Three alternative splicing variants of Loquacious play different roles in miRNA- and siRNA-mediated RNAi pathways in Locusta migratoria.

RNA interference (RNAi) is a specific post-transcriptional gene-silencing phenomenon, which plays an important role in the regulation of gene expression and the protection from transposable elements in eukaryotic organisms. In Drosophila melanogaster, RNAi can be induced by microRNA (miRNA), endogenous small interfering RNA (siRNA), or exogenous siRNA. However, the biogenesis of miRNA and siRNA in these RNAi pathways is aided by the double-stranded RNA binding proteins (dsRBPs) Loquacious (Loqs)-PB, Loqs-PD or R2D2. In this study, we identified three alternative splicing variants of Loqs, namely Loqs-PA, -PB, and -PC in the orthopteran Locusta migratoria. We performed in vitro and in vivo experiments to study the roles of the three Loqs variants in the miRNA- and siRNA-mediated RNAi pathways. Our results show that Loqs-PB assists the binding of pre-miRNA to Dicer-1 to lead to the cleavage of pre-miRNA to yield matured miRNA in the miRNA-mediated RNAi pathway. In contrast, different Loqs proteins participate in different siRNA-mediated RNAi pathways. In exogenous siRNA-mediated RNAi pathway, binding of Loqs-PA or LmLoqs-PB to exogenous dsRNA facilitates the cleavage of dsRNA by Dicer-2, whereas in endogenous siRNA-mediated RNAi pathway, binding of Loqs-PB or Loqs-PC to endogenous dsRNA facilitates the cleavage of dsRNA by Dicer-2. Our findings provide new insights into the functional importance of different Loqs proteins derived from alternative splicing variants of Loqs in achieving high RNAi efficiency in different RNAi pathways in insects.

First Report of Maize Stalk Rot Caused by Fusarium kyushuense in China.

During 2017 to 2019, a field survey for maize stalk rot was conducted in 21 counties (districts) across the Guangxi province of China. This disease caused yield losses ranging from 20% to 30%. Maize plants with stalk rot were collected during the late milk stage and pieces of diseased pith tissue were cultured as previously described (Shan et al. 2017). Fungal colonies and mycelia with morphological characteristics of Fusarium species were subcultured onto fresh potato dextrose agar (PDA) and carnation leaf agar (CLA) plates. Based on morphological characteristics and molecular detection by amplification of Fusarium genus-specific primers (Duan et al. 2016), 39 Fusarium isolates were identified. Among them, five isolates from Du'an, Pingguo, Debao, and Daxin had abundant, pale orange to yellow aerial mycelium with deep red pigments when grown on PDA (Fig. 1A; 1B). The average growth rate was 8.0 to 12.0 mm per day at 25°C in the dark. The fungi produced two types of spores on CLA. Microconidia were ovoid to clavate, generally 0- to 3-septate, and 4.6 to 9.4 µm in length (n = 30) (Fig. 1D); Macroconidia were slightly curved with an acute apical cell, mostly 3- to 4- septate, and 19.4 to 38.2 µm in length (n = 30) (Fig. 1C). No chlamydospores were observed. These five isolates were initially identified as Fusarium kyushuense based on morphological features. PCR was performed to amplify three phylogenetic genes (TEF1-α, RPB1, and RPB2) (O'Donnell et al. 1998) and species specific primers kyuR1F/kyuR1R (5-TTTTCCTCACCAAGGAGCAGATCATG-3/5-TCCAATGGACTGGGCAGCCAAAACACC-3), kyuR2F/kyuR2R (5-CAGATATACATTTGCCTCGACAC-3/5-TACTTGAGCACGGAGCTTG-3) were used to confirm species identity. The obtained sequences were deposited in GenBank under the accession numbers MT997084, MT997080, MT997081 (TEF1-α); MT550012, MT997085, MT997086 (RPB1); MT550009, MT997089, and MT997090 (RPB2), respectively. Using BLAST, sequences of TEF1-α, RPB1, and RPB2 of the isolates were 99.33% (MH582297.1) to 100% (MG282364.1) similar to those of F. kyushuense strains (Supplementary Table 1). Based on phylogenetic analysis with maximum likelihood methods using tools of the website of CIPRES (http://www.phylo.org), isolates GX27, GX167, and GX204 clustered with F. kyushuense with 100% bootstrap support (Fig. 2). The pathogenicity of the three isolates was tested using young seedlings and adult plants as previously described with modification (Ye et al. 2013; Zhang et al. 2016). The primary roots of three-leaf-old seedlings were inoculated by immersing the roots into a 1 × 106 macroconidia solution, incubating for 6 h at 25°C, and transferring to normal growth conditions (26°C, 16 h light/22°C, 8 h dark). The second or third internode above the soil surface of flowering stage plants grown in a greenhouse was bored with a Bosch electric drill to make a hole (ca. 8 mm in diameter) and inoculated with 0.5 mL of mycelia plug then sealed with petrolatum. The inoculum was created by homogenizing five plates of flourish hyphal mats (approximately 125 mL) with kitchen blender and adjusting to a final volume of 200 mL with sterilized ddH2O. No symptoms were observed in the seedlings or adult plants that were mock-inoculated with PDA plugs. Three days post-inoculation (dpi), roots of the infected seedling turned dark-brown and shrunk and the leaves wilted (Fig. 1E). Typical stalk rot symptoms observed in the inoculated plants were premature wilting of entire plant and hollow and weak stalks, leading to lodging; the longitudinal section of the internodes exhibited obvious dark brown necrosis and reddish discoloration at 14 dpi and 30 dpi, respectively (Fig. 1F). Fusarium kyushuense was re-isolated from the inoculated stalk lesions but not from the control. This is the first record of stalk rot caused by F. kyushuense on maize plants in China. However, F. kyushuense is known to cause maize ear rot in China (Wang et al. 2014) and can produce type A and type B trichothecene mycotoxins in kernels (Aoki and O'Donnell 1998). The occurrence of maize stalk rot and ear rot caused by F. kyushuense should be monitored in China due to the potential risk for crop loss and mycotoxin contamination.

