High-Mobility Toolkit for Quantum Dot Films

Semiconductor colloidal quantum dots (CQDs) are being increasingly exploited in electronics, optoelectronics, and solar energy harvesting, using a variety of different architectures, mostly based on ordered 2D or 3D arrays of these nanostructures. A crucial issue for optimizing the performance of such devices is the ability to predict and tune the transport properties of these assemblies. In this work we provide general guidelines to precisely that effect, indicating specific materials, crystal structures, lattice arrangements, surface stoichiometries, and morphologies that favor high electron mobilities in these systems and, conversely, materials that will exhibit low mobilities if nanostructured. At the same time our results evidence a surprising independence of the film’s transport properties from those of the bulk material from which the dots are made, highlighting the crucial role of theoretical modeling to guide device design

Effective Approach for an Order-of-Magnitude-Accurate Evaluation of the Electron Mobility in Colloidal Quantum Dot Films

Being able to estimate the electron mobility of colloidal quantum dot films is of great importance for determining their suitability to specific applications and would lead to huge savings in terms of time and resources that may otherwise be wasted trying to build and optimize a device whose transport characteristics can be predicted to be poor from the outset. This task is however complicated by the complexity of the system and the large number of parameters that can potentially affect the final result. Here, we derive a simple, fitting-parameter-free, order-of-magnitude-accurate expression to estimate the dark mobility of such 2D structures and validate it by applying it to real systems and comparing its predictions with those of other recently proposed approaches and with available experimental data. The results quantify the superiority of our expression to estimate mobilities in colloidal quantum dot films

Efficient, non-stochastic, Monte-Carlo-like-accurate method for the calculation of the temperature-dependent mobility in nanocrystal films

We present a new non-stochastic framework for the calculation of the temperature dependence of the mobility in nanocrystal films, that enables speed-ups of several orders of magnitude compared to conventional Monte Carlo approaches, while maintaining a similar accuracy. Our model identifies a new contribution to the reduction of the mobility with increasing temperature in these systems (conventionally attributed to interactions with phonons), that alone is sufficient to explain the observed experimental trend up to room temperature. Comparison of our results with the theoretical predictions of the hopping model and the observed temperature dependence of recent field-effect mobility measurements in nanocrystal films, provides the means to discriminate between band-like and hopping transport and a definitive answer to whether the former has been achieved in quantum dot films

The frequency of osteogenic activities and the pattern of intermittence between periods of physical activity and sedentary behaviour affects bone mineral content: the cross-sectional NHANES study

BACKGROUND: Sedentary behaviours, defined as non exercising seated activities, have been shown to have deleterious effects on health. It has been hypothesised that too much sitting time can have a detrimental effect on bone health in youth. The aim of this study is to test this hypothesis by exploring the association between objectively measured volume and patterns of time spent in sedentary behaviours, time spent in specific screen-based sedentary pursuits and bone mineral content (BMC) accrual in youth. METHODS: NHANES 2005–2006 cycle data includes BMC of the femoral and spinal region via dual-energy X-ray absorptiometry (DEXA), assessment of physical activity and sedentary behaviour patterns through accelerometry, self reported time spent in screen based pursuits (watching TV and using a computer), and frequency of vigorous playtime and strengthening activities. Multiple regression analysis, stratified by gender was performed on N = 671 males and N = 677 females aged from 8 to 22 years. RESULTS: Time spent in screen-based sedentary behaviours is negatively associated with femoral BMC (males and females) and spinal BMC (females only) after correction for time spent in moderate and vigorous activity. Regression coefficients indicate that an additional hour per day of screen-based sitting corresponds to a difference of −0.77 g femoral BMC in females [95% CI: -1.31 to −0.22] and of −0.45 g femoral BMC in males [95% CI: -0.83 to −0.06]. This association is attenuated when self-reported engagement in regular (average 5 times per week) strengthening exercise (for males) and vigorous playing (for both males and females) is taken into account. Total sitting time and non screen-based sitting do not appear to have a negative association with BMC, whereas screen based sedentary time does. Patterns of intermittence between periods of sitting and moderate to vigorous activity appears to be positively associated with bone health when activity is clustered in time and inter-spaced with long continuous bouts of sitting. CONCLUSIONS: Some specific sedentary pursuits (screen-based) are negatively associated with bone health in youth. This association is specific to gender and anatomical area. This relationship between screen-based time and bone health is independent of the total amount of physical activity measured objectively, but not independent of self-reported frequency of strengthening and vigorous play activities. The data clearly suggests that the frequency, rather than the volume, of osteogenic activities is important in counteracting the effect of sedentary behaviour on bone health. The pattern of intermittence between sedentary periods and activity also plays a role in bone accrual, with clustered short bouts of activity interspaced with long periods of sedentary behaviours appearing to be more beneficial than activities more evenly spread in time

