Wettability Inversion of Aluminum-Magnesium Alloy Surfaces

The paper presents the experimental results on the use of low-temperature heating to reduce time of wetting inversion (from superhydrophilicity to hydrophobicity) of aluminum-magnesium alloy surfaces textured by laser radiation. Stable growth of the contact angle to 137.3-144.2° after heating surfaces (wettability properties deteriorate) was recorded. Wetting inversion from superhydrophilicity to hydrophobicity occurs in 2-3 hours of low-temperature heating of textured samples. The wettability inversion time depends on the type of texture. A significant increase in carbon content of elemental composition of the near-surface layer of samples after their low-temperature heating was registered

The systemic angiogenic response during bone healing

Introduction: Angiogenesis is known to be a critical and closely regulated step during bone formation and fracture healing driven by a complex interaction of various cytokines. Delays in bone healing or even nonunion might therefore be associated with altered concentrations of specific angiogenic factors. These alterations might in turn be reflected by changes in serum concentrations. Method: To determine physiological time courses of angiogenic cytokines during fracture healing as well as possible changes associated with failed consolidation, we prospectively collected serum samples from patients who had sustained surgical treatment for a long bone fracture. Fifteen patients without fracture healing 4months after surgery (nonunion group) were matched to a collective of 15 patients with successful healing (union group). Serum concentrations of angiogenin (ANG), angiopoietin 2 (Ang-2), basic fibroblast growth factor (bFGF), platelet derived growth factor AB (PDGF-AB), pleiotrophin (PTN) and vascular endothelial growth factor (VEGF) were measured using enzyme linked immunosorbent assays over a period of 24weeks. Results: Compared to reference values of healthy uninjured controls serum concentrations of VEGF, bFGF and PDGF were increased in both groups. Peak concentrations of these cytokines were reached during early fracture healing. Serum concentrations of bFGF and PDGF-AB were significantly higher in the union group at 2 and 4weeks after the injury when compared to the nonunion group. Serum concentrations of ANG and Ang-2 declined steadily from the first measurement in normal healing fractures, while no significant changes over time could be detected for serum concentrations of these factures in nonunion patients. PTN serum levels increased asymptotically over the entire investigation in timely fracture healing while no such increase could be detected during delayed healing. Conclusion: We conclude that fracture healing in human subjects is accompanied by distinct changes in systemic levels of specific angiogenic factors. Significant alterations of these physiologic changes in patients developing a fracture nonunion over time could be detected as early as 2 (bFGF) and 4weeks (PDGF-AB) after initial trauma surger

Funding Era Free Speech Theory: Applying Traditional Speech Protection to the Regulation of Anonymous Cyberspace

Abstract Background Blunt trauma is the most frequent mechanism of injury in multiple trauma, commonly resulting from road traffic collisions or falls. Two of the most frequent injuries in patients with multiple trauma are chest trauma and extremity fracture. Several trauma mouse models combine chest trauma and head injury, but no trauma mouse model to date includes the combination of long bone fractures and chest trauma. Outcome is essentially determined by the combination of these injuries. In this study, we attempted to establish a reproducible novel multiple trauma model in mice that combines blunt trauma, major injuries and simple practicability. Methods Ninety-six male C57BL/6 N mice (n = 8/group) were subjected to trauma for isolated femur fracture and a combination of femur fracture and chest injury. Serum samples of mice were obtained by heart puncture at defined time points of 0 h (hour), 6 h, 12 h, 24 h, 3 d (days), and 7 d. Results A tendency toward reduced weight and temperature was observed at 24 h after chest trauma and femur fracture. Blood analyses revealed a decrease in hemoglobin during the first 24 h after trauma. Some animals were killed by heart puncture immediately after chest contusion; these animals showed the most severe lung contusion and hemorrhage. The extent of structural lung injury varied in different mice but was evident in all animals. Representative H&E-stained (Haematoxylin and Eosin-stained) paraffin lung sections of mice with multiple trauma revealed hemorrhage and an inflammatory immune response. Plasma samples of mice with chest trauma and femur fracture showed an up-regulation of IL-1β (Interleukin-1β), IL-6, IL-10, IL-12p70 and TNF-α (Tumor necrosis factor- α) compared with the control group. Mice with femur fracture and chest trauma showed a significant up-regulation of IL-6 compared to group with isolated femur fracture. Conclusions The multiple trauma mouse model comprising chest trauma and femur fracture enables many analogies to clinical cases of multiple trauma in humans and demonstrates associated characteristic clinical and pathophysiological changes. This model is easy to perform, is economical and can be used for further research examining specific immunological questions

