High-Precision Corrosion Detection via SH1 Guided Wave Based on Full Waveform Inversion.

Corrosion detection for industrial settings is crucial for safe and efficient operations. Due to its high imaging resolution, the guided-wave full-waveform inversion tomography technique has significant potential for corrosion detection of plate metals. Limited by the long wavelengths of A0 and S0 mode waves, this method exhibits inadequate detection resolution for the earlier shallow and small corrosion defects. Based on the relatively short wavelength characteristics of the SH1 mode wave, we propose a high-precision corrosion detection method via SH1 guided wave using the full waveform inversion algorithms. By conducting finite element simulations of ultrasonic-guided waves on aluminum plates with varying corrosion defects, a comparison was made to assess the detection precision across A0, S0, and SH1 modes. The comparison results showed that, whether for regular or irregular defects, the SH1 mode wave always exhibited higher imaging accuracy than the A0 and S0 mode waves for shallow and small-sized defects. The corresponding experiments were conducted on an aluminum plate with simple or complex defects. The results of the experiments reconfirmed that the full waveform inversion method using SH1 guided wave can effectively reconstruct the shape and size of small and shallow corrosion defects within aluminum plates.

SH1-dependent maize seed development and starch synthesis via modulating carbohydrate flow and osmotic potential balance.

BACKGROUND: As the main form of photoassimilates transported from vegetative tissues to the reproductive organs, sucrose and its degradation products are crucial for cell fate determination and development of maize kernels. Despite the relevance of sucrose synthase SH1 (shrunken 1)-mediated release of hexoses for kernel development, the underlying physiological and molecular mechanisms are not yet well understood in maize (Zea mays). RESULTS: Here, we identified a new allelic mutant of SH1 generated by EMS mutagenesis, designated as sh1*. The mutation of SH1 caused more than 90% loss of sucrose synthase activity in sh1* endosperm, which resulted in a significant reduction in starch contents while a dramatic increase in soluble sugars. As a result, an extremely high osmolality in endosperm cells of sh1* was generated, which caused kernel swelling and affected the seed development. Quantitative measurement of phosphorylated sugars showed that Glc-1-P in endosperm of sh1* (17 µg g- 1 FW) was only 5.2% of that of wild-type (326 µg g- 1 FW). As a direct source of starch synthesis, the decrease of Glc-1-P may cause a significant reduction in carbohydrates that flow to starch synthesis, ultimately contributing to the defects in starch granule development and reduction of starch content. CONCLUSIONS: Our results demonstrated that SH1-mediated sucrose degradation is critical for maize kernel development and starch synthesis by regulating the flow of carbohydrates and maintaining the balance of osmotic potential.

Transactivation of Sus1 and Sus2 by Opaque2 is an essential supplement to sucrose synthase-mediated endosperm filling in maize.

The endosperm-specific transcription factor Opaque2 (O2) acts as a central regulator for endosperm filling, but its functions have not been fully defined. Regular o2 mutants exhibit a non-vitreous phenotype, so we used its vitreous variety Quality Protein Maize to create EMS-mutagenesis mutants for screening o2 enhancers (oen). A mutant (oen1) restored non-vitreousness and produced a large cavity in the seed due to severely depleted endosperm filling. When oen1 was introgressed into inbred W64A with a normal O2 gene, the seeds appeared vitreous but had a shrunken crown. oen1 was determined to encode Shrunken1 (Sh1), a sucrose synthase (SUS, EC 2.4.1.13). Maize contains three SUS-encoding genes (Sh1, Sus1, and Sus2) with Sh1 contributing predominantly to the endosperm. We determined SUS activity and found a major and minor reduction in oen1 and o2, respectively. In o2;oen1-1, SUS activity was further decreased. We found all Sus gene promoters contain at least one O2 binding element that can be specifically recognized and be transactivated by O2. Sus1 and Sus2 promoters had a much stronger O2 transactivation than Sh1, consistent with their transcript reduction in o2 endosperm. Although sus1 and sus2 alone or in combination had no perceptible phenotype, either of them could dramatically enhance seed opacity and cavity in sh1, indicating that transactivation of Sus1 and Sus2 by O2 supplements SUS-mediated endosperm filling in maize. Our findings demonstrate that O2 transcriptionally regulates the metabolic source entry for protein and starch synthesis during endosperm filling.

