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A novel transient electronics technology that is capable of completely dissolving or decomposing in certain conditions after a period of operation offers unprecedented opportunities for medical implants, environmental sensors, and other applications. Here, we describe a biodegradable, flexible silicon-based electronic system that detects NO species with a record-breaking sensitivity of 136 Rs (5 ppm, NO2) and 100-fold selectivity for NO species over other substances with a fast response (~30 s) and recovery (~60 s). The exceptional features primarily depend on not only materials, dimensions, and design layouts but also temperatures and electrical operations. Large-scale sensor arrays in a mechanically pliable configuration exhibit negligible deterioration in performance under various modes of applied loads, consistent with mechanics modeling. In vitro evaluations demonstrate the capability and stability of integrated NOx devices in severe wet environments for biomedical applications. Biomedical electronics: Getting a whiff of bad health Degradable devices that monitor health by measuring gases emitted by the body have been developed by researchers in South Korea, the UK and the USA. Biodegradable electronics, devices that decay naturally over time, are potentially useful for medical devices. They can be used internally as implants that don't need to be surgically removed or externally as wearable health monitors. Chong-Yun Kang and Suk-Won Hwang from Korea University in Seoul and their colleagues have developed a biodegradable, flexible silicon nanomembrane to detect nitric oxide with a high sensitivity andselectivity and a fast response time. Nitric oxide sensors are important for health monitoring as the gas is associated with many physiological processes including regulation of the vascular system and blood flow. In vitro experiments in aqueous solutions demonstrated the feasibility of their devices for disposable medical implants. Soft, transient silicon-based gas sensing system capable of detecting nitrogen oxides with remarkable sensitivity and selectivity is presented in this report. The results provide materials, device layouts, manufacturing process, and theorectical modeling illlustrating the capabilities and operational aspects. In vitro experiments demonstrate the possibilities for disposable environmental monitors and temporary biomedical implants. [ABSTRACT FROM AUTHOR]

The original article can be found online at https://doi.org/10.1038/s41467-023-38860-4.Correction to: Nature Communicationshttps://doi.org/10.1038/s41467-023-38860-4, published online 29 May 2023In this article the affiliation details for Changxuan Xia, Kang Chong and Yunyuan Xu were incorrectly given as 'University of the Chinese Academy of Sciences, Beijing 100049, China' but should have been 'University of Chinese Academy of Sciences, Beijing 100049, China'.The original article has been corrected.By Changxuan Xia; Guohua Liang; Kang Chong and Yunyuan XuReported by Author; Author; Author; Author [Extracted from the article]

A K2-mNb2O6-m/2 single crystal with a pyrochlore phase formed when the Nb2O5 + x mol% KOH specimens with 0.6 ≤ x ≤ 1.2 were solvothermally heated at 230 °C for 24 h. They have an octahedral shape with a size of 100 μm, and the composition of this single crystal is close to K1.3Nb2O5.65. The single-crystal KNbO3 formed when the single-crystal K2-mNb2O6-m/2 was annealed at a temperature between 600 °C and 800 °C with K2CO3 powders. When annealing was conducted at 600 °C (or with a small amount of K2CO3), the KNbO3 single crystal has a rhombohedral structure that is stable at low temperatures (< − 10 °C). The formation of the rhombohedral KNbO3 structure can be explained by the presence of the K+ vacancies in the specimen. The KNbO3 single crystal with an orthorhombic structure formed when the K2-mNb2O6-m/2 single crystal was annealed at 800 °C with 20 wt% of K2CO3. [ABSTRACT FROM AUTHOR]

We designed and manufactured a novel annular-core hollow beam fiber which could directly yield ring light with a central dark spot inside the beam employing MCVD technique and a custom-made fiber drawing tower. The tapered fiber zone geometric shapes at varied stretching speed between the single-core fiber and the annular-core hollow beam fiber were studied theoretically. According to the beam propagation method, the bi-tapered coupling energy transmission between these two fibers was simulated and analyzed. Moreover, by adopting a fusion splicing and stretching technique at the fiber-linked point, an effective coupling approach had been fulfilled. [ABSTRACT FROM AUTHOR]

