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Objective: To find the optimal quantitative index of emphysema by comparing and analyzing the quantitative indexes of emphysema in patients with mild to moderate chronic obstruction pulmonary disease (COPD) via registered biphasic quantitative computed tomography (QCT). Methods: We retrospectively collected 55 healthy controls, 21 Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) 1 case, and 31 GOLD 2 cases in our hospital. We imported the CT raw DICOM data into the "Digital Lung" analysis platform and measured the LAA-950% at the end of deep inspiration and the LAA-910% at the end of deep expiration. The expiratory and inspiratory CT images were registered. Then, the percentage of emphysema area (PRMEmph%), the percentage of functional small airway disease area (PRMfSAD%), and the percentage of the normal area (PRMNormal%) were calculated according to the threshold method. Pulmonary function indicators included FVC, FEV1%, and FEV1/FVC. Differences in general data, CT quantitative indexes, and pulmonary function between groups were assessed using the independent sample t-test, Mann–Whitney U test, or chi-square test, and the correlation was analyzed using Spearman correlation. The receiver operating characteristic (ROC) curve was drawn to analyze the diagnostic performance of CT quantitative parameters for emphysema in patients with mild to moderate COPD. Results: There were significant differences in sex, smoking index, FEV1%, FEV1/FVC, inspiratory phase LAA%-950, expiratory phase LAA%-910, PRMEmph%, PRMfSAD%, and PRMNormal% between the mild to moderate COPD patients and normal control groups. The inspiratory phase LAA%-950 was negatively correlated with FEV1/FVC, the expiratory phase LAA%-910 and PRMEmph% were negatively correlated with FVC, FEV1%, and FEV1/FVC. ROC curve analysis results showed that the areas under the curve of inspiration phase LAA%-950, expiratory phase LAA%-910, and PRMEmph% were 0.742, 0.861, and 0.876, respectively. Among them, the area under the curve of the PRMEmph% index was the largest, with a corresponding critical value of 9.84%, a sensitivity of 76.90%, and a specificity of 94.50%. Conclusion: Quantitative CT emphysema index LAA%-950 in the inspiratory phase, LAA%-910 in the expiratory phase, and PRMEmph% in biphasic can objectively evaluate emphysema in patients with mild to moderate COPD, among which PRMEmph% is the best evaluation index.

Persistent organic pollutants seriously affect the growth and development of crops. 1,2,4-Trichlorobenzene (TCB), as one of the most widely used chlorobenzenes, can affect the yield of japonica rice. However, existing research on the effect of TCB on japonica rice yield is not in-depth, and a basic understanding of commonality has not yet been formed. In this study, 28 conventional japonica rice varieties were selected to investigate the effects of TCB stress on their yield, yield composition, and TCB accumulation. This study also evaluated the efficiency of conventional tolerance indices in evaluating the TCB stress tolerance of japonica rice. The results showed that TCB caused sustained inhibition of the growth of japonica rice, which was considerably manifested in plant height, root length, soil plant analysis development (SPAD), and dry weight at different growth stages. Under TCB stress, TCB accumulation in various tissues of japonica rice increased sharply. TCB stress reduces the yield of japonica rice by reducing the number of panicles per hill, the number of spikelets per panicle, the grain filling percentage, and the grain weight. Overall, the results of this study indicate that TCB stress can cause a decrease in the yield of japonica rice, and the decrease in panicle number is the main reason. The conventional tolerance index can effectively evaluate the tolerance of japonica rice to TCB. The results of this study are substantial for the breeding and cultivation of japonica rice.

Agrobacterium tumefaciens is a soil-borne pathogenic bacterium that causes crown gall disease in many plants. Chemotaxis offers A. tumefaciens the ability to find its host and establish infection. Being an aerobic bacterium, A. tumefaciens possesses one chemotaxis system with multiple potential chemoreceptors. Chemoreceptors play an important role in perceiving and responding to environmental signals. However, the studies of chemoreceptors in A. tumefaciens remain relatively restricted. Here, we characterized a cytoplasmic chemoreceptor of A. tumefaciens C58 that contains an N-terminal globin domain. The chemoreceptor was designated as Atu1027. The deletion of Atu1027 not only eliminated the aerotactic response of A. tumefaciens to atmospheric air but also resulted in a weakened chemotactic response to multiple carbon sources. Subsequent site-directed mutagenesis and phenotypic analysis showed that the conserved residue His100 in Atu1027 is essential for the globin domain’s function in both chemotaxis and aerotaxis. Furthermore, deleting Atu1027 impaired the biofilm formation and pathogenicity of A. tumefaciens. Collectively, our findings demonstrated that Atu1027 functions as an aerotaxis receptor that affects agrobacterial chemotaxis and the invasion of A. tumefaciens into its host.

