66 research outputs found

    Analysis of molecular mechanisms of drug resistance of Mycobacterium tuberculosis in patients with pulmonary tuberculosis and its pharmacoeconomics

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    Purpose: To investigate the molecular mechanisms of drug resistance of Mycobacterium tuberculosis in patients with pulmonary tuberculosis and its pharmacoeconomics. Methods: Data pertaining to patients with primary tuberculosis treated in the First Affiliated Hospital of Zhaoqing Medical College, Zhaoqing, China from January 2020 to June 2021 were retrospectively analyzed. Sputum specimens were collected from all eligible patients, and 151 uncontaminated specimens with good bacteriophage activity were screened. Results: A total of 107 Mycobacterium tuberculosis strains were isolated from the 151 specimens, 31 of which strains were resistant to varying degrees to rifampicin, isoniazid, streptomycin, and ethambutol with an overall resistance of 28.97 %. There were 16 strains with rpoB mutation, 22 strains with katG mutation, and 8 strains with inhA mutation. The difference in the sputum negative rate, lesion absorption rate, and tuberculosis cavity closure rate, and total medical cost between the two group were not statistically significant (p > 0.05). The incidence of adverse reactions in the FDC group was significantly lower than that in the blister pack group (p < 0.05). Conclusion: The total resistance of Mycobacterium tuberculosis in primary tuberculosis patients remains at a high level, and the development of resistance is associated with mutations in rpoB, katG, and inhA genes. FDC regimen provides more pharmacoeconomic and therapeutic benefits than blister pack regimen

    TROPOMI reveals dry-season increase of solar-induced chlorophyll fluorescence in the Amazon forest

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    Photosynthesis of the Amazon rainforest plays an important role in the regional and global carbon cycles, but, despite considerable in situ and space-based observations, it has been intensely debated whether there is a dry-season increase in greenness and photosynthesis of the moist tropical Amazonian forests. Solar-induced chlorophyll fluorescence (SIF), which is emitted by chlorophyll, has a strong positive linear relationship with photosynthesis at the canopy scale. Recent advancements have allowed us to observe SIF globally with Earth observation satellites. Here we show that forest SIF did not decrease in the early dry season and increased substantially in the late dry season and early part of wet season, using SIF data from the Tropospheric Monitoring Instrument (TROPOMI), which has unprecedented spatial resolution and near-daily global coverage. Using in situ CO_2 eddy flux data, we also show that cloud cover rarely affects photosynthesis at TROPOMIā€™s midday overpass, a time when the forest canopy is most often light-saturated. The observed dry-season increases of forest SIF are not strongly affected by sun-sensor geometry, which was attributed as creating a pseudo dry-season green-up in the surface reflectance data. Our results provide strong evidence that greenness, SIF, and photosynthesis of the tropical Amazonian forest increase during the dry season

    Spatiotemporal Changes of Winter Wheat Planted and Harvested Areas, Photosynthesis and Grain Production in the Contiguous United States from 2008ā€“2018

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    Winter wheat is a main cereal crop grown in the United States of America (USA), and the USA is the third largest wheat exporter globally. Timely and reliable in-season forecast and year-end estimation of winter wheat grain production in the USA are needed for regional and global food security. In this study, we assessed the consistency between the agricultural statistical reports and satellite-based data for winter wheat over the contiguous US (CONUS) at both the county and national scales. First, we compared the planted area estimates from the National Agricultural Statistics Service (NASS) and the Cropland Data Layer (CDL) from 2008ā€“2018. Second, we investigated the relationship between gross primary production (GPP) estimated by the vegetation photosynthesis model (VPM) and grain production from the NASS. Lastly, we explored the in-season utility of GPPVPM in monitoring seasonal production. Strong spatiotemporal consistency of planted areas was found between the NASS and CDL datasets. However, in the Southern Great Plains, both the CDL and NASS planted acreage were noticeable larger (>20%) than the NASS harvested area, where some winter wheat fields were used as forage for cattle grazing. County-level GPPVPM was linearly related with grain production of winter wheat, with an R2 value of 0.68 across the CONUS. The relationships between grain production and GPPVPM in those counties without a substantial difference (<20%) between planted and harvested area were much stronger and their harvest index (HIGPP) values ranged from 0.2ā€“0.3. GPPVPM in May could explain about 70ā€“90% of the variance of winter wheat grain production. Our findings highlight the potential of GPPVPM in winter wheat monitoring, especially for those high harvested/planted ratio, which could provide useful data to guide planning and marketing for decision makers, stakeholders, and the public.This research was supported in part by research grants from the USDA National Institute of Food and Agriculture (NIFA, 2016-68002-24967), the US National Science Foundation EPSCoR program (IIA-1946093, IIA-1920946), and the NASA Geostationary Carbon Cycle Observatory (GeoCarb) Mission (GeoCarb Contract # 80LARC17C0001). Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

