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During the long and high-intensity railway use, all kinds of defects emerge, which often produce light to moderate damage on the surface, which adversely affects the stable operation of trains and even endangers the safety of travel. Currently, models for detecting rail surface defects are ineffective, and self-collected rail surface images have poor illumination and insufficient defect data. In light of the aforementioned problems, this article suggests an improved YOLOX and image enhancement method for detecting rail surface defects. First, a fusion image enhancement algorithm is used in the HSV space to process the surface image of the steel rail, highlighting defects and enhancing background contrast. Then, this paper uses a more efficient and faster BiFPN for feature fusion in the neck structure of YOLOX. In addition, it introduces the NAM attention mechanism to increase image feature expression capability. The experimental results show that the detection of rail surface defects using the algorithm improves the mAP of the YOLOX network by 2.42%. The computational volume of the improved network increases, but the detection speed can still reach 71.33 fps. In conclusion, the upgraded YOLOX model can detect rail surface flaws with accuracy and speed, fulfilling the demands of real-time detection. The lightweight deployment of rail surface defect detection terminals also has some benefits.

A microfluidic system for rapid nucleic acid analysis based on real-time convective PCR is developed. To perform 'sample-in, answer-out' nucleic acid analysis, a microfluidic chip is developed to efficiently extract nucleic acid, and meanwhile convective PCR (CPCR) is applied for rapid nucleic acid amplification. With an integrated microfluidic chip consisting of reagent pre-storage chambers, a lysiswash chamber, an elution chamber and a waste chamber, nucleic acid extraction based on magnetic beads can be automatically performed for a large size of test sample within a limited time. Based on an easy-to-operate strategy, different pre-stored reagents can be conveniently released for consecutive reaction at different steps. To achieve efficient mixing, a portable companion device is developed to introduce properly controlled 3-D actuation to magnetic beads in nucleic acid extraction. In CPCR amplification, PCR reagent can be spontaneously and repeatedly circulated between hot and cool zones of the reactor for space-domain thermal cycling based on pseudo-isothermal heating. A handheld real-time CPCR device is developed to perform nucleic acid amplification and in-situ detection. To extend the detection throughput, multiple handheld real-time CPCR devices can be grouped together by a common control system. It is demonstrated that influenza A (H1N1) viruses with the reasonable concentration down to 1.0 TCID

An automated microfluidic system with functionalized beads has been developed for multiplexed TORCH detection at point-of-care testing. A concise microfluidic chip consisting of a one-dimensional beads array is developed to simultaneously detect TOX, RUB, CMV, HSV-I and HSV-II respectively with five functionalized beads. A compact liquid handling module has been developed to automate the sandwiched chemiluminescence immunoassay within the one-dimensional beads array of the microfluidic chip. A precise ram pump is adopted to not only add reagent into the microfluidic chip from outside, but also facilitate elaborate fluid control inside the microfluidic chip for improved performance. A large-size waste chamber with a liquid-absorbing sponge holds the waste reagent within the microfluidic chip to prevent backflow. The one-dimensional beads array is heated from double-sides at 37 ℃ for sensitive detection with reduced time. A sensitive CMOS camera is adopted to take chemiluminescence image from the one-dimensional beads array, and a custom processing algorithm is adopted to analyze the image. For each serum sample, five different infections can be simultaneously detected with the automated microfluidic system. Experimental results show that efficient, sensitive, and accurate multiplexed TORCH detection can be conveniently achieved with the integrated microfluidic system.

Applying high-frequency power devices, such as gallium nitride (GaN) semiconductor devices, to the motor drive can significantly reduce system volume, losses, audible noise, and increase system power density. In this article, an LC filter designed as a sine wave filter is introduced into the servo drive system based on the GaN power device. An undamped method with variable delay time is proposed to solve the electrical resonance issue caused by the LC filter and stator inductor. Detailed stability analysis is conducted, and rules on parameter tuning are provided. With additional proper time delay, the system can be stable without any extra sensors or power losses. Besides, this method is suitable for resonance suppression at a variable switching frequency. Moreover, a wait-free and phase-continuous spread spectrum frequency modulation is applied to solve the issue of electromagnetic interference (EMI). The field-programmable gate array is used to achieve high control bandwidth when implementing the control algorithm. Finally, the ideal sinusoidal drive and low conducted EMI of a permanent magnet synchronous motor is realized. Experiments on a 100 kHz GaN inverter with the LC filter verify the validity of the proposed design and method.

