Quantum and Classical divide: the gravitational case

We study the transition between quantum and classical behavior of particles in a gravitational quantum well. We analyze how an increase in the particles mass turns the energy spectrum into a continuous one, from an experimental point of view. We also discuss the way these effects could be tested by conducting experiments with atoms and fullerene-type molecules.Comment: Revtex4, 5 pages, 2 figures; version to appear in Physics Letters

Diffuse Dark and Bright Objects in the Hubble Deep Field

In the Hubble Deep Field (HDF) we have identified candidate regions where primordial galaxies might be forming. These regions are identified from negative or positive peaks in the difference maps obtained from the HDF maps smoothed over 0.8'' and 4''. They have apparent V magnitudes typically between 29 and 31 (missing flux below the local average level for the dark objects). The identified objects are shown to be real by two ways. First, the cross-correlations of these peaks detected in different filters are strong. Second, their auto-correlation functions indicate that these faint diffuse objects are self-clustered. The subset of objects dark in the F450W and F606W bandpasses, but bright in F814W, also shows stronger correlation compared to the whole dark sample. This further supports that our samples are indeed physical objects. The amplitude and slope of the angular correlation function of the bright objects indicates that these objects are ancestors of the present nearby bright galaxies. We have inspected individual bright objects and noted that they have several tiny spots embedded in extended backgrounds. They are likely to be the primordial galaxies at high redshifts in the process of active star formation and merging. Our subset of dark objects is thought to be the `intergalactic dark clouds' he blocking the background far UV light (at the rest frame) at high redshifts instead of empty spaces between the first galaxies at the edge of the universe of galaxies.Comment: ApJ, submitted.10 pages including 8 figures(1 large postscript figure file) uses kjhantwo.sty .Also available at http://astro.snu.ac.kr/preprint1997.htm

Exploiting metallophilicity for the assembly of inorganic nanocrystals and conjugated organic molecules

The accurate engineering of interfaces between inorganic nanocrystals and semiconducting organic molecules is currently viewed as key for further developments in critical fields such as photovoltaics and photocatalysis. In this work, a new and unconventional source of interface interaction based on metal–metal bonds is presented. With this aim, an AuI organometallic gelator was exploited for the formation of hydrogel-like nanocomposites containing inorganic nanoparticles and conjugated organic molecules. Noteworthy, the establishment of metallophilic interactions at the interface between the two moieties greatly enhances interparticle coupling in the composites. Thus, we believe that this new hybrid system might represent a promising alternative in several fields, such as in the fabrication of improved light-harvesting devices.Peer ReviewedPostprint (author's final draft

Compartmentalized PDE4A5 signaling impairs hippocampal synaptic plasticity and long-term memory

Alterations in cAMP signaling are thought to contribute to neurocognitive and neuropsychiatric disorders. Members of the cAMP-specific phosphodiesterase 4 (PDE4) family, which contains >25 different isoforms, play a key role in determining spatial cAMP degradation so as to orchestrate compartmentalized cAMP signaling in cells. Each isoform binds to a different set of protein complexes through its unique N-terminal domain, thereby leading to targeted degradation of cAMP in specific intracellular compartments. However, the functional role of specific compartmentalized PDE4 isoforms has not been examined in vivo. Here, we show that increasing protein levels of the PDE4A5 isoform in mouse hippocampal excitatory neurons impairs a long-lasting form of hippocampal synaptic plasticity and attenuates hippocampus-dependent long-term memories without affecting anxiety. In contrast, viral expression of a truncated version of PDE4A5, which lacks the unique N-terminal targeting domain, does not affect long-term memory. Further, overexpression of the PDE4A1 isoform, which targets a different subset of signalosomes, leaves memory undisturbed. Fluorescence resonance energy transfer sensor-based cAMP measurements reveal that the full-length PDE4A5, in contrast to the truncated form, hampers forskolin-mediated increases in neuronal cAMP levels. Our study indicates that the unique N-terminal localization domain of PDE4A5 is essential for the targeting of specific cAMP-dependent signaling underlying synaptic plasticity and memory. The development of compounds to disrupt the compartmentalization of individual PDE4 isoforms by targeting their unique N-terminal domains may provide a fruitful approach to prevent cognitive deficits in neuropsychiatric and neurocognitive disorders that are associated with alterations in cAMP signaling

