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Resistance seam welding additive manufacturing (RSAM) is a new solid-state additive manufacturing technique that utilizes pulsed current and pressure to welding powders layer by layer. In this study, Al1060 powder was employed as the raw material to prepare R0 and R10 samples through RSAM technology and subsequent repeated welding processes, respectively. The results showed that, compared to R0, the grain size of the R10 sample decreased from 34.3 μm to 8.7 μm, and the dislocation density increased from 4.355 × 1014 to 9.436 × 1014 m−2. Additionally, due to the additional heat and pressure from repeated welding, the porosity decreased from 0.998% to 0.017%, the ultimate tensile strength and elongation improved from 63.5 ± 0.5 MPa and 4.5 ± 0.1% in R0 to 93.3 ± 0.5 MPa and 34.3 ± 0.1% in R10. The improvement in mechanical properties is primarily due to the combined effects of grain refinement, dislocation strengthening, and pore self-healing. This study introduces a feasible new approach for additive manufacturing of aluminum alloys and other materials that is difficult to be additively manufactured by other methods.

The ubiquitin-proteasome system (UPS) plays a crucial role in modulating the proliferation, activation, and normal functioning of immune cells through the regulation of protein degradation and function. By influencing the expression of immune checkpoint-associated proteins, the UPS modulates T cell-mediated anti-tumor immune responses and can potentially facilitate the immune escape of tumor cells. Additionally, the UPS contributes to the remodeling of the tumor immunosuppressive microenvironment (TIME) by regulating B cells, dendritic cells (DCs), macrophages, and Treg cells. Targeting the UPS in conjunction with immune checkpoint-associated proteins, and combining these with other therapeutic approaches, may significantly enhance the efficacy of combination therapies and pave the way for novel cancer treatment strategies. In this review, we first summarize the composition and alterations of the TIME, with a particular emphasis on the role of the UPS in TIME and its interactions with various immune cell types. Finally, we explore the potential of combining UPS-targeted therapies with immunotherapy to substantially improve the effectiveness of immunotherapy and enhance patient survival outcomes.

Abstract Dent and flint kernel architectures are important characteristics that affect the physical properties of maize kernels and their grain end uses. The genes controlling these traits are unknown, so it is difficult to combine the advantageous kernel traits of both. We found mutation of ARFTF17 in a dent genetic background reduces IAA content in the seed pericarp, creating a flint-like kernel phenotype. ARFTF17 is highly expressed in the pericarp and encodes a protein that interacts with and inhibits MYB40, a transcription factor with the dual functions of repressing PIN1 expression and transactivating genes for flavonoid biosynthesis. Enhanced flavonoid biosynthesis could reduce the metabolic flux responsible for auxin biosynthesis. The decreased IAA content of the dent pericarp appears to reduce cell division and expansion, creating a shorter, denser kernel. Introgression of the ARFTF17 mutation into dent inbreds and hybrids improved their kernel texture, integrity, and desiccation, without affecting yield.

This study explores the corrosion resistance of AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA) in supercritical CO2 (S–CO2). The corrosion behavior was meticulously examined under conditions of 500 °C and 25 MPa CO2 over a duration of 800 h. The formation of distinct passivation layers on the face-centered cubic (FCC) and body-centered cubic (BCC) B2 phases was observed, leading to a cooperative passivation effect of Al and Cr. The protective Al2O3 oxide layers, which were dense and continuous, played a crucial role in inhibiting carburization and further oxidation, thereby significantly enhancing the corrosion resistance. Interestingly, no carburization was observed in this study.

Major depressive disorder (MDD) is a debilitating mental health condition that poses significant risks and burdens. Resting-state functional magnetic resonance imaging (fMRI) has emerged as a promising tool in investigating the neural mechanisms underlying MDD. However, a comprehensive bibliometric analysis of resting-state fMRI in MDD is currently lacking. Here, we aimed to thoroughly explore the trends and frontiers of resting-state fMRI in MDD research. The relevant publications were retrieved from the Web of Science database for the period between 1998 and 2022, and the CiteSpace software was employed to identify the influence of authors, institutions, countries/regions, and the latest research trends. A total of 1501 publications met the search criteria, revealing a gradual increase in the number of annual publications over the years. China contributed the largest publication output, accounting for the highest percentage among all countries. Particularly, the University of Electronic Science and Technology of China, Capital Medical University, and Harvard Medical School were identified as key institutions that have made substantial contributions to this growth. Neuroimage, Biological Psychiatry, Journal of Affective Disorders, and Proceedings of the National Academy of Sciences of the United States of America are among the influential journals in the field of resting-state fMRI research in MDD. Burst keywords analysis suggest the emerging research frontiers in this field are characterized by prominent keywords such as dynamic functional connectivity, cognitive control network, transcranial brain stimulation, and childhood trauma. Overall, our study provides a systematic overview into the historical development, current status, and future trends of resting-state fMRI in MDD, thus offering a useful guide for researchers to plan their future research.

Abstract Maize kernels are complex biological systems composed of three genetic sources, namely maternal tissues, progeny embryos, and progeny endosperms. The lack of gene expression profiles with spatial information has limited the understanding of the specific functions of each cell population, and hindered the exploration of superior genes in kernels. In our study, we conduct microscopic sectioning and spatial transcriptomics analysis during the grain filling stage of maize kernels. This enables us to visualize the expression patterns of all genes through electronical RNA in situ hybridization, and identify 11 cell populations and 332 molecular marker genes. Furthermore, we systematically elucidate the spatial storage mechanisms of the three major substances in maize kernels: starch, protein, and oil. These findings provide valuable insights into the functional genes that control agronomic traits in maize kernels.