We propose an efficient and effective method for real-time tracking a long-range magnetic target using total geomagnetic field intensity. This method is based on a scalar magnetometer sensor array and an improved particle swarm optimization algorithm. Due to the effect of the geomagnetic field variations, the detection distance range of the method based on the gradient tensor is short. To increase the detection range, the geomagnetic field variations must be eliminated in the method. In this paper, the geomagnetic quasi-gradient calculated from total geomagnetic field intensity in the sensor array is used. We design a sensor array with five magnetometers and use the geomagnetic quasi-gradient to eliminate the geomagnetic field variations. The improved particle swarm optimization (IPSO) algorithm, which minimizes the errors of total geomagnetic field values between measurements and calculations, is applied in this real-time tracking method to track a long-range magnetic target position. The detailed principle of the method and the steps of the IPSO algorithm are described in detail. The method is validated with a numerical simulation. The results show that the average relative error of position is less than 2 % and the execution time is less than 1.5 s. [ABSTRACT FROM AUTHOR]

The position of a magnetic target can be obtained through magnetic anomaly which is measured by a magnetic sensor. Comparing with vector magnetic sensor, the measurement value of the scalar magnetic sensor is almost not influenced by its orientation in measurement coordinate axes. Therefore, scalar magnetic sensors can be easily assembled into an array. Based on analysis of the total scalar magnetic anomaly measured by scalar magnetometer, we present an efficient method for tracking a magnetic target using scalar magnetometer array. In this method, we separate the position information and magnetic moment information of magnetic target by matrix transformation. Then, we can obtain the position of the magnetic target in real time by a scalar magnetometer array and a particle swarm optimization algorithm. In addition, the magnetic moment of the target can be estimated when the target's position had been calculated. The simulation shows that the position of the target can be calculated accurately and the relative error of the position is <5 %. The calculated magnetic moment of the target is close to the theoretical value. In addition, execution time of each calculation is <1 s. Thus, the position of the magnetic target can be obtained in real-time through this method. [ABSTRACT FROM AUTHOR]

At present, the generation of heterostructures with two dimensional electron gas (2DEG) in amorphous LaAlO (a-LAO)/SrTiO (STO) has been achieved. Herein, we analysed thermal stability of 2DEG at a-LAO/STO interfaces in comparison with 2DEG at crystalline LaAlO (c-LAO)/STO interfaces. To create 2DEG at LAO/STO interface, regardless of growing temperature from 25 to 700 °C, we found that environment with oxygen deficient during the deposition of LAO overlayer is essentially required. That indicates that the oxygen-poor condition in the system is more essential than the crystalline nature of LAO layer. 2DEG at a-LAO/STO interface is depleted upon ex situ annealing at 300 °C under 300 Torr of oxygen pressure, while that in c-LAO/STO interface is still maintained. Our result suggests that the LAO overlayer crystallinity critically affects the thermal-annealing-induced depletion of 2DEG at a-LAO/STO interface rather than the generation of 2DEG. We clearly provide that amorphous TiO can efficiently prevent the thermal degradation of 2DEG at the a-LAO/STO interface, which gives a cornerstone for achieving thermal-stable 2DEG at a-LAO/STO interface. [ABSTRACT FROM AUTHOR]

Here we report comprehensive study of 2DEG at a-LAO/STO interfaces in comparison with 2DEG at crystalline LaAlO (c-LAO)/STO interfaces. We observe that the oxygen deficient environment during the deposition of LAO overlayer is essentially required to create 2DEG at LAO/STO interface regardless of growth temperature from 25°C to 700°C, indicating that the oxygen-poor condition in the system is more important than the crystallinity of LAO layer. The critical thickness (2.6 nm) of 2DEG formation at a-LAO/STO heterostructure is thicker than (1.6 nm) that at c-LAO/STO. Upon ex-situ annealing at 300°C under 300 mTorr of oxygen pressure, 2DEG at a-LAO/STO interface is annihilated, while that in c-LAO/STO interface is still maintained. With combing these findings and scanning transmission electron microscope (STEM) analysis, we suggest that oxygen vacancies at the LAO surface is attributed to the origin of 2DEG formation at the LAO/STO and the crystallinity of the LAO overlayer plays a critical role in the annihilation of 2DEG at a-LAO/STO interface rather than in the formation of 2DEG. This work provides a framework to understand the importance of prohibiting the LAO surface from being oxidized for achieving thermally stable 2DEG at a-LAO/STO interface. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Unlike bulk materials, many physical properties of thin-film materials depend on film thickness due to extrinsic effects such as residual stress and the dead layer. In this work, the effect of thickness on the electrocaloric properties of PbLa(ZrTi)O(10/65/35) (PLZT) films grown by the sol-gel method was studied experimentally. In the sol-gel synthesis, the annealing process results in residual stress and the metal-dielectric contact generates a dead layer. These extrinsic effects influence the dielectric and ferroelectric properties of the thin films, and their roles are film thickness dependent. For PLZT of nanometer thickness (from 420 nm to 1080 nm), the permittivity and polarization, and their temperature dependences, showed strong dependence on film thickness. In particular, in the temperature range from 70°C to 350°C, the electrocaloric temperature change showed threefold improvement (from 0.2°C to 0.6°C) as the thickness was increased from 420 nm to 840 nm. This work will aid development of polycrystalline thin films including PLZT for electrocaloric applications. [ABSTRACT FROM AUTHOR]

