Tulip, being an important ornamental plant, generally requires lengthy and laborious procedures to develop new varieties using traditional breeding methods requires. But ionizing radiation ...potentially accelerates the breeding process of ornamental plant species. The biological effects of γ-ray irradiation on tulip, therefore, were investigated through establishing an irradiation-mediated mutation breeding protocol to accelerate its breeding process. ISSR-PCR molecular marker technique was further used to identify the mutants of phenotypic variation plants. This study showed that low irradiation doses (5 Gy) stimulated bulb germination to improve the survival rate of tulip, while high irradiation doses (20 to 100 Gy) significantly (
< 0.05) inhibited its seed germination and growth, and decreased the flowering rate, petal number, flower stem length and flower diameter. More than 40 Gy significantly (
< 0.05) decreased the total chlorophyll content and increased the malondialdehyde (MDA) content in tulips. Interestingly, three types of both stigma variations and flower pattern variations, and four types of flower colour variations were observed. With increasing the irradiation dose from 5 to 100 Gy, the anthocyanin and flavonoid contents continuously decreased. Scanning electron microscopy (SEM) analysis evidenced that high irradiation doses altered the micromorphology of leaf stomata. Microscopic observations of tulip root apical mitosis further showed the abnormal chromosomal division behaviour occurring at different mitotic phases under irradiation treatment (80 Gy). Increasing the irradiation dose from 20 to 100 Gy enhanced the micronucleus rate. Moreover, the suspected genetic variation in tulips was evaluated by inter-simple sequence repeat (ISSR) analysis, and the percentage of polymorphic bands was 68%. Finally, this study concludes that that 80 Gy may be an appropriate radiation does to better enhance the efficiency of mutagenic breeds in tulip plants. Using γ-ray irradiation, therefore, is expected to offer a theoretical basis for mutation breeding in tulips.
•Strain XJ-K1 was an extensively drug-resistant hypervirulent Klebsiella pneumoniae.•Strain XJ-K1 co-harboured one pLVPK-like virulence plasmid and two MDR plasmids.•ST11 strain XJ-K1 harboured ...aadA2, sul1, mph(A), dfrA12, rmtB, blaKPC-2, blaTEM-1, blaCTX-M-65, blaSHV-12, fosA and fosA3.
A single carbapenem-resistant, hypervirulent Klebsiella pneumoniae strain has attracted major public concern. The aim of the present study was to better understand the antimicrobial resistance and genetic characteristics of Klebsiella pneumoniae strain XJ-K1.
Klebsiella pneumoniae strain XJ-K1 was isolated from a urine specimen of a 69-year-old male patient in a teaching hospital in Shanghai, China, in January 2018. Antimicrobial susceptibility testing, string test, whole-genome sequencing, bioinformatics analysis and phylogenetic analysis were performed in this study.
Klebsiella pneumoniae XJ-K1 was an extensively drug-resistant (XDR) hypervirulent strain that showed high-level resistance to antibacterial agents. Three novel plasmids were discovered in strain XJ-K1, including a 207,409-bp IncHI1B-type rmpA2-bearing pLVPK-like virulence plasmid, a 130,628-bp Col156/IncFIB/IncFII-type aadA2-, sul1-, mph(A)- and dfrA12-bearing MDR plasmid, and a 99,408-bp IncFII/IncR-type blaKPC-2-, blaTEM-1-, blaCTX-M-65-, blaSHV-12-, rmtB- and fosA3-bearing MDR plasmid. Sequence analysis of the chromosome revealed that the aadA2, fosA and sul1 genes were harboured by XJ-K1. Multilocus sequence typing (MSLT) showed that XJ-K1 was ST11.
A large number of resistance genes and a pLVPK-like virulence plasmid carried by Klebsiella pneumoniae strain XJ-K1 might be the main reasons leading to the XDR and hypervirulent phenotype. To the best of our knowledge, this is the first report in China on the co-occurrence of a pLVPK-like virulence plasmid and two MDR plasmids in a single ST11 XDR and hypervirulent Klebsiella pneumoniae isolated from patient urine, which is a serious concern for its further spread.
The power distribution, high-order polynomial, bicubic spline interpolation, and geometric construction methods were used to reduce the edge thickness and weight of negative blended lenticular ...lenses. Four lenses with the same optical parameters were designed, simulated, machined, and evaluated using the four methods. Spherical and cylindrical power maps were generated and compared. The methods reduced the edge thickness by 78.73% for power distribution method, 77.40% for high-order polynomial method, 78.12% for bicubic spline interpolation method and 79.86% for geometric construction method for a 35 mm radius compared to that with the spherical surface. Geometric construction, power distribution, high-order polynomial, and bicubic spline interpolation reduced the lens weight by 43.86%, 35.98%, 33.06%, and 29.76%, respectively. The center optical area for the power distribution and geometric construction methods were larger than those with the other methods.
