RESUMEN
For high-precision industrial non-destructive testing, multimodal image registration technology can be employed to register X-ray and neutron images. X-ray and neutron image registration algorithms usually use conventional methods through iterative optimization. These methods will increase the cost of registration time and require more initialization parameters. The imaging results of internal sample structures can suffer from edge blurring due to the influence of a neutron beam collimator aperture, X-ray focal point, and imaging angles. We present an unsupervised learning model, EDIRNet, based on deep learning for deformable registration of X-ray and neutron images. We define the registration process as a function capable of estimating the flow field from input images. By leveraging deep learning techniques, we effectively parameterize this function. Consequently, given a registration image, our optimized network parameters enable rapid and direct estimation of the flow field between the images. We design an attention-based edge enhancement module to enhance the edge features of the image. For evaluating our presented network model, we utilize a dataset including 552 pairs of X-ray and neutron images. The experimental results show that the registration accuracy of EDIRNet reaches 93.09%. Compared with traditional algorithms, the accuracy of EDIRNet is improved by 3.17%, and the registration time is reduced by 28.75 s.
RESUMEN
The utilization of forages grown on metal-contaminated soil can increase the risk of heavy metals entering the food chain and affecting human health because of elevated toxic metal concentrations. Meanwhile, hydrogen sulfide (H2S) and nitric oxide (NO) as signaling molecules are known to promote plant growth in metal-contaminated soils. However, the regulatory mechanisms of such molecules in plant physiology and soil biochemistry have not been well-documented. Hence, we investigate the role of the exogenous application of H2S and NO on alfalfa growth in lead/cadmium (Pb/Cd)-contaminated soil. Our results indicate that the signaling molecules increase the alfalfa chlorophyll and biomass content and improve alfalfa growth. Further, H2S and NO reduce the translocation and bioconcentration factors of Pb and Cd, potentially reducing the risk of heavy metals entering the food chain. These signaling molecules reduce metal-induced oxidative damage to alfalfa by mitigating reactive oxygen species accumulation and increasing antioxidant enzyme activities. Their exogenous application increases soil enzymatic activities, particularly of catalase and polyphenol oxidase, without significantly changing the composition and structure of rhizosphere bacterial communities. Interestingly, H2S addition enriches the abundance of plant-growth-promoting rhizobacteria in soil, including Nocardioides, Rhizobium, and Glycomyces. H2S is more effective than NO in improving alfalfa growth and reducing heavy-metal contamination of the food chain. These results provide new insights into the exogenous application of signaling molecules in alleviating metal-induced phytotoxicity, including an efficient strategy for the safe use of forages.
Asunto(s)
Cadmio/análisis , Sulfuro de Hidrógeno/farmacología , Plomo/análisis , Medicago sativa/efectos de los fármacos , Óxido Nítrico/farmacología , Contaminantes del Suelo/análisis , Riego Agrícola , Biomasa , Cadmio/toxicidad , Fumigación , Sulfuro de Hidrógeno/administración & dosificación , Plomo/toxicidad , Medicago sativa/química , Medicago sativa/crecimiento & desarrollo , Microbiota/efectos de los fármacos , Óxido Nítrico/administración & dosificación , Contaminantes del Suelo/toxicidadRESUMEN
Methylglyoxal (MG) now is found to be an emerging signaling molecule. It can relieve the toxicity of cadmium (Cd), however its alleviating mechanism still remains unknown. In this study, compared with the Cd-stressed seedlings without MG treatment, MG treatment could stimulate the activities of glutathione reductase (GR) and gamma-glutamylcysteine synthetase (γ-ECS) in Cd-stressed wheat seedlings, which in turn induced an increase of reduced glutathione (GSH). Adversely, the activated enzymes related to GSH biosynthesis and increased GSH were weakened by N-acetyl-L-cysteine (NAC, MG scavenger), 2,4-dihydroxy-benzylamine (DHBA) and 1,3-bischloroethyl-nitrosourea (BCNU, both are specific inhibitors of GR), buthionine sulfoximine (BSO, a specific inhibitors of GSH biosynthesis), and N-ethylmaleimide (NEM, GSH scavenger), respectively. In addition, MG increased the activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) in Cd-treated seedlings, followed by declining an increase in endogenous MG as comparision to Cd-stressed seedlings alone. On the contrary, the increased glyoxalase activity and decreased endogenous MG level were reversed by NAC and specific inhibitors of Gly I (isoascorbate, IAS; squaric acid, SA). Furthermore, MG alleviated an increase in hydrogen peroxide (H2O2) and malondialdehyde (MDA) in Cd-treated wheat seedlings. These results indicated that MG could alleviate Cd toxicity and improve the growth of Cd-stressed wheat seedlings by a coordinated induction of glutathione pool and glyoxalase system.
Asunto(s)
Cadmio/toxicidad , Contaminantes Ambientales/toxicidad , Glutatión/metabolismo , Lactoilglutatión Liasa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Triticum/efectos de los fármacos , Antioxidantes/farmacología , Triticum/crecimiento & desarrollo , Triticum/metabolismoRESUMEN
Enzymes in the soil are vital for assessing heavy metal soil pollution. Although the presence of heavy metals is thought to change the soil enzyme system, the distribution of enzyme activities in heavy metal polluted-soil is still unknown. For the first time, using soil zymography, we analyzed the distribution of enzyme activities of alfalfa rhizosphere and soil surface in the metal-contaminated soil. The results showed that the growth of alfalfa was significantly inhibited, and an impact that was most pronounced in seedling biomass and chlorophyll content. Catalase activity (CAT) in alfalfa decreased with increasing heavy metal concentrations, while malondialdehyde (MDA) content continually increased. The distribution of enzyme activities showed that both phosphatase and ß-glucosidase activities were associated with the roots and were rarely distributed throughout the soil. In addition, the total hotspot areas of enzyme activities were the highest in extremely heavy pollution soil. The hotspot areas of phosphatase were 3.4%, 1.5% and 7.1% under none, moderate and extremely heavy pollution treatment, respectively, but increased from 0.1% to 0.9% for ß-glucosidase with the increasing pollution levels. Compared with the traditional method of enzyme activities, zymography can directly and accurately reflect the distribution and extent of enzyme activity in heavy metals polluted soil. The results provide an efficient research method for exploring the interaction between enzyme activities and plant rhizosphere.