The performance of cantilever piezoelectric energy harvesters using three types of piezoelectric materials, relaxor ferroelectric 0.7Pb(MgNb)O-0.3PbTiO (PMN-PT) single crystals oriented along the 〈110〉 and 〈001〉 directions, and a PZT-based ceramic, were investigated. The 〈110〉 and 〈001〉 oriented PMN-PT single crystals, which have a rhombohedral phase and spontaneous polarization along the 〈111〉 direction, presented electromechanical coupling factor k's of 0.78 and 0.42, respectively. The cantilever-type energy harvester operated by 31 resonance mode generated a larger output power of 1.07 mW for the 〈110〉 oriented PMN-PT single crystal compared to those of the other materials. The effective electromechanical coupling factor of the piezoelectric energy harvester with the 〈110〉 oriented crystal also reached 0.25, not achievable with the other piezoelectric materials. These results demonstrate that the domain engineering of the piezoelectric single crystals can provide higher design flexibility for a tiny energy harvester. [ABSTRACT FROM AUTHOR]

Chloroplast is a typical plant cell organelle where photosynthesis takes place. In this study, a total of 1 808 chloroplast core proteins in Arabidopsis thaliana were reliably identified by combining the results of previously published studies and our own predictions. We then constructed a chloroplast protein interaction network primarily based on these core protein interactions. The network had 22 925 protein interaction pairs which involved 2 214 proteins. A total of 160 previously uncharacterized proteins were annotated in this network. The subunits of the photosynthetic complexes were modularized, and the functional relationships among photosystem I (PSI), photosystem II (PSII), light harvesting complex of photosystem I (LHC I) and light harvesting complex of photosystem I (LHC II) could be deduced from the predicted protein interactions in this network. We further confirmed an interaction between an unknown protein AT1G52220 and a photosynthetic subunit PSI-D2 by yeast two-hybrid analysis. Our chloroplast protein interaction network should be useful for functional mining of photosynthetic proteins and investigation of chloroplast-related functions at the systems biology level in Arabidopsis.Cell Research (2008) 18:1007–1019. doi: 10.1038/cr.2008.286; published online 23 September 2008 [ABSTRACT FROM AUTHOR]

In many temperate perennial plants, floral transition is initiated in the first growth season but the development of flower is arrested during the winter to ensure production of mature flowers in the next spring. The molecular mechanisms of the process remain poorly understood with few well-characterized regulatory genes. Here, a MADS-box gene, named as TrMADS3, was isolated from the overwintering inflorescences of Taihangia rupestris, a temperate perennial in the rose family. Phylogenetic analysis reveals that TrMADS3 is more closely related to the homologs of the FLOWERING LOCUS C lineage than to any of the other MIKC-type MADS-box lineages known from Arabidopsis. The TrMADS3 transcripts are extensively distributed in inflorescences, roots, and leaves during the winter. In controlled conditions, the TrMADS3 expression level is upregulated by a chilling exposure for 1 to 2 weeks and remains high for a longer period of time in warm conditions after cold treatment. In situ hybridization reveals that TrMADS3 is predominately expressed in the vegetative and reproductive meristems. Ectopic expression of TrMADS3 in Arabidopsis promotes seed germination on the media containing relatively high NaCl or mannitol concentrations. These data indicate that TrMADS3 in a perennial species might have its role in both vegetative and reproductive meristems in response to cold. [ABSTRACT FROM AUTHOR]

