Current Understanding of Extracellular Vesicle Homing/Tropism

Extracellular vesicles (EVs) are membrane-enclosed packets that are released from cells and subsequently transfer bioactive molecules between cells without directly contacting the target cells. This transfer of molecules can activate consequential processes in recipient cells, including cell differentiation and migration, thus maintaining tissue homeostasis or promoting tissue pathology. A controversial but therapeutically promising aspect of EV biology is their ability to engage defined cells at specific sites. On the one hand, persuasive studies have shown that EVs express surface molecules that ensure EV tissue localization and enable cell-specific interactions, as demonstrated by in vitro and in vivo analyses. This feature of EV biology is being investigated in translational studies to control malignancies, and deliver chemicals and bioactive molecules to combat several diseases. On the other hand, several studies have shown that EVs fail to traffic in hosts in a targeted manner, thus calling the potential roles of EVs as vehicles in drug delivery and cell-free biomodulation into question. In this review, the biology of EV homing/tropism in mammalian hosts is discussed, including the biological characteristics that may explain the controversial aspects of the EV tropism

MVCSLAM: Mono-Vision Corner SLAM for Autonomous Micro-Helicopters in GPS Denied Environments

We present a real-time vision navigation and ranging method (VINAR) for the purpose of Simultaneous Localization and Mapping (SLAM) using monocular vision. Our navigation strategy assumes a GPS denied unknown environment, whose indoor architecture is represented via corner based feature points obtained through a monocular camera. We experiment on a case study mission of vision based SLAM through a conventional maze of corridors in a large building with an autonomous Micro Aerial Vehicle (MAV). We propose a method for gathering useful landmarks from a monocular camera for SLAM use. We make use of the corners by exploiting the architectural features of the manmade indoors

Experimental evaluation of the energy efficiency of a CO2 refrigerating plant working in transcritical conditions

[EN] This work presents the experimental evaluation of the energy efficiency and optimal gas-cooler pressures of a single-stage refrigerating plant working with carbon dioxide as refrigerant in transcritical conditions. The performance of the plant was tested at three different evaporating temperatures (-0.9, -10.1 and -18.1 degrees C), for three gas-cooler refrigerant outlet temperatures (31.2, 33.6 and 40.0 degrees C) at each evaporating temperature and in a wide range of gas-cooler pressures (74.4-104.7 bar). The experimental tests enabled us to calculate accurately the optimal gas-cooler pressures and compare them with the most commonly used relations to define this value in single-stage refrigerating cycles operating with carbon dioxide in transcritical conditions. Furthermore, an analysis of the reduction in energy efficiency produced in the plant if the optimum pressure is not well defined is also presented.The authors are indebted to Frost-Trol S.A. (www.frosttrol.com) and the Spanish Ministry of Education and Science (ENE2006-09972/CON) for the economical support given to the present work and for the Grant BES-2007-16820 linked to the Ministry projectCabello, R.; Sanchez, D.; Llopis, R.; Torrella Alcaraz, E. (2008). Experimental evaluation of the energy efficiency of a CO2 refrigerating plant working in transcritical conditions. Applied Thermal Engineering. 28(13):1596-1604. https://doi.org/10.1016/j.applthermaleng.2007.10.026S15961604281

Genetic disruption of KCC cotransporters in a mouse model of thalassemia intermedia

\u3b2-thalassemia (\u3b2-Thal) is caused by defective \u3b2-globin production leading to globin chain imbalance, aggregation of free alpha chain in developing erythroblasts, reticulocytes, and mature circulating red blood cells. The hypochromic thalassemic red cells exhibit increased cell dehydration in association with elevated K+ leak and increased K-Cl cotransport activity, each of which has been linked to globin chain imbalance and related oxidative stress. We therefore tested the effect of genetic inactivation of K-Cl cotransporters KCC1 and KCC3 in a mouse model of \u3b2-thalassemia intermedia. In the absence of these transporters, the anemia of \u3b2-Thal mice was ameliorated, in association with increased MCV and reductions in CHCM and hyperdense cells, as well as in spleen size. The resting K+ content of \u3b2-Thal red cells was greatly increased, and Thal-associated splenomegaly slightly decreased. Lack of KCC1 and KCC3 activity in Thal red cells reduced red cell density and improved \u3b2-Thal-associated osmotic fragility. We conclude that genetic inactivation of K-Cl cotransport can reverse red cell dehydration and partially attenuate the hematologic phenotype in a mouse model of \u3b2-thalassemia