With more and more agricultural parks are integrated to the electrical distribution network, the disordered characteristics of farmers’ irrigation water consumption will not only increase the cost of water and electricity, but also cause security problems in traditional term of rural distribution network, such as large short-term load fluctuation, overload and transformer load imbalance. In this context, this paper proposes a double-layer master–slave game model of power-water interaction and coordination between distribution network and agricultural irrigation park under photovoltaic (PV) assisted agricultural precision irrigation. The upper layer (electrical distribution network) plays an interactive game with the lower layer (agricultural irrigation parks) by establishing effective time-of-use (TOU) price. On the one hand, the electrical distribution network takes the operation security as the optimization objective, it could optimize line loss by network configuration and guides agricultural irrigation parks to consume electricity orderly by formulating electricity prices. On the other hand, agricultural irrigation parks take satisfaction and cost as the optimization objective after receiving TOU price from upper layer, and regulates the operation time and intensity of irrigation pumps to realize precise irrigation. Finally, an example is given to verify the model on the modified 148-node system. It is determined that the model can effectively support the safe and reliable operation of rural distribution network while realizing the transformation of agricultural irrigation water use from low efficiency to economical and high efficiency, so as to achieve win–win between agricultural irrigation park and distribution network.

Jamming recognition is a prerequisite for radar antijamming and actual radar deception jamming recognition; however, there is a problem of insufficient samples. To address this issue, we propose a multimodal radar active deception jamming recognition method based on small samples in this paper. This method is based on two modal information—feature parameters and time-frequency images extracted from radar signals—and utilizes prototype networks to train multimodal features. Furthermore, the model adopts the image denoising method and weighted Euclidean distance to improve the recognition performance at low signal-to-noise ratios. Thus, radar deception jamming recognition can be achieved under small sample conditions. Simulation results reveal that the proposed method achieves an average recognition accuracy of over 97% across 10 types of radar deception jamming when the jamming-to-signal ratio is 3 dB. Moreover, the test results from the simulator data verify the good generalization performance of the proposed method.

Abstract Biomimetic intelligent polymeric hydrogel actuators with cooperative fluorescence‐color switchable behaviors are expected to find great potential applications in soft robotics, visual detection/display, and camouflage applications. However, it remains challenging to realize the spatial manipulation of synergistic shape/color‐changing behaviors. Herein, we report an interfacial supramolecular assembly (ISA) approach that enables the construction of robust fluorescent polymeric hydrogel actuators with spatially anisotropic structures. On the basis of this ISA approach, diverse 2D/3D soft fluorescent hydrogel actuators, including chameleon‐ and octopi‐shaped ones with spatially anisotropic structures, were facilely assembled from two different fluorescent hydrogel building blocks sharing the same physically cross‐linked agar network. Spatially control over synergistic shape/color‐changing behaviors was then realized in one single anisotropic hydrogel actuator. The proposed ISA approach is universal and expected to open promising avenues for developing powerful bioinspired intelligent soft actuators/robotics with selective spatial shape/color‐changing behaviors.

Orthogonal frequency-division multiplexing (OFDM) chirp waveforms are an attractive candidate to be a dual-function signal scheme for the joint radar and communication systems. OFDM chirp signals can not only be employed to transmit communication data through classic phase modulation, but also can perform radar detection by applying linear frequency modulation for subcarriers. However, the performance of the OFDM chirp communication system under the phase noise environment still remains uninvestigated. This paper tries to discuss the influence of phase noise on OFDM chirp communication systems and proposes effective phase noise estimation and compensation methods. We find that the phase noise effect on OFDM chirp communication systems consists of a common phase error (CPE) and an inter-carrier interference (ICI). If not compensated, the performance of the dual-function systems can be seriously degraded. In particular, an exact expression for the signal-plus-interference to noise ratio (SINR) for the OFDM chirp communication system is derived and some critical parameters are analyzed to exhibit the phase noise effects on system performance. Moreover, two low-complexity estimation approaches, maximum likelihood (ML) and linear minimum mean square error (LMMSE), as well as two compensation approaches, the de-correlation and cancellation algorithms, are respectively utilized to eliminate the phase noise impairment. Finally, the phase noise effects and the effectiveness of the compensation approach are verified by extensive numerical results.

Due to the range dependence and time-varying array factor of Frequency Diverse Array (FDA) radar, it can overcome the miss of range variable in traditional phased-array factor and gain loss of Multiple-Input Multiple-Output (MIMO) radar array. In recent years, FDA radar techniques have attracted more and more attention of researches and institutions. Nevertheless, there are still many open problems to be solved in FDA radar system theory, signal processing and application implementation. In this overviewing paper, we introduced the FDA concepts, motivation and extending techniques. The latest research advances on FDA radars and their applications are comprehensively reviewed, and the typical application prospects of FDA in jamming radar and radar anti-jamming, ambiguous clutter suppression and blind velocity target detection together with localization deception are discussed. Finally, several key research problems that need to be solved in future work are pointed out.

Abstract In this paper, we investigate the Hajek–Renyi-type inequalities for ( α , β ) $(\alpha ,\beta )$ -mixing sequences. As an important application of the results, we further study the CUSUM-type estimator of mean change-point models for ( α , β ) $(\alpha , \beta )$ -mixing sequences. We establish the convergence rate of weak consistency for the CUSUM estimator. Moreover, we also present some simulation studies and a real data example to support the theoretical results.