Tomato yellow leaf curl virus (TYLCV) is the dominating pathogen of tomato yellow leaf curl disease that caused severe loss to tomato production in China. In this study, we found that a TYLCV-resistant tomato line drastically reduced the accumulation of viral complementary-sense strand mRNAs but just moderately inhibit that of viral DNA and virion-sense strand mRNAs. However, two other resistant lines did not have such virus inhibition pattern. Analysis of differential expressed genes showed that the potential host defense-relevant processes varied in different resistant tomatoes, as compared to the susceptible line, suggesting a diversity of tomato TYLCV-resistance mechanisms.

Model predictive direct power control (MPDPC) has been widely studied for the control of doubly fed induction generator (DFIG) systems because of its conceptual simplicity and multivariable control ability. However, conventional MPDPC suffers from the problems of high power ripples and intensive computational effort. Furthermore, this approach presents highly distorted currents under unbalanced networks. To address the problems mentioned above, this article proposes a universal and low-complexity MPDPC, which can work effectively under both balanced and unbalanced networks. On one hand, the proposed method unifies conventional MPDPC and multiple-vector-based MPDPC under a common framework with lower complexity. The optimal vectors and their respective durations in the proposed MPDPC are obtained in a substantially more efficient manner than conventional enumeration-based MPDPC. On the other hand, a flexible power control method with a universal power compensation expression is proposed. By adding the calculated power compensation value to the prior power reference value, the proposed universal MPDPC method can be applied to unbalanced networks. Three control objects under unbalanced network conditions can be realized. Current distortion and power ripple can vary smoothly among the three objects by regulating the coefficient determining the universal power compensation value. The presented experimental results confirm the effectiveness of the proposed method.

This paper proposes a novel direct power control (DPC) method for the doubly fed induction generators (DFIGs) power control system. The proposed DPC method is based on extended power theory rather than conventional instantaneous power theory. The proposed method calculates the rotor reference voltage based on the principle of deadbeat power control. Then, it synthesizes the rotor reference voltage using space vector modulation (SVM). As a result, the switching frequency is constant, and satisfactory control performance is achieved under both balanced and unbalanced network conditions. This technique achieves the control target of ensuring a constant stator-side active power, constant extended reactive power, and sinusoidal stator currents without power compensation terms or other measures under unbalanced network conditions. Different from other DPC-SVM methods, the phase-locked loop block is eliminated and the whole structure of the control system is simple and easy to use. No parameter needs to be tuned in the proposed method. The effectiveness of the proposed method is validated by the presented simulation and experimental results on a 1.5-kW laboratory DFIG control system.

Background In recent years, the incidence of wasp sting has increased annually in China. Organ damage and high mortality due to mass wasp envenomation remain major challenges. Timely and appropriate medical intervention can improve survival. However, there are currently no normalized tools for early assessment of severity. Methods The clinical data of wasp sting patients hospitalized from 2011 to 2019 were used as a training set. Logistic regression was used to explore major risk factors for the development of a severe case of wasp sting (SC). The Wasp Sting Severity Score (WSS) was determined considering these risk factors to identify SCs and was tested in a validation dataset that was prospectively collected in 2020. Results The data of 1131 wasp sting patients from 2011 to 2019 were included in the training set. Logistic regression analysis showed that tea-colored urine, number of stings, and lactate dehydrogenase and total bilirubin levels were risk factors for developing an SC. The WSS was developed considering these four risk factors, and the total possible WSS was 20 points. The WSS was tested using the validation dataset, comprising the data of 153 patients, in 2020, and we found that a WSS ≥3 points was an important indication for blood purification, with a sensitivity of 71.9%, specificity of 92.6% and an area under the curve of 0.918 (95% confidence interval 0.873–0.962). Among patients with more than 30 stings, mortality in those who underwent plasma exchange (PE) within 24 h after admission was significantly lower than that in those who did not receive PE treatment (14.3% versus 46.9%, P = 0.003). However, continuous venovenous hemofiltration (CVVH) (P = 0.317) and hemoperfusion (HP) (P = 0.869) did not significantly reduce mortality. Conclusions Patients with WSS scores ≥3 should be considered for blood purification as early as possible in addition to routine treatment. In addition, PE is better than CVVH and HP at reducing mortality in patients suffering from severe wasp stings.

