Natural selection has driven the recurrent loss of an immunity gene that protects Drosophila against a major natural parasite.

Polymorphisms in immunity genes can have large effects on susceptibility to infection. To understand the origins of this variation, we have investigated the genetic basis of resistance to the parasitoid wasp Leptopilina boulardi in Drosophila melanogaster. We found that increased expression of the gene lectin-24A after infection by parasitic wasps was associated with a faster cellular immune response and greatly increased rates of killing the parasite. lectin-24A encodes a protein that is strongly up-regulated in the fat body after infection and localizes to the surface of the parasite egg. In certain susceptible lines, a deletion upstream of the lectin-24A has largely abolished expression. Other mutations predicted to abolish the function of this gene have arisen recurrently in this gene, with multiple loss-of-expression alleles and premature stop codons segregating in natural populations. The frequency of these alleles varies greatly geographically, and in some southern African populations, natural selection has driven them near to fixation. We conclude that natural selection has favored the repeated loss of an important component of the immune system, suggesting that in some populations, a pleiotropic cost to lectin-24A expression outweighs the benefits of resistance.

Developing Wolbachia-based disease interventions for an extreme environment.

Aedes aegypti mosquitoes carrying self-spreading, virus-blocking Wolbachia bacteria are being deployed to suppress dengue transmission. However, there are challenges in applying this technology in extreme environments. We introduced two Wolbachia strains into Ae. aegypti from Saudi Arabia for a release program in the hot coastal city of Jeddah. Wolbachia reduced infection and dissemination of dengue virus (DENV2) in Saudi Arabian mosquitoes and showed complete maternal transmission and cytoplasmic incompatibility. Wolbachia reduced egg hatch under a range of environmental conditions, with the Wolbachia strains showing differential thermal stability. Wolbachia effects were similar across mosquito genetic backgrounds but we found evidence of local adaptation, with Saudi Arabian mosquitoes having lower egg viability but higher adult desiccation tolerance than Australian mosquitoes. Genetic background effects will influence Wolbachia invasion dynamics, reinforcing the need to use local genotypes for mosquito release programs, particularly in extreme environments like Jeddah. Our comprehensive characterization of Wolbachia strains provides a foundation for Wolbachia-based disease interventions in harsh climates.

Electrification-Enhanced Low-Temperature NOx Storage-Reduction on Pt and K Co-Supported Antimony-Doped Tin Oxides.

NOx storage-reduction (NSR), a promising approach for removing NOx pollutants from diesel vehicles, remains elusive to cope with the increasingly lower exhaust temperatures (especially below 250 °C). Here, we develop a conceptual electrified NSR strategy, where electricity with a low input power (0.5-4 W) is applied to conductive Pt and K co-supported antimony-doped tin oxides (Pt-K/ATO), with C3H6 as a reductant. The ignition temperature for 10% NOx conversion is nearly 100 °C lower than that of the traditional thermal counterpart. Furthermore, reducing the power in the fuel-lean period relative to that in the fuel-rich period increases the maximum energy efficiency by 23%. Electrically driven release of lattice oxygen is revealed to play vital roles in multiple steps in NSR, including NO adsorption, desorption, and reduction, for improved NSR activity. This work provides an electrification strategy for developing high-activity NSR catalysis utilizing electricity onboard hybrid vehicles.

[Development of a flexible embedded neurostimulator for animal robots].

The neural stimulator is a core component of animal robots. While the control effect of animal robots is influenced by various factors, the performance of the neural stimulator plays a decisive role in regulating animal robots. In order to optimize animal robots, embedded neural stimulators had been developed using flexible printed circuit board technology. This innovation not only enabled the stimulator to generate parameter-adjustable biphasic current pulses through control signals, but also optimized its carrying mode, material, and size, overcoming the disadvantages of traditional backpack or head-inserted stimulators, which have poor concealment and are prone to infection. Static, in vitro, and in vivo performance tests of the stimulator demonstrated that it not only had precise pulse waveform output capability, but also was lightweight and small in size. It had excellent in vivo performance in both laboratory and outdoor environments. Our study has high practical significance for the application of animal robots.