Abstract Stimuli-responsive hydrogel is regarded as one of the most promising smart soft materials for the next-generation advanced technologies and intelligence robots, but the limited variety of stimulus has become a non-negligible issue restricting its further development. Herein, we develop a new stimulus of “touch” (i.e., spatial contact with foreign object) for smart materials and propose a flytrap-inspired touch-responsive polymeric hydrogel based on supersaturated salt solution, exhibiting multiple responsive behaviors in crystallization, heat releasing, and electric signal under touch stimulation. Furthermore, utilizing flytrap-like cascade response strategy, a soft actuator with touch-responsive actuation is fabricated by employing the touch-responsive hydrogel and the thermo-responsive hydrogel. This investigation provides a facile and versatile strategy to design touch-responsive smart materials, enabling a profound potential application in intelligence areas.

When Frequency Diverse Array and Multiple-Input Multiple-Output (FDA-MIMO) radar detects moving targets, the frequency offset between transmitting arrays is coupled with the target velocity, resulting in severe Doppler spread in the slow time dimension. Further, the signal energy of each receiving channel cannot be coherently accumulated, thereby greatly reducing the detection performance of the system. To address this problem, a method of FDA-MIMO radar moving target detection based on Doppler spread compensation is proposed. Firstly, the moving target echo model of FDA-MIMO radar is established, and the Doppler spread caused by the frequency offset is analyzed. After establishing the maximum likelihood receiver model, a resampling method based on an interpolation filter is proposed to compensate for the Doppler spread caused by FDA-MIMO radar during the detection of moving targets. Simulation results reveal that the proposed method can suppress the Doppler spread, compensate for the cross-cell migration of subtarget echo in the range dimension, and realize the coherent accumulation of signal energy.

The direct position determination method based on compressed sensing depends on the accurate signal propagation model. With partially unknown propagation model parameters, its location performance will decline significantly. Thus, this study proposed a localization method via multi-dictionaries and hierarchical block sparse Bayesian framework. Herein, the emitter location problem is transformed into recovering signals from different dictionaries but with shared sparsity, and the emitter location with channel attenuation is solved by a multi-dictionary combination. Simulation results revealed that the algorithm has better performance than the traditional Sparse Bayesian Learning (SBL) method and Direct Position Determination (DPD) method under the condition of low signal-to-noise ratio and a few snapshots.

Conventional multitarget-tracking data association algorithms must have prior information, such as the target motion model and clutter density. However, such prior information cannot be obtained timely and accurately before tracking. To address this issue, a data association algorithm for multitarget tracking based on a transformer network is proposed. First, considering that the radar may not perform accurate detected the target, virtual measurements are performed to re-establish the data association model. Thus, a data association method based on the transformer network is proposed to solve the matching problem of multitargets and multimeasurements. Moreover, a loss function combining Masked Cross entropy loss and Dice (MCD) loss is designed to optimize the network parameters. Simulation data and real measurement data results show that the proposed algorithm outperforms classic data association algorithms and algorithms based on bidirectional long short-term memory network under varying detection probability conditions.

Abstract Young and middle-aged people are vulnerable to developing acute stress disorder (ASD) following acute myocardial infarction (AMI). This study aims to explore the factors that contribute to ASD in young and middle-aged AMI patients. 190 AMI patients aged 18 to 60 years were enrolled in this study. We assessed the association between ASD and demographic data, adult attachment, and social support. This study examined a total of 190 young and middle-aged people. Among them, 65 participants were diagnosed with ASD, representing a 34.21% positive rate. Multivariate stepwise regression showed that adult attachment, infarct-related artery, social support, in-hospital complications are the main factors affecting ASD. Path analysis showed that social support had mediated the relationship between adult attachment and ASD. The incidence of ASD in young and middle-aged patients with AMI is high. Social support plays an important role in adult attachment and ASD relationships. Adult attachment and social support should be incorporated into post-traumatic cardiac rehabilitation to help patients cope with traumatic occurrences.

The presence of another planetary companion in a transiting exoplanet system can impact its transit light curve, leading to sinusoidal transit-timing variations (TTV). By utilizing both χ ^2 and rms analysis, we have combined the TESS observation data with an N -body simulation to investigate the existence of an additional planet in the system and put a limit on its mass. We have developed CMAT, an efficient and user-friendly tool for fitting transit light curves and calculating TTV with a theoretical period, based on which we can give a limit on its hidden companion’s mass. We use 260 hot Jupiter systems from the complete TESS data set to demonstrate the use of CMAT. Our findings indicate that, for most systems, the upper mass limit of a companion planet can be restricted to several Jupiter masses. This constraint becomes stronger near resonance orbits, such as the 1:2, 2:1, 3:1, and 4:1 mean-motion resonance, where the limit is reduced to several Earth masses. These findings align with previous studies suggesting that a lack of companion planets with resonance in hot Jupiter systems could potentially support the high-eccentricity migration theory. Additionally, we observed that the choice between χ ^2 or rms method does not significantly affect the upper limit on companion mass; however, χ ^2 analysis may result in weaker restrictions but is statistically more robust compared to rms analysis in most cases.

Many hot Jupiters may experience orbital decays, which are manifested as long-term transit-timing variations. We have analyzed 7068 transits from the Transiting Exoplanet Survey Satellite (TESS) for a sample of 326 hot Jupiters. These new mid-transit-time data allow us to update ephemerides for these systems. By combining the new TESS transit-timing data with archival data, we searched for possible long-term variations in the orbital period in these hot Jupiters using a linear and a quadratic ephemeris model. We identified 26 candidates that exhibit possible long-term variations of the orbital period, including 18 candidates with decreasing orbital periods and eight candidates with increasing orbital periods. Among them, 12 candidates failed our leave-one-out cross validation test and thus should be considered to be marginal candidates. In addition to tidal interaction, alternative mechanisms such as apsidal precession, the Rømer effect, and the Applegate effect could also contribute to the variations during the observed period. The ephemerides derived in this work are useful for scheduling follow-up observations for these hot Jupiters in the future. The Python code ( PdotQuest , https://github.com/AeoN400/PdotQuest ) used to generate the ephemerides is made available online.