Localization of a bacterial group II intron-encoded protein in human cells

Group II introns are mobile retroelements that self-splice from precursor RNAs to form ribonucleoparticles (RNP), which can invade new specific genomic DNA sites. This specificity can be reprogrammed, for insertion into any desired DNA site, making these introns useful tools for bacterial genetic engineering. However, previous studies have suggested that these elements may function inefficiently in eukaryotes. We investigated the subcellular distribution, in cultured human cells, of the protein encoded by the group II intron RmInt1 (IEP) and several mutants. We created fusions with yellow fluorescent protein (YFP) and with a FLAG epitope. We found that the IEP was localized in the nucleus and nucleolus of the cells. Remarkably, it also accumulated at the periphery of the nuclear matrix. We were also able to identify spliced lariat intron RNA, which co-immunoprecipitated with the IEP, suggesting that functional RmInt1 RNPs can be assembled in cultured human cells.This work was supported by research grants CSD 2009–0006 from the Consolider-Ingenio, BIO2011-24401 and BIO2014-51953-P from the Spanish Ministerio de Economía y Competitividad all including ERDF (European Regional Development Funds). We thank Dr. Antonio Barrientos Durán for technical advice. MRC was supported by an FPI Ph.D grant. J.L.G.P´s laboratory is supported by CICE-FEDER-P09-CTS-4980, CICE-FEDER-P12-CTS-2256, Plan Nacional de I+D+I 2008–2011 and 2013–2016 (FIS-FEDER-PI11/01489 and FIS-FEDER-PI14/02152), PCIN-2014-115-ERA-NET NEURON II, the European Research Council (ERC-Consolidator ERC-STG-2012-233764) and by an International Early Career Scientist grant from the Howard Hughes Medical Institute (IECS-55007420).Peer Reviewe

Enhancing the use of Asthma and COPD Assessment Tools in Balearic Primary Care (ACATIB):a region-wide cluster-controlled implementation trial

Asthma and chronic obstructive pulmonary disease (COPD) health status assessment tools have demonstrated their value in guiding clinical management. Their use in primary care is still suboptimal. The objective of this study was to assess the effect of an educational intervention programme on the use of the Asthma Control Test (ACT), modified Medical Research Council (mMRC) and COPD Assessment Test (CAT) among primary care settings of the Balearic Islands, Spain. In this region-wide cluster-controlled implementation study, an educational intervention on the use of respiratory health status tools was provided to primary care practices in Mallorca (intervention group). Practices in Ibiza and Menorca functioned as control practices. Written and multimedia materials were provided to all participants to educate their colleagues. Primary outcome was the difference between intervention and control practices in the percentage of practices that increased the use-and recording-of ACT, CAT and mMRC tests between the 6-month period before intervention and the 6-month period after intervention. In the intervention group, 32 out of 45 (71%) centres enhanced the total number of tests, compared with 4 out of 12 (33%) in the non-intervention group (χ(2); P=0.02). Before intervention, 399 test scores were recorded in 88,194 patients (asthma: 57,339; COPD: 30,855). After intervention, 1,576 test scores were recorded in 92,714 patients (asthma: 61,841; COPD: 30,873). An educational intervention programme targeted on primary care physicians enhances the use of respiratory health status tools and promotes behavioural changes. However, the effect is very low and difficult to measure in clinical terms

Capsaicin Nanoparticles as Therapeutic Agents against Gliomas

Capsaicin is an alkaloid molecule with outstanding biological activity. Several reports have shown that capsaicin exerts significant antitumoral effects in several cancer cell lines, including gliomas. However, its application has been very limited due to its hydrophobicity, low affinity, and short life span. Gliomas are a heterogeneous group of brain malignant tumors with increasing prevalence worldwide. Standard therapy against these tumors generally includes resection by surgery, radiation, and chemotherapy or their combination. However, elicitation of tumor resistance to chemical or radiation treatments remains one of the main challenges to be resolved, particularly in the case of glioblastomas. Nanotechnology is an innovative approach to the treatment of Central Nervous System diseases and especially to gliomas treatment. Indeed, the use of nanotherapeutic formulations offers several advantages over the conventional methods of drug delivery therapy. In this review, we analyzed the current literature regarding the development of capsaicin-loaded nanoparticles as a promising approach for the treatment of malignant brain tumors

Tracking mite trophic interactions by multiplex PCR

BACKGROUND A thorough knowledge of trophic webs in agroecosystems is essential to achieve successful biological pest control. Phytoseiid mites are the most efficient natural enemies of tetranychid mites, which include several important pests worldwide. Nevertheless, phytoseiids may feed on other food sources including other microarthropods, plants and even other phytoseiids (intraguild predation), which can interfere with biological control services. Molecular gut content analysis is a valuable tool for characterizing trophic interactions, mainly when working on microarthropods such as mites. We have designed new primers for Phytoseiidae, Tetranychidae and Thysanoptera identification and they have been multiplexed in a polymerase chain reaction (PCR) together with universal plant primers. Additionally, we have estimated prey DNA detectability success over time (DS50) considering the most probable events in Spanish citrus orchards: the phytoseiid Euseius stipulatus as a predator, the phytoseiid Phytoseiulus persimilis as intraguild prey, and the thrips Frankliniella occidentalis and Anaphothrips obscurus as alternative prey to Tetranychus urticae. RESULTS The designed multiplex PCR allows the identification of phytoseiids (both predator and intraguild prey) and detects alternative food sources mentioned above in the gut of the phytoseiid predator. DS50 for E. stipulatus as the predator were 1.3, 2.3 and 18.7 h post feeding for F. occidentalis, A. obscurus and P. persimilis as prey, respectively. CONCLUSION Tracking of the trophic relationships within the citrus acarofauna, and the unveiling of the role of alternative food sources will pave the way for enhancing T. urticae biological control. This multiplex PCR approach could be applicable for these purposes in similar agroecosystems