•Power distribution, high-order polynomial, bicubic spline interpolation, and geometric construction profiles were applied.•Four NBL lenses were designed, simulated, manufactured and compared based on their powers, edge thickness and weight.•The optical area of high-order polynomial profile was the smallest to compare with other three profiles.•The edge thickness and weight of the lens obtained using the geometric construction profile showed maximum reduction.
As a major risk factor to human health, obesity presents a massive burden to people and society. Interestingly, the obese status of parents can cause progeny's lipid accumulation through epigenetic ...inheritance in multiple species. To date, many questions remain as to how lipid accumulation leads to signals that are transmitted across generations. In this study, we establish a nematode model of C. elegans raised on a high-fat diet (HFD) that leads to measurable lipid accumulation, which can transmit the lipid accumulation signal to their multigenerational progeny. Using this model, we find that transcription factors DAF-16/FOXO and SBP-1/SREBP, nuclear receptors NHR-49 and NHR-80, and delta-9 desaturases (fat-5, fat-6, and fat-7) are required for transgenerational lipid accumulation. Additionally, histone H3K4 trimethylation (H3K4me3) marks lipid metabolism genes and increases their transcription response to multigenerational obesogenic effects. In summary, this study establishes an interaction between a network of lipid metabolic genes and chromatin modifications, which work together to achieve transgenerational epigenetic inheritance of obesogenic effects.
Positive associations between ambient PM
and cardiorespiratory disease have been well demonstrated during the past decade. However, few studies have examined the adverse effects of PM
based on an ...entire population of a megalopolis. In addition, most studies in China have used averaged data, which results in variations between monitoring and personal exposure values, creating an inherent and unavoidable type of measurement error.
This study was conducted in Wuhan, a megacity in central China with about 10.9 million people. Daily hospital admission records, from October 2016 to December 2018, were obtained from the Wuhan Information center of Health and Family Planning, which administrates all hospitals in Wuhan. Daily air pollution concentrations and weather variables in Wuhan during the study period were collected. We developed a land use regression model (LUR) to assess individual PM
exposure. Time-stratified case-crossover design and conditional logistic regression models were adopted to estimate cardiorespiratory hospitalization risks associated with short-term exposure to PM
. We also conducted stratification analyses by age, sex, and season.
A total of 2,806,115 hospital admissions records were collected during the study period, from which we identified 332,090 cardiovascular disease admissions and 159,365 respiratory disease admissions. Short-term exposure to PM
was associated with an increased risk of a cardiorespiratory hospital admission. A 10 μg/m
increase in PM
(lag0-2 days) was associated with an increase in hospital admissions of 1.23% (95% CI 1.01-1.45%) and 1.95% (95% CI 1.63-2.27%) for cardiovascular and respiratory diseases, respectively. The elderly were at higher PM-induced risk. The associations appeared to be more evident in the cold season than in the warm season.
This study contributes evidence of short-term effects of PM
on cardiorespiratory hospital admissions, which may be helpful for air pollution control and disease prevention in Wuhan.
Shortening of the gestational duration has been found associated with ambient air pollution exposure. However, the critical exposure windows of ambient air pollution for gestational duration remain ...inconsistent, and the association between ambient air pollution and early term births (ETB, 37 to 38 weeks) has rarely been studied relative to preterm births (PTB, 28-37 weeks). A time-series study was conducted in Shiyan, a medium-sized city in China. Birth information was collected from the Shiyan Maternity and Child Health Hospital, and 13,111 pregnant women who gave birth between 2015 and 2017 were included. Data of the concentrations of air pollutants, including PM
, PM
, NO
, and SO
and meteorological data, were collected in the corresponding gestational period. The Cox regression analysis was performed to estimate the relationship between ambient air pollution exposure and the risk of preterm birth after controlling the confounders, including maternal age, education, Gravidity, parity, fetal gender, and delivery mode. Very preterm birth (VPTB, 28-32 weeks) as a subtype of PTB was also incorporated in this study. The risk of VPTB and ETB was positively associated with maternal ambient air pollution exposure, and the correlation of gaseous pollutants was stronger than particulate matter. With respect to exposure windows, the critical trimester of air pollutants for different adverse pregnancy outcomes was different. The exposure windows of PM
, PM
, and SO
for ETB were found in the third trimester, with HRs (hazard ratios) of 1.06 (95%CI: 1.04, 1.09), 1.07 (95%CI: 1.04, 1.11), and 1.28 (95%CI: 1.20, 1.35), respectively. However, for NO
, the second and third trimesters exhibited similar results, the HRs reaching 1.10 (95%CI: 1.03, 6.17) and 1.09 (95%CI: 1.03,1.15), respectively. This study extends and strengthen the evidence for a significant correlation between the ambient air pollution exposure during pregnancy and the risk of not only PTB but, also, ETB. Moreover, our findings suggest that the exposure windows during pregnancy vary with different air pollutants and pregnancy outcomes.
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