of Excess Soil P

A recent alternative strategy to reduce environmental problems associated with P transport from agricultural soils is the use of bioenergy crops to remediate excess soil P. In addition to the positive impacts associated with P mitigation, harvested biomass used as a renewable energy source can also offset the cost associated with plant-based P remediation strategies. The objective of this study was to identify potential crop species that can be used for remediation of soil P and as a cellulosic feedstock for production of renewable energy in South Florida. Fifteen crop entries were investigated for their potential to remove P from a P-enriched soil. Dry matter (DM) yield varied among crop species with greatest yield observed for elephantgrass (Pennisetum purpureum Schum.) and sugarcane (Saccharum spp.) (43 and 39 Mg?ha^?1 year^?1, respectively). Similarly, greater P removal rates were observed for elephantgrass (up to 126 kg?P?ha^?1 year^?1 in 2008) followed by sugarcane (62 kg?P?ha^?1 year^?1 in 2008). Although there was no effect (P?=?0.45) of crop species on P reduction in the soil, soil P concentrations decreased linearly during the 3-year study. Because of its relatively greater DM yield and P removal rates, elephantgrass was shown to be a good candidate for remediation of excess soil P in South Florida Spodosols.     

Malvidin-3-glucoside protects endothelial cells up-regulating endothelial NO synthase and inhibiting peroxynitrite-induced NF-kB activation

Anthocyanins are the most abundant flavonoid constituents of fruits and vegetables and several epidemiological studies suggest that the consumption of these compounds protect against several diseases, including vascular disorders. Previously, we have reported that anthocyanins are able to counteract peroxynitrite-induced apoptotic effects in endothelial cells through inhibition of several crucial signaling cascades, upstream and downstream of mitochondria. Following these studies, here we investigated possible effects of malvidin-3-glucoside, one of the main dietary anthocyanins, on NO bioavailability and on peroxynitrite-induced NF-kB activation in the same cell model.Our results show that treatment of bovine arterial endothelial cells with malvidin-3-glucoside up-regulated eNOS mRNA, leading to the enhancement of eNOS activity and NO production, an effect even greater when cells were further stimulated with peroxynitrite. On the other hand, in these activated endothelial cells, malvidin-3-glucoside suppressed pro-inflammatory mediators, namely iNOS expression/NO biosynthesis, COX-2 expression and IL-6 production, through inhibition of NF-kB activation.These findings suggest a potential role of malvidin-3-glucoside in NO balance and in inhibition of pro-inflammatory signaling pathways, supporting its benefits in cardiovascular health and pointing to anthocyanins as a promising tool for development of functional foods and nutraceuticals to improve endothelial function.     

The effects of water availability on root growth and morphology in an Amazon rainforest

This study examined how root growth and morphology were affected by variation in soil moisture at four Amazon rainforest sites with contrasting vegetation and soil types. Mean annual site root mass, length and surface area growth ranged between 3–7 t ha^?1, 2–4 km m^?2 and 8–12 m² m^?2 respectively. Mean site specific root length and surface area varied between 8–10 km kg^?1 and 24–34 m² kg^?1. Growth of root mass, length and surface area was lower when soil water was depleted (P?<?0.001) while specific root length and surface area showed the opposite pattern (P?<?0.001). These results indicate that changes in root length and surface area per unit mass, and pulses in root growth to exploit transient periods of high soil water availability may be important means for trees in this ecosystem to increase nutrient and water uptake under seasonal and longer-term drought conditions.     

Facultative secondary lecithotrophy in the megalopa of the shrimp Lysmata seticaudata (Risso, 1816) (Decapoda: Hippolytidae) under laboratory conditions

Certain decapod crustaceans can catabolize internal reservesto undergo partial or full larval development. This featureis termed secondary lecithotrophy, if energy used results fromplankton derived organic matter accumulated by earlier larvalstages. The present work reports the ability of Lysmata seticaudatamegalopa to molt to the first juvenile stage in the absenceof food. Unlike previous records of secondary lecithotrophydisplayed by non-feeding last larval stages of hermit crabsand spiny lobsters, the megalopa of L. seticaudata retains itsfeeding capacity. This is the first time such a feature hasbeen reported in decapods, and the term facultative secondarylecithotrophy is proposed. The build up of energy reserves continuesduring the last zoeal stage of L. seticaudata, with starvedzoea IX failing to molt to megalopa. Energy reserves that enablestarved megalopa to molt to juvenile seem to be partially depleted,with starved juveniles produced either from starved or fed megalopaebeing unable to molt to the next juvenile stage. The longerresistance of starved juveniles produced from fed megalopae(nine days), compared to that of starved juveniles producedfrom starved megalopae (five days), indicates that some energyreserves may pass to the juvenile, not being totally depletedat metamorphosis.     

