The location selection of facilities became a major interest for the organizations to establish their planned business for a long period of time. The choice of the best location among a set of ...candidate locations is a complex process. Although the multiple criteria decision making (MCDM) methods are applicable for location selection problems, different solutions can be obtained using different MCDM methods. Thus, a comparative study between four different MCDM methods was applied within numerical example to show the deviations in ranking of the alternatives that occurs when different methods are used. The weights of attributes are assigned using objective method namely Entropy weight method. The rank disagreements are expressed using spearman`s correlation coefficients.
An air‐stable dicationic Zn2+ complex (1) in a tripod‐type ligand with non‐bound phosphorus base and three pyridinyl “arms” (TPPh) was synthesized. Remarkably, while 2 mol% of 1 at room temperature ...selectively catalyzed dehydrogenative borylation of terminal alkynes with HBPin, a lower loading of 1 (0.5 mol%) at 90 °C selectively promoted hydroboration reaction of the same alkynes skipping the dehydrogenative borylation step. The mode of action of 1 was proposed based on experimental observations as well as the mechanism of dehydrogenative borylation was studied by DFT computations.
Alkyne dehydrogenative borylation and hydroboration: A catalytic amount of a dicationic Zn2+ complex, TPPh ⋅ Zn2+, selectively catalyzed the dehydrogenative borylation of terminal alkynes with HBPin at room temperature while lower TPPh ⋅ Zn2+ loading sborylation step.
The functional understanding of genetic interaction networks and cellular mechanisms governing health and disease requires the dissection, and multifaceted study, of discrete cell subtypes in ...developing and adult animal models. Recombinase-driven expression of transgenic effector alleles represents a significant and powerful approach to delineate cell populations for functional, molecular, and anatomical studies. In addition to single recombinase systems, the expression of two recombinases in distinct, but partially overlapping, populations allows for more defined target expression. Although the application of this method is becoming increasingly popular, its experimental implementation has been broadly restricted to manipulations of a limited set of common alleles that are often commercially produced at great expense, with costs and technical challenges associated with production of intersectional mouse lines hindering customized approaches to many researchers. Here, we present a simplified CRISPR toolkit for rapid, inexpensive, and facile intersectional allele production.
Briefly, we produced 7 intersectional mouse lines using a dual recombinase system, one mouse line with a single recombinase system, and three embryonic stem (ES) cell lines that are designed to study the way functional, molecular, and anatomical features relate to each other in building circuits that underlie physiology and behavior. As a proof-of-principle, we applied three of these lines to different neuronal populations for anatomical mapping and functional in vivo investigation of respiratory control. We also generated a mouse line with a single recombinase-responsive allele that controls the expression of the calcium sensor Twitch-2B. This mouse line was applied globally to study the effects of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on calcium release in the ovarian follicle.
The lines presented here are representative examples of outcomes possible with the successful application of our genetic toolkit for the facile development of diverse, modifiable animal models. This toolkit will allow labs to create single or dual recombinase effector lines easily for any cell population or subpopulation of interest when paired with the appropriate Cre and FLP recombinase mouse lines or viral vectors. We have made our tools and derivative intersectional mouse and ES cell lines openly available for non-commercial use through publicly curated repositories for plasmid DNA, ES cells, and transgenic mouse lines.
In this paper, we present a new method for electroencephalogram (EEG) signal classification based on fractional-order calculus. The method, termed fractional linear prediction (FLP), is used to model ...ictal and seizure-free EEG signals. It is found that the modeling error energy is substantially higher for ictal EEG signals compared to seizure-free EEG signals. Moreover, it is known that ictal EEG signals have higher energy than seizure-free EEG signals. These two parameters are then given as inputs to train a support vector machine (SVM). The trained SVM is then used to classify a set of EEG signals into ictal and seizure-free categories. It is found that the proposed method gives a classification accuracy of 95.33% when the SVM is trained with the radial basis function (RBF) kernel.
An Isolable Bis(Silanone–Borane) Adduct Luecke, Marcel‐Philip; Pens, Elron; Yao, Shenglai ...