This study aims to accurately determine the distribution of landslides in the complex terrain of Jiangdingya, Nanyu Township, Zhouqu County, Gansu Province. The digital orthophoto map (DOM) and digital elevation model (DEM) are used to accurately identify landslide areas and analyze associated data. Based on image-based supervised classification, the influence factor constraint analysis is used to further identify and delineate the landslide area. Three mathematical morphology operations—erosion, dilation, and opening—are then applied to automatically identify and extract landslides. Experimental results demonstrate that achieving an accuracy, precision, and recall of 98.02%, 85.24%, and 84.78% shows that it is possible to better avoid interference caused by complex terrain with rich features. High-resolution DEM and DOM data contain rich spectral and texture information. These data can accurately depict geomorphic features of complex terrain and aid in identifying landslide-prone areas when combined with mathematical morphology processing. This contribution is important for identifying landslides in complex terrain and emergency disaster management.

Dendritic cells (DCs), central participants in the allergic immune response, can capture and present allergens leading to allergic inflammation in the immunopathogenesis of allergic rhinitis (AR). In addition to initiating antigen-specific immune responses, DCs induce tolerance and modulate immune homeostasis. As a special type of DCs, tolerogenic DCs (tolDCs) achieve immune tolerance mainly by suppressing effector T cell responses and inducing regulatory T cells (Tregs). TolDCs suppress allergic inflammation by modulating immune tolerance, thereby reducing symptoms of AR. Activation of the TLR4/IRAK4/NF-κB signaling pathway contributes to the release of inflammatory cytokines, and inhibitors of this signaling pathway induce the production of tolDCs to alleviate allergic inflammatory responses. This review focuses on the relationship between tolDCs and TLR4/IRAK4/NF-κB signaling pathway with AR.

BackgroundSpinal meningioma is a common intraspinal tumor, which mainly occurs in the thoracic spine. Ossified meningioma (OSM) is an extremely rare histological variant. Our article reports a rare patient with dorsal complete OSM and reviews this subject.Case presentationA 68-year-old woman presented with a one-year history of progressive weakness in both lower limbs with gait disturbance. Physical examination revealed hypoesthesia with a sensory level below T10. Babinski and pathological signs on both sides were weakly positive. Magnetic resonance imaging (MRI) showed a mass at the T10 to T11 level causing severe compression of the spinal cord. Computed tomography (CT) showed complete ossification of the mass. 18F-Fluoro-deoxy-glucose positron emission tomography CT (18F-FDG PET/CT) scan combined with MRI revealed that the mass was an intradural extramedullary high-density ossified nodule. The patient underwent a gross total resection of the mass and pathologic examination indicated that the mass was a meningioma with diffused psammomatous bodies.ConclusionWe identified a rare case of dorsal complete OSM occurring in a 68-year-old woman. After complete surgical resection, although there were complications such as cerebral fluid leakage and fever, the patient finally recovered with a satisfactory result.

Abstract Background The Phenomenon of codon usage bias exists in the genomes of prokaryotes and eukaryotes. The codon usage pattern is affected by environmental factors, base mutation, gene flow and gene expression level, among which natural selection and mutation pressure are the main factors. The study of codon preference is an effective method to analyze the source of evolutionary driving forces in organisms. Epimedium species are perennial herbs with ornamental and medicinal value distributed worldwide. The chloroplast genome is self-replicating and maternally inherited which is usually used to study species evolution, gene expression and genetic transformation. Results The results suggested that chloroplast genomes of Epimedium species preferred to use codons ending with A/U. 17 common high-frequency codons and 2–6 optimal codons were found in the chloroplast genomes of Epimedium species, respectively. According to the ENc-plot, PR2-plot and neutrality-plot, the formation of codon preference in Epimedium was affected by multiple factors, and natural selection was the dominant factor. By comparing the codon usage frequency with 4 common model organisms, it was found that Arabidopsis thaliana, Populus trichocarpa, and Saccharomyces cerevisiae were suitable exogenous expression receptors. Conclusion The evolutionary driving force in the chloroplast genomes of 10 Epimedium species probably comes from mutation pressure. Our results provide an important theoretical basis for evolutionary analysis and transgenic research of chloroplast genes.