BackgroundThis study aimed to explore the psychosocial determinants of the physical activity (PA) levels in patients with coronary heart disease (CHD) using an integrated theoretical model based on the theory of planned behavior (TPB) and the temporal self-regulation theory (TST).MethodThis was a prospective study conducted at the Affiliated Hospital of Hangzhou Normal University, Zhejiang, China. A total of 279 patients with CHD [176 men aged 26–89 years, mean (M) = 64.69, standard deviation (SD) = 13.17] were selected under the study inclusion criteria by convenience sampling. The data on attitude, subjective norm (SN), perceived behavioral control (PBC), and intention variables for the TPB model and consideration of future consequences (CFC), habit, and self-control (SC) variables for the TST model were collected 1–2 days before the discharge (Time 1, T1) of the participants, and a telephone follow-up was made to assess the participants' self-reported PA levels 1 week after their discharge (Time 2, T2).ResultsThe results revealed that only 39.8% of the patients with CHD met the guidelines' recommendations on PA. The data analyses using structural equation modeling (SEM) in the Mplus 8.3 modeling program showed that, in the simple mediation model, attitude, PBC, and CFC were positively related to the intention to practice guideline-recommended levels of PA but SN was not. In addition, intention was shown to mediate the relationships between attitude, PBC, CFC, and PA levels. Furthermore, based on the moderated mediating model, intention and habit were shown to be positively associated with PA levels but SC was not. Moreover, SC played a significant moderating role between intention and PA levels. However, habit strength did not moderate the relationship between intention and PA levels.ConclusionAn integration of the TPB and TST models offers a good theoretical tool for understanding PA levels in patients with CHD.

Passive localization technology is an integral part of electronic warfare. However, most methods for countering passive localization systems, such as radio frequency stealth and electronic interference, have limitations. This paper proposes a new passive localization countermeasure method based on Frequency Diverse Array (FDA). The unique beam scanning property reduces dwell time at a certain azimuth direction, making it difficult for a passive localization system to intercept FDA signals for a long time. In contrast, the time-varying characteristics of the FDA considerably reduce the signal-to-noise ratio of the received signal, increasing the difficulty in accurately detecting the localization information of the radiation source. Thus, using this new technology, the electronic system platform can perceive the external environment through the signals radiated by the FDA antenna while deceiving the enemy’s passive localization system. Both theoretical analysis and numerical results showed that FDA transmitted signal achieved significantly better localization countermeasure performance in direction finding by an interferometer, frequency difference of arrival, and time difference of arrival, which are particularly useful for a new generation of electronic systems with reconnaissance detection and passive localization countermeasures capability.

Study objectivesTo characterize sleep disturbances and sleep patterns in children with Tic disorder (TD), and explore their association with TD severity and types.MethodsA case-control study was conducted in 271 children with TD recruited from a clinical setting and 271 non-TD children recruited from a primary school, matched by age (mean = 8.47 years, SD = 1.53 years) and gender (15.1% female). The Children's Sleep Habits Questionnaire (CSHQ) was used to assess sleep patterns and sleep disturbances. The TD types and severity were assessed with the Yale Global Tic Severity Scale (YGTSS).ResultsThe TD children scored higher on CSHQ total score than non-TD group (t = 29.50, p < 0.001) and demonstrated severer global sleep disturbance. Compared to non-TD children, TD children presented with increased risks for global sleep disturbance (aOR: 1.95; 95% CI = 1.20–3.06), and most specific sleep disturbances, including bedtime resistance (aOR: 3.15; 95% CI = 1.96–5.06), sleep onset delay (aOR: 3.43; 95% CI = 1.58–7.46), sleep anxiety (aOR: 2.83; 95%CI = 1.83–4.38), parasomnias (aOR: 3.68; 95% CI = 2.02–6.62), night waking (aOR: 9.29; 95% CI = 2.64–32.65), sleep disordered breathing (aOR: 1.72; 95% CI = 1.03-2.90) and daytime sleepiness (aOR: 1.72; 95% CI = 1.09–2.74). Children with mild and moderate tics, Provisional Tic Disorder (PTD), Chronic Tic Disorder (CTD) and Tourette Syndrome (TS) presented with more global and more specific sleep disturbances. In addition, combined ADHD, etc.ConclusionChildren with TD are major risks for increased sleep disturbances, especially for those with severe and chronic symptoms. Furthermore, comorbid ADHD increases risk in certain areas of sleep. These findings highlight the importance to consider sleep outcomes in the assessment and treatment for children with TD.

Very little is known about how vitreous endosperm in the mature maize kernel is created. Here, via map-based cloning, the authors find that mutation of a β-carotene hydroxylase 3 encoding gene Ven1 affects carotenoids and lipids composition, which consequently influences amyloplast envelope integrity.

