Occurrence of Fusarium mycotoxins in freshly harvested highland barley (qingke) grains from Tibet, China

Highland barley, also called "qingke" in Tibetan, is mainly cultivated in the Tibetan Plateau of China and has been used as a major staple food for Tibetans. Recently, Fusarium head blight (FHB) of qingke was frequently observed around the Brahmaputra River in Tibet. Considering the importance of qingke for Tibetans, the assessment of Fusarium mycotoxin contamination is essential for food safety. In this study, a total of 150 freshly harvested qingke grain samples were obtained from three regions around the Brahmaputra River in Tibet (China) in 2020. The samples were investigated for the occurrence of 20 Fusarium mycotoxins using high-performance liquid chromatography-tandem mass spectrometry (HPLC‒MS/MS). The most frequently occurring mycotoxin was enniatin B (ENB) (46%), followed by enniatin B₁ (ENB₁) (14.7%), zearalenone (ZEN) (6.0%), enniatin A₁ (ENA₁) (3.3%), enniatin A (ENA) (1.3%), beauvericin (BEA) (0.7%), and nivalenol (NIV) (0.7%). Due to the increase in altitude, the cumulative precipitation level and average temperature decreased from the downstream to the upstream of the Brahmaputra River; this directly correlated to the contamination level of ENB in qingke, which gradually decreased from downstream to upstream. In addition, the level of ENB in qingke obtained from qingke-rape rotation was significantly lower than that from qingke-wheat and qingke-qingke rotations (p < 0.05). These results disseminated the occurrence of Fusarium mycotoxins and provided further understanding of the effect of environmental factors and crop rotation on Fusarium mycotoxins.

USP20 regulates the stability of EMT transcription factor SOX4 and influences colorectal cancer metastasis

BACKGROUND

Colorectal cancer (CRC) is a familiar malignancy accompanied by higher morbidity and mortality. The deubiquitination enzyme USP20 has been discovered to be one key factor in several cancers progression. SOX4 is a critical transcription factor to regulate the expression of various genes, and participates into the occurrence and progression of cancers. In this study, it was aimed to illustrate the role of USP20 and the regulatory relationship between USP20 and SOX4 in CRC.

METHODS

The protein expressions of USP20, SOX4, E-cadherin, N-cadherin, Snail and slug were tested through western blot. The cell proliferation ability was verified through CCK-8 assay. The migration and invasion abilities were detected through Transwell assay. The mRNA expression of SOX4 was confirmed through RT-qPCR. The interaction between USP20 and SOX4 was notarized through Co-IP assay.

RESULT

Our study demonstrated that USP20 displayed higher expression, and facilitated CRC progression through regulating cell proliferation, migration, invasion and EMT process markers. USP20 was found to modulate SOX4 protein expression. Next, it was verified that USP20 regulated SOX4 degradation through deubiquitination. Finally, through rescue assays, we revealed that USP20 mediated SOX4 expression to accelerate CRC progression.

CONCLUSIONS

In this study, USP20 regulated the stability of EMT transcription factor SOX4 and aggravated colorectal cancer metastasis. This finding might highlight the function of USP20 in the treatment of CRC.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

Molecular Characterization, Fitness, and Mycotoxin Production of Fusarium asiaticum Strains Resistant to Fludioxonil

Fludioxonil is used in seedborne disease management of various fungal pathogens, including Fusarium asiaticum, the predominant causal agent of Fusarium head blight in China. In this study, we screened resistant strains from a large number of F. asiaticum strains collected from 2012 to 2016 and found that 4 of 1,000 field strains were highly resistant to fludioxonil. The 50% effective concentration values of the resistant strains and induced mutants ranged from 80 to >400 μg/ml. Compared with field-sensitive strains, all field-collected and laboratory-induced resistant strains exhibited fitness defects in traits including mycelial growth, conidial production, pathogenicity, and sensitivity to osmotic conditions. In the presence of fludioxonil, significantly higher glycerol accumulation was found in sensitive strains but not in resistant individuals. The fludioxonil-resistant strains produced lower amounts of glycerol in liquid culture and lower amounts of trichothecene mycotoxins in rice culture and inoculated wheat spikelets than the fludioxonil-sensitive strains. Sequence analyses of the key genes of the two-component histidine kinase signaling pathway showed various amino acid substitutions in the Os1, Os4, and Os5 genes between field-sensitive and resistant strains or mutants. The results of this study suggest a potential risk of fludioxonil resistance development and a possible influence of resistance mutations on fitness parameters and toxin production in F. asiaticum.

[Clinical features and therapy of persistent bacterial bronchitis in 31 children]

OBJECTIVE

To investigate the clinical features and therapy of persistent bacterial bronchitis (PBB).

METHOD

A retrospective review of 31 patients with PBB from Octorber 2010 to May 2014 in Department 2 of Respiratory Diseases in Beijing Children's Hospital was undertaken.

