Ion–Electron Coupling Enables Ionic Thermoelectric Material with New Operation Mode and High Energy Density

Ionic thermoelectrics(i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin. However,as ions cannot enter external circuit, the utilization of i-TE is currently based on capacitive charge/discharge, which results in discontinuous working mode and low energy density. Here,we introduce an ion–electron thermoelectric synergistic(IETS)effect by utilizing an ion–electron conductor. Electrons/holes can drift under the electric field generated by thermodiffusion of ions, thus converting the ionic current into electrical current that can pass through the external circuit. Due to the IETS effect, i-TE is able to operate continuously for over 3000 min.Moreover, our i-TE exhibits a thermopower of 32.7 mV K^(-1) and an energy density of 553.9 J m^(-2), which is more than 6.9 times of the highest reported value. Consequently, direct powering of electronics is achieved with i-TE. This work provides a novel strategy for the design of high-performance i-TE materials.

Identification of quantitative trait loci associated with resistance to Xanthomonas oryzae pv. oryzae pathotypes prevalent in South China

Bacterial blight(BB), which is caused by Xanthomonas oryzae pv. oryzae(Xoo), is an important rice disease responsible for significant yield losses. In the rice-growing regions of South China where BB outbreaks are common, the resistance of cultivars with BB resistance genes Xa4 and Xa21 has been lost because of rapid changes in the Xoo population structure and virulence. In this study, 421 diverse rice accessions were evaluated regarding their resistance to two Xoo strains, namely GD1358(C5) and IV, which are prevalent pathotypes in South China and overcame the resistance of Xa4 and Xa21, respectively. Using the 4.8 mio filtered SNP dataset, we conducted a genome-wide association study, which identified 13 loci associated with BB resistance, including eight new quantitative trait loci(QTL) and five QTL harboring known BB resistance genes: Xa3/Xa26, xa5, Xa35(t), Xa36(t), Xa40, Xa43(t), and xa44(t). Intriguingly, a steep peak was detected on chromosomes 5 and 11. Six QTL including three new ones, were distributed on chromosome 11, whereas a new QTL q BB5.1 and a known QTL were detected on chromosome 5. Haplotype analyses indicated that the LOC;s05 g01610(Os PRAF2) gene within the q BB5.1 region, which encodes a PRAF protein, is associated with BB resistance. Furthermore, Os PRAF2 knockout lines generated using the CRISPR-Cpf1 system were significantly more resistant to Xoo strains than the wild-type plants. Our results provide researchers and breeders with useful information regarding QTL and gene resources,which may be relevant for developing new BB-resistant rice cultivars.

Early performance of Pinus radiata provenances in the earthquakeravaged dry river valley area of Sichuan, southwest China

A provenance experiment involving five native provenances and an Australian landrace of Pinus radiata （D. Don） was established over three sites in the dry river valley area of Sichuan, southwest China in 2004 in order to select the most suitable provenance for environmental planting on the dry, steep and degraded slopes to reduce soil erosion. Although with much lower soil moisture supply and mean minimum temperatures in winter compared to P. radiata provenance trials estab- lished elsewhere in the world, these sites are within the working limits of the species defined by previous climate modelling and matching. Be- cause of the difficult site conditions and severe natural disturbances after the experiment was established, mortality was high across the three sites in comparison to provenance trials in other countries.

Annealing-free alcohol-processable MoO_(X) anode interlayer enables efficient light utilization in organic photovoltaics

Molybdenum oxide(MoO_(x))is a commonly used hole extraction material in organic photovoltaics.The MoO_(x) interlayer is deposited typically via thermal evaporation in vacuum.To meet the need for rollto-roll manufacturing,solution processing of MoO_(x) without post-annealing treatment is essential.Herein,we demonstrate an effective approach to produce annealing-free,alcohol-processable MoO_(x) anode interlayers,namely S-MoO_(x),by utilizing the bis(catecholato)diboron(B_(2) Cat_(2))molecule to modify the surface oxygen sites in MoO_(x).The formation of surface diboron-oxygen complex enables the alcohol solubility of S-MoO_(x).An enhanced light utilization is realized in the S-MoO_(x)-based organic photovoltaics.This affords a superior short-circuit current density(Jsc)close to 26 mA cm^(-2) and ultimately a high power-conversion efficiency(PCE)of 15.2%in the representative PM6:Y6 based inverted OPVs,which is one of the highest values in the inverted OPVs using an as-cast S-MoO_(x) anode interlayer.