Cucumis metuliferus, also called horned cucumber or jelly melon, is considered as a wild species in the Cucumis genus and a potential material for nematodes- or viruses-resistant breeding (Provvidenti, et al. 1977; Siguenza et al. 2005; Chen et al. 2020). This species, originating from Africa, has been cultivated as a fruit in China in recent years. In July 2020, a mosaic disease was observed on C. metuliferus growing in five fields (approximately 0.7 hectare) in Urumqi, Xijiang, China, where more than 85~100% of the field plants exhibited moderate to severe viral disease-like leaf mosaic and/or deformation symptoms. Delayed flowering and small and/or deformed fruits on the affected plants could result in yield loss of about 50%. To identify the causal pathogen, the symptomatic leaf samples were collected from the five fields (five plants/points for each field) and their total RNAs were extracted using a commercial RNA extraction kit. The universal potyviral primers (Ha et al. 2008) and specific primers for a number of frequently-occurring, cucurbit crop-infecting viruses including Papaya ringspot virus (PRSV) (Lin et al. 2013), Cucumber mosaic virus (CMV) and Watermelon mosaic virus (WMV) were designed and used for detection by RT-PCR. The result showed that only the WMV primers (forward: 5'-AAGTGTGACCAAGCTTGGACTGCA-3' and reverse: 5'-CTCACCCATTGTGCCAAAGAACGT-3') could amplify the corresponding target fragment from the total RNA templates, and direct sequencing of the RT-PCR products and GenBank BLAST confirmed the presence of WMV (genus Potyvirus) in the collected C. metuliferus samples. To complete Koch's postulates, the infected C. metuliferus leaves were ground in the sodium phosphate buffer (0.01 M, pH 7.0) and the sap was mechanically inoculated onto 30 four-leaf-stage C. metuliferus seedlings (two leaves for each seedling were inoculated) kept in an insect-proof, temperature-controlled greenhouse at 25~28℃. Twenty-five of the inoculated plants were observed to have apparent leaf mosaic similar to the field symptoms two weeks after inoculation, and positive result was obtained in RT-PCR detection for the symptomatic leaves of inoculated plants using the WMV primers aforementioned, confirming the virus as the pathogen of C. metuliferus in Urumqi. To our knowledge, this is the first report of WMV naturally infecting C. metuliferus in China. We obtained the full-length sequence of the WMV Urumqi isolation (WMV-Urumqi) by sequencing the RT-PCR amplicons from seven pairs of primers spanning the viral genome and the 5'RACE and 3'RACE products. The complete sequence of WMV-Urumqi (GenBank accession no. MW345911) is 10046 nucleotides (nt) long and contains an open reading frame that encodes a polyprotein of 3220 amino acids (aa). WMV-Urumqi shares the highest nt identity (95.9%) and aa identity (98.0%) with the Cucurbita pepo-infecting isolation (KX664483) from Shanxi province, China. Our findings provide a better understanding of the host range and genetic diversity of WMV, and a useful reference for virus-resistant breeding involving C. metuliferus.