Abstract Background Recent studies have suggested that the gut microbiota is altered in children with juvenile idiopathic arthritis (JIA). However, age, sex, and body mass index (BMI) were not matched in the previous studies, and the results are inconsistent. We conducted an age-, sex-, and BMI-matched cross-sectional study to characterize the gut microbiota in children with JIA, and evaluate its potential in clinical prediction. Methods A total of 40 patients with JIA and 42 healthy controls, ranging from 1 to 16 years, were enrolled in this study. Fecal samples were collected for 16S rDNA sequencing. The data were analyzed using QIIME software and R packages. Specifically, the random forest model was used to identify biomarkers, and the receiver operating characteristic curve and the decision curve analysis were used to evaluate model performance. Results A total of 39 fecal samples from patients with JIA, and 42 fecal samples from healthy controls were sequenced successfully. The Chao 1 and Shannon–Wiener index in the JIA group were significantly lower than those in the control group, and the Bray-Curtis dissimilarity also differed significantly between the two groups. The relative abundance of 4 genera, Anaerostipes, Dialister, Lachnospira, and Roseburia, decreased significantly in the JIA group compared to those in the control group. The 4 genera included microbes that produce short-chain fatty acids (SCFAs) and were negatively correlated with some rheumatic indices. Moreover, 12 genera were identified as potential biomarkers by using the nested cross-validation function of the random forest. A random forest model constructed using these genera was able to differentiate the patients with JIA from the healthy controls, and the area under the receiver operating characteristic curve was 0.7975. The decision curve analysis indicated that the model had usefulness in clinical practice. Conclusions The gut microbiota in patients with JIA is altered and characterized by a decreased abundance of 4 SCFA-producing genera. The decreases in the 4 genera correlated with more serious clinical indices. Twelve genera could be used as biomarkers and predictors in clinical practice. Trial registration The study is registered online at the Chinese Clinical Trial Registry on 11 May 2018 (registration number: ChiCTR1800016110).

There are global concerns about dietary exposure to metal(loid)s in foods. However, little is known about the relative contribution of rice versus fish to multiple metal(loid) exposure for the general population, especially in Asia where rice and fish are major food sources. We compared relative contributions of rice and fish consumption to multi-metal(loid) exposure on the city-scale (Nanjing) and province-scale in China. The effects of ingestion rate, metal(loid) level, and bioaccessibility were examined to calculate modeled risk from Cu, Zn, total As (TAs), inorganic As (iAs), Se, Cd, Pb, and methylmercury (MeHg). Metal(loid) levels in rice and fish samples collected from Nanjing City were generally low, except iAs. Metal(loid) bioaccessibilities in fish were higher than those in rice, except Se. Calculated carcinogenic risks induced by iAs intake (indicated by increased lifetime cancer risk, ILCR) were above the acceptable level (1 0 −4) in Nanjing City (median: 3 × 10−4 for female and 4 × 10−4 for male) and nine provinces (1.4 × 10−4 to 5.9 × 10−4) in China. Rice consumption accounted for 85.0% to 99.8% of carcinogenic risk. The non-carcinogenic hazard quotients (HQ) for single metals and hazard index (HI) for multi-metal exposure were

Abstract Background Duckweeds (Lemnaceae) are aquatic plants distributed all over the world. The chloroplast genome, as an efficient solar-powered reactor, is an invaluable resource to study biodiversity and to carry foreign genes. The chloroplast genome sequencing has become routine and less expensive with the delivery of high-throughput sequencing technologies, allowing us to deeply investigate genomics and transcriptomics of duckweed organelles. Results Here, the complete chloroplast genome of Spirodela polyrhiza 7498 (SpV2) is assembled by PacBio sequencing. The length of 168,956 bp circular genome is composed of a pair of inverted repeats of 31,844 bp, a large single copy of 91,210 bp and a small single copy of 14,058 bp. Compared to the previous version (SpV1) assembled from short reads, the integrity and quality of SpV2 are improved, especially with the retrieval of two repeated fragments in ycf2 gene. There are a number of 107 unique genes, including 78 protein-coding genes, 25 tRNA genes and 4 rRNA genes. With the evidence of full-length cDNAs generated from PacBio isoform sequencing, seven genes (ycf3, clpP, atpF, rpoC1, rpl2, rps12 and ndhA) are detected to contain type-II introns. The ndhA intron has 50% more sequence divergence than the species-barcoding marker of atpF-atpH, showing the potential power to discriminate close species. A number of 37 RNA editing sites are recognized to have cytosine (C) to uracil (U) substitutions, eight of which are newly defined including six from the intergenic regions and two from the coding sequences of rpoC2 and ndhA genes. In addition, nine operon classes are identified using transcriptomic data. It is found that the operons contain multiple subunit genes encoding the same functional complexes comprising of ATP synthase, photosynthesis system, ribosomal proteins, et.al., which could be simultaneously transcribed and coordinately translated in response to the cell stimuli. Conclusions The understanding of the chloroplast genomics and the transcriptomics of S.polyrhiza would greatly facilitate the study of phylogenetic evolution and the application of genetically engineering duckweeds.

Road traffic sign detection and recognition play an important role in advanced driver assistance systems (ADAS) by providing real-time road sign perception information. In this paper, we propose an improved (Single Shot Detector) SSD algorithm via multi-feature fusion and enhancement, named MF-SSD, for traffic sign recognition. First, low-level features are fused into high-level features to improve the detection performance of small targets in the SSD. We then enhance the features in different channels to detect the target by enhancing effective channel features and suppressing invalid channel features. Our algorithm gets good results in domestic real-time traffic signs. The proposed MF-SSD algorithm is evaluated with the German Traffic Sign Recognition Benchmark (GTSRB) dataset. The experimental results show that the MF-SSD algorithm has advantages in detecting small traffic signs. Compared with existing methods, it achieves higher detection accuracy, better efficiency, and better robustness in complex traffic environment.

The South African quality protein maize (QPM) cultivars have the desired high lysine content and kernel hardness due to o2 mutation and the introgression of modifiers of o2 (Mo2) QTLs, respectively. Here, the authors assemble the genome of a QPM line and identify candidate genes underlying Mo2 QTLs.