First Report of Fusarium thapsinum Causing Maize Stalk Rot in China.

Maize (Zea mays L.) is the most widely grown crop in China, which was planted 41.28 million hectares in 2019 (http://data.stats.gov.cnw/easyquery.htm?cn=C01&zb=A0D0F&sj=2019). Several fungal diseases of maize are reported in which stalk rot has become one of the most destructive diseases in China. The average yield losses affected by the disease are estimated at 10% to 20% (Yu et al. 2016). From 2017 to 2019, a survey was conducted to determine the population diversity of Fusarium species associated with maize diseases in 18 cities across Henan province. Fusarium stalk rot of maize with disease incidence more than 25% was observed in two continuous maize fields at Xuchang city. The diseased stem tissues from junctions in health and disease were chopped into small pieces (3 × 8 mm), superficially disinfected (70% ethyl alcohol for 1 min), placed onto potato dextrose agar (PDA) amended with L-(+)-Lactic-acid (1 g/L), poured in petri plates and incubated at 25°C for 4 days. Mycelia showing morphological characteristic of Fusarium spp. were sub-cultured from single conidium. The pure fungal isolates produced fluffy colonies, white aerial mycelium with yellow pigment in agar. The radial mycelial growth was measured and calculated at an average growth rate 10.9 mm/day at 25°C (Fig. 1A; 1B). Macroconidia produced on carnation leaf agar (CLA) were relatively slender, slightly curved and thick-walled, mostly 3 to 5 marked septa, with a curved and tapering apical cell and poorly developed foot cell, 46.9 ± 5.6 µm × 4.9 ± 0.2 µm (Fig. 1C). Microconidia formed abundantly and were generally oval on CLA, 8.2 ± 0.5 µm × 3.4± 0.1 µm (Fig. 1D). No chlamydospores were observed. Morphological characteristics of the isolates matched the description of Fusarium thapsinum (Leslie and Summerell 2006). To further get the phylogenetic evidence, TEF1-α (translation elongation factor), RPB1 (the largest subunit of RNA polymerase II) and RPB2 (the second largest subunit of RNA polymerase II) were amplified with primer pairs EF1/EF2 (O'Donnell et al. 1998), thapR1F (5'-TTTTCCTCACAAAGGAGCAAATCATG-3')/thapR1R (5'-GTTCACCCAAGATATGGTCGAAAGCC-3'), and thapR2F (5'-ACTCTTTCACATTTGCGCCGAAC-3')/thapR2R (5'-CGGAGCTTTCGTCCAGTGTGAC-3'), and sequenced, respectively. The BLAST search of the sequences of EF1-α, RPB1 and RPB2 shared 99.87% to 100% identity with those of F. thapsinum strains deposited in the GenBank (Supplementary Table 1). Sequences from two isolates (XCCG-3-B-1 and XCCG-3-A-1) were deposited in GenBank (Accession No. MT550014, MT997082 for EF-1α; MT550011, MT997087 for RPB1 and MT550008, MT997091 for RPB2). The phylogenetic relationships based on analysis of the partial sequences showed the representive isolates clustered together with F. thapsinum at 96% bootstrap values (Fig. 2). Combined with the results of morphological characteristics and phylogenetic analysis, the strain designated as Fusarium thapsinum. To complete Koch's postulates, the pathogenicity of the isolates was tested using the silking-stage plants in a greenhouse based on previously described method with modification (Zhang et al. 2016). An 8 mm in diameter wound hole was created at the second or third internode of the plant above the soil surface and injected with 0.5 ml of mycelia plug. The inoculated stalk exhibited internal dark brown necrotic regions and the brown area elongated obviously around the insertion at 14 dpi (days post inoculation). At 30 dpi, the stalks turned soft, hollow and even lodging of the plants for those severe ones, which are similar to those observed on naturally infected maize plants in the field (Fig. 1F). When the roots of the three-leaf-stage seedlings were inoculated with 1×106 macroconidia solution (Ye et al. 2013), the root rot and leaf wilting symptoms were observed (Fig. 1E). While the control plants that were inoculated with only sterile water showed no disease symptoms. The pathogen was re-isolated from the inoculated tissues and the identity was confirmed by the morphological characters. Fusarium thapsinum had been described as causal agent of maize stalk rot in Pakistan (Tahir et al. 2018). To our knowledge, this is the first report of F. thapsinum associated with maize stalk rot in China. The discovery will strengthen the theoretical foundation of maize stalk rot disease management.