Efficient Pyrazolo[5,4-f]quinoxaline Functionalized Os(II) Based Emitter with an Electroluminescence Peak Maximum at 811†nm.

Upon fusing the pyrazinyl pyrazole entity in giving pyrazolo[3,4-f]quinoxaline chelate, the corresponding Os(II) based NIR emitter exhibited "invisible" and efficient electroluminescence with a peak maximum at 811 nm. A maximum external quantum efficiency of 0.97 % and a suppressed efficiency roll-off till a current density of 300 mA cm-2 was also exhibited.

Regioselective Syntheses of Imidazo[4,5-b]pyrazin-2-ylidene-Based Chelates and Blue Emissive Iridium(III) Phosphors for Solution-Processed OLEDs.

Six homoleptic Ir(III) complexes bearing imidazo[4,5-b]pyrazin-2-ylidene chelates were successfully designed and synthesized. Narrowband blue emission (λmax = 466-485 nm) and broadened green emission (λmax = 518-532 nm) in degassed toluene solution with high photoluminescent quantum yields in the range of 75-81 and 45-48% were observed for f-timpz, t2impz, and t2empz as well as m-timpz, t2impz, and t2empz, respectively. In addition, the tert-butylphenyl cyclometalate is more electron donating than N-phenyl cyclometalate and, hence, all tert-butylphenyl-substituted derivatives, that is, m- and f-t2impz and m- and f-t2empz, give more red-shifted emission in comparison to that of m- and f-timpz. Moreover, solution-processed OLED with f-t2empz (20 wt %) as the dopant gave electrophosphorescence at 474 nm with maximum external quantum efficiency (max. EQE) of 5.1%, while hyper-OLED with assistant sensitizer f-t2empz (10 wt %) and the multi-resonance thermally activated delayed fluorescence emitter BCzBN (0.5 wt %) afforded narrowband emission centered at 485 nm and max. EQE up to 17.4%, confirming the high potential of this class of Ir(III) metal phosphors.

A strategy to comprehensively analyze the bioactivity of complex herbal prescriptions via peak-by-peak cutting and knock-out chromatography: Qiliqiangxin capsule as an example.

An herbal prescription is usually composed of several herbal medicines. The complex and diverse components bring great challenges to its bioactivity study. To comprehensively analyze the bioactivity of an herbal prescription, a new strategy based on peak-by-peak cutting and knock-out chromatography was proposed. In this strategy, active compounds were screened out via peak-by-peak cutting from an herbal extract, and the influence of a compound on the overall activity of the herbal extract was evaluated by knock-out chromatography. Qiliqiangxin capsule is an herbal prescription composed of 11 herbal medicines for the treatment of chronic heart failure. A total of 71 peaks were collected through peak-by-peak cutting, and each peak was identified by a high-resolution mass spectrum. The bioassay against 1,1-diphenyl-2-picrylhydrazyl showed that two types of compounds namely salvianolic acids and caffeoylquinic acids were potent scavengers. Knock-out chromatography suggested that the removal of one single compound had no obvious influence on the overall activity of the Qiliqiangxin capsule. After all the main peaks in the Qiliqiangxin capsule were knocked out, the remaining part still exhibited a potent activity, indicating high activity stability of the Qiliqiangxin capsule. The proposed strategy is helpful for the comprehensive analysis of the bioactivity of other herbal prescriptions.

Using GC Content to Compare Recombination Patterns on the Sex Chromosomes and Autosomes of the Guppy, Poecilia reticulata, and Its Close Outgroup Species.