Myoelectric activation and kinetics of different plyometric push-up exercises

The kinetic and myoelectric differences between 3 types of plyometric push-ups were investigated. Twenty-seven healthy, physically active men served as subjects and completed both familiarization and testing sessions. During these sessions, subjects performed 2 series of 3 plyometric push-up variations in a counterbalanced order according to the following techniques: Countermovement push-ups (CPUs) were push-ups performed with the maximum speed of movement; jump push-ups (JPUs) were similar to clapping push-ups; and fall push-ups (FPUs) required kneeling subjects to drop and then attempt to return to their initial position. Vertical ground reaction forces were determined by using a force plate. Myoelectric activity was recorded by means of electromyography. Impact force and impact rate of force development were significantly (p < 0.05) higher for FPUs than for JPUs. The maximum rate of force development was higher for CPUs (p < 0.05) than for JPUs, and the maximum force was higher for the CPUs than for the FPUs (p < 0.05). There were differences among exercises for the mean muscle activation of the pectoralis major (PM; p < 0.001), triceps brachii (p < 0.001), external oblique (p < 0.005) and anterior deltoid (p < 0.001), and in the maximum muscle activation of the PM (p < 0.001). Plyometric push-ups with countermovement achieved a higher maximum force and rate of force and did not cause impact forces. Thus, this type of push-up exercise may be regarded as the best for improving explosive force. The FPU exercise achieved higher levels of muscular activation in the agonist and synergist muscle groups, and greater impact forces and impact force development rates.     

Dietary anthocyanins protect endothelial cells against peroxynitrite-induced mitochondrial apoptosis pathway and Bax nuclear translocation: an in vitro approach

Anthocyanins have received increasing attention because of their relatively high intake in humans and wide range of potential health-promoting effects, including anti-atherogenic properties. Evidences support their vascular protective effects but the involved molecular mechanisms have not been well clarified. The endothelium seems to have a central role in atherogenesis and apoptosis is emerging as a crucial event in this disease progression. Following our previous work on the biochemical pathways underlying peroxynitrite-triggered apoptosis in endothelial cells, here we investigated potential mechanisms responsible for the cytoprotective actions of three common anthocyanins, namely cyanidin- delphinidin- and pelargonidin-3-glucoside, against this process. Beyond their antioxidant properties, all these flavonoids, possessing either catecholic or monophenolic structures, were able to counteract peroxynitrite-induced apoptotic effects in endothelial cells through the inhibition of several crucial signaling cascades. Actually, pre-incubation of cells with 25 μM anthocyanins prevented them from peroxynitrite-mediated apoptosis, which was evaluated by the loss of mitochondrial membrane potential, caspases-9 and-3 activation, the increase in cytoplasmatic Bax levels and the inactivation of the PI3 K/Akt pathway. Moreover, they counteracted the translocation of Bax into the nucleus, as observed by immunocytochemistry and immunoblot, an event shown for the first time in endothelial cells apoptotic process. Such cellular actions could not be inferred from their in vitro antioxidant properties. These results suggest a potential role of dietary anthocyanins in the modulation of several apoptotic signaling pathways triggered by peroxynitrite in endothelial cells, supporting mechanistically their health benefits in the context of prevention of endothelial dysfunction and, ultimately, of atherosclerosis.     

Proteomic analysis of an immortalized mouse pancreatic stellate cell line identifies differentially-expressed proteins in activated vs nonproliferating cell states

Pancreatic stellate cells (PaSC) are mediators in chronic pancreatitis and pancreatic cancer pathogenesis. Proteins regulating the biomolecular pathways involved in the conversion of activated to quiescent PaSC may have a significant influence in the development of chronic pancreatitis. We aim to compare differentially expressed proteins from an immortalized cell line of mouse PaSC in the activated and serum-starved cell states using mass spectrometry-based proteomics. PaSC cultured in media supplemented with fetal bovine serum (FBS) proliferate in the activated state, while serum starvation promotes the cellular transition to a "pseudo-quiescent" state. Using these two cell states, we performed a comparative mass spectrometry (GeLC-MS/MS) proteomic analysis. We identified over 2000 nonredundant proteins in PaSC. Qualitative and label-free quantitative analysis revealed several hundred proteins that were differentially abundant between the cell states. Proteins that were more abundant in activated PaSC included cytoskeletal proteins and ribosomal proteins, while those more abundant in pseudoquiescent PaSC included proteins involved in protein degradation-related pathways (lysosome, ubiquitin-mediated proteolysis, and the proteasome). Investigation of the role of PaSC in the pathogenesis of chronic pancreatitis using the mass spectrometry-based proteomics strategy described herein will lead to further insights into the molecular mechanisms associated with the disease.