The trajectory planning of multiple unmanned aerial vehicles (UAVs) is the core of efficient UAV mission execution. Existing studies have mainly transformed this problem into a single-objective optimization problem using a single metric to evaluate multi-UAV trajectory planning methods. However, multi-UAV trajectory planning evolves into a many-objective optimization problem due to the complexity of the demand and the environment. Therefore, a multi-UAV cooperative trajectory planning model based on many-objective optimization is proposed to optimize trajectory distance, trajectory time, trajectory threat, and trajectory coordination distance costs of UAVs. The NSGA-III algorithm, which overcomes the problems of traditional trajectory planning, is used to solve the model. This paper also designs a segmented crossover strategy and introduces dynamic crossover probability in the crossover operator to improve the solving efficiency of the model and accelerate the convergence speed of the algorithm. Experimental results prove the effectiveness of the multi-UAV cooperative trajectory planning algorithm, thereby addressing different actual needs.

To address domestication and improvement studies of soybean seed size- and oil-related traits, a series of domesticated and improved regions, loci, and candidate genes were identified in 286 soybean accessions using domestication and improvement analyses, genome-wide association studies, quantitative trait locus (QTL) mapping and bulked segregant analyses in this study. As a result, 534 candidate domestication regions (CDRs) and 458 candidate improvement regions (CIRs) were identified in this study and integrated with those in five and three previous studies, respectively, to obtain 952 CDRs and 538 CIRs; 1469 loci for soybean seed size- and oil-related traits were identified in this study and integrated with those in Soybase to obtain 433 QTL clusters. The two results were intersected to obtain 245 domestication and 221 improvement loci for the above traits. Around these trait-related domestication and improvement loci, 7 domestication and 7 improvement genes were found to be truly associated with these traits, and 372 candidate domestication and 87 candidate improvement genes were identified using gene expression, SNP variants in genome, miRNA binding, KEGG pathway, DNA methylation, and haplotype analysis. These genes were used to explain the trait changes in domestication and improvement. As a result, the trait changes can be explained by their frequencies of elite haplotypes, base mutations in coding region, and three factors affecting their expression levels. In addition, 56 domestication and 15 improvement genes may be valuable for future soybean breeding. This study can provide useful gene resources for future soybean breeding and molecular biology research.

The electrical characteristics of a single-phase grounding fault in a low-resistance grounding system was aualyzed, and a fault protection scheme was proposed for low-resistance grounding systems according to the ratio of the zero-sequence current projection components. The primary line selection was performed according to the zero-sequence current projection method and then the phase difference value was used for the secondary judgment. The proposed protection scheme was verified by Matlab/Simulink. The simulation results show that the scheme has a certain ability to withstand transition resistance, which effectively improves the sensitivity of the ground fault protection.

Abstract Rosa rugosa × Rosa sertata, which belongs to the family Rosaceae, is one of the native oil-bearing roses in China. Most research has focused on its essential oil components and medicinal values. However, there have been few studies about its chloroplast genome. In this study, the whole chloroplast genome of R. rugosa × R. sertata was sequenced, analyzed, and compared to other genus Rosa species. The chloroplast genome of R. rugosa × R. sertata is a circular structure and 157,120 bp in length. The large single copy and small single copy is 86,173 bp and 18,743 bp in size, respectively, and the inverted repeats are 26,102 bp in size. The GC content of the whole genome is 37.96%, while those of regions of LSC, SSC, and IR are 35.20%, 31.18%, and 42.73%, respectively. There are 130 different genes annotated in this chloroplast genome, including 84 protein coding genes, 37 tRNA genes, 8 rRNA genes, and 1 pseudogene. Phylogenetic analysis of 19 species revealed that R. rugosa × R. sertata belong to the Sect. Cinnamomeae. Overall, this study, providing genomic resources of R. rugosa × R. sertata, will be beneficial for species identification and biological research.