Genetic and physical mapping of the guppy (Poecilia reticulata) have shown that recombination patterns differ greatly between males and females. Crossover events occur evenly across the chromosomes in females, but in male meiosis they are restricted to the tip furthest from the centromere of each chromosome, creating very high recombination rates per megabase, as in pseudoautosomal regions of mammalian sex chromosomes. We used GC content to indirectly infer recombination patterns on guppy chromosomes, based on evidence that recombination is associated with GC-biased gene conversion, so that genome regions with high recombination rates should be detectable by high GC content. We used intron sequences and third positions of codons to make comparisons between sequences that are matched, as far as possible, and are all probably under weak selection. Almost all guppy chromosomes, including the sex chromosome (LG12), have very high GC values near their assembly ends, suggesting high recombination rates due to strong crossover localization in male meiosis. Our test does not suggest that the guppy XY pair has stronger crossover localization than the autosomes, or than the homologous chromosome in the close relative, the platyfish (Xiphophorus maculatus). We therefore conclude that the guppy XY pair has not recently undergone an evolutionary change to a different recombination pattern, or reduced its crossover rate, but that the guppy evolved Y-linkage due to acquiring a male-determining factor that also conferred the male crossover pattern. We also identify the centromere ends of guppy chromosomes, which were not determined in the genome assembly.

Simultaneous Surface-Enhanced Resonant Raman and Fluorescence Spectroscopy of Monolayer MoSe2: Determination of Ultrafast Decay Rates in Nanometer Dimension.

The fact that metallic nanostructures are an excellent light receiver and transmitter connects the underlying principles of two widely applied optical processes: surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF). A comparative study of SERS and SEF can eliminate the typical unknown quantities of the system and reveal important parameters that cannot be accessed by conventional techniques. Here, we use this simultaneous SERS and SEF technique in a monolayer MoSe2 coupled plasmonic nanocavity. After optimizing the spatial and the spectral overlaps between excitonic and plasmonic resonances, the SERS and SEF enhancement factors can exceed 107 and 6000, respectively, at the same time on the same nanocube. The comparison of the SERS and SEF enhancements allows the estimation of the ultrafast total decay rate of the bright exciton in monolayer MoSe2 in the nanocavity down to tens of femtoseconds, which is otherwise hard to realize using time-resolved techniques.

Identification and functional analysis of genetic variants in TBX5 gene promoter in patients with acute myocardial infarction.

BACKGROUND: Coronary artery disease (CAD), including acute myocardial infarction (AMI), is a common complex disease. Although a great number of genetic loci and variants for CAD have been identified, genetic causes and underlying mechanisms remain largely unclear. Epidemiological studies have revealed that CAD incidence is strikingly higher in patients with congenital heart disease than that in normal population. T-box transcription factors play critical roles in embryonic development. In particular, TBX5 as a dosage-sensitive regulator is required for cardiac development and function. Thus, dysregulated TBX5 gene expression may be involved in CAD development. METHODS: TBX5 gene promoter was genetically and functionally analysed in large groups of AMI patients (n = 432) and ethnic-matched healthy controls (n = 448). RESULTS: Six novel heterozygous DNA sequence variants (DSVs) in the TBX5 gene promoter (g.4100A > G, g.4194G > A, g.4260 T > C, g.4367C > A, g.4581A > G and g.5004G > T) were found in AMI patients, but in none of controls. These DSVs significantly changed the activity of TBX5 gene promoter in cultured cells (P < 0.05). Furthermore, three of the DSVs (g.4100A > G, g.4260 T > C and g.4581A > G) evidently modified the binding sites of unknown transcription factors. CONCLUSIONS: The DSVs identified in AMI patients may alter TBX5 gene promoter activity and change TBX5 level, contributing to AMI development as a rare risk factor.

Evaluation of different Saccharomyces cerevisiae strains on the profile of volatile compounds in pineapple wine.

Yeast strain plays a central role in the formation of aroma and flavour of fruit wine. The effect of four commercial Saccharomyces cerevisiae strains (D254, VIC, BV818 and CECA) on volatile compounds of fermented pineapple (Ananas comosus L. Merr.) juice was investigated. Alcohols and esters were the most abundant groups in terms of the amounts of identified volatiles in four pineapple wines, followed by acids and sulphur compounds. Different S. cerevisiae strains possess various capacities to release or synthesize volatiles during pineapple wine fermentation. For global aroma, strain D254 yielded the highest total number and concentration of volatiles and could be used as a starter culture for the making of intense pineapple wine. Strain BV818 produced wine with the highest amounts of volatiles with OAVs > 1 and scored the highest in global aroma. Thus, BV818 might be the appropriate strain that could impart characteristic aromas and enhance wine complexity. The relative content of esters formed by strain VIC was higher than that yielded by the other strains. Strain CECA produced the highest relative contents of alcohols, aldehydes and ketones. However, VIC and CECA were not ideal starter cultures because of their low sense scores. This study provided a foundation for the production of pineapple wine with the desired flavour profile.