RESULT

(1) The patients (17 boys and 14 girls) were 6 months to 3 years old. The main complaint was chronic wet cough (>4 weeks); 13 cases had fever and 25 cases had wheezing. Rattle was heard on auscultation in all patients. (2) Chest X ray showed an increase in bronchovascular markings in all cases, accompanied by patchy infiltration in 6 cases. The high resolution computed tomography (HRCT) demonstrated bronchial wall thickening in 25 cases, associated with peri-bronchial patchy infiltration in 18 cases, with organized pneumonia in 7 cases ( atelectasis in 5 cases). Centrilobular nodules and ground-glass opacity were observed in the remaining 6 patients. (3) Purulent secretion was seen in endobronchial cavity by bronchoscopy. Streptococcus pneumoniae was isolated from sputum culture or bronchoalveolar lavage fluid culture in 16 patients. (4)Patients recovered completely after over 2 weeks'treatment with amoxicillin-clavulanate or the second and third generation cephalosporin (including enzyme inhibitors) in 28 cases, carbapenems, teicoplanin , linezolid in 1 case respectively.

CONCLUSION

PBB often occurred in 3 years old or younger patients and had chronic wet cough for more than 4 weeks, fever and wheezing. HRCT may reveal bronchial wall thickening, respiratory secretions culture may reveal Streptococcus pneumoniae. Most of patients recovered completely after over 2 weeks'treatment with amoxicillin-clavulanate or the second or third generation cephalosporins (including enzyme inhibitors).

Expressions of Mast Cell Tryptase and Brain Natriuretic Peptide in Myocardium of Sudden Death due to Hypersensitivity and Coronary Atherosclerotic Heart Disease

OBJECTIVES

To explore the value of mast cell tryptase and brain natriuretic peptide（BNP） in the differential diagnostic of sudden death due to hypersensitivity and coronary atherosclerotic heart disease.

METHODS

Totally 30 myocardial samples were collected from the autopsy cases in the Department of Forensic Pathology, Shanxi Medical University during 2010-2015. All samples were divided into three groups： death of craniocerebral injury group, sudden death of hypersensitivity group and sudden death of coronary atherosclerotic heart disease group, 10 cases in each group. Mast cell tryptase and BNP in myocardium were detected by immunofluorescence staining and Western Blotting.

RESULTS

Immunofluorescence staining showed that the positive staining mast cell tryptase appeared in myocardium of sudden death of hypersensitivity group and coronary atherosclerotic heart disease group. Among the three groups, the expression of mast cell tryptase showed significantly differences through pairwise comparison （P<0.05）; The expression level of BNP in sudden death of coronary atherosclerotic heart disease group were significantly higher than the sudden death of hypersensitivity group and death of craniocerebral injury group （P<0.05）. The difference of the expression level of BNP between the sudden death of hypersensitivity group and the death of craniocerebral injury group had no statistical significance （P>0.05）.

CONCLUSIONS

The combined detection of the mast cell tryptase and BNP in myocardium is expected to provide help for the forensic differential diagnosis of sudden death due to hypersensitivity and coronary atherosclerotic heart disease.

Gate-voltage control of chemical potential and weak antilocalization in Bi₂Se₃

We report that Bi₂Se₃ thin films can be epitaxially grown on SrTiO₃ substrates, which allow for very large tunablity in carrier density with a back gate. The observed low field magnetoconductivity due to weak antilocalization (WAL) has a very weak gate-voltage dependence unless the electron density is reduced to very low values. Such a transition in WAL is correlated with unusual changes in longitudinal and Hall resistivities. Our results suggest a much suppressed bulk conductivity at large negative gate voltages and a possible role of surface states in the WAL phenomena.

DNA marker analysis for pyramided of Fusarium head blight (FHB) resistance QTLs from different germplasm

A pyramided FHB resistance line of wheat (WSY) was previously developed from three FHB resistant cultivars (Sumai 3, Wangshuibai, and Nobeokabouzu) in the Jiangsu Academy of Agricultural Sciences, China. In the present study, we analyzed the genetic relationship between WSY and the three parental cultivars using DNA markers in order to clarify how many and which resistance genes had accumulated in WSY. We analyzed 282 DNA markers from the 21 wheat chromosomes. WSY was found to include different chromosome regions that harbored putative FHB QTLs of the three parental germplasm. Haplotypes of DNA markers on these QTL regions revealed that the 1BL, 2BL, 5AS, and 7AL QTL regions were from Sumai 3, the 2AS, 2DS, 3AS, and 6BS QTL regions were from Wangshuibai, and the 3BS QTL region was from Nobeokabouzu. This study showed that different resistance genes from the different resistant germplasm had indeed accumulated in WSY. WSY is a potential resistant resource for FHB resistance in wheat breeding programs.

Doping dependence of the coupling of electrons to bosonic modes in the single-layer high-temperature Bi2Sr2CuO6 superconductor

A recent highlight in the study of high-T(c) superconductors is the observation of band renormalization or self-energy effects on the quasiparticles. This is seen in the form of kinks in the quasiparticle dispersions as measured by photoemission and interpreted as signatures of collective bosonic modes coupling to the electrons. Here we compare for the first time the self-energies in an optimally doped and strongly overdoped, nonsuperconducting single-layer Bi-cuprate (Bi2Sr2CuO6). In addition to the appearance of a strong overall weakening, we also find that the weight of the self-energy in the overdoped system shifts to higher energies. We present evidence that this is related to a change in the coupling to c-axis phonons due to the rapid change of the c-axis screening in this doping range.