Thermal Properties of Carbon Nanotube–Copper Composites for Thermal Management Applications

Carbon nanotube–copper (CNT/Cu) composites have been successfully synthesized by means of a novel particles-compositing process followed by spark plasma sintering (SPS) technique. The thermal conductivity of the composites was measured by a laser flash technique and theoretical analyzed using an effective medium approach. The experimental results showed that the thermal conductivity unusually decreased after the incorporation of CNTs. Theoretical analyses revealed that the interfacial thermal resistance between the CNTs and the Cu matrix plays a crucial role in determining the thermal conductivity of bulk composites, and only small interfacial thermal resistance can induce a significant degradation in thermal conductivity for CNT/Cu composites. The influence of sintering condition on the thermal conductivity depended on the combined effects of multiple factors, i.e. porosity, CNTs distribution and CNT kinks or twists. The composites sintered at 600°C for 5 min under 50 MPa showed the maximum thermal conductivity. CNT/Cu composites are considered to be a promising material for thermal management applications

Identification of Leishmania Proteins Preferentially Released in Infected Cells Using Change Mediated Antigen Technology (CMAT)

Although Leishmania parasites have been shown to modulate their host cell's responses to multiple stimuli, there is limited evidence that parasite molecules are released into infected cells. In this study, we present an implementation of the change mediated antigen technology (CMAT) to identify parasite molecules that are preferentially expressed in infected cells. Sera from mice immunized with cell lysates prepared from L. donovani or L. pifanoi-infected macrophages were adsorbed with lysates of axenically grown amastigotes of L. donovani or L. pifanoi, respectively, as well as uninfected macrophages. The sera were then used to screen inducible parasite expression libraries constructed with genomic DNA. Eleven clones from the L. pifanoi and the L. donovani screen were selected to evaluate the characteristics of the molecules identified by this approach. The CMAT screen identified genes whose homologs encode molecules with unknown function as well as genes that had previously been shown to be preferentially expressed in the amastigote form of the parasite. In addition a variant of Tryparedoxin peroxidase that is preferentially expressed within infected cells was identified. Antisera that were then raised to recombinant products of the clones were used to validate that the endogenous molecules are preferentially expressed in infected cells. Evaluation of the distribution of the endogenous molecules in infected cells showed that some of these molecules are secreted into parasitophorous vacuoles (PVs) and that they then traffic out of PVs in vesicles with distinct morphologies. This study is a proof of concept study that the CMAT approach can be applied to identify putative Leishmania parasite effectors molecules that are preferentially expressed in infected cells. In addition we provide evidence that Leishmania molecules traffic out of the PV into the host cell cytosol and nucleus

Interaction of Hydrogen with Graphitic Surfaces, Clean and Doped with Metal Clusters

Producción CientíficaHydrogen is viewed as a possible alternative to the fossil fuels in transportation. The technology of fuel-cell engines is fully developed, and the outstanding remaining problem is the storage of hydrogen in the vehicle. Porous materials, in which hydrogen is adsorbed on the pore walls, and in particular nanoporous carbons, have been investigated as potential onboard containers. Furthermore, metallic nanoparticles embedded in porous carbons catalyze the dissociation of hydrogen in the anode of the fuel cells. For these reasons the interaction of hydrogen with the surfaces of carbon materials is a topic of high technological interest. Computational modeling and the density functional formalism (DFT) are helping in the task of discovering the basic mechanisms of the interaction of hydrogen with clean and doped carbon surfaces. Planar and curved graphene provide good models for the walls of porous carbons. We first review work on the interaction of molecular and atomic hydrogen with graphene and graphene nanoribbons, and next we address the effects due to the presence of metal clusters on the surface because of the evidence of their role in enhancing hydrogen storage.Ministerio de Economía, Industria y Competitividad (Grant MAT2014-54378-R