[Current quality standards of cattle bile and sheep bile quality standards and discussion on related problems].

To analyze quality standards of cattle bile and sheep bile, and to discuss the related problems in the standards. The results showed that physical forms of the related medicinal materials of cattle bile and sheep bile were chaotic, and the technical methods adopted in the quality standards were generally backward. In addition, there were still problems that some medicinal material standards lacked necessary test items, which were especially obvious in the relevant medicinal material standards of sheep bile and brought difficulties to quality evaluation and control. We suggest that physical forms of cattle bile and sheep bile in quality standards should be determined, and inspection items should be completed. Based on mainstream analytical technology, some technical methods of these standards should be improved.

Integrating a genome-wide association study with transcriptomic analysis to detect genes controlling grain drying rate in maize (Zea may, L.).

KEY MESSAGE: Candidate genes on grain drying rate (GDR) were identified, and drying molecular mechanism of grain was explored by integrating genome-wide association with transcriptomic analysis in maize. Grain drying rate (GDR) is a key determinant of grain moisture at harvest. Here, a genome-wide association study (GWAS) of 309 inbred maize lines was used to identify single-nucleotide polymorphisms (SNPs) associated with drying rates of grain, cob and bract. Out of 217,933 SNPs, seven significant SNPs were repeatedly identified in four environments (P < 10-4). Based on genomic position of significant SNPs, six candidate genes were identified, one of which (Zm00001d047468) was verified by transcriptomic data between inbred lines with high and low GDR, indicating stable and reliable correlation with GDR. To further detect more genes correlated with GDR and explore drying molecular mechanism of grain, expression profile of all GWAS-identified genes (4941) detected from different environments, tissues and developmental stage was evaluated by transcriptomic data of six inbred lines with high or low GDR. Results revealed 162 genes exhibit up-regulated expression and another 123 down-regulated in three higher-GDR inbred lines. Based on GO enrichment, 162 up-regulated genes were significantly enriched into grain primary metabolic process, nitrogen compound metabolic process and macromolecule metabolic process (P < 0.05), which indicated grain filling imposes notable influence on GDR before and after physiological maturity. Our results lay foundation in accelerating development of higher-GDR maize germplasm through marker-assisted selection and clarifying genetic mechanism of GDR in maize.

MicroRNA-193a-5p exerts a tumor suppressor role in glioblastoma via modulating NOVA1.