Abstract  ERFs, the largest group of AP2/EREBP transcription factors, are involved in diverse processes in plants. However, their importance in growth and development is not fully understood. Here, we report OsRAF (a Root Abundant Factor gene in Oryza sativa), a new member of the rice ERF group, expressed more abundantly in roots than in other organs of rice at the transcriptional level. Moreover, the expression could be up-regulated by ethylene or low temperature. Transient expression of OsRAF::GFP fusion in onion epidermis cells and its overexpression in Arabidopsis revealed that OsRAF was a nucleus localized protein. Down-regulation of OsRAF’s expression by RNAi method failed to produce aberrance in transgenic rice, which suggests existence of functionally redundant gene(s). [ABSTRACT FROM AUTHOR]

Developmental gene families have diversified during land plant evolution. The primary role of YABBY gene family is promoting abaxial fate in model eudicot, Arabidopsis thaliana. However recent results suggest that roles of YABBY genes are not conserved in the angiosperms. In this paper, a rice YABBY gene was isolated, and its expression patterns were analyzed in detail. Sequence characterization and phylogenetic analyses showed the gene is OsYABBY4, which is group-classified into FIL/YAB3 subfamily. Beta-glucuronidase reporter assay and in situ analysis consistently revealed that OsYABBY4 was expressed in the meristems and developing vascular tissue of rice, predominantly in the phloem tissue, suggesting that the function of the rice gene is different from those of its counterparts in eudicots. OsYABBY4 may have been recruited to regulate the development of vasculature in rice. However, transgenic Arabidopsis plants ectopically expressing OsYABBY4 behaved very like those over-expressing FIL or YAB3 with abaxialized lateral organs, suggesting the OsYABBY4 protein domain is conserved with its Arabidopsis counterparts in sequences. Our results also indicate that the functional diversification of OsYABBY4 may be associated with the divergent spatial–temporal expression patterns, and YABBY family members may have preserved different expression regulatory systems and functions during the evolution of different kinds of species. [ABSTRACT FROM AUTHOR]

Rice ( Oryza sativa L.) plant is sensitive to chilling, particularly at early stages of seedling development. Here a novel cold-inducible gene, designated OsCOIN ( O ryza s ativa cold- inducible), was isolated and characterized. Results showed that OsCOIN protein, a RING finger protein, was localized in both nuclear and cytoplasm membrane. OsCOIN is expressed in all rice organs and strongly induced by low temperature, ABA, salt and drought. Over-expression of OsCOIN in transgenic rice lines significantly enhanced their tolerance to cold, salt and drought, accompanied by an up-regulation of OsP5CS expression and an increase of cellular proline level. [ABSTRACT FROM AUTHOR]

Carotenoids, a class of natural pigments found in all photosynthetic organisms, are involved in a variety of physiological processes, including coloration, photoprotection, biosynthesis of abscisic acid (ABA) and chloroplast biogenesis. Although carotenoid biosynthesis has been well studied biochemically, the genetic basis of the pathway is not well understood. Here, we report the characterization of two allelic Arabidopsis mutants, spontaneous cell death1-1 (spc1-1) and spc1-2. The weak allele spc1-1 mutant showed characteristics of bleached leaves, accumulation of superoxide and mosaic cell death. The strong mutant allele spc1-2 caused a complete arrest of plant growth and development shortly after germination, leading to a seedling-lethal phenotype. Genetic and molecular analyses indicated that SPC1 encodes a putative ζ-carotene desaturase (ZDS) in the carotenoid biosynthesis pathway. Analysis of carotenoids revealed that several major carotenoid compounds downstream of SPC1/ZDS were substantially reduced in spc1-1, suggesting that SPC1 is a functional ZDS. Consistent with the downregulated expression of CAO and PORB, the chlorophyll content was decreased in spc1-1 plants. In addition, expression of Lhcb1.1, Lhcb1.4 and RbcS was absent in spc1-2, suggesting the possible involvement of carotenoids in the plastid-to-nucleus retrograde signaling. The spc1-1 mutant also displays an ABA-deficient phenotype that can be partially rescued by the externally supplied phytohormone. These results suggest that SPC1/ZDS is essential for biosynthesis of carotenoids and plays a crucial role in plant growth and development.Cell Research (2007) 17:458–470 doi: 10.1038/cr.2007.37; published online 30 April 2007 [ABSTRACT FROM AUTHOR]