Cooperation between Apoptotic and Viable Metacyclics Enhances the Pathogenesis of Leishmaniasis

Mimicking mammalian apoptotic cells by exposing phosphatidylserine (PS) is a strategy used by virus and parasitic protozoa to escape host protective inflammatory responses. With Leishmania amazonensis (La), apoptotic mimicry is a prerogative of the intramacrophagic amastigote form of the parasite and is modulated by the host. Now we show that differently from what happens with amastigotes, promastigotes exposing PS are non-viable, non-infective cells, undergoing apoptotic death. As part of the normal metacyclogenic process occurring in axenic cultures and in the gut of sand fly vectors, a sub-population of metacyclic promastigotes exposes PS. Apoptotic death of the purified PS-positive (PSPOS) sub-population was confirmed by TUNEL staining and DNA laddering. Transmission electron microscopy revealed morphological alterations in PSPOS metacyclics such as DNA condensation, cytoplasm degradation and mitochondrion and kinetoplast destruction, both in in vitro cultures and in sand fly guts. TUNELPOS promastigotes were detected only in the anterior midgut to foregut boundary of infected sand flies. Interestingly, caspase inhibitors modulated parasite death and PS exposure, when added to parasite cultures in a specific time window. Efficient in vitro macrophage infections and in vivo lesions only occur when PSPOS and PS-negative (PSNEG) parasites were simultaneously added to the cell culture or inoculated in the mammalian host. The viable PSNEG promastigote was the infective form, as shown by following the fate of fluorescently labeled parasites, while the PSPOS apoptotic sub-population inhibited host macrophage inflammatory response. PS exposure and macrophage inhibition by a subpopulation of promastigotes is a different mechanism than the one previously described with amastigotes, where the entire population exposes PS. Both mechanisms co-exist and play a role in the transmission and development of the disease in case of infection by La. Since both processes confer selective advantages to the infective microorganism they justify the occurrence of apoptotic features in a unicellular pathogen

The use of complementary and alternative medicine by 7427 Australian women with cyclic perimenstrual pain and discomfort: A cross-sectional study

© 2016 Fisher et al. Background: To assess the prevalence of cyclic perimenstrual pain and discomfort and to detail the pattern of complementary and alternative (CAM) use adopted by women for the treatment of these symptoms. Methods: Data from the 2012 national Australian Longitudinal Study of Women's Health (ALSWH) cross-sectional survey of 7427 women aged 34-39 years were analysed to estimate the prevalence of endometriosis, premenstrual syndrome (PMS), irregular or heavy periods and severe dysmenorrhoea and to examine the association between their symptoms and their visits to CAM practitioners as well as their use of CAM therapies and products in the previous 12 months. Results: The prevalence of endometriosis was 3.7 % and of the perimenstrual symptoms assessed, PMS was most prevalent at 41.2 % whilst irregular bleeding (22.2 %), heavy periods (29.8 %) and severe period pain (24.1 %) were reported at lower levels. Women with endometriosis were more likely than non-sufferers to have consulted with a massage therapist or acupuncturist and to have used vitamins/minerals, yoga/meditation or Chinese medicines (p < 0.05). PMS sufferers were more likely to consult with an osteopath, massage therapist, naturopath/herbalist or alternative health practitioner and to have used all forms of CAM therapies except Chinese medicines than women who had infrequent PMS (all p < 0.05). Women with irregular periods did not have different patterns of CAM use from non-sufferers and those with heavy periods did not favour any form of CAM but were less likely to visit a massage therapist or use yoga/meditation than non-sufferers (p < 0.05). For women with severe dysmenorrhoea there was no difference in their visits to CAM practitioners compared to non-sufferers but they were more likely to use aromatherapy oils (p < 0.05) and for more frequent dysmenorrhoea also herbal medicines, Chinese medicines and other alternative therapies compared to non-sufferers (all p < 0.05). Conclusions: There is a high prevalence of cyclic perimenstrual pain and discomfort amongst women in this age group. Women were using CAM differentially when they had specific symptoms of cyclic perimenstrual pain and discomfort. The use of CAM needs to be properly assessed to ensure their safe, effective use and to ascertain their significance as a treatment option enabling women with menstrual problems and their care providers to improve their quality of life