Background: Equipoise exists regarding the implementation of evidence-based guidelines for nutritional therapy in critical illness because some previous cluster-randomised controlled trials (cRCTs) demonstrate patient benefits whilst others do not. We aimed to resolve this issue by initiating an appropriately powered cRCT to assess whether active implementation of an evidence-based guideline for nutrition therapy in critical illness could reduce mortality. Methods: We did a multicentre, cluster-randomised, parallel-controlled trial in 97 intensive care units (ICUs) throughout China. We developed an up-to-date, evidence-based nutrition guideline. ICUs randomly allocated to implement the guideline formed a local "intervention team", which actively implemented the guideline using standardized educational materials. ICUs assigned to the control group remained unaware of the guideline. All ICUs enroled critically ill patients who were expected to stay longer than seven days. The primary outcome was all-cause mortality within 28 days of enrolment . Findings Between March, 2018 and July, 2019, we enrolled 1,373 patients at 48 guideline ICUs and 1,399 patients at 49 control ICUs. Implementation of the nutrition guideline resulted in significantly earlier enteral nutrition (EN) initiation (1.20 vs. 1.55 mean days to initiation of EN; difference -0.40 [95% CI, -0.71 to -0.09]; P=0.01) and delayed parenteral nutrition (PN) initiation (1.29 vs. 0.80 mean days to start of PN; difference 1.06 [95% CI, 0.44 to 1.67]; P=0.001). There was no significant difference in 28-day mortality (14.2% vs. 15.2%; difference -1.6% [95% CI -4.3% to 1.2%]; p=0.42) between study groups. Interpretation: Active implementation of an evidence-based guideline can change practice. Our active implementation strategy improved the provision of nutrition therapy to critically ill patients. However, in our cRCT, this improvement in care did not translate to a reduction in mortality. We did not identify any safety concerns associated with the active implementation of our evidence-based guideline for nutrition therapy. Trial Registration: The study was registered in the ISRCTN registry before enrolment commenced (No. ISRCTN12233792). Funding Statement: The study was funded by the Key Research and Development Program Foundation of Jiangsu Province of China (no. BE2015685) and Nutricia, Wuxi, China. Declaration of Interests: Dr. GSD reported receiving academic research grants related to nutrition in critical illness from the Australian National Health and Medical Research Council, Fresenius Kabi Deutschland GmbH and Baxter Healthcare Pty Ltd and speakers honoraria from Fresenius Kabi Deutschland GmbH, Baxter Healthcare Australia, Pty Ltd, Nestle Healthcare, Vevy, Switzerland and Nutricia Pharmaceutical (Wuxi) Co., Ltd. China. Dr. AvZ reports personal fees from Baxter, personal fees from Nestle, personal fees from Fresenius Kabi, grants and personal fees from Nutricia, grants from Cardinal Health grants from Mermaid grants from Lyric, outside the submitted work. Dr. WqL reported receiving speakers honoraria from Nutricia Pharmaceutical (Wuxi) Co., Ltd. China. No other disclosures were reported. Ethics Approval Statement: The study was approved by the local hospital ethics committees of all the participating ICUs. At each site, informed consent was obtained from the patients or their next of kin before enrolment.

The adoption high-frequency power devices such as gallium nitride (GaN) in motor drive field can significantly reduce system volume, reduce losses, increase system power density, and reduce audible noise during motor drive system operation. But it also brings about the problem of excessive dv/dt and di/dt. In this paper, the LC filter is introduced into the servo drive system based on GaN power device. An active damping method based on virtual damping is proposed to solve the electrical resonance problem caused by the LC filter. Compared with the traditional hybrid damping method, the active damping method proposed in this paper reduces the power loss caused by damping network under the condition of similar adjustment time. Moreover, this method is suitable for LCL resonance suppression in motor drive system. Finally, the experiment results verify that the method can suppress the resonance caused by the output filter and realize the sine wave motor drive on an inverter with 100 kHz switching frequency.

The use of gallium nitride (GaN) high-electron mobility transistors (HEMTs) is a promising solution to increase switching frequency of motor drive due to their high-switching speed and low on-state resistance. Unfortunately, high-speed switching characteristic of GaN HEMT generates high dv/dt and di/dt causing crosstalk and voltage oscillation. In this paper, equivalent circuit models incorporating all parasitic elements are developed for analyzing switching transient. It provides further insight on the effect of each parasitic element on crosstalk and voltage oscillation. Besides, some optimization methods based on this research are also proposed. The experimental results show that the proposed methods can suppress crosstalk and voltage oscillation and improve the stability of motor drive.