Abstract Background The photosynthetic parameters of cotton plants may be modified by the timing of film removal during their growing period. This study was undertaken during 2015–2017 in Xinjiang, China, to determine to what extent the film mulching removal time, 1 and 10 days before the first irrigation and 1 day before the second irrigation after seedling emergence, influenced cotton’s photosynthetic characteristics. The control group (CK) was film-mulched throughout the growth stages. Results The results suggested the following: (1) Removing mulching-film within 50 days since seedling emergence had adverse effects on soil temperature and moisture. (2) Film-removal before the first or second irrigation after emergence improved the net photosynthetic rate in cotton’s later flowering stage and its transpiration rate in mid and later flowering stages while enhancing the actual electron transport rate (ETR) and maximum electron transfer rate (ETRmax) between cotton photosystems I and II. (3) Film-removal treatment also increased cotton plants’ tolerance to high irradiation after emergence, the trend was more pronounced in the early flowering stage in wetter years. (4) Leaf area index (LAI) of cotton was reduced in the film-removal treatment for which the least accumulation of dry matter occurred in a drought year (i.e., 2015). (5) Film removal caused a yield decrease in the dry year (2015), and the earlier the film was removed, the more seriously the yield decreased. Removing mulching film before the second irrigation could increase the yield of XLZ42 in the rainy year (2016) and the normal rainfall year (2017). Early film removal can increase the yield of XLZ45 in the rainy year (2016). Conclusions Collectively, our study’s experimental results indicate that applying mulch film removal at an appropriate, targeted time after seedling emergence had no adverse effects on soil moisture and temperature, and improved the photosynthetic performance of cotton, thus increased cotton yield and fiber quality, but no significant difference was reached.

Systematic evaluation of water environment carrying capacity (WECC) is a prerequisite for achieving sustainable development, which reflects the water environment comprehensive condition of lake basin under the current economic development scenario. Therefore, taking the Taihu Basin as a case study, a scientific comprehensive evaluation index system of WECC was established based on the Pressure-State-Response (PSR) assessment framework, which included water resources (WR), pollution emission (PE), water quality (WQ), water ecology (WE), and land use (LU) sub-systems. An expert group was invited to determine the weights of each indicator using the group analytic hierarchy process (G-AHP) method, and the indicators in the WR, PE, WQ, WE, and LU sub-systems were 6.5%, 21.8%, 27.9%, 11.1%, and 32.9%, respectively. According to the evaluation results, the WECC index of Taihu Basin increased by 51.4% from 2007 to 2019, but it still slightly exceeded the carrying capacity of the water environment; the water quality and pollution discharge indices had the most significant improvement. Algal blooms are a major factor challenging WECC in the Taihu Basin. Therefore, the overall restoration of the water eco-system must receive more attention in the future.

Salt stress severely restricts the growth of plants and threatens the development of agriculture throughout the world. Worldwide studies have shown that exogenous melatonin (MT) can effectively improve the growth of plants under salt stress. Through a meta-analysis of 549 observations, this study first explored the effects of salt stress characteristics and MT application characteristics on MT regulated plant growth under salt stress. The results show that MT has a wide range of regulatory effects on plant growth indicators under salt stress, of which the regulatory effect on root indexes is the strongest, and this regulatory effect is not species-specific. The intensity of salt stress did not affect the positive effect of MT on plant growth, but the application effect of MT in soil was stronger than that in rooting medium. This meta-analysis also revealed that the foliar application of a concentration between 100–200 μM is the best condition for MT to enhance plant growth under salt stress. The results can inspire scientific research and practical production, while seeking the maximum improvement in plant salt tolerance under salt stress.

