Tomatoes, a major vegetable crop, are not only delicious but can also prevent cancer and lower blood pressure. However, they are easily infected with diseases during the growth process, so it is of great significance to find a technology for nondestructive testing of the tomato growth state. In this study, partial least squares regression (PLSR) was used to establish a prediction model of the tomato leaf greenness value and photosynthetic rate based on laser-induced fluorescence spectroscopy and a hyperspectral imaging system. The results showed that the best preprocessing method for the fluorescence spectral model was SD+SNV, and the best methods for the hyperspectral model were FD+SNV and FD+MSC. The results for the prediction of the photosynthetic rate based on the fluorescence spectral and hyperspectral models were as follows: the coefficient of determination (R2) values were 0.9982 and 0.9739, respectively, and the root-mean-square error of prediction (RMSEP) values were 0.2781 and 0.3374, respectively. When measuring greenness, the R2 values were 0.9816 and 0.9595, and the RMSEP values were 0.1696 and 0.4032, respectively. The experimental results showed that the model based on the fluorescence spectrum had higher accuracy and lower deviation in the detection and prediction of the tomato growth state; these results provide a specific method and reference for subsequent research.
Seed dormancy is a mechanism that prevents seeds from germinating at times of the year when conditions are unfavorable, that is, when the chance of seed survival is low. Determining the seasonal dynamics of seed dormancy is important for exploring how plant regeneration is adapted to the environment. We studied the seed dormancy status of Taxus chinensis var. mairei , an endangered species in China, under simulated seasonal temperature regimes. The embryo length, embryo-to-seed (E : S) ratio, and percentage of seeds with a split seed coat increased when seeds were stratified at spring and autumn temperature regimes. The abscisic acid (ABA) content decreased during stratification at simulated seasonal temperatures, but no obvious pattern in the content of gibberellic acid (GA) and indole acetic acid (IAA) was observed. The GA–ABA and IAA–ABA ratios increased during stratification. These results suggest that T. chinensis var. mairei seeds have morphophysiological dormancy, and that the seasonal dynamics of seed dormancy break are controlled by endogenous hormones and their balances, which was confirmed by the results of a field experiment. Our study provides useful information for understanding the natural population regeneration and propagation of this threatened species.
Abstract Objectives: To investigate the quantitative parameters of dual-layer spectral detector CT in the assessment of benign and malignant laryngeal tumors. Methods: Spectral images of 47 patients were retrospectively analyzed in both the arterial phase (AP) and the venous phase (VP), including 26 larynx squamous carcinoma (LSCC) lesions and 28 benign lesions. For the 54 lesions in the AP and VP, the slope of the spectral curve (λHUa and λHUv) from 40keV to 90keV, CT values of conventional images (CTa and CTv), iodine concentrations (ICa and ICv), normalized IC (NICa and NICv), effective atomic number (Zeff-a and Zeff-v), and normalized Zeff (nZeff-a and nZeff-v) were calculated and analyzed between LSCC and benign patients. ROC curve, independent sample t-test, and Spearman rank-sum test were used in statistical analysis. Results: λHUv 40-60keV had the highest diagnostic efficiency in all slope of the spectral curve. So λHU 40-60keV was the best slope. All parameters in AP didn’t have well identifying efficiency. But all parameters in VP had perfect identifying efficiency. Especially the ICv was the highest, which sensitivity and specificity were 88.5% and 85.7%. All measured quantitative parameters except CTa and nZeff-a of AP were statistically significant difference between LSCC and benign laryngeal tumors. In the AP, quantitative parameters were weakly positively correlated with two kinds of tumors, especially CTa. But five quantitative parameters ( λHUv 40-60keV ,CTv,ICv, NICv, Zeff-v) were strongly positively in the VP,which the r values are 0.734, 0.696, 0.748, 0.691, 0.730 respectively.
A Ni-catalyzed enantioselective reductive three-component alkylalkenylation of β,γ-alkenyl ketones with cis-alkenyl iodides and fluoroalkyl iodides in the presence of Mn is reported. By leveraging five-membered nickellacycles stabilized by pendant ketone group and chiral bis(oxazoline) (BiOx) ligand, this three-component protocol allows efficient access to enantioenriched β-alkenyl ketones from simple starting materials. Ni-catalyzed three-component alkylalkenylation of diverse electronically unbiased alkenes beyond β,γ-alkenyl ketones that enables regioselective construction of two C(sp3)–C(sp3) and C(sp3)–(sp2) bonds in one single operation is also demonstrated.
Additional file 3: Supplement Table 7. Biological process of genes based on the gene ontology. Supplement Table 8. Cellular component of genes based on the gene ontology. Supplement Table 9. Molecular function of genes based on gene ontology.
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