•The values of αc in the generalized nonlinear complementary relationship have shown both temporal and spatial variability.•The change characteristics of αc is closely correlated to aridity index ...(AI) and average NDVI during growing season in the Loess Plateau.•Climate change and revegetation result in evapotranspiration increase in the Loess Plateau.
Evapotranspiration (ET) is a key component in terrestrial climate and vegetation interactions. A generalized complementary relationship proposed by Brutsaert (2015); Brutsaert et al. (2020) has been shown to be a powerful tool for ET estimation. As the single parameter in the generalized complementary relationship, it is generally accepted that αc has high spatial variability and is closely correlated to the land-surface conditions. However, understanding of the temporal variability in αc is also important in a changing environment. In this study, we investigated the impacts of climate change and revegetation on ET by establishing the relationship between αc and the climatic-vegetation factors in 14 catchments of the Loess Plateau. The results showed that αc presented both spatial and temporal variability, where the aridity index (AI) and the average Normalized Difference Vegetation Index (NDVI) during the growing season are two dominant factors that control the variability in αc. Furthermore, combing the generalized complementary relationship and the empirical model of αc proposed in this study, the impacts of climate change and revegetation on the ET increase were quantified in the Loess Plateau. The results show that climate change (mainly expressed by an increase in precipitation) contributed the most to the ET increase (approximately 68% on average), whereas revegetation (quantified by the NDVI increase) also played a dominant role (approximately 32% on average) in the ET increase, which suggests that revegetation planning management should pay more attention to the increased water consumption by evapotranspiration in the sustainable economic and ecological development of the Loess Plateau.
Hypoxia is the major influence factor in physiological and pathological courses which are mainly mediated by hypoxia-inducible factors (HIFs) in response to low oxygen tensions within solid tumors. ...Under normoxia, HIF signaling pathway is inhibited due to HIF-α subunits degradation. However, in hypoxic conditions, HIF-α is activated and stabilized, and HIF target genes are successively activated, resulting in a series of tumour-specific activities. The activation of HIFs, including HIF-1α, HIF-2α and HIF-3α, subsequently induce downstream target genes which leads to series of responses, the resulting abnormal processes or metabolites in turn affect HIFs stability. Given its functions in tumors progression, HIFs have been regarded as therapeutic targets for improved treatment efficacy. Epigenetics refers to alterations in gene expression that are stable between cell divisions, and sometimes between generations, but do not involve changes in the underlying DNA sequence of the organism. And with the development of research, epigenetic regulation has been found to play an important role in the development of tumors, which providing accumulating basic or clinical evidences for tumor treatments. Here, given how little has been reported about the overall association between hypoxic tumors and epigenetics, we made a more systematic review from epigenetic perspective in hope of helping others better understand hypoxia or HIF pathway, and providing more established and potential therapeutic strategies in tumors to facilitate epigenetic studies of tumors.
The deformation resistance would be increased with the addition of Nb and Ti, which makes it difficult to accurately control the rolling process, resulting in mixed grains and cracks. The hot ...deformation behavior of Nb–Ti microalloyed high strength steel was investigated in the temperature range of 900–1100 °C with the strain rate between 0.1 and 5 s−1. The recrystallization active energy was obtained by regression calculation, and the thermal deformation equation was established. The dynamic recrystallization critical strain model was established by changing the work hardening rate. The results show that a higher deformation temperature and lower strain rate are conducive to dynamic recrystallization. The active energy of dynamic recrystallization is 386.30 kJ mol−1, εp = 1.23 × 10−2 Z0.087, and εc = 1.95 × 10−3 Z0.111. The high strength steel is strengthened by the strengthening of grain refining and precipitation of Nb–Ti microalloys. The second phase particles are TiN with a size of about 100 nm, (Nb, Ti)C with the size between 50 and 80 nm, and NbC with the size between 10 and 20 nm.