Sucrose non-fermenting 1-related protein kinases (SnRKs) are a kind of plant-specific serine/threonine (Ser/Thr) protein kinase, which play an important role in plant stress resistance. However, the scale analysis of SnRK in the cucumber genome is currently unclear. In the study, a total of 30 CsSnRK genes were identified from genomic data. They were distributed on six chromosomes, including 1 CsSnRK1, 10 CsSnRK2s and 19 CsSnRK3s. According to the analysis of gene structure and motif composition, CsSnRKs showed obvious differences among the three subfamilies. The ratio of synonymous (Ks) and nonsynonymous (Ka) nucleotide substitutions (Ka/Ks) of three paralogues indicates that the CsSnRK gene family undergoes a purifying selection. The analysis of cis-acting elements shows that the promoter region of each CsSnRK gene contained different classes of hormone and stress-related cis-acting elements. Furthermore, based on RNA-sequencing data from the Short Read Archive (SRA) database of NCBI, the expression patterns of CsSnRK genes in six tissues were investigated, indicating that the expression of multiple CsSnRK genes was prevalent in these tissues. Transcription levels of CsSnRK genes after drought, methyl jasmonate (MeJA) and abscisic acid (ABA) treatments were analyzed by quantitative RT-PCR, and the results show that most of the CsSnRK genes responded to these stresses. However, under different treatments, individual genes played a major role. For example, under ABA treatment, CsSnRK2.2 and CsSnRK2.3 played a major role in the response to ABA. These results provide clear evidence that CsSnRKs may be involved in cucumber growth, development and stress response, and provide valuable information for future functional studies of CsSnRKs.

Trehalose-6-phosphate synthase (TPS) is significant in the growth, development and stress resistance of plants. We identified the cucumber TPS family and its physicochemical properties, domains, gene structures, evolutionary relationships, gene locations, cis-acting elements, conserved motifs, and expression patterns using bioinformatics. Our results uncovered seven CsTPS genes in the cucumber genome and named CsTPS1–CsTPS7 according to their locations in the chromosomes. Seven CsTPS genes were randomly distributed in six cucumber chromosomes. Domain analysis showed that the TPS and TPP domains exist in all CsTPSs, and an additional hydrolase-3 domain exist in CsTPS3, CsTPS5 and CsTPS6. Phylogenetic analysis showed that TPS proteins from Arabidopsis, rice, soybean, and cucumber were divided into two subfamilies (Class I and Class II) and they were further divided into seven subgroups. TPS proteins from Arabidopsis and cucumber were grouped together, suggesting a close evolutionary relationship. Gene structure analysis indicated that most Class I genes contained 16–17 introns, while Class II genes (except CsTPS7) had two introns. Motif analysis showed that Class II genes had 10 complete conserved motifs, while Class I genes lacked motif 8 and motif 9. Furthermore, CsTPS genes possessed numerous cis-acting elements related to stress, hormone, and light response in the promoter regions. GO analysis indicated multiple functions for the CsTPS proteins. Expression analysis of CsTPS genes in different tissues found that they were expressed in roots, stems and leaves, with the highest expression levels in roots. The expression analysis of CsTPSs under different treatments showed that CsTPS genes may participate in the response to abiotic stress, plant hormones and sugar treatments.

Food chain length is a significant ecosystem index and it greatly affects ecosystem processes and their outcomes. In recent decades, determinants or indicators of FCL have been investigated in different ecological contexts, but few studies analyzed the relationships between macrophyte community structure and the food chain length of freshwater ecosystems despite the crucial role of macrophyte community in determining food web structure. This study investigated the influence of macrophyte community structure on food chain length by conducting a field survey in Lake Poyang, the largest freshwater lake in China. Plant volume inhabited (PVI), Shannon-Wiener diversity index and Pielou’s evenness index were used to indicate macrophyte community structure. Our results suggested that intermediate levels of PVI and diversity (PVI 44% and diversity 0.61) with greater evenness could support longer food chain in sub-lakes of Lake Poyang. We proposed that macrophyte community structure indexes could be useful indicators in indicating food chain length in freshwater ecosystem. These novel findings also highlight that within suitable ranges of PVI and diversity, better restoration effect could be achieved by higher macrophyte evenness in lake management. Our findings provide new insights for the restoration and management of macrophytes in freshwater ecosystems.

Prinsepia uniflora Batalin 1892 is a medicinal plant widely distributed in northwest China. In this study, we report and characterize the complete chloroplast (cp) genome sequence of P. uniflora. The entire sequence is 159,179 bp in length, consisting of the large single-copy region (LSC) and small single copy region (SSC) (87,239 and 19,180 bp, respectively); these two regions are separated by a pair of 26,380-bp inverted repeat (IR) regions. The genome contains 131 genes, including 86 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The overall GC content of the genome is 36.7%. A phylogenetic tree constructed from 18 chloroplast genomes revealed that P. uniflora was clustered with Prinsepia sinensis and Prinsepia utilis, all of which belong to the genus Prinsepia, which is supported as a sister group by a moderate bootstrap support value of 55% with the Malus and Pyrus genera.