BACKGROUND AND OBJECTIVES: Glioblastoma (GBM) is the most common and lethal of intracranial tumors, which is characterized by extensive proliferation and the diffused invasion of tumor cells. MicroRNA-193a-5p (miR-193a-5p) have been demonstrated previously as a functional suppressor in the development and progression of various cancers. The current study aimed to investigate whether miR-193a-5p influences cell proliferation and migration through the mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway by targeting neuro-oncological ventral antigen 1 (NOVA1) in glioblastoma. MATERIALS AND METHODS: The miR-193a-5p expression was detected by quantitative real-time polymerase chain reaction assay in GBM tissues and cell lines. Cell Counting Kit-8 assay, colony formation analysis, wound-healing, and transwell invasion assays were performed to evaluate cell proliferation, colony formation, migration, and invasion, respectively. Western blot analysis and luciferase reporter gene assay were performed to verify the downstream target gene of miR-193a-5p. RESULTS: The expression of miR-193a-5p was significantly downregulated in GBM tissues and cell lines. Kaplan-Meier analysis showed that patients with low miR-193a-5p expression had a shorter disease-free survival (P < 0.05). Functionally, miR-193a-5p overexpression dramatically suppressed the proliferation, colony formation, migration, and invasion in glioma cells. Bioinformatics prediction and a luciferase assay confirmed that NOVA1 was a direct functional target of miR-193a-5p. Moreover, ectopic expression of NOVA1 could partially reverse the inhibitory effects of miR-193a-5p on glioma cell proliferation, colony formation, migration, and invasion. NOVA1 overexpression abrogated the inhibitory effect of miR-193a-5p on the PTEN/PI3k/AKT pathway. CONCLUSION: Taken together, our findings suggested that miR-193a-5p functions as a tumor suppressor in glioma cells by directly targeting NOVA1.

Photoswitchable de/adsorption of an azobenzene-derived surfactant on a silica surface.

The control of surfactant adsorption/desorption, a fundamental process in colloid and surface chemistry, is of crucial importance for surfactant recycling and pollution-free waste treatment. Using first-principles simulations, we designed a photoswitchable approach to realize separation of a photoresponsive surfactant from the adsorbate. We chose a 4-butyl-(4'-(3-trimethylammoniumpropoxy)phenyl)azobenzene cation and quartz as the model system of a surfactant and adsorbate, respectively. Through first-principles calculations, we found that the trans isomer of the surfactant tends to assemble on the silica surface, while the cis isomer tends to be detached from the surface and is instead surrounded by water molecules. The chemical origin of the difference arises from the interactions between the surfactant and solvent, which depend on the molecular conformational change and associated redistribution of charges before and after the isomerization. Intriguingly, the interaction energy between the silica surface and the surfactant does not change significantly with the conformational change of the molecule. Meanwhile, an appreciable void space of the cis conformer attributed to the steric hindrance disfavors the assembling of surfactants on the silica surface, and its significant polarity favors the water environment, which prompts its desorption from the surface. The prediction from computations was then validated by experimental results. We expect our proof-of-concept study on the phototriggered separation of azobenzene-derived surfactant from a silica surface to provide an alternative way of achieving stimuli-responsive separation of surfactant from adsorbates.

Heterosis-related genes under different planting densities in maize.

Heterosis and increasing planting density have contributed to improving maize grain yield (GY) for several decades. As planting densities increase, the GY per plot also increases, whereas the contribution of heterosis to GY decreases. There are trade-offs between heterosis and planting density, and the transcriptional characterization of heterosis may explain the mechanism involved. In this study, 48 transcriptome libraries were sequenced from four inbred Chinese maize lines and their F1 hybrids. They were planted at densities of 45000 and 67500 plants ha-1. Maternal-effect differentially expressed genes (DEGs) played important roles in processes related to photosynthesis and carbohydrate biosynthesis and metabolism. Paternal-effect DEGs participated in abiotic/biotic stress response and plant hormone production under high planting density. Weighted gene co-expression network analysis revealed that high planting density induced heterosis-related genes regulating abiotic/biotic stress response, plant hormone biosynthesis, and ubiquitin-mediated proteolysis, but repressed other genes regulating energy formation. Under high planting density, maternal genes were mainly enriched in the photosynthesis reaction center, while paternal genes were mostly concentrated in the peripheral antenna system. Four important genes were identified in maize heterosis and high planting density, all with functions in photosynthesis, starch biosynthesis, auxin metabolism, gene silencing, and RNAi.

Widom line, dynamical crossover, and percolation transition of supercritical oxygen via molecular dynamics simulations.

