A data-driven method for the estimation of truck-state parameters and braking force distribution

In the study of braking force distribution of trucks, the accurate estimation of the state parameters of the vehicle is very critical. However, during the braking process, the state parameters of the vehicle present a highly nonlinear relationship that is difficult to estimate accurately and that seriously affects the accuracy of the braking force distribution strategy. To solve this problem, this paper proposes a machine-learning-based state-parameter estimation method to provide a solid data base for the braking force distribution strategy of the vehicle. Firstly, the actual collected complete vehicle information is processed for data; secondly, random forest is applied for the feature screening of data to reduce the data dimensionality; subsequently, the generalized regression neural network (GRNN) model is trained offline, and the vehicle state parameters are estimated online; the estimated parameters are used to implement the four-wheel braking force distribution strategy; finally, the effectiveness of the method is verified by joint simulation using MATLAB/Simulink and TruckSim

Systematic Isolation and Characterization of Cadmium Tolerant Genes in Tobacco: A cDNA Library Construction and Screening Approach

<div><p>Heavy metal pollution is a major limiting factor that severely affects plant growth worldwide, and the accumulation of heavy metal in the plant may be hazardous to human health. To identify the processes involved in cadmium detoxification, we constructed a cDNA library of tobacco roots acclimated to cadmium (Cd) stress. According to the results of functional screening cDNA library with a yeast Cd-sensitive mutant, <i>ycf1Δ</i>, we obtained a series of candidate genes that were involved in Cd response. Sequence analysis and yeast functional complementation of 24 positive cDNA clones revealed that, in addition to antioxidant genes, genes implicated in abiotic and biotic stress defenses, cellular metabolism, and signal transduction showed Cd detoxification effects in yeast. The real time RT-PCR analyses revealed that some Cd tolerance/ detoxification genes may be able to anticipate in other stresses such as biotic defense and water balance in tobacco. Taken together, our data suggest that plants’ acclimation to Cd stress is a highly complex process associated with broad gene functions. Moreover, our results provide insights into the Cd detoxification mechanisms along with the antioxidant system, defense gene induction, and calcium signal pathway.</p></div

Silver(I), nickel(II) N-heterocyclic carbene complexes based on bidentate bis-imidazolium salt with a quinoxaline linker: syntheses, structures, and characterization

<p>Quinoxaline-bridged bidentate bis-imidazolium dicarbene ligand 1,1′-(quinoxaline-2,3-diyl)bis(3-methyl-1H-imidazol-3-ium) hexafluorophosphate salt H₂L·2PF₆ (<b>3</b>) was prepared by a two-step reaction based on 2,3-bis(imidazol-1-yl)quinoxaline (<b>1</b>). First, the 2,3-bis(imidazol-1-yl)quinoxaline reacted with CH₃I resulting in the 1,1′-(quinoxaline-2,3-diyl)bis(3-methyl-1H-imidazol-3-ium) iodide salt H₂L·2I (<b>2</b>), then through anion exchange reactions with NH₄PF₆ in water produced the desired bis-imidazolium bidentate ligand H₂L·2PF₆ (<b>3</b>). Reaction of the bidentate bis-imidazolium ligands H₂L·2PF₆ (<b>3</b>) with Ag₂O in acetonitrile gave the macrocyclic binuclear silver(I) carbene complex [Ag₂(L)₂]·2PF₆·CH₃CN (<b>4</b>). Nickel carbene complex [Ni(L)PPh₃Cl]·PF₆·2DMSO (<b>5</b>) was obtained via transmetalation of <b>4</b> with Ni(PPh₃)₂Cl₂ in DMSO. The bidentate carbene ligand is a chelating ligand in <b>5</b>, while bridging in <b>4</b>. The imidazolium ligand H₂L·2PF₆ (<b>3</b>) and transition metal carbene complexes <b>4</b> and <b>5</b> have been fully characterized by elemental analysis, NMR, ESI-MS spectroscopy, and X-ray diffraction analyses. Furthermore, the UV and luminescent properties of <b>3</b>–<b>5</b> were also studied.</p

Gene expression analyses of 24 candidate Cd detoxification genes in tobacco seedling roots and leaves under Cd stress (50 μM CdCl₂).

<p>Results represent means ± standard error of three biological replicates. Error bars: “a” indicates no significant differences (<i>P</i> > 0.05, compared with CK); “b” indicates a significant difference (0.01 < <i>P</i> < 0.05, compared with CK); and “c” indicates a highly significant difference (<i>P</i> < 0.01, compared with CK).</p

Cd tolerant genes’ classification statistics among nine functional categories.