Sucrose non-fermenting-1-related protein kinase 1 (SnRK1) plays an important role in plant carbohydrate metabolism and starch biosynthesis. The regulatory role of GmSnRK1 from soybean in regulating carbohydrate metabolism and starch accumulation has not been reported. In the present study, a gene encoding the SnRK1 protein, named GmSnRK1, was successfully isolated from soybean, and the functions of this gene were studied. Subcellular localisation analysis in onion epidermal cells indicated that GmSnRK1 protein was localised to the nucleus. The GmSnRK1 gene was introduced into Arabidopsis to obtain transgenic plants. Its overexpression significantly increased the starch content, as well as the sucrose, glucose and fructose content in the transgenic plants compared to the wild-type (WT). Real-time quantitative polymerase chain reaction (PCR) analysis showed that overexpression of GmSnRK1 up-regulated the genes involved in starch biosynthesis, including sucrose synthase (AtSUS), phosphoglucomutase (AtPGM), ADP-glucose pyrophosphorylase (AtAGPase), granule-bound starch synthases (AtGBSS I and AtGBSS II), soluble starch synthases (AtSSS I, AtSSS II, AtSSS III and AtSSS IV) and starch branching enzymes (AtSBE I and AtSBE II) genes. In contrast, the expression of sucrose phosphate synthase (SPS) gene was decreased in the transgenic plants. Meanwhile, the enzyme activity levels of the five starch biosynthetic enzymes (SUS, AGPase, GBSS, SSS and SBE) exhibited higher activities, while the SPS activity was decreased in the transgenic plants compared to WT. These results suggest that the manipulation of GmSnRK1 expression might be used for improving the starch content in engineered plants for biofuel production.

Cucumber is the most important vegetable crop in the Cucurbitaceae family. Condon usage bias (CUB) is a valuable character of species evolution. However, there is little research on the CUB of cucumber. Thus, this study analyzes the codon usage patterns of cucumber and its relatives within Cucurbitaceae on the genomic level. The analysis of fundamental indicators of codon characteristics shows that it was slightly GC poor, and there was weak codon usage bias in cucumber. We conduct the analysis of neutrality plot, ENC plot, P2 index, and COA indicates that the nucleotide composition, mutation pressure, and translational selection might play roles in CUB in cucumber and its relatives. Among these factors, nucleotide composition might play the most critical role. Based on these analyses, 30 optimal codons were identified in cucumber, most of them ending with U or A. Meanwhile, based on the RSCU values of species, a cluster tree was constructed, in which the situation of cucumber is consistent with the current taxonomic and evolutionary studies in Cucurbitaceae. This study systematically compared the CUB patterns and shaping factors of cucumber and its relatives, laying a foundation for future research on genetic engineering and evolutionary mechanisms in Cucurbitaceae.

The air quality of Handan, a typical industrial city in China, has been significantly improved through atmospheric pollution control, except for ozone (O3) pollution. We found that, in summer, emissions of anthropogenic volatile organic compounds (VOCs) and NOx decreased yearly in Handan, but the O3 concentration significantly declined yearly during 2013–2015, whereas it experienced worsening O3 pollution after 2015. Therefore, we used the Weather Research and Forecasting Community Multiscale Air Quality (WRF–CMAQ) modeling system to simulate the influence of the meteorological conditions and emission changes in Handan during the typical period (June) of O3 pollution in 2013–2018. For benchmarked June 2013, the results showed that the reduction of the O3 concentration in June of 2014–2016 was mainly caused by emission reduction, while in June of 2017–2018, the combined effect of changes in emissions and meteorological conditions led to aggravated O3 pollution. Sensitivity analysis indicated that combined VOCs and NOx emission controls would effectively reduce incremental O3 formation when the abatement ratio of VOCs/NOx should be no less than 0.84, and we found that VOCs reduction would continusouly bring about O3 decreases under various NOx reductions, but its positive sensitivity to O3 would become smaller with NOx reduction. However, the positive influence of NOx reduction on O3 would happen until NOx reduction exceeding 45–60%. The findings will be helpful in formulating emission control strategies for coping with O3 pollution in an industrial city.