Plant flowering is a crucial developmental transition from the vegetative to reproductive phase and is properly timed by a number of intrinsic and environmental cues. Genetic studies have identified that chromatin modification influences the expression of FLOWERING LOCUS C (FLC), a MADS-box transcription factor that controls flowering time. Histone deacetylation and methylation at H3K9 and H3K27 are associated with repression of FLC; in contrast, methylation at H3K4 and H3K36 activates FLC expression. However, little is known about the functions of histone arginine methylation in plants. Here, we report that Arabidopsis Shk1 binding protein 1 (SKB1) catalyzes histone H4R3 symmetric dimethylation (H4R3sme2). SKB1 lesion results in upregulation of FLC and late flowering under both long and short days, but late flowering is reversed by vernalization and gibberellin treatments. An skb1-1flc-3 double mutant blocks late-flowering phenotype, which suggests that SKB1 promotes flowering by suppressing FLC transcription. SKB1 binds to the FLC promoter, and disruption of SKB1 results in reduced H4R3sme2, especially in the promoter of FLC chromatin. Thus, SKB1-mediated H4R3sme2 is a novel histone mark required for repression of FLC expression and flowering time control. [ABSTRACT FROM AUTHOR]

Heterotrimeric G proteins are known to function as messengers in numerous signal transduction pathways. The null mutation of RGA (rice heterotrimeric G protein α subunit), which encodes the α subunit of heterotrimeric G protein in rice, causes severe dwarfism and reduced responsiveness to gibberellic acid in rice. However, less is known about heterotrimeric G protein in brassinosteroid (BR) signaling, one of the well-understood phytohormone pathways. In the present study, we used root elongation inhibition assay, lamina inclination assay and coleoptile elongation analysis to demonstrated reduced sensitivity of d1 mutant plants (caused by the null mutation of RGA) to 24-epibrassinolide (24-epiBL), which belongs to brassinosteroids and plays a wide variety of roles in plant growth and development. Moreover, RGA transcript level was decreased in 24-epiBL-treated seedlings in a dose-dependent manner. Our results show that RGA is involved in rice brassinosteroid response, which may be beneficial to elucidate the molecular mechanisms of G protein signaling and provide a novel perspective to understand BR signaling in higher plants.Cell Research (2006) 16: 916–922. doi: 10.1038/sj.cr.7310111; published online November 21 2006 [ABSTRACT FROM AUTHOR]

Steroids function as signaling molecules in both animals and plants. While animal steroid hormones are perceived by nuclear receptor family of transcription factors, brassinosteroids (BR) in plants are perceived by a cell surface receptor kinase, BRI1. Recent studies have demonstrated that BR binding to the extracellular domain of BRI1 induces kinase activation and dimerization with another receptor kinase, BAK1. Activated BRI1 or BAK1 then regulate, possibly indirectly, the activities of BIN2 kinase and/or BSU1 phosphatase, which directly regulate the phosphorylation status and nuclear accumulation of two homologous transcription factors, BZR1 and BES1. BZR1 and BES1 directly bind to promoters of BR responsive genes to regulate their expression. The BR signaling pathway has become a paradigm for both receptor kinase signaling in plants and steroid signaling by cell surface receptors in general.Cell Research (2006) 16: 427–434. doi:10.1038/sj.cr.7310054; published online 15 May 2006 [ABSTRACT FROM AUTHOR]

Soybean is a short-day plant and its flowering process can be reversed when switching from short-day to long-day conditions. Flowering reversion provides a useful system to study the flowering process in both forward and backward directions. In this study, we optimized a soybean flowering reversion system using a photoperiod-sensitive cultivar Zigongdongdou. Three types of terminal structures were found during flowering reversion: reversed terminal raceme (RTR), short terminal raceme (STR), and vegetative terminal (VT). The relative frequency of these terminal structures during flowering reversion under long day was dependent on the duration of the prior short day (SD) pretreatment. This process is phytochrome dependent and young plants were more susceptible to flowering reversion. Leaf removal increased the minimal SD period needed for the induction of STR. To demonstrate the application of this system, we studied the patterns of in situ expression of the GmNMH7 gene during flowering development and reversion. NMH7 family members encode MADS-box proteins and are unique in legume families since their expression can be detected in both developing flowers and nodules. In situ hybridization experiments using plants grown under different photoperiod cycles provided several lines of evidence supporting a close relationship between GmNMH7 gene expression and floral development in soybean. Furthermore, it seems that GmNMH7 may participate in flower development at different stages. Interestingly, the expression pattern of GmNMH7 in root nodules was also found to be regulated by photoperiod. These results support the notion that the photoperiod sensitive GmNMH7 gene may play multiple roles in growth and development in soybean. [ABSTRACT FROM AUTHOR]