Asunto(s)
Catalasa/metabolismo , Medicago sativa/enzimología , Metales Pesados/análisis , Monoéster Fosfórico Hidrolasas/metabolismo , beta-Glucosidasa/metabolismo , Biomasa , Clorofila/análisis , Malondialdehído/metabolismo , Medicago sativa/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/enzimología , Rizosfera , Suelo/química , Contaminantes del Suelo/análisisRESUMEN
Being signaling molecules, nitric oxide (NO) and hydrogen sulfide (H2S) can mediate a wide range of physiological processes caused by plant metal toxicity. Moreover, legume-rhizobium symbiosis has gained increasing attention in mitigating heavy metal stress. However, systematic regulatory mechanisms used for the exogenous application of signaling molecules to alter the resistance of legume-rhizobium symbiosis under metal stress are currently unknown. In this study, we examined the exogenous effects of sodium nitroprusside (SNP) as an NO donor additive and sodium hydrosulfide (NaHS) as a H2S donor additive on the phytotoxicity and soil quality of alfalfa (Medicago sativa)-rhizobium symbiosis in lead/cadmium (Pb/Cd)-contaminated soils. Results showed that rhizobia inoculation markedly promoted alfalfa growth by increasing chlorophyll content, fresh weight, and plant height and biomass. Compared to the inoculated rhizobia treatment alone, the addition of NO and H2S significantly reduced the bioaccumulation of Pb and Cd in alfalfa-rhizobium symbiosis, respectively, thus avoiding the phytotoxicity caused by the excessive presence of metals. The addition of signaling molecules also alleviated metal-induced phytotoxicity by increasing antioxidant enzyme activity and inhibiting the level of lipid peroxidation and reactive oxygen species (ROS) in legume-rhizobium symbiosis. Also, signaling molecules improved soil nutrient cycling, increased soil enzyme activities, and promoted rhizosphere bacterial community diversity. Both partial least squares path modeling (PLS-PM) and variation partitioning analysis (VPA) identified that using signaling molecules can improve plant growth by regulating major controlling variables (i.e., soil enzymes, soil nutrients, and microbial diversity/plant oxidative damage) in legume-rhizobium symbiosis. This study offers integrated insight that confirms that the exogenous application of signaling molecules can enhance the resistance of legume-rhizobium symbiosis under metal toxicity by regulating the biochemical response of the plant-soil system, thereby minimizing potential health risks.
Asunto(s)
Rhizobium , Contaminantes del Suelo/análisis , Cadmio , Plomo , Suelo , SimbiosisRESUMEN
BACKGROUND: Myelodysplastic syndromes (MDSs), also called preleukemias, are a group of myeloid hematopoietic malignant disorders. We studied the transformation of MDS into acute myeloid leukemia (AML). METHODS: Leukemic transformation in 151 patients with MDS was dynamically followed up. The clinical manifestation, peripheral blood and bone marrow condition, karyotypes, immunophenotypes, response to treatment, and prognosis of AML evolution from MDS (MDS-AML) were also observed. RESULTS: During the course of this study, over the past eight years and seven months, 21 (13.91%) of 151 MDS patients progressed to overt leukemia, with a median interval of 5 (1 - 23) months. There were no significant differences between rates of leukemic transformation in comparison with the refractory anemia (RA), RA with excess of blasts (RAEB), and RAEB in transformation (RAEB-t) patient groups. Transformation occurred either gradually or rapidly. There were five parameters positively correlated to leukemic transformation: under 40 years of age, pancytopenia of 3 lineages, more than 15% blasts in the bone marrow, at least two abnormal karyotypes, and treatment with combined chemotherapy. All of the 21 patients with leukemia suffered from MDS-AML, and most of them were M2, M4, or M5. Two (9.52%) MDS-AML patients developed extramedullary infiltration. Leukopenia was found in 47.62% of these patients. Two thirds of these patients, whose bone marrows were generally hypercellular, suffered from neutropenia. After developing AML, 8 (47.06%) patients developed abnormal karyotypes. High expression of immature myeloid antigens, including CD33 [(49.83 +/- 24.50)%], CD13 [(36.38 +/- 33.84)%], monocytic antigen CD14 [(38.50 +/- 24.60)%], and stem cell marker CD34 [(34.67 +/- 30.59)%], were found on bone marrow mononuclear cells from MDS-AML patients after leukemic transformation. In some cases, lymphoid antigens, such as CD5, CD7, CD9, and CD19, coexisted with myeloid antigens. A low complete remission rate (31.25%) and a short survival time, with median survival of 6 (1 - 28) months, were found in patients with MDS-AML treated by induction chemotherapy. CONCLUSIONS: MDS has a high risk of developing into AML, either gradually or rapidly. Patients with MDS-AML have specific biological characteristics and a worse prognosis.