Beta satellite DNA (satDNA) sequences, also known as Sau3A sequences, are repeated DNA elements reported in human and primate genomes. Beta satDNAs may play roles in genome stability and chromosome segregation during mitosis. It is previously thought that beta satDNAs originated in old world monkeys and bursted in great apes. However, global and high-throughput studies on beta satDNAs are still absent.Results: In this study, we searched 7,821 genome assemblies of 3,767 eukaryotic species and found that beta satDNAs actually are widely distributed across eukaryotes. The four major branches of eukaryotes, animals, fungi, plants and Harosa/SAR, all have multiple clades containing beta satDNAs. These results were also confirmed by searching whole genome sequencing data (SRA) and PCR assay. Beta satDNA might have originated during the early evolution of eukaryotes. The widely patchy distribution of beta satDNAs across eukaryotes presents a typical scenario of multiple horizontal transfers (HT). In contrast, beta satDNA sequences were found in all the primate clades, Primatomorpha and Euarchonta, indicating an origin in the common ancestor and vertical transfers thereafter. Besides in eukaryotes, beta satDNAs were even found in some archaea and bacteria, which should have been acquired from eukaryotes via HTs.Conclusion:Beta satDNAs widely exist in eukaryotes. The current distribution landscape of beta satDNA is the result of countless HTs. Our study shows for the first time that satellite DNAs can also undergo HT, and will provide new ideas for the future investigations in HT/HGT field.Keywords: Beta satellite DNA, Sau3A sequences, Eukaryotes, Horizontal gene transfer, Primates

Model predictive control (MPC) is emerging as a powerful control method for the high performance control of permanent magnet synchronous motor (PMSM) drives due to its merits of simple principle, quick response, and flexibility to handle multiple variables and constraints. However, conventional MPC applies only one voltage vector during one control period to minimize the cost function, which produces relatively high steady-state ripples and high computational burden due to the enumeration-based predictions. Introducing duty cycle control into MPC can improve its steady-state performance, but the control complexity is further increased. This paper proposes a generalized multiple-vector-based MPC for PMSM drives, which unifies the prior MPC methods in one frame with much lower complexity and computational burden by eliminating the enumeration-based predictions and complex calculations in conventional MPC methods. This is achieved by reconstructing the three-phase duties obtained from the classical deadbeat control with modulator, which also reveals the inherent relationship between deadbeat control and the proposed MPC methods. The presented experimental results confirm the effectiveness of the proposed method.

Background There is a lack of large-scale epidemiological data on the clinical practice of enteral nutrition (EN) feeding in China. This study aimed to provide such data on Chinese hospitals and to investigate factors associated with EN delivery. Methods This cross-sectional study was launched in 118 intensive care units (ICUs) of 116 mainland hospitals and conducted on April 26, 2017. At 00:00 on April 26, all patients in these ICUs were included. Demographic and clinical variables of patients on April 25 were obtained. The dates of hospitalization, ICU admission and nutrition initiation were reviewed. The outcome status 28 days after the day of investigation was obtained. Results A total of 1953 patients were included for analysis, including 1483 survivors and 312 nonsurvivors. The median study day was day 7 (IQR 2–19 days) after ICU entry. The proportions of subjects starting EN within 24, 48 and 72 h after ICU entry was 24.8% (84/352), 32.7% (150/459) and 40.0% (200/541), respectively. The proportion of subjects receiving > 80% estimated energy target within 24, 48, 72 h and 7 days after ICU entry was 10.5% (37/352), 10.9% (50/459), 11.8% (64/541) and 17.8% (162/910), respectively. Using acute gastrointestinal injury (AGI) 1 as the reference in a Cox model, patients with AGI 2–3 were associated with reduced likelihood of EN initiation (HR 0.46, 95% CI 0.353–0.599; p

An investigation on the soil microbe populations from an agricultural inning area at the Pearl River estuary in Guangdong province, China was conducted via high through-put sequencing. The results revealed abundant diversity in the soil bacterial and fungal populations. In total, 197103 sequence tags were obtained from soil samples, most of which represented bacterial genera Actinomycetes, Bacillus and Marinobacter, while a majority of 118378 tags obtained were derived from fungal genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, Penicillium, and Emericella. Furthermore, nine physiological indexes (pH, available phosphorous, basic-group nitrogen, available potassium, catalase, sucrose, urease, phosphatase, and organic matters) were measured in three soil samples, and the association between these physiological indexes and microbe population composition was examined. The results revealed obvious inter-sample differences associated with ten dominating microbial groups: genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, and Penicillium were mainly impacted by pH (with a positive correlation), genera Sphingomonas and Acinetobacter mainly by available phosphorous (positive correlation), and genera Gemmatimonas and Pseudomonas by both pH and available phosphorous (negative correlation). Our study suggested that regulation of microbial species/populations might help improve soil environment to facilitate the growth of crops’ above-ground parts, and this provides practical information for inning agriculture.