Abstract AtFPF1 (FLOWERING PROMOTING FACTOR 1) is a gene that promotes flowering in Arabidopsis. An expression vector containing AtFPF1 driven by a Ubi-1 promoter was constructed. The gene was introduced into rice callus by Agrobacterium-mediated transformation and fertile plants were obtained. The presence of AtFPF1 in rice plants was confirmed by PCR, Southern and Northern blot analyses, as well as by -glucuronidase assay. The results showed that, as in Arabidopsis, AtFPF1 reduced flowering time in rice. Furthermore, introduction of AtFPF1 enhanced adventitious root formation but inhibited root growth in rice during the seedling stage. The results suggest that AtFPF1 promotes flowering time in both dicots and monocots, and plays a role in the initiation of adventitious roots in rice. [ABSTRACT FROM AUTHOR]

Abstract A gain-of-function Arabidopsis mutant was identified via activation tagging genetic screening. The mutant exhibited clustered ectopic floral buds on the surface of inflorescence stems. The mutant was designated as sef for stem ectopic flowers. Our detailed studies indicate that the ectopic flower meristems are initiated from the differentiated cortex cells. Inverse PCR and sequence analysis indicated that the enhancer-containing T-DNA from the activation tagging construct, SKI015, was inserted upstream of the previously cloned WUS gene encoding a homeodomain protein. Studies from RT-PCR, RNA in situ hybridization and transgenic plant analysis further confirmed that the phenotypes of sef are caused by the overexpression of WUS. Our results suggest that overexpression of WUS could trigger the cell pluripotence and reestablish a new meristem in cortex. The type of new meristems caused by WUS overexpression was dependent upon the developmental and physiological stages of a plant. With the help of some undefined factors in the reproductive organs the new meristems differentiated into floral buds. In a vegetative growth plant, however, only the new vegetative buds can be initiated upon the overexpression of WUS. These studies provide new insights of WUS on flower development. [ABSTRACT FROM AUTHOR]

In the last decade, RNA interference (RNAi) has proven to be an effective strategy to knock out homologous genes in a wide range of species. Based on its principle, a new generation of vectors containing an inverted target sequence separated by an intron as a loop, developing simplifications to the procedure of RNAi construction are required to improve the efficiency of gene inactivation techniques. Here, a novel polymerase chain reaction (PCR)-based RNAi vector pTCK3O3 with a maize ubiquitin promoter, 2 specific multiple enzyme sites, and a rice intron was constructed for monocot gene silencing. With this vector, only 1 PCR product amplified by a single pair of primers and 2 ligation reactions were needed to create an RNAi construct, which shortened the time span before being transformed into the plant. To test the efficiency of vector pTCK3O3, a rice gene OsGAS1 was used, and its RNAi construct was introdnced into rice calli. Southern blot analysis of the transgenic rice confirmed the presence of the OsGASI RNAi structure. The decrease in OsGAS1 level in the transgenic rice was detected by Northern blot probed with an OsGAS1-specific sequence. Moreover, the rate of inhibition of the RNA expression level in RNAi transgenic rice was approximately 85% according to our real-time PCR. Therefore, the RNAi vector pTCK3O3 based on the homology-dependent gene-silencing mechanisms facilitated the inhibition of endogenous genes in a monocot and was proven to be a practical and efficient platform for silencing a rice gene. [ABSTRACT FROM AUTHOR]