    Low Concentrations of Caffeine and Its Analogs Extend the Lifespan of Caenorhabditis elegans by Modulating IGF-1-Like Pathway

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    Caffeine has been reported to delay aging and protect aging-associated disorders in Caenorhabditis elegans. However, the effects of low concentration of caffeine and its analogs on lifespan are currently missing. Herein, we report that at much lower concentrations (as low as 10 Ī¼g/ml), caffeine extended the lifespan of C. elegans without affecting food intake and reproduction. The effect of caffeine was dependent on IGF-1-like pathway, although the insulin receptor homolog, daf-2 allele, e1371, was dispensable. Four caffeine analogs, 1-methylxanthine, 7-methylxanthine, 1,3-dimethylxanthine, and 1,7-dimethylxanthine, also extended lifespan, whereas 3-methylxanthine and 3,7-dimethylxanthine did not exhibit lifespan-extending activity

    Identification of Acoustic Characteristic Parameters and Improvement of Sound Absorption Performance for Porous Metal

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    Porous metal is widely used in the fields of sound absorption and noise reduction, and it is a critical procedure to identify acoustic characteristic parameters and to improve sound absorption performances. Based on the constructed theoretical sound absorption model and experimental data, acoustic characteristic parameters of the porous metal were identified through the cuckoo search identification algorithm, and their reliabilities were certified through comparing with these labeled parameters and further experimental validation. By adding the microperforated metal panel in front of the porous metal, a composite sound-absorbing structure was formed, which aimed to improve the sound absorption performance of the original porous metal by optimizing the parameters. Finite element simulation and a standing wave tube measurement were conducted to validate the effectiveness and practicability of the optimal composite sound-absorbing structure. Consistencies among theoretical predictions, simulation results, and experimental data proved the effectiveness of the identification and optimization method. When the target frequency ranges were 100&ndash;1000 Hz, 100&ndash;2000 Hz, 100&ndash;3000 Hz, and 100&ndash;4000 Hz. Actual average sound absorption coefficients of the optimal composite structures were 0.5154, 0.6369, 0.6770, and 0.7378, respectively, which exhibited the obvious improvements with a tiny increase in the occupied space and a small addition in weight

    Influences of Compression Ratios on Sound Absorption Performance of Porous Nickelā€“Iron Alloy

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    The improvement of sound absorption performance of porous metal is a focus of research in the field of noise reduction. Influences of compression ratios on sound absorption performance of a porous nickelā€“iron (Niā€“Fe) alloy were investigated. The samples were compressed with ratios from 10% to 80% at an interval of 10%. Based on the standing wave method, sound absorption coefficients of compressed samples with different thicknesses were obtained. It could be found that with the same compression ratio, sound absorption performance was improved with the increase of thickness. Based on the modified Johnsonā€“Allard model with a correction factor, the sound absorption coefficient of the porous Niā€“Fe with a thickness of 20 mm for different compression ratios was derived, whose aim was to quantificationally analyze influences of the compression ratio. The results indicated that the sample with a compression ratio of 70% exhibited optimal sound absorption performance, and its average sound absorption coefficient reached 88.97% in a frequency range of 1000ā€“6000 Hz. Meanwhile, the section morphologies of compressed samples were investigated by a scanning electron microscope, which studied the sound absorption performance by analyzing structures of the porous Niā€“Fe samples with different compression ratios. The obtained achievements will promote the application of the porous Niā€“Fe alloy in the field of acoustics
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