Single-photon sources are one of the most basic devices for quantum optical experiments and applications. Here, Lin et al. present an electrically driven single-photon source based on solution-processed colloidal quantum dots with near-optimal antibunching at room temperature.

The plastidic thioredoxin F-type (TrxF) protein plays a key role in plant carbohydrate metabolism. In this work, a gene encoding the TrxF protein, named StTrxF, was successfully isolated from potato and transformed into Arabidopsis thaliana to obtain transgenic plants. Constitutive expression of StTrxF significantly increased the starch accumulation in the transgenic plants. Real-time quantitative polymerase chain reaction analysis showed that constitutive expression of StTrxF up-regulated the expression of the adenosine diphosphate (ADP)-glucose pyrophosphorylase (AGPase) small subunit (AtAGPase-S1 and AtAGPase-S2), AGPase large subunit (AtAGPase-L1 and AtAGPase-L2) and soluble starch synthases (AtSSS I, AtSSS II, AtSSS III and AtSSS IV) genes involved in starch biosynthesis in the transgenic A. thaliana plants. Meanwhile, enzymatic analyses indicated that the major enzymes (AGPase and SSS) involved in the starch biosynthesis exhibited higher activities in the transgenic plants compared to the wild-type. These results suggest that StTrxF may improve the starch content of A. thaliana by up-regulating the expression of the related genes and increasing the activities of the major enzymes involved in starch biosynthesis. The StTrxF gene may be applied for increasing starch accumulation of plants in the future.

Soybean, an important source of vegetable oils and proteins for humans, has undergone significant phenotypic changes during domestication and improvement. However, there is limited knowledge about genes related to these domesticated and improved traits, such as flowering time, seed development, alkaline-salt tolerance, and seed oil content (SOC). In this study, more than 106,000 single nucleotide polymorphisms (SNPs) were identified by restriction site associated DNA sequencing of 14 wild, 153 landrace, and 119 bred soybean accessions, and 198 candidate domestication regions (CDRs) were identified via multiple genetic diversity analyses. Of the 1489 candidate domestication genes (CDGs) within these CDRs, a total of 330 CDGs were related to the above four traits in the domestication, gene ontology (GO) enrichment, gene expression, and pathway analyses. Eighteen, 60, 66, and 10 of the 330 CDGs were significantly associated with the above four traits, respectively. Of 134 trait-associated CDGs, 29 overlapped with previous CDGs, 11 were consistent with candidate genes in previous trait association studies, and 66 were covered by the domesticated and improved quantitative trait loci or their adjacent regions, having six common CDGs, such as one functionally characterized gene (). Of the 68 seed size (SS) and SOC CDGs, 37 were further confirmed by gene expression analysis. In addition, eight genes were found to be related to artificial selection during modern breeding. Therefore, this study provides an integrated method for efficiently identifying CDGs and valuable information for domestication and genetic research.

A field survey of the seasonal variation of microcystin (MC) concentration was performed in Gonghu Bay (a total of 15 sampling sites) of Lake Taihu from January to December 2008. Microcystis spp. biomass and intra-/extracellular MCs were significantly correlated with water temperature, suggesting the importance of temperature in cyanobacterial blooming in the lake. Higher MC concentration was found in summer and autumn, and peaks of Microcystis biomass and intra-/extracellular MC concentrations were all present in October. Spatially, risk of MCs was higher in littoral zones than in the pelagic area. There were significant correlations between N or P concentrations, and Microcystis biomass or MC content, suggesting that N and P levels affected MC production through influencing Microcystis biomass. Intra-/extracellular MCs and Microcystis biomass had negative exponential relationships with TN:TP, and the maximum values all occurred when TN:TP was