Supercritical oxygen, a cryogenic fluid, is widely used as an oxidizer in jet propulsion systems and is therefore of paramount importance in gaining physical insights into processes such as transcritical and supercritical vaporization. It is well established in the scientific literature that the supercritical state is not homogeneous but, in fact, can be demarcated into regions with liquid-like and vapor-like properties, separated by the "Widom line." In this study, we identified the Widom line for oxygen, constituted by the loci of the extrema of thermodynamic response functions (heat capacity, volumetric thermal expansion coefficient, and isothermal compressibility) in the supercritical region, via atomistic molecular dynamics simulations. We found that the Widom lines derived from these response functions all coincide near the critical point until about 25 bars and 15-20 K, beyond which the isothermal compressibility line begins to deviate. We also obtained the crossover from liquid-like to vapor-like behavior of the translational diffusion coefficient, shear viscosity, and rotational relaxation time of supercritical oxygen. While the crossover of the translational diffusion coefficient and shear viscosity coincided with the Widom lines, the rotational relaxation time showed a crossover that was largely independent of the Widom line. Further, we characterized the clustering behavior and percolation transition of supercritical oxygen molecules, identified the percolation threshold based on the fractal dimension of the largest cluster and the probability of finding a cluster that spans the system in all three dimensions, and found that the locus of the percolation threshold also coincided with the isothermal compressibility Widom line. It is therefore clear that supercritical oxygen is far more complex than originally perceived and that the Widom line, dynamical crossovers, and percolation transitions serve as useful routes to better our understanding of the supercritical state.

Subcellular Distribution of NTL Transcription Factors in Arabidopsis thaliana.

NAC with a transmembrane (TM) motif1-like (NTL) transcription factors, containing three regions: the N-terminal NAC domain (ND), the middle regulation region (RR), and the C-terminal TM domain, belong to the tail-anchored proteins. Although these NTLs play numerous essential roles in plants, their subcellular distribution and the mechanism of translocation into the nucleus (NU) remain unclear. In this study, we found that most of the full-length NTLs were localized in the endoplasmic reticulum (ER), with the exception of NTL11 and NTL5, which were restricted to the NU. Furthermore, we found that NTL11 contains a TM domain, whereas NTL5 does not. The ND of all of the NTLs was responsible for nuclear localization in plants. After truncation of the TM domain, NTL8_NR, NTL10_NR and NTL13_NR localized in the cytoplasm (CT) and NU, and other NTL_NRs were only localized in the NU, suggesting that the RR of NTL8, NTL10 and NTL13 contains some inhibitory region to mask the nuclear localization signal sequence in the ND domain and permit their diffusion between CT and NU. Furthermore, the N-terminus of NTL11 was translocated to the NU, but the C-terminus was degraded in Arabidopsis mesophyll protoplasts. The chimeric construct of NTL11_ND with NTL10_RR and TM domain (11ND-10RT) was localized exclusively in the ER, and not in the NU. However, 10ND-11RT was found mainly in the NU. Our results indicated that the TM domain is essential for NTL targeting the ER and the N-terminal fragment, including ND and RR, is translocated into the NU after activation through proteolytic cleavage events upon stimulation by internal and external environmental signals.

ZD958 is a low-nitrogen-efficient maize hybrid at the seedling stage among five maize and two teosinte lines.

MAIN CONCLUSION: ZD958 was the most low-N-efficient line among five maize and two teosinte lines. Zea parviglumis and Zea diploperennis were insensitive to N limitation. Maize and teosinte genetically and evolutionarily diverged in gene regulation. GDH2, ASN2, and T4 were consistently down-regulated across seven lines. Maternal asymmetric inheritance and heterosis vigor made ZD958 low-N-efficient. Nitrogen (N) deficiency remains a serious limiting factor for maize production in many developing countries. It is particularly important to better understand how hybrid maize responds to N limitation. ZD958, a dominant high-yield hybrid in North China, was comparatively analyzed with four other maize and two teosinte lines at physiological and transcriptional levels. ZD958 was the most low-N-efficient line among five maize and two teosinte lines due to its largest biomass accumulation at a lowest N concentration under N limitation; while Zea parviglumis and Zea diploperennis had large root systems and were insensitive to N limitation. In anti-parallel with down-regulation of N metabolic genes in the ZD958 root, carbon allocation towards the root was enhanced for the significant increase in the root length. Variations in expression patterns of ten genes mediating N uptake, transport, and metabolism indicated large genetic and evolutionary divergence among seven lines under N limitation. Notably, GDH2, ASN2, and VAAT5 were consistently down-regulated under N limitation across these maize and teosinte lines, suggesting essential evolutionary conservation of gene regulation in response to N limitation and providing molecular markers for N nutritional diagnosis. Asymmetric inheritance, mostly from its maternal donor Z58, and heterosis vigor made ZD958 low-N-efficient at the seedling stage. The superior traits in crown roots in ZD958 may be derived from its paternal donor Chang7-2. Thus, Z58, Chang7-2, and two wild maize lines (Z. parviglumis and Z. diploperennis) provide valuable germplasms for N-efficient and large-root maize breeding.

