59 research outputs found

    SCFSAP controls organ size by targeting PPD proteins for degradation in Arabidopsis thaliana

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    Control of organ size by cell proliferation and growth is a fundamental process, but the mechanisms that determine the final size of organs are largely elusive in plants. We have previously revealed that the ubiquitin receptor DA1 regulates organ size by repressing cell proliferation in Arabidopsis. Here we report that a mutant allele of STERILE APETALA (SAP) suppresses the da1-1 mutant phenotype. We show that SAP is an F-box protein that forms part of a SKP1/Cullin/F-box E3 ubiquitin ligase complex and controls organ size by promoting the proliferation of meristemoid cells. Genetic analyses suggest that SAP may act in the same pathway with PEAPOD1 and PEAPOD2, which are negative regulators of meristemoid proliferation, to control organ size, but does so independently of DA1. Further results reveal that SAP physically associates with PEAPOD1 and PEAPOD2, and targets them for degradation. These findings define a molecular mechanism by which SAP and PEAPOD control organ size

    Highly accurate and reliable ultrasonic focusing capability in heterogeneous media using a spherical cavity transducer

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    Introduction: Focused ultrasound ablation surgery (FUAS) has been emerging to treat a wide range of conditions non-invasively and effectively with promising therapeutic outcomes. The focusing capability of an ultrasound transducer (i.e., focus shift, beam distortion, and acoustic pressure at the focus) determines the ablation effects. However, the focus shift and focal beam distortion after ultrasound propagating through multi-layered heterogeneous viscoelastic biological tissues become significant and are found to deteriorate the performance of FUAS in clinics.Methods: To achieve an accurate and reliable focal field among patients with large variations in the anatomical structures and properties, a spherical cavity transducer with open ends and sub-wavelength focal size (Li et al., APL, 2013,102:204102) was applied here. Both experimental measurements and numerical simulations were performed to characterize the acoustic fields of the spherical cavity transducer in water, the multi-layered concentric cylindrical phantom, and the heterogeneous tissue model (an adult male pelvis enclosed by porcine skin, fat, and muscle) and then compared with those of a conventional concave transducer at the same electrical power output.Results: It is found that standing-wave focusing using the spherical cavity transducer results in much less focus shift (0.25λ vs. 1.67λ) along the transducer axis and focal beam distortion (−6 dB beam area of 0.71 mm2vs. 4.72 mm2 in water and 2.55 mm2vs. 17.30 mm2 in tissue) in the focal plane but higher pressure focusing gain (40.05 dB vs. 33.61 dB in tissue).Discussion: Such a highly accurate and reliable focal field is due to the excitation at an appropriate eigen-frequency of the spherical cavity with the varied media inside rather than the reverberation from the concave surface. Together with its sub-wavelength focal size, the spherical cavity transducer is technically advantageous in comparison to the concave one. The improved focusing capability would benefit ultrasound exposure for not only safer and more effective FUAS in clinics, but also broad acoustic applications

    Overprotection and overcontrol in childhood: An evaluation on reliability and validity of 33-item expanded Childhood Trauma Questionnaire (CTQ-33), Chinese version

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    Overprotection and overcontrol from parents or other family members, which are not rare in the Chinese culture, have been suggested to be traumatic experiences for some children. However, research on overprotection/overcontrol is much rarer in China compared with other childhood trauma subtypes. One of the possible reasons for this is the lack of easy and feasible screening tools. In this study, we therefore translated and validated a Chinese version of the 33-item Childhood Trauma Questionnaire (CTQ-33), which was expanded from the widely-used 28-item CTQ with an additional overprotection/overcontrol subscale. A total of 248 young healthy participants were recruited and completed the Chinese version of CTQ-33, and 50 of them were retested after an interval of two weeks. At baseline, all participants also completed the 9-item Patient Health Questionnaire and the 7-item Generalized Anxiety Disorder Scale to assess their depression and anxiety, respectively. Our main findings include that: (1) the Chinese version of CTQ-33 showed a good internal consistency (Cronbach\u27s α coefficient = 0.733) and an excellent test-retest reliability over a two-week period (ICC = 0.861); (2) the previously reported significant associations between the overprotection/overcontrol and other subtypes of childhood trauma (abuse and neglect), as well as psychopathological conditions such as depression can all be replicated using the Chinese version of CTQ-33. These results suggest that the Chinese version of CTQ-33 would be a promising tool for assessing various subtypes of childhood adversities, especially the overprotection/overcontrol experiences in Chinese populations