<p>The percentage proportion (out of the total number of genes) of genes belonging to a particular functional group is shown.</p

Tobacco candidate Cd detoxification genes mediate Cd tolerance in yeast.

<p>Yeast tolerance toward Cd following overexpression of <i>T9</i>, <i>T10</i>, <i>T11</i>, <i>T15</i>, <i>T17</i>, <i>T18</i>, <i>T19</i>, <i>T22</i>, <i>T24</i>, <i>T30</i>, <i>T39</i>, <i>T40</i>, <i>T53</i>, <i>T57</i>, <i>T60</i>, <i>T61</i>, <i>T64</i>, <i>T79</i>, <i>T80</i>, <i>T85</i>, <i>T89</i>, <i>T90</i>, <i>T97</i> and <i>T129</i> (24 tobacco cDNA in total) in <i>ycf1Δ</i>. The yeast cells were spotted in four concentrations (OD₆₀₀ = 2, 0.2, 0.02, 0.002). YNB represents control culture medium with 2% galactose and without Cd added. As a negative control, the mutant strain <i>ycf1Δ</i> was transformed with the empty vector pYES260 (EV). As a positive control, wild type yeast BY4741 (WT) was transformed with the empty vector pYES260 (EV). Plates were incubated for 4 days to 1 week at 30°C.</p

Oxidation resistance test of tobacco cDNA (24 candidate Cd detoxification cDNA in total) overexpression in yeast mutant <i>skn7Δ</i>.

<p>Yeast cultures were adjusted to OD₆₀₀ = 2, 0.2, 0.02, 0.002 and 2 μl serial dilutions (from left to right in each panel) were spotted on SD medium without (YNB) or with different H₂O₂ (0.5 mM and 0.75 mM) concentrations. As a negative control, the mutant strain <i>skn7Δ</i> was transformed with the empty vector pYES260 (EV). As a positive control, wild type yeast BY4741 (WT) was transformed with the empty vector pYES260 (EV). Plates were incubated for 6 days at 30°C.</p

The oxidation resistance test of tobacco cDNA (24 candidate Cd detoxification cDNA in total) overexpression in yeast mutant <i>yap1Δ</i>.

<p>Yeast cultures were adjusted to OD₆₀₀ = 2, 0.2, 0.02, 0.002 and 2 μl serial dilutions (from left to right in each panel) were spotted on SD medium without (YNB) or with different H₂O₂ (0.5 mM and 0.75 mM) concentrations. As a negative control, the mutant strain <i>yap1Δ</i> was transformed with the empty vector pYES260 (EV). As a positive control, wild type yeast BY4741 (WT) was transformed with the empty vector pYES260 (EV). Plates were incubated for 6 days at 30°C.</p

Tobacco cDNA overexpression affects Cd accumulation in yeast.

<p>15 tobacco Cd detoxification gene cDNA (including 5 <i>metallothioneins</i>: <i>T10</i>, <i>T11</i>, <i>T15</i>, <i>T60</i>, <i>T89</i> and other cDNA: <i>T17</i>, <i>T19</i>, <i>T22</i>, <i>T53</i>, <i>T9</i>, <i>T18</i>, <i>T24</i>, <i>T39</i>, <i>T40</i>, <i>T57</i>) were overexpressed in yeast mutant <i>ycf1Δ</i>, and the Cd contents were detected using an inductively coupled plasma atomic absorption spectrometer (ICP-AAS). Here, “+” represents a Cd content that is higher than that in <i>ycf1Δ</i> expressing empty vector pYES260, “-” represents the Cd content is lower than that in <i>ycf1Δ</i> expressing empty vector pYES260 (EV), and WT represents the wild type yeast strain (BY4741). Results represent means ± standard error of three biological replicates.</p

Gene expression analyses of drought-related genes under Cd stress (50 μM CdCl₂) and mannitol treatment (300 mM, analogy of dehydration stress).

<p>A: <i>NtDREB1</i>; B: <i>NtDREB2</i>; C: <i>NtPIP1;1</i>; D: <i>NtPIP2;1</i>. Results represent means ± standard error of three biological replicates. Error bars: “a” indicates no significant differences (<i>P</i> > 0.05, compared with CK); “b” indicates a significant difference (0.01 < <i>P</i> < 0.05, compared with CK); and “c” indicates a highly significant difference (<i>P</i> < 0.01, compared with CK).</p