Fully biobased hydrogel based on chitosan and tannic acid coated cotton fabric for underwater superoleophobicity and efficient oil/water separation.

Underwater superoleophobic (UWSO) materials have garnered significant attention in separating oil/water mixtures. But, the majority of these materials are made from non-degradable and non-renewable raw materials, polluting the environment and wasting scarce resources while using them. Against this backdrop, this study aimed to fabricate an environmental-friendly UWSO textile using biobased materials. To achieve this, hydrogel consisting of chitosan (CS) and poly(tannic acid) (PTA) were formed and coated on cotton fabric (CTF) via dip-coating followed by oxidative polymerization. CS&PTA hydrogel endowed the CTF with a rough surface and high surface energy, leading to an UWSO CTF with an underwater oil contact angle as high as 166.84°. The CS&PTA/CTF had excellent separation capability toward various oil/water mixtures, showing separation efficiency above 99.84 % and water flux higher than 23, 999 L m-2 h-1. Moreover, CS&PTA/CTF possessed excellent mechanical and environmental stability with underwater superoleophobicity unchanged after sandpaper friction, ultrasonication, organic solvents, NaCl (m/v, 30 %) solution, and acid/base solution immersion, due to the strong interaction between the hydrogel and cotton fabric generated by the mussel-inspired adhesion owing to the presence of PTA. The fully biobased UWSO CTF exhibits great promising to be an alternative to traditional superwetting materials for separation of oil/water mixtures.

Selection against domestication alleles in introduced rabbit populations.

Humans have moved domestic animals around the globe for thousands of years. These have occasionally established feral populations in nature, often with devastating ecological consequences. To understand how natural selection shapes re-adaptation into the wild, we investigated one of the most successful colonizers in history, the European rabbit. By sequencing the genomes of 297 rabbits across three continents, we show that introduced populations exhibit a mixed wild-domestic ancestry. We show that alleles that increased in frequency during domestication were preferentially selected against in novel natural environments. Interestingly, causative mutations for common domestication traits sometimes segregate at considerable frequencies if associated with less drastic phenotypes (for example, coat colour dilution), whereas mutations that are probably strongly maladaptive in nature are absent. Whereas natural selection largely targeted different genomic regions in each introduced population, some of the strongest signals of parallelism overlap genes associated with neuronal or brain function. This limited parallelism is probably explained by extensive standing genetic variation resulting from domestication together with the complex mixed ancestry of introduced populations. Our findings shed light on the selective and molecular mechanisms that enable domestic animals to re-adapt to the wild and provide important insights for the mitigation and management of invasive populations.

Mitigating the Trade-Off between Non-Radiative Recombination and Charge Transport to Enable Efficient Ternary Organic Solar Cells.

Ternary organic solar cells (OSCs) have attracted intensive studies due to their promising potential for attaining high-performing photovoltaics, whereas there has been an opening challenge in minimizing the open circuit voltage (Voc) loss while retaining the optimal carrier extraction in the multiple mixture absorbers. Here, we systemically investigate a ternary absorber comprised of two acceptors and a donor, in which the resultant Voc and fill factor are varied and determined by the ratios of acceptor components as a result of the unbalance of non-radiative recombination rates and charge transport. The transient absorption spectroscopy and electroluminescence techniques verify two distinguishable charge-transfer (CT) states in the ternary absorber, and the mismatch of non-radiative recombination rates of those two CT states is demonstrated to be associated with the Voc deficit, whilst the high-emissive acceptor molecule delivers inferior electron mobility, resulting in poor charge transport and a subpar fill factor. These findings enable us to optimize the mixture configuration for attaining the maximal-performing devices. Our results not only provide insight into maximizing the photovoltage of organic solar cells but can also motivate researchers to further unravel the photophysical mechanisms underlying the intermolecular electronic states of organic semiconductors.