Omicron emerged following COVID-19 vaccination campaigns, displaced previous SARS-CoV-2 variants of concern worldwide, and gave rise to lineages that continue to spread. Here, we show that Omicron ...exhibits increased infectivity in primary adult upper airway tissue relative to Delta. Using recombinant forms of SARS-CoV-2 and nasal epithelial cells cultured at the liquid-air interface, we show that mutations unique to Omicron Spike enable enhanced entry into nasal tissue. Unlike earlier variants of SARS-CoV-2, our findings suggest that Omicron enters nasal cells independently of serine transmembrane proteases and instead relies upon metalloproteinases to catalyze membrane fusion. Furthermore, we demonstrate that this entry pathway unlocked by Omicron Spike enables evasion from constitutive and interferon-induced antiviral factors that restrict SARS-CoV-2 entry following attachment. Therefore, the increased transmissibility exhibited by Omicron in humans may be attributed not only to its evasion of vaccine-elicited adaptive immunity, but also to its superior invasion of nasal epithelia and resistance to the cell-intrinsic barriers present therein.
With the widespread popularity of social software and self-media, online public opinion incidents in colleges and universities occur frequently and present a complicated situation. In the big data ...era, university students have gained a more relaxed environment in which to receive and disseminate public opinion information, enabling them to spread their opinions and insights to the Internet more rapidly, thus exacerbating the riskiness of public opinion information dissemination. We constructed CUOPO, the first risk classification dataset of China university online public opinion, and screened out 10,255 representative public opinion texts from a large number of university online public opinion information, including 3,641 risk-free and 6,614 risky texts. These risky texts cover many fields, including 1,755 college livelihood risk texts, 767 campus safety risk texts, 1,395 school order risk texts, 906 university reputation risk texts, and 1,793 advertisement risk texts. The dataset contains various information about each network opinion, including authentic labels, text information, time information, and network information. Through an in-depth study of CUOPO, we found that universities have significant risk issues in the areas of livelihood, safety, teaching order, reputation, and advertisement diversion, which require great attention from university administrators. To validate the effectiveness of the CUOPO, we conduct extensive experiments on the dataset using a series of neural network methods to provide benchmark results for predicting online public opinion risk texts. We expect that CUOPO can provide strong data support for the study of the types of online public opinion risks in colleges and universities and thus play a positive role in promoting the progress of college and university public opinion research. The dataset is available at https://github.com/TianShengLee98/CUOPO-Dataset .
All reported α-l-fucosidases catalyze the removal of nonreducing terminal l-fucoses from oligosaccharides or their conjugates, while having no capacity to hydrolyze core fucoses in glycoproteins ...directly. Here, we identified an α-fucosidase from the bacterium Elizabethkingia meningoseptica with catalytic activity against core α-1,3-fucosylated substrates, and we named it core fucosidase I (cFase I). Using site-specific mutational analysis, we found that three acidic residues (Asp-242, Glu-302, and Glu-315) in the predicted active pocket are critical for cFase I activity, with Asp-242 and Glu-315 acting as a pair of classic nucleophile and acid/base residues and Glu-302 acting in an as yet undefined role. These findings suggest a catalytic mechanism for cFase I that is different from known α-fucosidase catalytic models. In summary, cFase I exhibits glycosidase activity that removes core α-1,3-fucoses from substrates, suggesting cFase I as a new tool for glycobiology, especially for studies of proteins with core fucosylation.
Introduction
Cotton straw biochar (biochar) and compound
Bacillus
biofertilizer (biofertilizer) have attracted wide attentions in the remediation of heavy metal-contaminated soils in recent years. ...However, few studies have explored the metabolomics of lateral roots of Cd-stressed cotton to determine the mechanism of biochar and biofertilizer alleviating Cd stress.
Methods
In this pot experiment, biochar and biofertilizer were applied to the soils with different Cd contamination levels (1, 2, and 4 mg kg
-1
). Then, the responses of cotton root morphology, vitality, Cd content, and antioxidant enzyme activities were analyzed, and the mechanism of biochar and biofertilizer alleviating Cd stress was determined by metabolomic analysis.