Observation and confirmation of oxidation reactions occurring on ultra-high-performance liquid chromatography columns.

RATIONALE: Ultra-high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (UPLC/ESI-MS) has been frequently used for chemical analysis. A redox reaction in the ESI source has been observed during the ionization process. However, it is still unclear whether this redox reaction can take place on UPLC columns. METHODS: In this study, the oxidation reactions potentially occurring on UPLC columns were investigated using polyphenols including baicalin, baicalein, propyl gallate (PG), quercetin-3-rhamnoside (QR), rutin, naringin and 2,3,5,4'-tetrahydroxystilbene-2-Ο-ß-D-glucoside (THS-G) as model compounds. The on-column oxidation reaction was ascertained by post-column infusion of antioxidants such as ammonium sulfide ((NH4)2S). The oxidized products were reduced to their parent forms in the ESI source. This on-column oxidation reaction was further confirmed by means of post-column infusion of baicalin solution. RESULTS: On-column oxidation reactions were observed and confirmed for baicalin, baicalein, PG, rutin, and QR. The exact reaction site was located at the outlet frits of the UPLC columns. (NH4)2S was proved to be the most suitable reducing agent among the tested antioxidants for eliminating negative effects caused by on-column oxidation reaction. It was subsequently proposed to be an efficient additive to suppress oxidation reactions in the ESI source. CONCLUSIONS: Oxidation reactions can take place at the outlet frits of UPLC columns. Ascertaining on-column oxidation reactions and consequently eliminating relevant negative effects are of great interest for determination of oxidation-sensitive compounds such as polyphenols.

Reflection reduction on DDR3 high-speed bus by improved PSO.

The signal integrity of the circuit, as one of the important design issues in high-speed digital system, is usually seriously affected by the signal reflection due to impedance mismatch in the DDR3 bus. In this paper, a novel optimization method is proposed to optimize impedance mismatch and reduce the signal reflection. Specifically, by applying the via parasitic, an equivalent model of DDR3 high-speed signal transmission, which bases on the match between the on-die-termination (ODT) value of DDR3 and the characteristic impedance of the transmission line, is established. Additionally, an improved particle swarm optimization algorithm with adaptive perturbation is presented to solve the impedance mismatch problem (IPSO-IMp) based on the above model. The algorithm dynamically judges particles' state and introduces perturbation strategy for local aggregation, from which the local optimum is avoided and the ability of optimization-searching is activated. IPSO-IMp achieves higher accuracy than the standard algorithm, and the speed increases nearly 33% as well. Finally, the simulation results verify that the solution obviously decreases the signal reflection, with the signal transmission quality increasing by 1.3 dB compared with the existing method.

Magnetically Assembled Ultrablack Surface with Omnidirectional and Broadband Light Absorption.

Ultrablack surfaces with stable and omnidirectional light absorption over a wide spectral range are fundamentally crucial for applications concerning strict optical requirements from high-end optical to solar-heat conversion devices. Inspired by nature, we report a needle-like array structure (NAS) prepared by spraying and self-assembling the magnetic composite ink under an external magnetic field. With high structure regularity and small feature size, the NAS presents extremely low hemispherical reflectance (≤0.3%) over a wide spectral range of 300-2000 nm and stable omnidirectional absorption (incident angle insensitivity up to 70°), which could be one of the darkest surfaces ever reported. The exciting light absorption performance can be attributed to the synergistic effects of (1) structural absorption caused by multiple scattering between array units and (2) strong forward scattering and high light absorptivity of magnetic particles. The NAS exhibits outstanding photothermal conversion for solar harvesting, self-cleaning performance, good flexibility, and thermal-aging resistance, offering an appealing alternative to construct ultrablack surfaces for practical applications.

The epidemic of HIV and syphilis and the correlation with substance abuse among men who have sex with men in China: A systematic review and meta-analysis.