Recognition-mediated hydrogel swelling controlled by interaction with a negative thermoresponsive LCST polymer

Most polymeric thermoresponsive hydrogels contract upon heating beyond the lower critical solution temperature (LCST) of the polymers used. Herein, we report a supramolecular hydrogel system that shows the opposite temperature dependence. When the non-thermosesponsive hydrogel NaphtGel, containing dialkoxynaphthalene guest molecules, becomes complexed with the tetra cationic macrocyclic host CBPQT4+, swelling occurred as a result of host–guest complex formation leading to charge repulsion between the host units, as well as an osmotic contribution of chloride counter-ions embedded in the network. The immersion of NaphtGel in a solution of poly(N-isopropylacrylamide) with tetrathiafulvalene (TTF) end groups complexed with CBPQT4+ induced positive thermoresponsive behaviour. The LCST-induced dethreading of the polymer-based pseudorotaxane upon heating led to transfer of the CBPQT4+ host and a concomitant swelling of NaphtGel. Subsequent cooling led to reformation of the TTF-based host–guest complexes in solution and contraction of the hydrogel

Biochar production from late-harvest grass – Challenges and potential for farm-scale implementation

[Abstract:] Grasslands play a crucial role in European agriculture and ecology, but are often underutilized due to low-value end-products. The utilisation of late-harvest grass for biochar and heat generation on farm-level is being studied as a potential negative emissions technology. Technical (energy provision and carbon sink), economic (cost vs. benefit), political (regulatory framework) and social (SWOT) perspectives are being evaluated. Technical feasibility has been demonstrated with three different farm-scale technologies and the energetic and carbon-sink potential evaluated. When a continuously operating allothermal unit is evaluated, 35 % of the input biomass energy content can be utilized for heating a farm, in combination with the potential to provide a carbon sink. The cost-benefit analysis shows important monetary savings when including the agronomic value (based on the market price) of the produced biochar. An assessment of the regulatory framework of biochar production in Germany presents a multitude of regulations applying to such technologies some of which provide a hurdle to navigate and may incur excessive costs for farmers as small-scale biochar producers. A SWOT analysis of a case in Brandenburg, Germany highlights strengths and opportunities, but also obstacles such as lack of infrastructure and regulatory support. This study highlights the need for further development of suitable technology and research on the long-term economic and carbon sink potential of biochar.This work was performed within the GO-GRASS project and has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 862674. We thank all the partners who collaborated with the data collection. We would also like to thank Philipp Grundmann for the coordination of the GO-GRASS project

Do cultivar, geographical location and crop season influence phenolic profile of walnut leaves?

Walnut leaves from nine different cultivars (Arco, Franquette, Hartley, Lara, Marbot, Mayette, Meylannaise, Parisienne and Rego) were studied for their phenolic compounds. Samples were harvested along three consecutive years, at two different geographical locations, in order to evaluate if significant differences in the phenolics composition can be related with genetic, climatic or geographical factors. Nine compounds (3-caffeoylquinic, 3-p-coumaroylquinic and 4-p-coumaroylquinic acids, quercetin 3- galactoside, quercetin 3-arabinoside, quercetin 3-xyloside, quercetin 3-rhamnoside, a quercetin 3-pentoside derivative and a kaempferol 3-pentoside derivative) were quantified using an HPLC-DAD methodology. The qualitative profiles were identical for all samples, but differences were observed in terms of individual compounds’ contents. Multivariate statistical analysis was carried out, showing that significant differences exist among production years, which can be related to climatic reasons.Direcção Regional de Agricultura da Beira Litoral (DRABL)Instituto Politécnico de Bragança (ESA

Physical and structural properties and thermal behaviour of starch-poly(ɛ-caprolactone) blend films for food packaging