Model-predictive current control (MPCC) is widely recognized as a high-performance control strategy of permanent magnet synchronous machine (PMSM) drives due to its quick response and simple principle. It uses a cost function to select the best voltage vector minimizing the current error between the reference value and the feedback value. However, as only one voltage vector is applied during one control period, it fails to give satisfactory performance due to the limited voltage vectors, especially in the case of two-level converters. This paper proposes an improved MPCC strategy for PMSM drives, which first estimates the back electromotive force (EMF) based on the past value of stator voltage and currents and then applies the estimated EMF in the stator current prediction. To achieve steady-state performance improvement, a null vector along with the active vector obtained from conventional MPCC is applied during one control period. Two methods are proposed to achieve optimal vector selection and vector duration. The first one requires six predictions and the calculation of current differentiation, while the second one only requires one prediction to obtain the best voltage vector and its optimal duty can be obtained in a very efficient way. The proposed methods are comparatively studied and compared to conventional MPCC and deadbeat control with space vector modulation. Both simulation and experimental results confirm the effectiveness of the proposed methods in achieving good steady-state performance while maintaining quick dynamic response.

This paper presents a gallium nitride (GaN) - based servo motor drive system. Compared to actual inverters based on insulated gate bipolar transistors (IGBTs), the proposed design extends the pulse width modulation (PWM) frequency to 100 kHz. This allows motor filters with small component sizes. Based on this, an LC filter is added to the motor drive system, and an undamped resonance suppression algorithm is proposed to suppress the resonance introduced by the filter. By adding a proper time delay, system can be stable without any additional sensors or power losses. As a result, ideal sinusoidal line-line voltage at the motor terminals, high motor efficiency and low switching noise are achieved.

Model predictive direct power control (MPDPC) has been widely concerned in the control of doubly fed induction generator (DFIG) systems owing to its simple concept and good multivariate control ability. The optimal voltage vector is selected based on the principle of power error minimization. Nevertheless, the conventional MPDPC still presents relatively high power ripples and the switching frequency is variable. To cope with the problems above, recently multiple-vector-based MPDPC is proposed to improve the steady state performance, however, at the cost of increased control complexity. This paper proposes a universal multiple-vectors-based MPDPC. It firstly obtains the desired rotor voltage vector reference based on the principle of deadbeat power control, and then calculates the three-phase duties using carrier-based pulse width modulation (PWM) with injection of zero sequence component. The vector selection and duty cycle calculation in the proposed MPDPC are obtained according to the three-phase duties, which is much simpler than conventional multiple-vectors-based MPDPC. Furthermore, this method reveals the inherent relationship between multiple-vectors-based MPDPC and deadbeat control. The effectiveness of the proposed method is validated by the presented simulation results from a 15 kW DFIG system.

Model predictive direct power control (MPDPC) has been widely noticed in the field of doubly fed induction generator (DFIG) control. The optimal vector is selected based on the principle of power error minimization. However, conventional MPDPC will produce high power ripples and large current distortion under unbalanced grid voltage condition. To achieve sinusoidal stator currents and/or constant powers, both positive and negative sequence extraction of stator voltage and/or currents are required to calculate the power or current compensation value. The calculation is really complicated. To cope with the problems above, this paper proposes an improved MPDPC using a new defined instantaneous reactive power. Furthermore, there will be two vectors (including one active-vector and one zero-vector) applied during the coming control period to achieve better steady-stage performance. In this way, the sinusoidal but unbalanced stator currents are obtained without complicated calculation of power or current compensation and positive/negative sequence extraction of stator voltage and/or currents. Simulation results for conventional and proposed MPDPC are presented and compared with each other to validate the effectiveness of the proposed method.