Reactive oxygen species induce expression of vascular endothelial growth factor in chondrocytes and human articular cartilage explants

Vascular endothelial growth factor (VEGF) promotes cartilage-degrading pathways, and there is evidence for the involvement of reactive oxygen species (ROS) in cartilage degeneration. However, a relationship between ROS and VEGF has not been reported. Here, we investigate whether the expression of VEGF is modulated by ROS. Aspirates of synovial fluid from patients with osteoarthritis (OA) were examined for intra-articular VEGF using ELISA. Immortalized C28/I2 chondrocytes and human knee cartilage explants were exposed to phorbol myristate acetate (PMA; 0–20 μg/ml), which is a ROS inducer, or 3-morpholino-sydnonimine hydrochloride (SIN-1; 0–20 μM), which is a ROS donor. The levels of VEGF protein and nitric oxide (NO) production were determined in the medium supernatant, using ELISA and Griess reagent, respectively. Gene expression of VEGF-121 and VEGF-165 was determined by splice variant RT-PCR. Expression of VEGF and VEGF receptors (VEGFR-1 and VEGFR-2) was quantified by real-time RT-PCR. Synovial fluid from OA patients revealed markedly elevated levels of VEGF. Common RT-PCR revealed that the splice variants were present in both immortalized chondrocytes and cartilage discs. In immortalized chondrocytes, stimulation with PMA or SIN-1 caused increases in the levels of VEGF, VEGFR-1 and VEGFR-2 mRNA expression. Cartilage explants produced similar results, but VEGFR-1 was only detectable after stimulation with SIN-1. Stimulation with PMA or SIN-1 resulted in a dose-dependent upregulation of the VEGF protein (as determined using ELISA) and an increase in the level of NO in the medium. Our findings indicate ROS-mediated induction of VEGF and VEGF receptors in chondrocytes and cartilage explants. These results demonstrate a relationship between ROS and VEGF as multiplex mediators in articular cartilage degeneration

Destruction of molecular compounds in gaseous and liquid medium in microwave discharge plasma

The paper presents the results of experimental studies of molecular destruction in gaseous and liquid medium using microwave discharge plasma at atmospheric pressure. As the gas medium hydrocarbon gas is used, the liquid medium were aqueous solutions of methylene blue and more complex organic compound in the form of humic substances. As a result of the destruction of hydrocarbon gas molecules in microwave discharge plasma new products such as hydrogen, ethylene, acetylene and carbon nanostructured material have been formed. In experiments on destruction of molecular compounds in aqueous organic solutions we used air, nitrogen and argon for plasma gases. It is shown that the process of molecular destruction in aqueous organic solutions in the microwave discharge plasma is based on oxidation-reduction reactions. It is found that the maximum efficiency of removal of organic compounds from the solution occurs when using air as the plasma gas

Properties of nickel-phosphorous coatings codeposited by the electroless and electrochemical plating process

At present, despite numerous studies and practical application, the process of chemical nickel plating remains imperfect. The low nickel deposition rate, the high consumption of the solution components, and the complexity of the deposition process do not contribute to the widespread use of chemical nickel plating. At the same time, chemically deposited coatings are significantly different from the electrochemical: they possess valuable properties. In the paper, the intensification method of chemical nickel plating considered through the use of the co-deposition process with chemical and electrochemical methods. The co-deposition was carried out in an acidic electrolyte solution on an aluminum plate with the stationary potential shift from - 0.01 to - 0.25 V with the use of three electrode system. The presented technique of intensification due to the combination of nickel deposition processes by chemical and electrochemical methods is able to increase the deposition rate of the coatings, and also allows influencing their composition and mechanical properties

Ontogenetic conflicts and rank reversals in two Mediterranean oak species: Implications for coexistence