    Isolation and characterization of a genotype 4 Hepatitis E virus strain from an infant in China

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    In the present study, a genotype 4 HEV strain was identified in the fecal specimen from a seven months old infant with no symptom of hepatitis in Shanghai Children's hospital. The full capsid protein gene (ORF2) sequence of this strain was determined by RT-PCR method. Sequence analysis based on the full ORF2 sequence indicated that this HEV strain shared the highest sequence identity (97.6%) with another human HEV strain isolated from a Japanese patient who was infected by genotype 4 HEV during traveling in Shanghai. Phylogenetic analysis showed that this genotype 4 HEV was phylogenetically far from the genotype 4 HEV strain that was commonly prevalent in Shanghai swine group, suggesting that this strain may not come from swine group and not involved in zoonotic transmission in this area

    Composition analysis and preliminary safety evaluation of edible Monascus red pigment

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    ObjectiveTo provide scientific basis for the development and utilization of edible pigment Monascus red, the analysis of its key components and toxicological evaluation were carried out.MethodsIdentification test and physicochemical indexes test were carried out based on the samples according to the method in National food safety standard GB 1886.181—2016. The content of citrinin (CIT) and Monacolin K were detected through high performance liquid chromatography (HPLC). UPLC-Orbitrap-MS2 were used for chemical composition and content determination, in which the molecular structure was also characterized. The 14-day oral toxicity test of SD rats was carried out, based on the acute oral toxicity test of Monascus red by the limited method.ResultsThe quality and specification of test samples conformed to the provisions of China National Food Safety Standard. The content of CIT and Monacolin K was 0.030 8 mg/kg (converted as one color value) and 0.166 mg/g. Twenty compounds were separated in Monascus red by UPLC-Orbitrap-MS2, red pigment, orange pigment and yellow pigment of it accounted for 88.38%, 2.04% and 5.96%, respectively. The results of acute oral toxicity showed that Monascus red was innocuous (LD50>20 g/kg·BW). In the 14-day repeated oral dose toxicity test, compared with the control group, rats in 5 g/kg·BW dose group exhibited no significant differences in the general clinical observation, growth and development, hematology, blood biochemistry, routine urine detection, gross anatomy,organ weight,organ-to-body ratio, and histopathological examinations.ConclusionMonascus red is composed of multiple components characterized by red pigments. There is no obvious toxic effects found in the preliminary safety evaluation, which can provide reference for further long-term research

    Hepatitis E Virus Infection in Central China Reveals No Evidence of Cross-Species Transmission between Human and Swine in This Area

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    Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Swine stands out as the major reservoir for HEV infection in humans, as suggested by the close genetic relationship of swine and human virus. Since 2000, Genotype 4 HEV has become the dominant cause of hepatitis E disease in China. Recent reports showed that genotype 4 HEV is freely transmitted between humans and swine in eastern and southern China. However, the infection status of HEV in human and swine populations in central China is still unclear. This study was conducted in a rural area of central China, where there are many commercial swine farms. A total of 1476 serum and 554 fecal specimens were collected from the general human and swine populations in this area, respectively. The seroepidemiological study was conducted by enzyme-linked immunosorbent assay. Conserved genomic sequences of open reading frame 2 were detected using reverse transcription-PCR. The results indicated that the overall viral burden of the general human subjects was 0.95% (14/1476), while 7.0% (39/554) of the swine excreted HEV in stool. The positive rate of anti-HEV IgG and IgM in the serum samples was 7.9% (117/1476) and 1.6% (24/1476), respectively. Phylogenetic analysis based on the 150 nt partial sequence of the capsid protein gene showed that the 53 swine and human HEV isolates in the current study all belonged to genotype 4, clustering into three major groups. However, the HEV isolates prevalent in the human and swine populations were classified into known distinct subgenotypes, which suggested that no cross-species transmission between swine and humans had taken place in this area. This result was confirmed by cloning and phylogenetic analysis of the complete capsid protein gene sequence of three representative HEV strains in the three major groups. The cross reactivity between anti-HEV IgG from human sera and the two representative strains from swine in central China was confirmed by Dot-blot assay. In conclusion, although all the HEV strains prevalent in central China belonged to genotype 4, there is no evidence of cross-species transmission between human and swine in this area