Conventional table-based direct power control (DPC) achieves quick dynamic response with very simple structure, which has been widely studied for power control of doubly fed induction generator (DFIG) system. However, DPC presents high steady power ripples and rich current harmonics with variable switching frequency. Furthermore, it would produce highly distorted stator current and power oscillations under unbalanced grid voltage conditions if no special measure is taken. This paper proposes a novel DPC method to solve the problems above. On one hand, it uses space vector modulation (SVM) to synthesis the rotor voltage reference, which is obtained based on the principle of deadbeat power control. As a result, the switching frequency is constant and the power ripples as well as current harmonics are significantly reduced. On the other hand, it uses extended power theory to replace the conventional instantaneous power theory, which can achieve autonomous active power ripple elimination in the stator side with sinusoidal stator currents even under unbalanced grid voltage condition. The positive/negative sequence extraction of stator voltages and currents are not required, which further simplifies the structure of system. The effectiveness of the proposed method is validated by the presented simulation results from a 15 kW DFIG system.

Background Virus-derived siRNAs (vsiRNAs)-mediated RNA silencing plays important roles in interaction between plant viruses and their hosts. Southern rice black-streaked dwarf virus (SRBSDV) is a newly emerged devastating rice reovirus with ten dsRNA genomic segments. The characteristics of SRBSDV-derived siRNAs and their biological implications in SRBSDV-rice interaction remain unexplored. Methods VsiRNAs profiling from SRBSDV-infected rice samples was done via small RNA deep sequencing. The putative rice targets of abundantly expressed vsiRNAs were bioinformatically predicted and subjected to functional annotation. Differential expression analysis of rice targets and RNA silencing components between infected and healthy samples was done using RT-qPCR. Results The vsiRNA was barely detectable at 14 days post infection (dpi) but abundantly present along with elevated expression level of the viral genome at 28 dpi. From the 28-dpi sample, 70,878 reads of 18 ~ 30-nt vsiRNAs were recognized (which mostly were 21-nt and 22-nt), covering 75 ~ 91% of the length of the ten genomic segments respectively. 86% of the vsiRNAs had a

An improved RT-PCR was developed and validated for the detection of Yam mild mosaic virus (YMMV). Sequences of the coat protein core region of 19 Chinese isolates were obtained, and analysis indicated the presence of different genetic variants. Phylogenetic analyses showed that the Chinese isolates were divided into two distinct clusters. Complete genomic sequences of two distinct Chinese variants were determined to be 9527 and 9529 nucleotides long, excluding the 3′ poly (A) tail. Their genomic structure and organization were virtually identical to that of a Brazilian isolate. The two variants shared identity of 87.3% to one another and 83.9–84.6% to the Brazilian variant at the genomic sequence level. Phylogenetic analyses supported that they represented two distinct YMMV lineages.

Southern rice black-streaked dwarf virus (SRBSDV) is a recently emerged rice virus that has spread across Asia. This devastating virus causes rice plants to produce a variety of symptoms during different growth stages. MicroRNAs (miRNAs) comprise a large group of 21-24-nt RNA molecules that are important regulators of plant development processes and stress responses. In this study, we used microarray profiling to investigate rice miRNAs responding to SRBSDV infection at 3, 9, 15, and 20 days post-inoculation (dpi). Expression levels of 56 miRNAs were altered in SRBSDV-infected rice plants, with these changes classified into eight different regulation patterns according to their temporal expression dynamics. Fourteen miRNAs belonging to six families (miR164, R396, R530, R1846, R1858, and R2097) were significantly regulated at 20 dpi. We used RT-qPCR to search for expression level correlations between members of these families and their putative targets at 3, 9, and 15 dpi. Some members of the miR164, R396, R530, and R1846 families were found to be positively or negatively correlated with their respective targets during 3-15 days after SRBSDV infection, whereas in more cases the rice miRNAs were not in correlation with their targets along the post-inoculation period, suggesting that some additional factors may be involved in rice miRNA-target interactions. The reported functions of rice genes targeted by the miR164, R396, R530, R1846, and R1858 families indicated that these genes are associated with symptom development. These results provide insights into miRNA-mediated SRBSDV-rice interactions.