Background: In China, the HIV/AIDS epidemic among men who have sex with men (MSM) has been expanding in recent years. Substance abuse in MSM was not well studied as the independent risk factor for HIV and syphilis infection and other sexually transmitted diseases. The present review aimed to determine the correlation between HIV/Syphilis infections and substance abuse and other sexual risk behaviors among MSM. Methods: We conducted a comprehensive search of PubMed, Web of Science, Embase, Scopus, Chinese National Knowledge Infrastructure, Chinese Wanfang Data, and VIP Chinese Journal Database for relevant articles of quantitative studies published between 2010 and May 31, 2022. Meta-analysis was performed using R software. Pooled estimated of the association-odds ratio, with 95% confidence intervals were calculated using random-effects models stratified by study design. Q statistics and I2 were used to measure the heterogeneity. Results: Our meta-analysis included 61,719 Chinese MSM from 52 eligible studies. The pooled HIV prevalence rate among substance-abusing MSM was 10.0% (95% CI = 0.08-0.13). Substance abusers were more likely to have a higher prevalence of HIV (OR = 1.59) and syphilis (OR = 1.48) infections than non-substance abusers. Substance abusers were also more likely to seek sexual partners through the internet or social media applications (OR = 1.63), engage in unprotected anal intercourse (UAI) (OR = 1.69), group sex (OR = 2.78), and engage in commercial intercourse (OR = 2.04) compared to non-users. Regarding testing behaviors, substance abusers had a higher proportion of HIV or STI testing in their lifetime (OR = 1.70) compared with non-substance abusers (p < 0.05). They were also more likely to have had more sexual partners (≥2; OR = 2.31) and more likely to have consumed alcohol (OR = 1.49) in the past 6 months. Conclusions: Our study shows the correlation between substance abuse and HIV/Syphilis infection. Eliminating disparities in HIV/Syphilis infection among substance abusing men who have sex with men (MSM) can be achieved if the Chinese government and public health sectors could provide targeted knowledge popularization and diagnosis interventions among high-risk populations.

Optimizing drip fertigation at different periods to improve yield, volatile compounds and cup quality of Arabica coffee.

How to improve and regulate coffee bean yield and quality through split fertilization in the whole life cycle of coffee is still unclear and deserves further study. A field experiment of 5-year-old Arabica coffee trees was conducted for 2 consecutive years from 2020 to 2022. The fertilizer (750 kg ha-1 year-1, N-P2O5-K2O:20%-20%-20%) was split in three times at early flowering (FL), the berry expansion (BE), and the berry ripening (BR). Taking equal fertilization throughout the growth cycle (FL250BE250BR250) as the control check, variable fertilizations including FL150BE250BR350, FL150BE350BR250, FL250BE150BR350, FL250BE350BR150, FL350BE150BR250, and FL350BE250BR150. Leaf net photosynthetic rate (A net), stomatal conductance (g s), transpiration rate (T r), leaf water use efficiency (LWUE), carboxylation efficiency (CE), partial factor productivity of fertilizer (PFP), bean yield, crop water use efficiency (WUE), bean nutrients, volatile compounds and cup quality, and the correlation of nutrients with volatile compounds and cup quality was evaluated. FL350BE250BR150 had the maximum A net and g s, followed by FL250BE350BR150. The highest dry bean yield and WUE were obtained from FL250BE350BR150, which increased by 8.86% and 8.47% compared with FL250BE250BR250 in two-year average. The ash, total sugar, fat, protein, caffeine and chlorogenic acid in FL250BE350BR150 were 6.47%, 9.48%, 3.60%, 14.02%, 4.85% and 15.42% higher than FL250BE250BR250. Cluster analysis indicated FL150BE350BR250, FL250BE350BR150, FL350BE150BR250 and FL350BE250BR150 under medium roasted degree increased pyrazines, esters, ketones and furans, FL150BE350BR250 and FL250BE350BR150 under dark roasted degree increased ketones and furans. The aroma, flavor, acidity and overall score of medium roasted coffee were higher than dark roasted coffee, while the body score of dark roasted coffee was higher than medium roasted coffee. The nutrient contents were correlated with the volatile compounds and cup quality. TOPSIS indicated that FL250BE350BR150 was the optimal fertilization mode in the xerothermic regions. The obtained optimum fertilization mode can provide a scientific basis for coffee fertilization optimization and management.

Genome-wide association study of maize resistance to Pythium aristosporum stalk rot.

Stalk rot, a severe and widespread soil-borne disease in maize, globally reduces yield and quality. Recent documentation reveals that Pythium aristosporum has emerged as one of the dominant causal agents of maize stalk rot. However, a previous study of maize stalk rot disease resistance mechanisms and breeding had mainly focused on other pathogens, neglecting P. aristosporum. To mitigate crop loss, resistance breeding is the most economical and effective strategy against this disease. This study involved characterizing resistance in 295 inbred lines using the drilling inoculation method and genotyping them via sequencing. By combining with population structure, disease resistance phenotype, and genome-wide association study (GWAS), we identified 39 significant single-nucleotide polymorphisms (SNPs) associated with P. aristosporum stalk rot resistance by utilizing six statistical methods. Bioinformatics analysis of these SNPs revealed 69 potential resistance genes, among which Zm00001d051313 was finally evaluated for its roles in host defense response to P. aristosporum infection. Through virus-induced gene silencing (VIGS) verification and physiological index determination, we found that transient silencing of Zm00001d051313 promoted P. aristosporum infection, indicating a positive regulatory role of this gene in maize's antifungal defense mechanism. Therefore, these findings will help advance our current understanding of the underlying mechanisms of maize defense to Pythium stalk rot.