    Transcriptional profiles of drought-responsive genes in modulating transcription signal transduction, and biochemical pathways in tomato

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    To unravel the molecular mechanisms of drought responses in tomato, gene expression profiles of two drought-tolerant lines identified from a population of Solanum pennellii introgression lines, and the recurrent parent S. lycopersicum cv. M82, a drought-sensitive cultivar, were investigated under drought stress using tomato microarrays. Around 400 genes identified were responsive to drought stress only in the drought-tolerant lines. These changes in genes expression are most likely caused by the two inserted chromosome segments of S. pennellii, which possibly contain drought-tolerance quantitative trait loci (QTLs). Among these genes are a number of transcription factors and signalling proteins which could be global regulators involved in the tomato responses to drought stress. Genes involved in organism growth and development processes were also specifically regulated by drought stress, including those controlling cell wall structure, wax biosynthesis, and plant height. Moreover, key enzymes in the pathways of gluconeogenesis (fructose-bisphosphate aldolase), purine and pyrimidine nucleotide biosynthesis (adenylate kinase), tryptophan degradation (aldehyde oxidase), starch degradation (β-amylase), methionine biosynthesis (cystathionine β-lyase), and the removal of superoxide radicals (catalase) were also specifically affected by drought stress. These results indicated that tomato plants could adapt to water-deficit conditions through decreasing energy dissipation, increasing ATP energy provision, and reducing oxidative damage. The drought-responsive genes identified in this study could provide further information for understanding the mechanisms of drought tolerance in tomato

    Comparative Grain Yield, Straw Yield, Chemical Composition, Carbohydrate and Protein Fractions, In Vitro Digestibility and Rumen Degradability of Four Common Vetch Varieties Grown on the Qinghai-Tibetan Plateau

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    Four varieties of common vetch, including three improved varieties (Lanjian No. 1, Lanjian No. 2, and Lanjian No. 3) and one local variety (333A), were evaluated for varietal variations in grain yield, straw yield and straw quality attributes on the Qinghai-Tibetan Plateau. Crops were harvested at pod maturity to determine grain yield, straw yield, harvest index, and potential utility index (PUI). Straw quality was determined by measuring chemical composition, carbohydrate and protein fractions, in vitro gas production and in situ ruminal degradability. Results showed a significant effect (p < 0.01) of variety on the grain yield [875.2–1255 kg dry matter (DM)/ha], straw yield (3154–5556 kg DM/ha), harvest index (15.6–28.7%) and PUI (53.3–63.2%). Variety also had a significant effect on chemical composition, carbohydrate and protein fractions (p < 0.05) except non-structural carbohydrates and rapidly degradable sugars. Significant differences (p < 0.05) were observed among the varieties in potential gas production [188–234 mL/g DM], in vitro organic matter (OM) digestibility (43.7–54.2% of OM), and metabolizable energy (6.40–7.92 MJ/kg DM) of straw. Significant differences (p < 0.001) were also observed among the varieties in rapidly degradable DM fraction and effective DM degradability of straw; however, no difference was observed in other DM degradation parameters and neutral detergent fiber degradation parameters. In conclusion, based on straw yield and quality, Lanjian No. 1 has the greatest potential among the tested varieties as a crop for supplementing ruminant diets for smallholder farmers on the Qinghai-Tibetan plateau
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