A vernalization-related gene VER2 was isolated from winter wheat (Triticum aestivum L.) using a differential screening approach. The deduced VER2 is a lectin-like protein of 300 amino acids, which contains the presence of a jacalin-like GWG domain. RNA in situ hybridization results demonstrated that VER2 gene expression is restricted to the marginal meristems of immature leaves in vernalized wheat seedlings. No hybridization signal was detected in the epidermal tissue and vascular bundles. However, "devernalization" resulted in the silencing of VER2 gene activity. The gene expression pattern of VER2 induced by jasmonate was similar to that induced by vernalization. Antisense inhibition of VER2 in transgenic wheat showed that heading and maturation time were delayed up to 6 weeks compared with non-transformed wheat and the pBI121empty-vector-transformed wheat. Tissue degeneration at the top of the spike was also noticed in the antisense inhibited transgenic wheat. These results suggest that VER2 plays an important role in vernalization signaling and spike development in winter wheat. [ABSTRACT FROM AUTHOR]

The microwave dielectric properties of $$\left( {1 - x} \right)\left( {Al_{1/2} Ta_{1/2} } \right)O_2 - x\left( {Mg_{1/3} Ta_{2/3} } \right)O_2$$ (AMT) $$\left( {0 \leqslant x \leqslant 1.0} \right)$$ ceramics and the design of small coplanar waveguide fed antenna (CPWFA) have been investigated. ( $$\left( {Al_{1/2} Ta_{1/2} } \right)O_2$$ and ( $$\left( {Mg_{1/3} Ta_{2/3} } \right)O_2$$ have orthorhombic and tetragonal structure, respectively. As ( $$\left( {Mg_{1/3} Ta_{2/3} } \right)O_2$$ concentration increased, AMT ceramics transformed into the tetragonal structure. Specimens having tetragonal single phase could be obtained above x=0.6. As ( $$\left( {Mg_{1/3} Ta_{2/3} } \right)O_2$$ concentration increased, the grain size, dielectric constant $$\varepsilon _r$$ and quality factor (Q) significantly increased and the temperature coefficient of resonant frequency $$\tau _f$$ changed from negative to positive. The $$\tau _f$$ of $$0 ppm ^\circ C^{ - 1}$$ was realized at x=0.65 and the Q · fO value and $$\varepsilon _f$$ for this composition were 112 470 GHz and 26.1, respectively. Newly developed $$0.35\left( {Al_{1/2} Ta_{1/2} } \right)O_2 - 0.65\left( {Mg_{1/3} Ta_{2/3} } \right)O_2$$ dielectric materials were used for 1.5 GHz band CPWFA design and fabrication. The size of the CPWFA can be reduced by using high dielectric constant AMT ceramics, insetting slits into the patch, and fabricating CPW feed line in the ground plane. The slits play a role in not only lowering a center frequency but also fine tuning for the proposed antenna together with the open stub of CPW feed line. The CPWFA with slits has a lower center frequency than the conventional CPWFA, which suggests that the antenna size can be reduced by as much as 16.3%. The structure simulations of the CPWFAs have been performed to obtain impedance matching and to investigate the effects of slits. Experimental results of the fabricated device were in good agreement with the simulation. [ABSTRACT FROM AUTHOR]

The microwave dielectric properties of (Pb1-xCax){(Fe0.5Nb0.5)1-ySny}O3 ceramics (0.4 ≤ x ≤ 0.6, y = 0.05, 0.1) and design of 900 MHz band 2-pole monoblock band pass filter (BPF) have been investigated to fabricate BPF. Single-phase specimens having orthorhombic perovskite structure similar to CaTiO3 could be obtained in the compositions of Pb1-xCax){(Fe0.5Nb0.5)1-ySny}O3 (0.4 ≤ x ≤ 0.6, y = 0.05, 0.1). The substitution of Sn for Fe0.5Nb0.5) significantly increased the quality factor Q and slightly decreased the dielectric constant (ɛr). The temperature coefficient of the resonant frequency of 0 ppm °C−1 was realized at x = 0.55 and y = 0.1. The Q · f0 value and (ɛr) for this composition were found to be 8600 GHz and 86, respectively. A monoblock λ/4 dielectric BPF for 900 MHz band portable telephone terminal is presented. This BPF is a kind of combline filter. Computer-aided design (CAD) was used in the modeling procedure. The equivalent circuit of the monoblock BPF is represented by transmission lines and lumped elements based on Zoe and Zoo. A BPF model was designed for surface mounted device (SMD) types. The simulations of the equivalent circuit and BPF structure have been performed to optimize the filter design. Newly developed Pb0.45Ca0.55){(Fe0.5Nb0.5)0.9Sn0.1}O3 dielectric materials were used for BPF fabrication. Experimental results of the fabricated device were in good agreement with the simulation. [ABSTRACT FROM AUTHOR]

The stress inevitably imposed during electrochemical reactions is expected to fundamentally affect the electrochemistry, phase behavior and morphology of electrodes in service. Here, we show a strong stress-composition coupling in lithium binary alloys during the lithiation of tin-tin oxide core-shell nanoparticles. Using in situ graphene liquid cell electron microscopy imaging, we visualise the generation of a non-uniform composition field in the nanoparticles during lithiation. Stress models based on density functional theory calculations show that the composition gradient is proportional to the applied stress. Based on this coupling, we demonstrate that we can directionally control the lithium distribution by applying different stresses to lithium alloy materials. Our results provide insights into stress-lithium electrochemistry coupling at the nanoscale and suggest potential applications of lithium alloy nanoparticles. Electrochemical reactions can generate stresses that detrimentally affect battery electrodes. Here, the authors directly image the lithiation of core-shell tin-based nanoparticles and show that lithium can be redistributed by applying stress and change the nanoparticle composition. [ABSTRACT FROM AUTHOR]

Manipulation of electrons in a solid through transmitting, storing, and switching is the fundamental basis for the microelectronic devices. Recently, the electroresistance effect in the ferroelectric capacitors has provided a novel way to modulate the electron transport by polarization reversal. Here, we demonstrate a giant electroresistive ferroelectric diode integrating a ferroelectric capacitor into two-dimensional electron gas (2DEG) at oxide interface. As a model system, we fabricate an epitaxial Au/Pb(Zr0.2Ti0.8)O3/LaAlO3/SrTiO3 heterostructure, where 2DEG is formed at LaAlO3/SrTiO3 interface. This device functions as a two-terminal, non-volatile memory of 1 diode-1 resistor with a large I+/I− ratio (>108 at ±6 V) and Ion/Ioff ratio (>107). This is attributed to not only Schottky barrier modulation at metal/ferroelectric interface by polarization reversal but also the field-effect metal-insulator transition of 2DEG. Moreover, using this heterostructure, we can demonstrate a memristive behavior for an artificial synapse memory, where the resistance can be continuously tuned by partial polarization switching, and the electrons are only unidirectionally transmitted. Beyond non-volatile memory and logic devices, our results will provide new opportunities to emerging electronic devices such as multifunctional nanoelectronics and neuromorphic electronics. [ABSTRACT FROM AUTHOR]

Piezoelectric materials capable of converting between mechanical and electrical energy have a great range of potential applications in micro- and nano-scale smart devices; however, their performance tends to be greatly degraded when reduced to a thin film due to the large clamping force by the substrate and surrounding materials. Herein, we report an effective method for synthesizing isolated piezoelectric nano-materials as means to relax the clamping force and recover original piezoelectric properties of the materials. Using this, environmentally friendly single-crystalline NaxK1-xNbO3 (NKN) piezoelectric nano-rod arrays were successfully synthesized by conventional pulsed-laser deposition and demonstrated to have a remarkably enhanced piezoelectric performance. The shape of the nano-structure was also found to be easily manipulated by varying the energy conditions of the physical vapor. We anticipate that this work will provide a way to produce piezoelectric micro- and nano-devices suitable for practical application, and in doing so, open a new path for the development of complex metal-oxide nano-structures. [ABSTRACT FROM AUTHOR]

Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable in term of the large scale and long-time durability of the device. Here, we demonstrate a hybrid generator which does not use nanostructure but generates much higher output power by a small mechanical force and integrates piezoelectric generator into triboelectric generator, derived from the simultaneous use of piezoelectric and triboelectric mechanisms in one press-and-release cycle. This hybrid generator combines high piezoelectric output current and triboelectric output voltage, which produces peak output voltage of ~370 V, current density of ~12 μA·cm−2, and average power density of ~4.44 mW·cm−2. The output power successfully lit up 600 LED bulbs by the application of a 0.2 N mechanical force and it charged a 10 μF capacitor to 10 V in 25 s. Beyond energy harvesting, this work will provide new opportunities for developing a small, built-in power source in self-powered electronics such as mobile electronics. [ABSTRACT FROM AUTHOR]