Dynamic Performance Analysis of STEP System in Internet of Vehicles Based on Queuing Theory.

The Internet of vehicles (IoV) is an important research area of the intelligent transportation systems using Internet of things theory. The complex event processing technology is a basic issue for processing the data stream in IoV. In recent years, many researchers process the temporal and spatial data flow by complex event processing technology. Spatial Temporal Event Processing (STEP) is a complex event query language focusing on the temporal and spatial data flow in Internet of vehicles. There are four processing models of the event stream processing system based on the complex event query language: finite automata model, matching tree model, directed acyclic graph model, and Petri net model. In addition, the worst-case response time of the event stream processing system is an important indicator of evaluating the performance of the system. Firstly, this paper proposed a core algorithm of the temporal and spatial event stream processing program based on STEP by Petri net model. Secondly, we proposed a novel method to estimate the worst-case response time of the event stream processing system, which is based on stochastic Petri net and queuing theory. Finally, through the simulation experiment based on queuing theory, this paper proves that the data stream processing system based on STEP has good dynamic performance in processing the spatiotemporal data stream in Internet of vehicles.

Correlated mechanochemical maps of Arabidopsis thaliana primary cell walls using atomic force microscope infrared spectroscopy.

Spatial heterogeneity in composition and organisation of the primary cell wall affects the mechanics of cellular morphogenesis. However, directly correlating cell wall composition, organisation and mechanics has been challenging. To overcome this barrier, we applied atomic force microscopy coupled with infrared (AFM-IR) spectroscopy to generate spatially correlated maps of chemical and mechanical properties for paraformaldehyde-fixed, intact Arabidopsis thaliana epidermal cell walls. AFM-IR spectra were deconvoluted by non-negative matrix factorisation (NMF) into a linear combination of IR spectral factors representing sets of chemical groups comprising different cell wall components. This approach enables quantification of chemical composition from IR spectral signatures and visualisation of chemical heterogeneity at nanometer resolution. Cross-correlation analysis of the spatial distribution of NMFs and mechanical properties suggests that the carbohydrate composition of cell wall junctions correlates with increased local stiffness. Together, our work establishes new methodology to use AFM-IR for the mechanochemical analysis of intact plant primary cell walls.

Cloning and characterization of a maize SnRK2 protein kinase gene confers enhanced salt tolerance in transgenic Arabidopsis.

SnRK2 (sucrose non-fermenting 1-related protein kinases 2) represents a unique family of protein kinase in regulating signaling transduction in plants. Although the regulatory mechanisms of SnRK2 have been well demonstrated in Arabidopsis thaliana, their functions in maize are still unknown. In our study, we cloned an SnRK2 gene from maize, ZmSAPK8, which encoded a putative homolog of the rice SAPK8 protein. ZmSAPK8 had two copies in the maize genome and harbored eight introns in its coding region. We demonstrated that ZmSAPK8 expressed differentially in various organs of maize plants and was up-regulated by high-salinity and drought treatment. A green fluorescent protein (GFP)-tagged ZmSAPK8 showed subcellular localization in the cell membrane, cytoplasm and nucleus. In vitro kinase assays indicated that ZmSAPK8 preferred Mn(2+) to Mg(2+) as cofactor for phosphorylation, and Ser-182 and Thr-183 in activation loop was important for its activity. Heterologous overexpression of ZmSAPK8 in Arabidopsis could significantly strengthen tolerance to salt stress. Under salt treatment, ZmSAPK8-overexpressed transgenic plants exhibited higher germination rate and proline content, low electrolyte leakage and higher survival rate than wild type. Further analysis indicated that transgenic plants showed increased transcription of the stress-related genes, RD29A, RD29B, RAB18, ABI1, DREB2A and P5CS1, under high-salinity conditions. The results demonstrated that ZmSAPK8 was involved in diverse stress signal transduction. Moreover, no obvious adverse effects on growth and development in the ZmSAPK8-overexpressed transgenic plants implied that ZmSAPK8 was potentially useful in transgenic breeding to improve salt tolerance in crops.