Abstract Background Sorghum bicolor (L.) is an important bioenergy source. The stems of sweet sorghum function as carbon sinks and accumulate large amounts of sugars and lignocellulosic biomass and considerable amounts of starch, therefore providing a model of carbon allocation and accumulation for other bioenergy crops. While omics data sets for sugar accumulation have been reported in different genotypes, the common features of primary metabolism in sweet genotypes remain unclear. To obtain a cohesive and comparative picture of carbohydrate metabolism between sorghum genotypes, we compared the phenotypes and transcriptome dynamics of sugar-accumulating internodes among three different sweet genotypes (Della, Rio, and SIL-05) and two non-sweet genotypes (BTx406 and R9188). Results Field experiments showed that Della and Rio had similar dynamics and internode patterns of sugar concentration, albeit distinct other phenotypes. Interestingly, cellulose synthases for primary cell wall and key genes in starch synthesis and degradation were coordinately upregulated in sweet genotypes. Sweet sorghums maintained active monolignol biosynthesis compared to the non-sweet genotypes. Comparative RNA-seq results support the role of candidate Tonoplast Sugar Transporter gene (TST), but not the Sugars Will Eventually be Exported Transporter genes (SWEETs) in the different sugar accumulations between sweet and non-sweet genotypes. Conclusions Comparisons of the expression dynamics of carbon metabolic genes across the RNA-seq data sets identify several candidate genes with contrasting expression patterns between sweet and non-sweet sorghum lines, including genes required for cellulose and monolignol synthesis (CesA, PTAL, and CCR), starch metabolism (AGPase, SS, SBE, and G6P-translocator SbGPT2), and sucrose metabolism and transport (TPP and TST2). The common transcriptome features of primary metabolism identified here suggest the metabolic networks contributing to carbon sink strength in sorghum internodes, prioritize the candidate genes for manipulating carbon allocation with bioenergy purposes, and provide a comparative and cohesive picture of the complexity of carbon sink strength in sorghum stem.

We have previously demonstrated that placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) dysfunction contributes to PE pathogenesis. We sought to elucidate molecular mechanisms underlying 11β-HSD2 dysfunction-induced PE and to seek potential therapeutic targets using a 11β-HSD2 dysfunction-induced PE-like rat model as well as cultured extravillous trophoblasts (EVTs) since PE begins with impaired function of EVTs. In 11β-HSD2 dysfunction-induced PE-like rat model, we revealed that placental mitochondrial dysfunction occurred, which was associated with mitDNA instability and impaired mitochondrial dynamics, such as decreased optic atrophy 1 (OPA1) expression. MitoTEMPO treatment significantly alleviated the hallmark of PE-like features and improved mitDNA stability and mitochondrial dynamics in the placentas of rat PE-like model. In cultured human EVTs, we found that 11β-HSD2 dysfunction led to mitochondrial dysfunction and disrupted mtDNA stability. MitoTEMPO treatment improved impaired invasion and migration induced by 11β-HSD2 dysfunction in cultured EVTs. Further, we revealed that OPA1 was one of the key factors that mediated 11β-HSD2 dysfunction-induced excess ROS production, mitochondrial dysfunction and mtDNA reduction. Our data indicates that 11β-HSD2 dysfunction causes mitochondrial dysfunctions, which impairs trophoblast function and subsequently results in PE development. Our study immediately highlights that excess ROS is a potential therapeutic target for PE.

In this study, the AlFeCrCo medium-entropy alloy coating was first fabricated on a magnesium alloy using a resistance seam welding method. After welding, the AlFeCrCo medium entropy amorphous alloy powders were transformed into a body-centered cubic structure coating having an average thickness of 430 μm. The effect of instantaneous temperature on the formation ability of the coating was analyzed by theoretical calculations and experimental results. Based on the calculations, the instant Joule heating effect was only concentrated in the minute bonding area, and no direct or immediate increase in temperature occurred at the substrate. The experimental results demonstrated that the temperature gradient did not engender an obvious dilution of the matrix. The average microhardness of the coating (870 HV0.2) was approximately 12 times higher than that of the substrate. The wear performance was systematically evaluated in dry and 3.5 wt% NaCl solution conditions under different normal loads. Compared with the substrate and other high entropy alloy-related systems, the AlFeCrCo medium-entropy alloy coating exhibited good wear resistance. The wear resistance improved when the metal films and corrosive behavior were occurred in corrosive environments, which was anomalous to wear mechanism under dry conditions.

Acoustic double-zero-index metamaterials (DZIM) characterized by extremely large phase velocity along with no phase changes of the wave propagation inside the materials have received tremendous attention due to the fascinating physics and potential applications. However, due to the requirement of the degeneracy of dipolar and monopolar resonances and the available resonance-induced losses, the realization of highly efficient and broadband near-zero index metamaterials is still facing challenges. Here we report that by coupling two identical Helmholtz resonators with a connecting channel, acoustic DZIM can be realized. Owing to the presence of a connecting tube, the system can generate the dipolar mode that is independently tunable and the monopolar mode that is virtually unchanged. It thereby makes the mass density ( ρ ) and the reciprocal of the bulk modulus (1/ B ) simultaneously crossing zero possible. We numerically obtain the transmission and phase, and then calculate the effective mass density and bulk modulus, which agree remarkably well with the experimental results. Finally, we successfully cloak a rectangle block inside a two-dimensional waveguide grafted by the designed acoustic DZIM array of unit cells. A broadband cloaking is experimentally demonstrated at 1865–1925 Hz, which can offer potential possibilities for vast practical applications.

This study seeks to address the finite-time robust stability of delayed genetic regulatory networks (GRNs) with uncertain parameters and reaction-diffusion terms. We employ an appropriate Lyapunov-Krasovskii functional to derive some less conservative stability criteria for GRNs under Dirichlet boundary conditions, which are delay-dependent, delay-derivative-dependent, and reaction-diffusion-dependent. The time-varying delays and their derivatives are both bounded with lower and upper bounds, where the lower bound of them can be zero or non-zero. In addition, we define some new variables to deal with uncertain parameters. Moreover, Jensen’s integral inequality, Wirtinger-type integral inequality, reciprocally convex combination inequality, Gronwall inequality, and Green formula are employed to handle integral terms. Finally, a numerical example is presented to illustrate the feasibility and effectiveness of the obtained stability criteria.