Post-Synthetic Modification of an Amino-Functionalized Metal-Organic Framework for Highly In Situ Luminescent Detection of Mercury (II).

A sulfur-containing metal-organic framework, donated as UiO-66-NSMe, was prepared by the post-synthetic modification (PSM) of UiO-66-NH2 with 2-(Methylthio)benzaldehyde, and the successful synthesis of PSM was confirmed by X-ray photoelectron spectroscopy (XPS), FT-IR and 1H NMR studies. According to the characteristics of mercury thiophilic, UiO-66-NSMe could be used as a luminescent sensor for Hg2+ detection with a high selectivity and sensitivity (Ksv = 2.5 × 104 M-1; LOD = 20 nM), which could be attributed to the coordination between sulfur sites and Hg2+ based on XPS results. In practical applications, UiO-66-NSMe yielded satisfactory recovery rates (ranging from 96.1% to 99.5%) when it was employed for detecting Hg2+ in spiked environmental samples. Furthermore, UiO-66-NSMe was successfully employed to detect mercury (II) residues with the in situ rapid nondestructive imaging in simulated fresh agricultural products. Thus, this PSM strategy could provide good guidance for environmental protection methodologies in the future.

Direct spectroscopic evidence of CO spillover and subsequent reaction with preadsorbed NOx on Pd and K cosupported Mg-Al mixed oxides.

The CO adsorption and subsequent reaction with preadsorbed NO(x) on Pd and K cosupported Mg-Al mixed oxides (Pd-K/MgAlO, 1/8/100 w/w) were investigated using in situ FTIR spectroscopy. During CO adsorption, a peculiar and well-defined IR band at 2160 cm(-1) was observed. Several elaborately designed experiments such as the competitive adsorption of CO and CO(2) demonstrated that the 2160 cm(-1) band was exclusively assigned to a carbonyl species on K sites due to the CO spillover from Pd to K, which results from a strong Pd-K interaction based on temperature-programmed reduction with H(2) experiments. Importantly, the spillover of CO is found to be involved in the reduction of preadsorbed NO(x) from temperature-programmed surface reactions with CO. Thus, all adsorbed NO(x) can be reduced by CO before desorption. Like the process of "pumping" CO by Pd from the atmosphere to "irrigate the field" of the nitrates/nitrites, the adsorbed NO(x) at not only K sites adjacent to Pd but also at the remote K sites can be reduced into N(2) and N(2)O effectively.

Solution combustion derived oxygen vacancy-rich Co3O4 catalysts for catalytic formaldehyde oxidation at room temperature.

Fabricating abundant oxygen vacancies is crucial for non-noble metal oxides to catalyze formaldehyde (HCHO) oxidation at room temperature. Here, a simple one-pot preparation method via solution combustion was found to produce oxygen vacancy-rich Co3O4 catalysts, avoiding delicate defect engineering. The catalyst was evaluated to result in 52% HCHO conversion in a dynamic flow reaction with ∼6 ppm HCHO, which was higher as compared to some other Co3O4 catalysts prepared in three methods of sol-gel, deposition precipitation and thermal decomposition. The optimal catalyst also exhibited high durability with steady HCHO conversion (∼47%) for more than 50 h. The catalyst characterizations revealed that the explosive solution combustion brought out two particular features of Co3O4, namely, the porous network structure with nano-holes and the abundant oxygen vacancies. The latter was demonstrated to increase the reactive oxygen species and to improve the reducibility and the oxygen transport capacity of Co3O4. The two features and the derived properties are beneficial to the activity and durability of Co3O4. The solution combustion method can serve as a simple and feasible way to fabricate abundant oxygen vacancies to provide room-temperature activity of Co3O4 for HCHO elimination at room temperature.

Blue Phosphorescence and Hyperluminescence Generated from Imidazo[4,5-b]pyridin-2-ylidene-Based Iridium(III) Phosphors.