[EN] Structural and physical properties (barrier, mechanical, and optical properties) and thermal behaviour of corn starch-PCL blend films, containing glycerol as plasticizer, obtained by compression moulding, at 160 °C and 130 bars, were studied. The stability on the films properties was also evaluated. Blend films showed phase separation of the polymers in a heterogeneous matrix with starch rich regions and PCL rich regions. Nevertheless, a small miscibility of PCL in the starch phase was detected trough the shift in the glass transition temperature of the starch phase, which leads to a partial inhibition of amylose crystallization during film formation and storage. The lack of interfacial adhesion of PCL and starch phases promoted films fragility and reduced stretchability, although elastic modulus of the films with small PCL ratios increased. Water barrier properties of starch films were improved as the PCL increased in the blend, but oxygen permeability increased. Due to the food compatibility of this polymer blends (without any toxic compound) these could be an interesting alternative for food packaging, where some drawbacks of starch films has been overcome.The authors acknowledge the financial support from the Ministerio de Economi'a y Competitividad (Spain) throughout the project AGL2013-42989-R. Rodrigo Ortega-Toro thanks the Conselleria de Educacio de la Comunitat Valenciana for the Santiago Grisolia grant. Authors also thank to Electron Microscopy Service of the UPV for their technical assistance.Ortega Toro, R.; Contreras, J.; Talens Oliag, P.; Chiralt, A. (2015). Physical and structural properties and thermal behaviour of starch-poly(ɛ-caprolactone) blend films for food packaging. Food Packaging and Shelf Life. 5:10-20. https://doi.org/10.1016/j.fpsl.2015.04.001S1020

Gene Expression Signature-Based Screening Identifies New Broadly Effective Influenza A Antivirals

Classical antiviral therapies target viral proteins and are consequently subject to resistance. To counteract this limitation, alternative strategies have been developed that target cellular factors. We hypothesized that such an approach could also be useful to identify broad-spectrum antivirals. The influenza A virus was used as a model for its viral diversity and because of the need to develop therapies against unpredictable viruses as recently underlined by the H1N1 pandemic. We proposed to identify a gene-expression signature associated with infection by different influenza A virus subtypes which would allow the identification of potential antiviral drugs with a broad anti-influenza spectrum of activity. We analyzed the cellular gene expression response to infection with five different human and avian influenza A virus strains and identified 300 genes as differentially expressed between infected and non-infected samples. The most 20 dysregulated genes were used to screen the connectivity map, a database of drug-associated gene expression profiles. Candidate antivirals were then identified by their inverse correlation to the query signature. We hypothesized that such molecules would induce an unfavorable cellular environment for influenza virus replication. Eight potential antivirals including ribavirin were identified and their effects were tested in vitro on five influenza A strains. Six of the molecules inhibited influenza viral growth. The new pandemic H1N1 virus, which was not used to define the gene expression signature of infection, was inhibited by five out of the eight identified molecules, demonstrating that this strategy could contribute to identifying new broad anti-influenza agents acting on cellular gene expression. The identified infection signature genes, the expression of which are modified upon infection, could encode cellular proteins involved in the viral life cycle. This is the first study showing that gene expression-based screening can be used to identify antivirals. Such an approach could accelerate drug discovery and be extended to other pathogens

Tailoring Crohn's disease treatment : the impact of small bowel capsule endoscopy

"Article in Press"; "Epub 2014 Mar 14"BACKGROUND AND AIMS: Small bowel capsule endoscopy (SBCE) may detect proximal small bowel lesions that have been previously missed by ileocolonoscopy and small bowel imaging in patients with known ileal and/or colonic Crohn's disease (CD). We aimed to evaluate whether the therapeutic management is influenced by SBCE findings. METHODS: Retrospective single center study. Inclusion of consecutive patients with known non-stricturing and non-penetrating ileal and/or colonic CD, submitted to SBCE to evaluate disease extension and activity, with ≥ 1year follow-up. Lesions were classified with the Lewis score (LS) as non-significant (LS790). Therapeutic changes were assessed three months after SBCE. RESULTS: Fifty consecutive patients (35±13years, 52% females) were included. At ileocolonoscopy, disease location was ileal (L1) in 60%, colonic (L2) in 10% and ileocolonic (L3) in 30% of the patients. In 33 patients (66%) SBCE detected significant proximal lesions previously missed by other modalities. The proportion of patients on thiopurines and/or biologics before SBCE was 2/50 (4%); this was significantly higher three months after SBCE, 15/50 (30%), p=0.023. Treatment with thiopurines and/or biologics was started more often in patients with proximal small bowel lesions [13/33 (39%) vs. 1/17 (6%), p=0.011, relative risk (RR) 6.5], particularly when severe (6%, 36% and 45% of patients with non-significant, mild and moderate-to-severe inflammation, respectively). CONCLUSIONS: SBCE diagnoses previously undetected lesions and it influences therapeutic management of CD, triggering an earlier introduction of immunomodulators and/or biological therapy