Host range of a cilantro isolate of Carrot thin leaf virus (CTLV-Cs) was determined to include 15 plant species. The virus was also transmitted to nine of 11 tested apiaceous species by aphids. Complete genomic sequences of CTLV-Cs and a carrot isolate of CTLV (CTLV-Dc) were determined to be 9,491 and 9,490 nucleotides, respectively, excluding the 3′-poly(A) tail. Sequence analyses showed that the two isolates shared 98 % identities at both genomic and polyprotein sequence levels. Their genomic organization is typical of potyviruses, and their polyproteins contain conserved motifs found in members of the genus Potyvirus. Pairwise comparisons show that the virus shares 52.0–59.6 % identities to those of other members in the genus Potyvirus at genomic sequence level. Phylogenetic analyses confirm that CTLV is a distinct potyvirus most closely related to Konjac mosaic virus. Both biological and molecular results also showed that the two CTLV isolates were very similar although they were isolated from different hosts at different times.

Two novel soluble chemosensors based on Schiff-base diaminomaleonitrile derivatives which were modified by an aza-crown ether moiety have been synthesized. These chemosensors were fully characterized by 1H NMR, 13C NMR spectroscopy, mass spectrometry, IR, DSC and single crystal X-ray diffraction. The recognition abilities of the sensors with a range of metal ions were evaluated and their photophysical properties have been systematically investigated. DFT theoretical calculations were employed to understand the behavior of the sensors toward the Cu(II). The sensing mechanism was derived through experimental and theoretical calculations. The results consistently indicated that the monoaza-10-crown-5 species was the ideal sensor, which can be utilized to monitor Cu(II) in solution over a wide pH range.

Southern rice black-streaked dwarf virus (SRBSDV), a newly emerged fijivirus causing great loss to rice production in eastern and southeastern Asian countries in recent years, is efficiently transmitted by a rice pest, white-backed planthopper (WBPH, Sogatella furcifera) in a persistent, circulative propagative manner and can be considered as an insect virus. In this study, SRBSDV infection in WBPH was found to increase the vector’s death rate under extreme cold stress but improve its survival rate under extreme heat stress. Digital gene expression profiling based on RNA-Seq revealed different gene regulation patterns in WBPH under viral and/or temperature stress. Under cold stress, the virus infection upregulated 1540 genes and downregulated 131 genes in the insect, most of which were related to membrane properties and biological processes of actin and cytoskeleton; whereas under heat stress, it upregulated 363 genes and downregulated 548 genes, most of which were associated to metabolism and intracellular organelles. Several types of stress-responsive genes involving intestinal mucin, cuticle protein, ubiquitin protease, immune response, RNA interference and heat shock response, were largely upregulated under cold stress, but largely downregulated under heat stress, by SRBSDV infection. Our results suggest two distinct mechanisms of virus-altered vector insect tolerance to temperature stress.

The complete genomic sequence of Celery mosaic virus (CeMV) was found to be 9999 nucleotides in length, excluding the 3' poly(A) tail. The genome contains a single large open reading frame encoding a polyprotein of 3181 amino acids. Its genomic organization is typical of potyviruses and contains conserved motifs found in members of the genus Potyvirus. Pairwise comparison of the polyprotein sequences shows that CeMV shares 39.0-71.9% sequence identity with other members of the genus Potyvirus. Phylogenetic analysis based on the polyprotein sequences indicates that CeMV is most closely related to Apium virus Y, and together with Panax virus Y, the three viruses form a distinct clade.

A celery isolate of Apium virus Y (ApVY-Ce) from diseased plants in a commercial field in California was characterized. The experimental host range of the virus included 13 plant species in the families Apiaceae , Chenopodiaceae and Solanaceae . Almost all infected plant species showed foliar chlorosis and distortion or severe stunting and systemic chlorosis. ApVY-Ce was transmitted to all 10 host species in the Apiaceae by green peach aphids. It reacted with the potyvirus group antibody and Celery mosaic virus (CeMV) antiserum. The complete genomic sequence of ApVY-Ce was determined to be 9917 nucleotides, excluding the 3′ poly(A) tail, and it comprises a large open reading frame encoding a polyprotein of 3184 amino acid residues. Its genomic organization is typical of potyviruses, and contains conserved motifs found in the genus Potyvirus . Comparisons with available genomic sequences of other potyviruses indicate that ApVY-Ce shares 26.1–52.9% identities with species of the existing genera and unassigned viruses in the Potyviridae at the polyprotein sequence level. Extensive phylogenetic analysis based on the 3′-partial sequences confirms that ApVY-Ce is most closely related to CeMV and is a distinct species of the genus Potyvirus .