Four isomeric, homoleptic iridium(III) metal complexes bearing 5-(trifluoromethyl)imidazo[4,5-b]pyridin-2-ylidene and 6-(trifluoromethyl)imidazo[4,5-b]pyridin-2-ylidene-based cyclometalating chelates are successfully synthesized. The meridional isomers can be converted to facial isomers through acid induced isomerization. The m-isomers display a relatively broadened and red-shifted emission, while f-isomers exhibit narrowed blue emission band, together with higher photoluminescent quantum yields and reduced radiative lifetime relative to the mer-counterparts. Maximum external quantum efficiencies of 13.5% and 22.8% are achieved for the electrophosphorescent devices based on f-tpb1 and m-tpb1 as dopant emitter together with CIE coordinates of (0.15, 0.23) and (0.22, 0.45), respectively. By using f-tpb1 as the sensitizing phosphor and t-DABNA as thermally activated delayed fluorescence (TADF) terminal emitter, hyperluminescent OLEDs are successfully fabricated, giving high efficiency of 29.6%, full width at half maximum (FWHM) of 30 nm, and CIE coordinates of (0.13, 0.11), confirming the efficient Förster resonance energy transfer (FRET) process.

TFEB Gene Promoter Variants Effect on Gene Expression in Acute Myocardial Infarction.

Autophagy is involved in many physiological processes. Transcription factor EB (TFEB) is a master regulator of autophagy and coordinates the expression of autophagic proteins, lysosomal hydrolases, and lysosomal membrane proteins. Though autophagy has been implicated in several human diseases, little is known regarding TFEB gene expression and regulation in the process. Since dysfunctional autophagy plays critical roles in acute myocardial infarction (AMI), dysregulated TFEB gene expression may be associated with AMI by regulating autophagy. In this study, the TFEB gene promoter was genetically and functionally analyzed in AMI patients (n = 352) and ethnic-matched controls (n = 337). A total of fifteen regulatory variants of the TFEB gene, including eight single-nucleotide polymorphisms (SNPs), were identified in this population. Among these, six regulatory variants [g.41737274T>C (rs533895008), g.41737144A>G, g.41736987C > T (rs760293138), g.41736806C > T (rs748537297), g.41736635T > C (rs975050638), and g.41736544C > T] were only identified in AMI patients. These regulatory variants significantly altered the transcriptional activity of the TFEB gene promoter. Further electrophoretic mobility shift assay revealed that three of the variants evidently affected the binding of transcription factors. Therefore, this study identified novel TFEB gene regulatory variants which affect the gene expression. These TFEB gene regulatory variants may contribute to AMI development as a rare risk factor.

Determination of intermediates and mechanism for soot combustion with NOx/O2 on potassium-supported Mg-Al hydrotalcite mixed oxides by in situ FTIR.

The soot combustion with NO(x) and/or O(2) on potassium-supported Mg-Al hydrotalcite mixed oxides under tight contact condition was studied using temperature-programmed oxidation (TPO), isothermal reaction and in situ FTIR techniques. The presence of NO(x) in O(2) favors the soot combustion at lower temperatures (<300 °C). However, a little suppression was observed at higher temperatures (>300 °C), which was accompanied by a substantial NO(x) reduction. The ketene (C═C═O) and isocyanate (NCO(-)) species were determined as the reaction intermediates. In NO(x) + O(2), NO(2) directly interacts with the free carbon sites (C═C*) through two parallel reactions: (1) NO(2) + C═C* → C═C═O + NO; (2) NO(2) + C═C* → NCO(-) + CO(2). The two reactions can proceed easily, which accounts for the promotion effect of NO(x) on soot combustion at lower temperatures. The further oxidation of NCO(-) by NO(2) or O(2) is responsible for the simultaneous reduction of NO(x). However, the reactions between NO(2) and C═C* are limited by the amount of free carbon sites, which can be provided by the oxidation of soot by O(2) at higher temperatures. The interaction of NO(x) and catalyst results in the formation of nitrates and nitrites, which poisoned the active K sites.