Results
The results showed that exogenous Cd addition decreased the SOD and POD activities in cotton taproot and lateral root. Besides, with the increase of soil Cd content, the maximum Cd content in taproot (0.0250 mg kg
-1
) and lateral root (0.0288 mg kg
-1
) increased by 89.11% and 33.95%, respectively compared with those in the control (
p<
0.05). After the application of biochar and biofertilizer, the SOD and POD activities in cotton taproot and lateral root increased. The Cd content of cotton taproot in biochar and biofertilizer treatments decreased by 16.36% and 19.73%, respectively, and that of lateral root decreased by 13.99% and 16.68%, respectively. The metabolomic analysis results showed that the application of biochar and biofertilizer could improve the resistance of cotton root to Cd stress through regulating the pathways of ABC transporters and phenylalanine metabolism.
Discussion
Therefore, the application of biochar and biofertilizer could improve cotton resistance to Cd stress by increasing antioxidant enzyme activities, regulating root metabolites (phenols and amino acids), and reducing Cd content, thus promoting cotton root growth.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in immunocompromised individuals is associated with prolonged virus shedding and evolution of viral variants. Rapamycin and its ...analogs (rapalogs, including everolimus, temsirolimus, and ridaforolimus) are FDA approved as mTOR inhibitors for the treatment of human diseases, including cancer and autoimmunity. Rapalog use is commonly associated with an increased susceptibility to infection, which has been traditionally explained by impaired adaptive immunity. Here, we show that exposure to rapalogs increased susceptibility to SARS-CoV-2 infection in tissue culture and in immunologically naive rodents by antagonizing the cell-intrinsic immune response. We identified 1 rapalog (ridaforolimus) that was less potent in this regard and demonstrated that rapalogs promote spike-mediated entry into cells, by triggering the degradation of the antiviral proteins IFITM2 and IFITM3 via an endolysosomal remodeling program called microautophagy. Rapalogs that increased virus entry inhibited mTOR-mediated phosphorylation of the transcription factor TFEB, which facilitated its nuclear translocation and triggered microautophagy. In rodent models of infection, injection of rapamycin prior to and after virus exposure resulted in elevated SARS-CoV-2 replication and exacerbated viral disease, while ridaforolimus had milder effects. Overall, our findings indicate that preexisting use of certain rapalogs may elevate host susceptibility to SARS-CoV-2 infection and disease by activating lysosome-mediated suppression of intrinsic immunity.
Soil salinization greatly restricts crop production in arid areas for salinity stress can inhibit crop photosynthesis and growth. Chlorophyll fluorescence and photosynthetic gas exchange (CFPGE) ...parameters are important indicators of crop photosynthesis and have been widely used to evaluate the impacts of salinity stress on crop photosynthesis and growth. Remote sensing technology can quickly and non-destructively obtain crop information under salinity stress, however, at present, the distribution of spectral features of CFPGE parameters in different regions is still unclear. In this study (2019-2020), under salinity stress conditions, the spectral data of rapeseed leaves were acquired and the CFPGE parameters were simultaneously determined. Then, continuous wavelet transformation (CWT) and standard normal variate (SNV) transformation were utilized to preprocess the raw spectral data. After that, a CFPGE parameter estimation model was constructed by using the partial least squares regression (PLSR) algorithm and the support vector machines (SVM) algorithm based on the spectral features in the red region (600-800 nm) and those in the red, blue-green (350-600 nm), and near-infrared (800-2500 nm) regions. The results showed that the spectral features of CFPGE parameters could be extracted by successive projections algorithm (SPA) based on the CWT preprocessing. The CFPGE parameter estimation model constructed based on the spectral features in the red region (675 nm, 680 nm, 688 nm, 749 nm, and 782 nm) had the highest Fv/Fm estimation accuracy on day 30, with R
c, R
p, and RPD of 0.723, 0.585, and 1.68, respectively. Based on this, the spectral features (578 nm, 976 nm, 1088 nm, 1476 nm, and 2250 nm) in the blue-green and near-infrared regions were added in the variables for modeling, which significantly improved the accuracy and stability of the model, with R
c, R
p, and RPD of 0.886, 0.815, and 2.58, respectively. Therefore, the fusion of the spectral features in the red, blue-green, and near-infrared regions could improve the estimation accuracy of rapeseed leaf CFPGE parameters. This study will provide technical reference for rapid estimation of photosynthetic performance of crops under salinity stress in arid and semi-arid areas.
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