Duckweeds (Lemnaceae family) are the smallest flowering plants that adapt to the aquatic environment. They are regarded as the promising sustainable feedstock with the characteristics of high starch storage, fast propagation, and global distribution. The duckweed genome size varies 13-fold ranging from 150 Mb in Spirodela polyrhiza to 1,881 Mb in Wolffia arrhiza. With the development of sequencing technology and bioinformatics, five duckweed genomes from Spirodela and Lemna genera are sequenced and assembled. The genome annotations discover that they share similar protein orthologs, whereas the repeat contents could mainly explain the genome size difference. The gene families responsible for cell growth and expansion, lignin biosynthesis, and flowering are greatly contracted. However, the gene family of glutamate synthase has experienced expansion, indicating their significance in ammonia assimilation and nitrogen transport. The transcriptome is comprehensively sequenced for the genera of Spirodela, Landoltia, and Lemna, including various treatments such as abscisic acid, radiation, heavy metal, and starvation. The analysis of the underlying molecular mechanism and the regulatory network would accelerate their applications in the fields of bioenergy and phytoremediation. The comparative genomics has shown that duckweed genomes contain relatively low gene numbers and more contracted gene families, which may be in parallel with their highly reduced morphology with a simple leaf and primary roots. Still, we are waiting for the advancement of the long read sequencing technology to resolve the complex genomes and transcriptomes for unsequenced Wolffiella and Wolffia due to the large genome sizes and the similarity in their polyploidy.

DDB1 and CUL4 associated factor 13 (DCAF13) is a protein coding gene located on chromosome 8q22.3, which is a hotspot amplified in various cancers. DCAF13 has been reported to be frequently amplified in breast cancer patients. However, the genetic alteration and potential role of DCAF13 in other cancers, including hepatocellular carcinoma, have not been investigated yet. In this study, we found that DCAF13 was amplified in 14.7% of the cases and its expression was upregulated (p < 0.001) in hepatocellular carcinoma samples in The Cancer Genome Atlas dataset. Increased expression of DCAF13 was also noticed in 40 paired hepatocellular carcinoma and adjacent non-tumor tissues both at messenger RNA and protein levels (p = 0.0002 and 0.0016, respectively). A positive relationship was observed between augmented DCAF13 levels and poorer tumor grade (p = 0.005), and we also found that hepatocellular carcinoma patients with increased DCAF13 expression in their tumors had significantly poorer survival compared with those with decreased DCAF13 expression (median survival time: 45.73 and 70.53 months, respectively). Multivariate Cox regression analysis showed that DCAF13 was an independent prognostic predictor of survival in hepatocellular carcinoma patients. Gene ontology and Kyoto Encyclopedia of Genes and genomes analysis indicated the potential role of DCAF13 as a crucial cell cycle regulator. Collectively, our findings revealed that the overexpression of DCAF13 in hepatocellular carcinoma was significantly associated with poor survival and may participate in the regulation of cell cycle progression.

The original version of the article [1] unfortunately contained a mistake in author’s first name. The name of the author has been corrected from Wenqing Wang to Wenqin Wang in this correction article. The original article [1] has been corrected.

The limitations of hyperspectral sensors usually lead to coarse spatial resolution of acquired images. A well-known fusion method called coupled non-negative matrix factorization (CNMF) often amounts to an ill-posed inverse problem with poor anti-noise performance. Moreover, from the perspective of matrix decomposition, the matrixing of remotely-sensed cubic data results in the loss of data’s structural information, which causes the performance degradation of reconstructed images. In addition to three-dimensional tensor-based fusion methods, Craig’s minimum-volume belief in hyperspectral unmixing can also be utilized to restore the data structure information for hyperspectral image super-resolution. To address the above difficulties simultaneously, this article incorporates the regularization of joint spatial-spectral smoothing in a minimum-volume simplex, and spatial sparsity—into the original CNMF, to redefine a bi-convex problem. After the convexification of the regularizers, the alternating optimization is utilized to decouple the regularized problem into two convex subproblems, which are then reformulated by separately vectorizing the variables via vector-matrix operators. The alternating direction method of multipliers is employed to split the variables and yield the closed-form solutions. In addition, in order to solve the bottleneck of high computational burden, especially when the size of the problem is large, complexity reduction is conducted to simplify the solutions with constructed matrices and tensor operators. Experimental results illustrate that the proposed algorithm outperforms state-of-the-art fusion methods, which verifies the validity of the new fusion approach in this article.

Three-dimensional (3D) microwave imaging has been proven to be well suited for concealed weapon detection application. For the 3D image reconstruction under two-dimensional (2D) planar aperture condition, most of current imaging algorithms focus on decomposing the 3D free space Green function by exploiting the stationary phase and, consequently, the accuracy of the final imagery is obtained at a sacrifice of computational complexity due to the need of interpolation. In this paper, from an alternative viewpoint, we propose a novel interpolation-free imaging algorithm based on wavefront reconstruction theory. The algorithm is an extension of the 2D range stacking algorithm (RSA) with the advantages of low computational cost and high precision. The algorithm uses different reference signal spectrums at different range bins and then forms the target functions at desired range bin by a concise coherent summation. Several practical issues such as the propagation loss compensation, wavefront reconstruction, and aliasing mitigating are also considered. The sampling criterion and the achievable resolutions for the proposed algorithm are also derived. Finally, the proposed method is validated through extensive computer simulations and real-field experiments. The results show that accurate 3D image can be generated at a very high speed by utilizing the proposed algorithm.