Sediment cores taken from different areas of the mesotrophic Lake Erhai were analysed to investigate the vertical distribution of bacterial community composition (BCC), as well as physicochemical parameters. PCR-denaturing gradient gel electrophoresis (DGGE), stable carbon isotope (δ13C), C/N atomic ratio and canonical correspondence analysis (CCA) were used to explore the relationships between the succession of bacterial communities and environmental variables, emphasising changes in the sources of organic matter (OM). The BCC in natural environments was characterised by DGGE of the 16S rRNA gene with subsequent sequencing of bands of interest. The CCA revealed that the depth-related variation in sediment bacterial communities in different areas of the lake was significantly influenced by varying environmental factors. The OM source, however, played an important role in structuring BCC at all sites. The DGGE banding patterns revealed that the abundance of Deltaproteobacteria decreased with accompanying elevated levels of C4 plant-derived organic carbon. The sequencing of DGGE bands suggested that the majority of the sequences were affiliated with common phylogenetic groups in lake sediments: Chloroflexi, Deltaproteobacteria and Firmicutes. Betaproteobacteria detected in our study appeared as a prominent phylotype in the upper sediment. The Shannon-Wiener diversity index of bacterial communities was directly affected by the OM source. Constant OM sources resulted in a stable higher diversity of bacterial communities and broader enzymatic capabilities to access OM. We conclude that the differences in the diversity of bacterial communities in sediments differing in their sources of OM were related to environmental variables (e.g. water level, river runoff and terrestrial vegetation composition). Our study provided insights into the relationships between natural BCC and OM sources, facilitating a better understanding of microbial community structure in lake sediment.

Soil salinity and alkalinity are important abiotic components that frequently have critical effects on crop growth, productivity and quality. Developing soybean cultivars with high salt tolerance is recognized as an efficient way to maintain sustainable soybean production in a salt stress environment. However, the genetic mechanism of the tolerance must first be elucidated. In this study, 257 soybean cultivars with 135 SSR markers were used to perform epistatic association mapping for salt tolerance. Tolerance was evaluated by assessing the main root length (RL), the fresh and dry weights of roots (FWR and DWR), the biomass of seedlings (BS) and the length of hypocotyls (LH) of healthy seedlings after treatments with control, 100 mM NaCl or 10 mM Na2CO3 solutions for approximately one week under greenhouse conditions. A total of 83 QTL-by-environment (QE) interactions for salt tolerance index were detected: 24 for LR, 12 for FWR, 11 for DWR, 15 for LH and 21 for BS, as well as one epistatic QTL for FWR. Furthermore, 86 QE interactions for alkaline tolerance index were found: 17 for LR, 16 for FWR, 17 for DWR, 18 for LH and 18 for BS. A total of 77 QE interactions for the original trait indicator were detected: 17 for LR, 14 for FWR, 4 for DWR, 21 for LH and 21 for BS, as well as 3 epistatic QTL for BS. Small-effect QTL were frequently observed. Several soybean genes with homology to Arabidopsis thaliana and soybean salt tolerance genes were found in close proximity to the above QTL. Using the novel alleles of the QTL detected above, some elite parental combinations were designed, although these QTL need to be further confirmed. The above results provide a valuable foundation for fine mapping, cloning and molecular breeding by design for soybean alkaline and salt tolerance.

Taste and odor (T&O) problems, which have adversely affected the quality of water supplied to millions of residents, have repeatedly occurred in Taihu Lake (e.g., a serious odor accident occurred in 2007). Because these accidents are difficult for water resource managers to forecast in a timely manner, there is an urgent need to develop optimum models to predict these T&O problems. For this purpose, various biotic and abiotic environmental parameters were monitored monthly for one year at 30 sites across Taihu Lake. This is the first investigation of this huge lake to sample T&O compounds at the whole-lake level. Certain phytoplankton taxa were important variables in the models; for instance, the concentrations of the particle-bound 2-methylisoborneol (p-MIB) were correlated with the presence of Oscillatoria, whereas those of the p-β-cyclocitral and p-β-ionone were correlated with Microcystis levels. Abiotic factors such as nitrogen (TN, TDN, NO(3)-N, and NO(2)-N), pH, DO, COND, COD and Chl-a also contributed significantly to the T&O predictive models. The dissolved (d) T&O compounds were related to both the algal biomass and to certain abiotic environmental factors, whereas the particle-bound (p) T&O compounds were more strongly related to the algal presence. We also tested the validity of these models using an independent data set that was previously collected from Taihu Lake in 2008. In comparing the concentrations of the T&O compounds observed in 2008 with those concentrations predicted from our models, we found that most of the predicted data points fell within the 90% confidence intervals of the observed values. This result supported the validity of these models in the studied system. These models, basing on easily collected environmental data, will be of practical value to the water resource managers of Taihu Lake for evaluating the probability of T&O accidents.

Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation.