•This paper reports the first self-powered, flexible, and high-performance single SiC nanowire ultraviolet photodetector.•The device shows an excellent detectivity of 7.2 × 1010 cm.Hz1/2. W−1 and ...external quantum efficiency (EQE) of 83% at 0 V.•The device shows remarkable performance parameters with the sensitivity of 1756% and responsivity of 0.17 A/W at 0 V.
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This paper reports a very fine-pattern, flexible, self-powered, and cost-effective silicon carbide single nanowire ultraviolet photodetector (SiCNW-UVPD) with a high sensitivity of 1756%, a responsivity of 0.17 A/W, and a shallow dark current of ~0.08 pA. The device exhibits an excellent detectivity value of 7.2 × 1010 cm.Hz1/2. W−1 and external quantum efficiency (EQE) of 83% without the need of any external power (0 V) under 254 nm ultraviolet light. The remarkable performance parameters having the highest reported sensitivity and responsivity values for a self-powered SiC nanowire-based photodetector along with very small size and cost-efficiency could offer unique opportunities in new generation, flexible, self-powered nanoscale optoelectronics.
Summary
Introduction
The most widely used protocol for the induction of experimental allergic airway inflammation in mice involves sensitization by intraperitoneal (i.p.) injections of the antigen ...ovalbumin (OVA) used in conjunction with the adjuvant aluminium hydroxide (alum). Although adjuvants are frequently used, there are questions regarding the necessity of alum for murine asthma studies due to the non‐physiological nature of this chemical.
Objective
The objective of this study was to compare experimental asthma phenotypes between adjuvant and adjuvant‐free protocols of murine allergic airway inflammation in an attempt to develop a standardized alternative to adjuvant use.
Method
An adjuvant‐free OVA model of experimental asthma was investigated in BALB/c mice using i.p. or subcutaneous (s.c.) sensitization routes. For the s.c. sensitization, β‐galactosidase (β‐gal) was also tested as an antigen. In addition, OVA adjuvant and adjuvant‐free sensitization protocols were compared in BALB/c and C57BL/6 mice. Open‐field testing was performed to assess the effect of alum on mouse behaviour.
Results
Comparison of adjuvant vs. adjuvant‐free and i.p. vs. s.c. protocols revealed that both adjuvant use and route of antigen application significantly influenced OVA‐specific antibody production. Comparison of adjuvant and adjuvant‐free protocols in this study clearly demonstrated the non‐requirement of alum for the induction of acute allergic airway inflammation, as both protocols induce a similar disease phenotype. BALB/c mice were significantly more susceptible than C57BL/6 mice to sensitization. Using the improved s.c. adjuvant‐free protocol, it was demonstrated that alternative antigens such as β‐gal can also be utilized. Behavioural studies indicated severe distress in mice treated with alum.
Conclusion
The OVA s.c. adjuvant‐free protocol used in this study generates a phenotype comparable to the benchmark adjuvant protocol widely used in the literature. The adjuvant‐free alternative avoids the added complication of non‐physiological adjuvants that may interfere with asthma treatment or prevention strategies.
Mg
regulates many physiological processes and signalling pathways. However, little is known about the mechanisms underlying the organismal balance of Mg
. Capitalizing on a set of newly generated ...mouse models, we provide an integrated mechanistic model of the regulation of organismal Mg
balance during prenatal development and in adult mice by the ion channel TRPM6. We show that TRPM6 activity in the placenta and yolk sac is essential for embryonic development. In adult mice, TRPM6 is required in the intestine to maintain organismal Mg
balance, but is dispensable in the kidney.
inactivation in adult mice leads to a shortened lifespan, growth deficit and metabolic alterations indicative of impaired energy balance. Dietary Mg
supplementation not only rescues all phenotypes displayed by
-deficient adult mice, but also may extend the lifespan of wildtype mice. Hence, maintenance of organismal Mg
balance by TRPM6 is crucial for prenatal development and survival to adulthood.
MicroRNA (miRNA) regulation clearly impacts animal development, but the extent to which development—with its resulting diversity of cellular contexts—impacts miRNA regulation is unclear. Here, we ...compared cohorts of genes repressed by the same miRNAs in different cell lines and tissues and found that target repertoires were largely unaffected, with secondary effects explaining most of the differential responses detected. Outliers resulting from differential direct targeting were often attributable to alternative 3′ UTR isoform usage that modulated the presence of miRNA sites. More inclusive examination of alternative 3′ UTR isoforms revealed that they influence ∼10% of predicted targets when comparing any two cell types. Indeed, considering alternative 3′ UTR isoform usage improved prediction of targeting efficacy significantly beyond the improvements observed when considering constitutive isoform usage. Thus, although miRNA targeting is remarkably consistent in different cell types, considering the 3′ UTR landscape helps predict targeting efficacy and explain differential regulation that is observed.
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•Cellular context does not detectably affect the majority of miRNA targets•Differential 3′ UTR isoforms explain cell-type-specific targeting that is observed•Considering the 3′ UTR landscape improves prediction of targeting efficacy•miRNA-mediated repression shapes the 3′ UTR landscape
MicroRNAs function in many biological contexts, but the extent to which these different contexts modulate the cohort of genes regulated by a miRNA was unclear. Nam et al. show that miRNA targeting is remarkably consistent between different cell types and that most differential targeting that is observed is explained by differences in 3′ UTR isoforms.