Genome editing with engineered nucleases enabling site-directed sequence modifications bears a great potential for advanced plant breeding and crop protection. Remarkably, the RNA-guided endonuclease technology (RGEN) based on the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) is an extremely powerful and easy tool that revolutionizes both basic research and plant breeding. Here, we review the major technical advances and recent applications of the CRISPR-Cas9 system for manipulation of model and crop plant genomes. We also discuss the future prospects of this technology in molecular plant breeding.

The Clemmensen reduction is a common example of a reaction demonstrating the deoxygenation of carbonyl groups, which is a topic that has been widely studied in the field of organic chemistry. The use of trimethylchlorosilane, as a substitute for concentrated hydrochloric acid, allows for the reduction of carbonyl groups. The Clemmensen reduction experiment is performed by undergraduates for project-based learning. As a part of this program, students evaluate the influence of active functional groups, electron-donating and electron-withdrawing groups, steric hindrance, and other factors on the modified Clemmensen reduction using different reaction substrates. This lab activity aims to show the effectiveness of teaching organic chemistry laboratory methodologies to undergraduate students and serves as a tool for the final evaluation of practical knowledge using experiments. Project-based learning not only effectively improves the experimental ability of organic chemistry students but also has great importance in the development of interpersonal skills, including teamwork and innovative thinking. This helps to achieve the integration of applied-project-based learning and organic chemistry experimental teaching objectives.

RNA editing is the post-transcriptional conversion from C to U before translation, providing a unique feature in the regulation of gene expression. Here, we used a robust and efficient method based on RNA-seq from non-ribosomal total RNA to simultaneously measure chloroplast-gene expression and RNA editing efficiency in the Greater Duckweed, Spirodela polyrhiza, a species that provides a new reference for the phylogenetic studies of monocotyledonous plants. We identified 66 editing sites at the genome-wide level, with an average editing efficiency of 76%. We found that the expression levels of chloroplast genes were relatively constant, but 11 RNA editing sites show significant changes in editing efficiency, when fronds turn into turions. Thus, RNA editing efficiency contributes more to the yield of translatable transcripts than steady state mRNA levels. Comparison of RNA editing sites in coconut, Spirodela, maize, and rice suggests that RNA editing originated from a common ancestor.

BackgroundSpirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales. Its complete sequence of the mitochondrial (mt) genome could provide clues for the understanding of the evolution of mt genomes in plant.MethodsSpirodela polyrhiza mt genome was sequenced from total genomic DNA without physical separation of chloroplast and nuclear DNA using the SOLiD platform. Using a genome copy number sensitive assembly algorithm, the mt genome was successfully assembled. Gap closure and accuracy was determined with PCR products sequenced with the dideoxy method.ConclusionsThis is the most compact monocot mitochondrial genome with 228,493 bp. A total of 57 genes encode 35 known proteins, 3 ribosomal RNAs, and 19 tRNAs that recognize 15 amino acids. There are about 600 RNA editing sites predicted and three lineage specific protein-coding-gene losses. The mitochondrial genes, pseudogenes, and other hypothetical genes (ORFs) cover 71,783 bp (31.0%) of the genome. Imported plastid DNA accounts for an additional 9,295 bp (4.1%) of the mitochondrial DNA. Absence of transposable element sequences suggests that very few nuclear sequences have migrated into Spirodela mtDNA. Phylogenetic analysis of conserved protein-coding genes suggests that Spirodela shares the common ancestor with other monocots, but there is no obvious synteny between Spirodela and rice mtDNAs. After eliminating genes, introns, ORFs, and plastid-derived DNA, nearly four-fifths of the Spirodela mitochondrial genome is of unknown origin and function. Although it contains a similar chloroplast DNA content and range of RNA editing as other monocots, it is void of nuclear insertions, active gene loss, and comprises large regions of sequences of unknown origin in non-coding regions. Moreover, the lack of synteny with known mitochondrial genomic sequences shed new light on the early evolution of monocot mitochondrial genomes.

BackgroundChloroplast genomes provide a wealth of information for evolutionary and population genetic studies. Chloroplasts play a particularly important role in the adaption for aquatic plants because they float on water and their major surface is exposed continuously to sunlight. The subfamily of Lemnoideae represents such a collection of aquatic species that because of photosynthesis represents one of the fastest growing plant species on earth.MethodsWe sequenced the chloroplast genomes from three different genera of Lemnoideae, Spirodela polyrhiza, Wolffiella lingulata and Wolffia australiana by high-throughput DNA sequencing of genomic DNA using the SOLiD platform. Unfractionated total DNA contains high copies of plastid DNA so that sequences from the nucleus and mitochondria can easily be filtered computationally. Remaining sequence reads were assembled into contiguous sequences (contigs) using SOLiD software tools. Contigs were mapped to a reference genome of Lemna minor and gaps, selected by PCR, were sequenced on the ABI3730xl platform.ConclusionsThis combinatorial approach yielded whole genomic contiguous sequences in a cost-effective manner. Over 1,000-time coverage of chloroplast from total DNA were reached by the SOLiD platform in a single spot on a quadrant slide without purification. Comparative analysis indicated that the chloroplast genome was conserved in gene number and organization with respect to the reference genome of L. minor. However, higher nucleotide substitution, abundant deletions and insertions occurred in non-coding regions of these genomes, indicating a greater genomic dynamics than expected from the comparison of other related species in the Pooideae. Noticeably, there was no transition bias over transversion in Lemnoideae. The data should have immediate applications in evolutionary biology and plant taxonomy with increased resolution and statistical power.