Purification and Characterization of a Novel Endolytic Alginate Lyase from Microbulbifer sp. SH-1 and Its Agricultural Application.

Alginate, an important acidic polysaccharide in marine multicellular algae, has attracted attention as a promising biomass resource for the production of medical and agricultural chemicals. Alginate lyase is critical for saccharification and utilization of alginate. Discovering appropriate and efficient enzymes for depolymerizing alginate into fermentable fractions plays a vital role in alginate commercial exploitation. Herein, a unique alginate lyase, AlgSH7, belonging to polysaccharide lyase 7 family is purified and characterized from an alginate-utilizing bacterium Microbulbifer sp. SH-1. The purified AlgSH7 shows a specific activity of 12,908.26 U/mg, and its molecular weight is approximately 66.4 kDa. The optimal temperature and pH of AlgSH7 are 40 °C and pH 9.0, respectively. The enzyme exhibits stability at temperatures below 30 °C and within an extensive pH range of 5.0-9.0. Metal ions including Na+, K+, Al3+, and Fe3+ considerably enhance the activity of the enzyme. AlgSH7 displays a preference for poly-mannuronic acid (polyM) and a very low activity towards poly-guluronic acid (polyG). TLC and ESI-MS analysis indicated that the enzymatic hydrolysates mainly include disaccharides, trisaccharides, and tetrasaccharides. Noteworthy, the alginate oligosaccharides (AOS) prepared by AlgSH7 have an eliciting activity against chilling stress in Chinese flowering cabbage (Brassica parachinensis L.). These results suggest that AlgSH7 has a great potential to design an effective process for the production of alginate oligomers for agricultural applications.

Pure SH1 Guided-Wave Generation Method with Dual Periodic-Permanent-Magnet Electromagnetic Acoustic Transducers for Plates Inspection.

High frequency guided-waves offer a trade-off between the high sensitivity of local bulk ultrasonic thickness measurements and the large area scanning of lower frequency guided-waves, so it has been a growing interest for corrosion inspection with the dispersive SH1 mode. However, according to the dispersive curve, it is hard to generate the pure SH1 mode since the non-dispersive SH0 mode will be excited simultaneously. Thus, this paper investigates a transducer design method to generate a pure SH1 guided-wave, where the dual periodic-permanent-magnet electromagnetic acoustic transducers (PPM EMATs) are placed on exactly opposite positions either side of the plate symmetrically. The suppression effect for SH0 and the enhancement effect for SH1 of the dual PPM EMATs are mainly discussed by theoretical analysis and simulation analysis, and the influence of positioning errors of PPM EMATs placed on opposite sides of the plate on its performances are analyzed. Employing the proposed dual PPM EMATs, some experiments are performed to verify the reliability of finite element simulation. The results indicate that the dual PPM EMATs can suppress the SH0 mode and generate the pure SH1 mode effectively. Moreover, the longitudinal and lateral positioning errors can affect the dual PPM EMATs performances significantly.

Production, Characterization and Valuable Applications of Exopolysaccharides from Marine Bacillus subtilis SH1.

Exopolysaccharides (EPSs) are high molecular weight polymers consisting of different sugar residues they are preferable for replacing synthetic polymers as they are degradable and nontoxic. Many microorganisms possess the ability to synthesize and excrete exopolysaccharides with novel chemical compositions, properties and structures to have potential applications in different fields. The present study attempt to optimize the production of EPS by marine Bacillus subtilis SH1 in addition to characterization and investigation of different valuable applications. Effect of medium type, incubation period and pH were studied using the one factor at a time experiments. It was shown that the highest productivity (24 gl-1) of exopolysaccharides was recorded by using yeast malt glucose medium with pH 9 at the fourth day of incubation. Experimental design using Response Surface Methodology (RSM) was applied to optimize various nutrients at different concentrations. The finalized optimized medium contained (gl-1) glucose (5), peptone (2.5), yeast extract (4.5) and malt extract (4.5) increased the production of EPS to 33.8 gl-1 with1.4 fold increase compared to the basal medium. Chemical characterization of the extracted EPS showed that, FTIR spectra exhibited bands at various regions. Moreover, HPLC chromatogram indicated that the EPS was a heteropolysaccharide consisting of maltose and rhamnose. The study was extended to evaluate the potentiality of the extracted polysaccharides in different medical applications. Results concluded that, EPS exhibited antibacterial activity against Aeromonas hydrophila, Pseudomonas aeruginosa and Streptococcus faecalis and the highest antibacterial activity (7.8, 9 and 10.4 AU/ml) was against S. faecalis at 50, 100 and 200 mg/ml respectively. The EPS exhibited various degree of antitumor effect toward the tested cell lines (MCF-7, HCT-116 and HepG2). In addition, EPS exhibited antiviral activity at 500 µg/ml. The antioxidant capacity increased with increasing the concentration of the sample. Scanning electron microscopic analysis showed that EPS had compact film-like structure, which could make it a useful in the future applications as in preparing plasticized film.