Development and mapping of microsatellite (SSR) markers in wheat

Microsatellite DNA markers are consistently found to be more informative than other classes of markers in hexaploid wheat. The objectives of this research were to develop new primers flanking wheat microsatellites and to position the associated loci on the wheat genome map by genetic linkage mapping in the ITMI W7984 x Opata85 recombinant inbred line (RIL) population and/or by physical mapping with cytogenetic stocks. We observed that the efficiency of marker development could be increased in wheat by creating libraries from sheared rather than enzyme-digested DNA fragments for microsatellite screening, by focusing on microsatellites with the [ATT/TAA]n motif, and by adding an untemplated G-C clamp to the 5'-end of primers. A total of 540 microsatellite-flanking primer pairs were developed, tested, and annotated from random genomic libraries. Primer pairs and associated loci were assigned identifiers prefixed with BARC (the acronym for the USDA-ARS Beltsville Agricultural Research Center) or Xbarc, respectively. A subset of 315 primer sets was used to map 347 loci. One hundred and twenty-five loci were localized by physical mapping alone. Of the 222 loci mapped with the ITMI population, 126 were also physically mapped. Considering all mapped loci, 126, 125, and 96 mapped to the A, B, and D genomes, respectively. Twenty-three of the new loci were positioned in gaps larger than 10 cM in the map based on pre-existing markers, and 14 mapped to the ends of chromosomes. The length of the linkage map was extended by 80.7 cM. Map positions were consistent for 111 of the 126 loci positioned by both genetic and physical mapping. The majority of the 15 discrepancies between genetic and physical mapping involved chromosome group 5.

Association of body size and fat distribution with risk of breast cancer among Chinese women

Most previous studies addressing the association of body size, weight change and body fat distribution with the risk of breast cancer were conducted in Western societies with a high proportion of overweight people. It remains unclear whether the dose-response relation observed in earlier studies can be extended to women with "normal" weight based on prevailing Western standards. To address this issue, we analyzed data from a population-based case-control study of breast cancer recently completed among Chinese women in urban Shanghai. In-person interviews and anthropometric measurements were completed for 1,459 women newly diagnosed with breast cancer from 25 to 64 years of age and 1,556 controls frequency-matched to cases on age. Unconditional logistic regression was employed to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI) related to anthropometric variables and self-reported body weight. Currently measured weight, body mass index [BMI: weight (kg)/height(m)(2)] or height was each found to be positively related to risk of postmenopausal breast cancer in a dose-response manner, with ORs (95% CI) being 2.0 (1.4-3.0), 2.0 (1.2-3.2) or 1.7 (1.2-2.5), respectively, for the highest category of weight, BMI or height compared to the lowest category of these variables. These variables were unrelated to premenopausal breast cancer risk. Reported weight at ages >40 years and weight gain after age 20 were more predictive for postmenopausal breast cancer than weight at an earlier age. After adjustment for BMI, waist-to-hip ratio was related to an increased risk of premenopausal [OR = 1.7 (1.3-2.3) for the highest category compared to the lowest category] but not postmenopausal breast cancer. This study suggests that, even in a relatively thin Chinese population, weight gain and height are related to an increased risk of postmenopausal breast cancer, while central fat distribution was associated with premenopausal breast cancer. General weight control may be an effective measurement for breast cancer prevention.

Effects of 50 Hz magnetic fields on gap junctional intercellular communication

To explore whether the extremely low frequency (ELF) electromagnetic fields (EMFs) may act as cancer promoters or be synergistic with 12-O-tetradecanoylphorbol-13-acetate (TPA) in cancer promotion, an experiment was conducted on the effects of 50 Hz magnetic fields (MFs) on gap junctional intercellular communication (GJIC) of Chinese hamster lung (CHL) cells. Lucifer dye was loaded into CHL cells by iontophoretic injection, and the number of dye-coupled cells (DCC) 5 min after the injection was adopted as the index of GJIC. The effects of TPA at different concentrations and magnetic fields at different intensities, combined with 5 ng/ml TPA, were studied. The results showed that the suppression of TPA on GJIC was dependent on TPA concentration; the threshold concentration of TPA for CHL cells was between 1 and 5 ng/ml. After exposure to 0.8 mT magnetic field for 24 h, the number of DCC decreased to 6.08 +/- 1.59, whereas the number of DCC in the control group was 9.84 +/- 2.27 (P < .05). When the cells were exposed at 0.2, 0.4, and 0.8 mT for 24 h, combined with 5 ng/ml TPA treatment during the last 1 h, the number of DCC decreased to 5.52 +/- 1.53, 5.00 +/- 1.22, and 4.00 +/- 1.29, respectively, which were significantly lower than the values for the group treated with 5 ng/ml TPA alone (6.38 +/- 1.39). It is suggested that certain intensities of 50 Hz magnetic field might act as cancer promoters, be additive with other promoters in cancer promotion, or both.