Comparative microRNA profiling reveals microRNAs involved in rice resistant response to bacterial blight

Bacterial blight(BB), which is caused by Xanthomonas oryzae pv. oryzae(Xoo), is one of the most destructive bacterial diseases of rice(Oryza sativa L.). During plant defense responses, micro RNAs(mi RNAs) play important roles in regulating disease resistance. However, the functions of mi RNAs in the interaction between rice and Xoo remain relatively uncharacterized. In this study, we compared the mi RNA profiles of the BB resistant rice introgression line F329 and its susceptible recurrent parent Huang-Hua-Zhan(HHZ) at multiple time points after inoculation with Xoo. A total of 538 known and 312 novel mi RNAs were identified, among which only 17 and 26 were responsive to Xoo infection in F329 and HHZ, respectively. Compared with the expression levels in HHZ, 37 up-regulated and 53 down-regulated mi RNAs were detected in F329. The predicted target genes for the mi RNAs differentially expressed between F329 and HHZ were revealed to be associated with flavonoid synthesis, the reactive oxygen species regulatory pathway, plant hormone signal transduction, defense responses, and growth and development.Additionally, the patterns of interactions between osa-mi R390-3 p, novel_mi R_104, novel_mi R_238,osa-mi R166 k-5 p, osa-mi R529 b, and osa-mi R167 h-3 p and their target genes were further validated by quantitative real-time PCR. Furthermore, we overexpressed osa-mi R167 h-3 p in transgenic plants and proved that this mi RNA positively regulates the resistance of rice to BB. These results provide novel information regarding the mi RNA-based molecular mechanisms underlying the disease resistance of rice. The data presented herein may be useful for engineering rice BB resistance via mi RNAs.

Self-adhesive and biocompatible dry electrodes with conformal contact to skin for epidermal electrophysiology

Long-term biopotential monitoring requires high-performance biocompatible wearable dry electrodes.But currently,it is challenging to establish a form-preserving fit with the skin,resulting in high interface impedance and motion artifacts.This research aims to present an innovative solution using an all-green organic dry electrode that eliminates the aforementioned challenges.The dry electrode is prepared by introducing biocompatible maltitol into the chosen conductive polymer,poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate).Thanks to the secondary doping and plasticizer effect of maltitol,the dry electrode exhibits good stretchability(62%),strong self-adhesion(0.46 N/cm),high conductivity(102 S/cm),and low Young's modulus(7 MPa).It can always form a conformal contact with the skin even during body movements.Together with good electrical properties,the electrode enables a lower skin contact impedance compared to the current standard Ag/AgCl gel electrode.Consequently,the application of this dry electrode in bioelectrical signal measurement(electromyography,electrocardiography,electroencephalogra-phy)and long-term biopotential monitoring was successfully demonstrated.

Theoretical study on two-dimensional MoS2 piezoelectric nanogenerators

Recent experiments have demonstrated that nanogenerators fabricated using two-dimensional MoS2 flakes may find potential applications in electromechanical sensing, wearable technology, pervasive computing, and implanted devices. In the present study, we theoretically examined the effect of the number of atomic layers in MoS2 flakes on the nanogenerator output. Under a square-wave applied strain, MoS2 flakes with an even number of atomic layers did not exhibit a piezoelectric output, owing to the presence of a projected inversion symmetry. On the other hand, for MoS2 flakes with an odd number of layers, owing to the lack of inversion symmetry, piezoelectric output voltage and current were generated, and decreased with the increase of the number of layers. Furthermore, as MoS2 flakes were only a few atoms thick, the capacitance of the MoS2 nanogenerators was at least an order of magnitude smaller than that of the nanowire- and nanofilm-based nanogenerators, enabling the use of MoS2 nano- generators in high-frequency applications. Our results explain the experimental observations and provide guidance on optimizing and designing two-dimensional nanogenerators.

C-V characteristics of piezotronic metal-insulator-semiconductor transistor

Third generation semiconductors for piezotronics and piezo-phototronics,such as Zn O and Ga N,have both piezoelectric and semiconducting properties.Piezotronic devices normally exhibit high strain sensitivity because strain-induced piezoelectric charges control or tune the carrier transport at junctions,contacts and interfaces.The distribution width of piezoelectric charges in a junction is one of important parameters.Capacitance-voltage(C-V)characteristics can be used to estimate the distribution width of strain-induced piezoelectric charges.Piezotronic metal–insulator-semiconductor(MIS)has been modelled by analytical solutions and numerical simulations in this paper,which can serve as guidance for C-V measurements and experimental designs of piezotronic devices.

The methylenetetrahydrofolate reductase genotype 677CT and non-alcoholic fatty liver disease have a synergistic effect on the increasing homocysteine levels in subjects from Chongqing,China

The methylenetetrahydrofolate reductase(MTHFR)genotypes 677CT and 677TT are associated with elevated serum homocysteine(Hcy)levels by means of lowering the activity of MTHFR,and the increase in serum Hcy may be linked to increased susceptibility to nonalcoholic fatty liver disease(NAFLD).However,there are contradictory reports of the relationship among the MTHFR 677CT gene polymorphism,Hcy,and NAFLD.Therefore,the aim of this study was to identify potential associations and interactions of either Hcy levels or the MTHFR 677CT gene polymorphism with the susceptibility to NAFLD in a Chinese population.The association between the MTHFR 677 CT gene polymorphism and Hcy levels was determined in 243 subjects with NAFLD and 388 healthy subjects without NAFLD using polymerase chain reactionrestriction fragment length polymorphism analysis and high-performance liquid chromatography.In subjects with NAFLD,there was no statistical difference in the genotypic and allelic frequencies of the MTHFR 677 CT gene polymorphism,while serum Hcy levels were significantly higher in subjects with NAFLD.Furthermore,these results strongly suggest that the MTHFR 677CT gene polymorphism and NAFLD have a potential synergistic effect on Hcy elevation,although the MTHFR 677CT gene polymorphism was not correlated with NAFLD in a Chinese population.