Genomic footprints of sorghum domestication and breeding selection for multiple end uses.

Domestication and diversification have had profound effects on crop genomes. Originating in Africa and subsequently spreading to different continents, sorghum (Sorghum bicolor) has experienced multiple onsets of domestication and intensive breeding selection for various end uses. However, how these processes have shaped sorghum genomes is not fully understood. In the present study, population genomics analyses were performed on a worldwide collection of 445 sorghum accessions, covering wild sorghum and four end-use subpopulations with diverse agronomic traits. Frequent genetic exchanges were found among various subpopulations, and strong selective sweeps affected 14.68% (∼107.5 Mb) of the sorghum genome, including 3649, 4287, and 3888 genes during sorghum domestication, improvement of grain sorghum, and improvement of sweet sorghum, respectively. Eight different models of haplotype changes in domestication genes from wild sorghum to landraces and improved sorghum were observed, and Sh1- and SbTB1-type genes were representative of two prominent models, one of soft selection or multiple origins and one of hard selection or an early single domestication event. We also demonstrated that the Dry gene, which regulates stem juiciness, was unconsciously selected during the improvement of grain sorghum. Taken together, these findings provide new genomic insights into sorghum domestication and breeding selection, and will facilitate further dissection of the domestication and molecular breeding of sorghum.

The C. elegans gonadal sheath Sh1 cells extend asymmetrically over a differentiating germ cell population in the proliferative zone.

The Caenorhabditis elegans adult hermaphrodite germline is surrounded by a thin tube formed by somatic sheath cells that support germ cells as they mature from the stem-like mitotic state through meiosis, gametogenesis, and ovulation. Recently, we discovered that the distal Sh1 sheath cells associate with mitotic germ cells as they exit the niche Gordon et al., 2020. Here, we report that these sheath-associated germ cells differentiate first in animals with temperature-sensitive mutations affecting germ cell state, and stem-like germ cells are maintained distal to the Sh1 boundary. We analyze several markers of the distal sheath, which is best visualized with endogenously tagged membrane proteins, as overexpressed fluorescent proteins fail to localize to distal membrane processes and can cause gonad morphology defects. However, such reagents with highly variable expression can be used to determine the relative positions of the two Sh1 cells, one of which often extends further distal than the other.

Bi-annular shear-horizontal wave MPT tailored to generate the SH1 mode in a plate.

The use of a specific wave mode is critical in ultrasonic non-destructive evaluations but it is difficult to generate a specific mode, especially a higher mode at a frequency where there exist multiple wave modes. Here, we propose a compact omnidirectional shear-horizontal wave MPT (magnetostrictive patch transducer) having two annular magnetostrictive patches for the generation of a nearly pure SH1 (second shear-horizontal) mode in a plate for frequencies above the first cutoff frequency. While a common wavelength-matching approach would typically require the use of several patches and does not appear completely to eliminate unwanted omnidirectional wave modes, the proposed MPT, with only two annular patches, generates the desired SH1 mode predominantly with the unwanted SH0 (first shear-horizontal) mode nearly eliminated. For the design, the geometries of the annular patches are optimally configured to maximize the ratio of the SH1 mode to the SH0 mode. Numerical simulations and experiments confirm the effectiveness of the proposed bi-annular shear-horizontal wave MPT. Because the SH1 mode near the first cutoff frequency is highly dispersive, the developed transducer is expected to be critically useful in various applications, such as ultrasonic inspections of wall thinning.