Measuring similarities between objects based on their attributes has been an important problem in many disciplines. Object-attribute associations can be depicted as links on a bipartite graph. A ...similarity measure can be thought as a unipartite projection of this bipartite graph. The most widely used bipartite projection techniques make assumptions that are not often fulfilled in real life systems, or have the focus on the bipartite connections more than on the unipartite connections. Here, we define a new similarity measure that utilizes a practical procedure to extract unipartite graphs without making a priori assumptions about underlying distributions. Our similarity measure captures the relatedness between two objects via the likelihood of a random walker passing through these nodes sequentially on the bipartite graph. An important aspect of the method is that it is robust to heterogeneous bipartite structures and it controls for the transitivity similarity, avoiding the creation of unrealistic homogeneous degree distributions in the resulting unipartite graphs. We test this method using real world examples and compare the obtained results with alternative similarity measures, by validating the actual and orthogonal relations between the entities.
The prevalent affirmative action policy in school choice limits the number of admitted majority students to give minority students higher chances to attend their desired schools. There have been ...numerous efforts to reconcile affirmative action policies with celebrated matching mechanisms such as the deferred acceptance and top trading cycles algorithms. Nevertheless, it is theoretically shown that under these algorithms, the policy based on majority quotas may be detrimental to minorities. Using simulations we find that this is a more common phenomenon rather than a peculiarity-up to 25% of minorities and 55% of majorities can be worse off. To circumvent the inefficiency caused by majority quotas, we offer a different interpretation of the affirmative action policies based on minority reserves. With minority reserves, schools give higher priority to minority students up to the point that the minorities fill the reserves. We compare the welfare effects of these policies. The deferred acceptance algorithm with minority reserves Pareto dominates the one with majority quotas. Our simulations, which allows for correlations between student preferences and school priorities, indicate that minorities are on average better off with minority reserves while adverse effects on majorities are mitigated.
Proto―genes and de novo gene birth CARVUNIS, Anne-Ruxandra; ROLAND, Thomas; BRAR, Gloria A ...
Nature (London),
07/2012, Letnik:
487, Številka:
7407
Journal Article, Web Resource
Recenzirano
Odprti dostop
Novel protein-coding genes can arise either through re-organization of pre-existing genes or de novo. Processes involving re-organization of pre-existing genes, notably after gene duplication, have ...been extensively described. In contrast, de novo gene birth remains poorly understood, mainly because translation of sequences devoid of genes, or 'non-genic' sequences, is expected to produce insignificant polypeptides rather than proteins with specific biological functions. Here we formalize an evolutionary model according to which functional genes evolve de novo through transitory proto-genes generated by widespread translational activity in non-genic sequences. Testing this model at the genome scale in Saccharomyces cerevisiae, we detect translation of hundreds of short species-specific open reading frames (ORFs) located in non-genic sequences. These translation events seem to provide adaptive potential, as suggested by their differential regulation upon stress and by signatures of retention by natural selection. In line with our model, we establish that S. cerevisiae ORFs can be placed within an evolutionary continuum ranging from non-genic sequences to genes. We identify ~1,900 candidate proto-genes among S. cerevisiae ORFs and find that de novo gene birth from such a reservoir may be more prevalent than sporadic gene duplication. Our work illustrates that evolution exploits seemingly dispensable sequences to generate adaptive functional innovation.
Summary
Background
Non‐selective cation influx through canonical transient receptor potential channels (TRPCs) is thought to be an important event leading to airway inflammation. TRPC6 is highly ...expressed in the lung, but its role in allergic processes is still poorly understood.
Objective
The purpose of this study was to evaluate the role of TRPC6 in airway hyperresponsiveness (AHR) and allergic inflammation of the lung.
Methods
Methacholine‐induced AHR was assessed by head‐out body plethysmography of wild type (WT) and TRPC6−/− mice. Experimental airway inflammation was induced by intraperitoneal ovalbumin (OVA) sensitization, followed by OVA aerosol challenges. Allergic inflammation and mucus production were analysed 24 h after the last allergen challenge.
Results
Methacholine‐induced AHR and agonist‐induced contractility of tracheal rings were increased in TRPC6−/− mice compared with WT mice, most probably due to compensatory up‐regulation of TRPC3 in airway smooth muscle cells. Most interestingly, when compared with WT mice, TRPC6−/− mice exhibited reduced allergic responses after allergen challenge as evidenced by a decrease in airway eosinophilia and blood IgE levels, as well as decreased levels of T‐helper type 2 (Th2) cytokines (IL‐5, IL‐13) in the bronchoalveolar lavage. However, lung mucus production after allergen challenge was not altered by TRPC6 deficiency.
Conclusions
TRPC6 deficiency inhibits specific allergic immune responses, pointing to an important immunological function of this cation channel in Th2 cells, eosinophils, mast cells and B cells.
This paper studies the problem of computing a (1+epsilon)-approximation to the minimum-volume enclosing ellipsoid of a given point set. Based on a simple, initial volume approximation method, it ...proposes a modification of the Khachiyan first-order algorithm.
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