In heterogeneous environments, species segregate spatially in response to selective abiotic and biotic filters occurring throughout plant ontogeny. Ontogenetic conflicts in recruitment may lead to spatially discordant patterns of regeneration among microhabitats with different plant cover. In addition, species differing in seed size may be subjected to opposing ecological and evolutionary pressures throughout the life cycle of the plant. We used a multi-stage demographic approach aimed at characterizing the main stage-specific probabilities of recruitment (seed survival, seed germination, seedling emergence and survival during the first 3years of life) in two Mediterranean oak species coexisting at southern Spain. We calibrated linear and nonlinear likelihood models for each of these consecutive life history stages and calculated overall probabilities of recruitment along a wide range of plant cover and seed size variation. Seed predation and seedling mortality over the dry season were the most limiting processes for the two studied oak species. However, species ranking diverged substantially through the life history stages considered in this study due to different ontogenetic trends among species. At the intraspecific level, recruitment-driving processes during the seed and the seedling stages showed opposing tendencies along the explored range of plant cover and seed size. Thus, small-sized acorns and open areas were favoured for the seed stage, whereas large acorns and dense microhabitats did for the seedling stage. The existence of opposing selective pressures on seed mass and their differential influence on the two studied oak species determined the occurrence of species-specific optimal seed sizes (small acorns for Quercus canariensis vs. acorns of large or intermediate size for Quercus suber). The spatial patterns predicted by our overall-recruitment models provided some evidence of regeneration niche partitioning in the two coexisting oak species, supporting their current distribution patterns as saplings and adults at the study area. Synthesis. We conclude that within- and among-species differences through plant ontogeny, arising from species differential response to microhabitat heterogeneity and seed size variation, could be of great importance for oak species niche segregation, driving stand dynamics and spatial pattern distribution along the landscape. The information provided by this study could be also applied to optimize management and restoration programmes since it has enabled us to identify the most favourable conditions and traits for recruitment in oak species that exhibit serious constraints for natural regeneration.This study was supported by a JAE-doc—contract to IMPR, by the Spanish MEC projects Heteromed (REN2002-4041-C02-02), Dinamed (CGL2005-5830-C03-01) and Interbos (CGL2008-04503-C03-01), the Andalusian PE2010-RNM-5782 project, and by European FEDER funds. This research is part of the Globimed (http:// www.globimed.net) network in forest ecology.Peer Reviewe

The formyl peptide receptor like-1 and scavenger receptor MARCO are involved in glial cell activation in bacterial meningitis

<p>Abstract</p> <p>Background</p> <p>Recent studies have suggested that the scavenger receptor MARCO (macrophage receptor with collagenous structure) mediates activation of the immune response in bacterial infection of the central nervous system (CNS). The chemotactic G-protein-coupled receptor (GPCR) formyl-peptide-receptor like-1 (FPRL1) plays an essential role in the inflammatory responses of host defence mechanisms and neurodegenerative disorders such as Alzheimer's disease (AD). Expression of the antimicrobial peptide cathelicidin CRAMP/LL-37 is up-regulated in bacterial meningitis, but the mechanisms underlying CRAMP expression are far from clear.</p> <p>Methods</p> <p>Using a rat meningitis model, we investigated the influence of MARCO and FPRL1 on rCRAMP (rat cathelin-related antimicrobial peptide) expression after infection with bacterial supernatants of <it>Streptococcus pneumoniae </it>(SP) and <it>Neisseria meningitides </it>(NM). Expression of FPRL1 and MARCO was analyzed by immunofluorescence and real-time RT-PCR in a rat meningitis model. Furthermore, we examined the receptor involvement by real-time RT-PCR, extracellular-signal regulated kinases 1/2 (ERK1/2) phosphorylation and cAMP level measurement in glial cells (astrocytes and microglia) and transfected HEK293 cells using receptor deactivation by antagonists. Receptors were inhibited by small interference RNA and the consequences in NM- and SP-induced Camp (rCRAMP gene) expression and signal transduction were determined.</p> <p>Results</p> <p>We show an NM-induced increase of MARCO expression by immunofluorescence and real-time RT-PCR in glial and meningeal cells. Receptor deactivation by antagonists and small interfering RNA (siRNA) verified the importance of FPRL1 and MARCO for NM- and SP-induced Camp and interleukin-1β expression in glial cells. Furthermore, we demonstrated a functional interaction between FPRL1 and MARCO in NM-induced signalling by real-time RT-PCR, ERK1/2 phosphorylation and cAMP level measurement and show differences between NM- or SP-induced signal transduction.</p> <p>Conclusions</p> <p>We propose that NM and SP induce glial cell activation and rCRAMP expression also via FPRL1 and MARCO. Thus the receptors contribute an important part to the host defence against infection.</p