Bidirectional Regulation of COX-2 Expression Between Cancer Cells and Macrophages.

BACKGROUND/AIM: Our aim was to investigate the crosstalk between tumor and immune cells (M2 macrophages) and its effects on cyclo-oxygenase-2 (COX2) regulation in canine mammary tumors (CMT). MATERIALS AND METHODS: Sh1b CMT cells and human BT474 mammary or HT29 colon cancer cells were co-cultured with canine peripheral blood mononuclear cells (PBMCs) or with macrophage-like differentiated THP1 monocytes (dTHP1). Intracellular COX2 expression by PBMCs, dTHP1 and cancer cells was evaluated by flow cytometry. RESULTS: Co-culturing of Sh1b and canine PBMCs induced COX2 overexpression in CMT cells. In turn, COX2 expression by PBMCs, mostly CD68+ macrophages, was attenuated by co-culture with Sh1b (p=0.0001). In accordance, co-culture with dTHP1 prompted intracellular production of COX2 in both Sh1b CMT cells and HT29 human colon cancer cells and reduced production of COX2 in BT474 human mammary cancer cells. The intracellular COX2 expression from dTHP1 decreased when treated with conditioned medium from cultured Sh1b and HT29 cancer cells. CONCLUSION: Bidirectional COX2 regulation between cancer and monocytes/macrophages might shape a tolerogenic tumor microenvironment in CMT.

Monitoring Physiological Changes in Haloarchaeal Cell during Virus Release.

The slow rate of adsorption and non-synchronous release of some archaeal viruses have hindered more thorough analyses of the mechanisms of archaeal virus release. To address this deficit, we utilized four viruses that infect Haloarcula hispanica that represent the four virion morphotypes currently known for halophilic euryarchaeal viruses: (1) icosahedral internal membrane-containing SH1; (2) icosahedral tailed HHTV-1; (3) spindle-shaped His1; and (4) pleomorphic His2. To discern the events occurring as the progeny viruses exit, we monitored culture turbidity, as well as viable cell and progeny virus counts of infected and uninfected cultures. In addition to these traditional metrics, we measured three parameters associated with membrane integrity: the binding of the lipophilic anion phenyldicarbaundecaborane, oxygen consumption, and both intra- and extra-cellular ATP levels.

Tissue-specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides.

Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A. flavus or F. verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance.

Permanent draft genome of Rhodopirellula sallentina SM41.

The genome of Rhodopirellula sallentina SM41 was sequenced as a permanent draft to supplement the full genome sequence of the type strain Rhodopirellula baltica SH1(T). This isolate is part of a larger study to gain insights into the biogeography of Rhodopirellula species in European marine waters, as well as to amend the genus description of R. baltica. This genomics resource article is the third of a series of five publications reporting in total eight new permanent daft genomes of Rhodopirellula species.

Permanent draft genomes of the three Rhodopirellula baltica strains SH28, SWK14 and WH47.

The genomes of three Rhodopirellula baltica strains were sequenced as permanent drafts to complement the full genome sequence of the type strain R. baltica SH1(T). The isolates are part of a larger study to infer the biogeography of Rhodopirellula species in European marine waters, as well as to amend the genus description of R. baltica. This genomics resource article is the first of a series of five publications reporting in total eight new permanent daft genomes of Rhodopirellula species.

Permanent draft genomes of the Rhodopirellula maiorica strain SM1.

The genome of Rhodopirellula maiorica strain SM1 was sequenced as a permanent draft to complement the full genome sequence of the type strain Rhodopirellula baltica SH1(T). This isolate is part of a larger study to infer the biogeography of Rhodopirellula species in European marine waters, as well as to amend the genus description of R. baltica. This genomics resource article is the fifth of a series of five publications reporting in total eight new permanent daft genomes of Rhodopirellula species.

Permanent draft genome of Rhodopirellula rubra SWK7.

The genome of Rhodopirellula rubra strain SWK7 was sequenced as a permanent draft to complement the full genome sequence of the type strain Rhodopirellula baltica SH1(T). This isolate is part of a larger study to infer the biogeography of Rhodopirellula species in European marine waters, as well as to amend the genus description of R. baltica. This genomics resource article is the fourth among a series of five publications reporting in a total of eight new permanent draft genomes of Rhodopirellula species.