Chemistry : a European journal,
April 6, 2020, Volume:
26, Issue:
20
Journal Article
Peer reviewed
Open access
The reaction of bis(silylenyl)‐substituted ferrocene 1 with two molar equivalents of BPh3 yields the corresponding bis(silylene–borane) Lewis adduct 2. The latter is capable to activate CO2 to ...furnish the borane‐stabilized bis(silanone) 3 through mono‐oxygenation of the dative SiII→B silicon centers under release of CO. Removal of BPh3 from 3 with PMe3 affords the corresponding 1,3,2,4‐cyclodisiloxane and the Me3P−BPh3 adduct. All isolated new compounds were characterized and their molecular structures were determined by single‐crystal X‐ray diffraction analyses.
Si=O→B in a bis(silanone): Reaction of ferrocene‐bridged bis(silylene–borane) 2, prepared from the bis(silylene) and BPh3, with CO2 quantitatively generates a Lewis acid‐stabilized bis(silanone) 3 with two Si=O→B moieties. Removal off BPh3 with PMe3 yields 1,3,2,4‐cyclodisiloxane 4 through intramolecular Si=O head‐to‐tail dimerization. In contrast, reaction of 2 with elemental sulfur furnishes the borane‐free bis(silathione) 5.
Summary
The bacterium Erwinia amylovora, the causal agent of fire blight disease in apple, triggers its infection through the DspA/E effector which interacts with the apple susceptibility protein ...MdDIPM4. In this work, MdDIPM4 knockout has been produced in two Malus × domestica susceptible cultivars using the CRISPR/Cas9 system delivered via Agrobacterium tumefaciens. Fifty‐seven transgenic lines were screened to identify CRISPR/Cas9‐induced mutations. An editing efficiency of 75% was obtained. Seven edited lines with a loss‐of‐function mutation were inoculated with the pathogen. Highly significant reduction in susceptibility was observed compared to control plants. Sequencing of five potential off‐target sites revealed no mutation event. Moreover, our construct contained a heat‐shock inducible FLP/FRT recombination system designed specifically to remove the T‐DNA harbouring the expression cassettes for CRISPR/Cas9, the marker gene and the FLP itself. Six plant lines with reduced susceptibility to the pathogen were heat‐treated and screened by real‐time PCR to quantify the exogenous DNA elimination. The T‐DNA removal was further validated by sequencing in one plant line. To our knowledge, this work demonstrates for the first time the development and application of a CRISPR/Cas9‐FLP/FRT gene editing system for the production of edited apple plants carrying a minimal trace of exogenous DNA.
A series of novel, intramolecular Zr(IV)/P frustrated Lewis pairs (FLPs) based on cationic zirconocene fragments with a variety of ancillary cyclopentadienyl and 2-phosphinoaryloxide (−O(C6H4)PR2, ...R = tBu and 3,5-CF3-(C6H3)) ligands are reported and their activity as catalysts for the dehydrocoupling of dimethylamine–borane (Me2NH·BH3) assessed. The FLP system (C9H7)2ZrO(C6H4)PtBu2B(C6F5)4 is shown to give unprecedented turnover frequencies (TOF) for a catalyst based on a group 4 metal (TOF ≥ 600 h–1), while also proving to be the most efficient FLP catalyst reported to date. The mechanism of this reaction has been probed using analogous intermolecular Zr(IV)/P FLPs, permitting deconvolution of the reactions taking place at both the Lewis acidic and basic sites. Elucidation of this mechanism revealed an interesting cooperative two-cycle process where one cycle is FLP mediated and the other, a redistribution of a linear diborazane intermediate, relies solely on the presence of a Zr(IV) Lewis acid.
DFT calculations were performed to gain insight in to the mechanism of SS bond cleavage in disulfides mediated by Frustrated Lewis Pairs.
Display omitted
DFT calculations were performed to gain ...insight into the detailed mechanism of SS bond cleavage in disulfides (i.e., iPrSSiPr) by a frustrated Lewis pair (FLP) (tBu)3P/B(C6F5)3. The calculations revealed that the reaction initiates from the generation of weak complex B(C6F5)3/iPrSSiPr (IM1) between iPrSSiPr and Lewis acid B(C6F5)3. Subsequently, the Lewis base (tBu)3P can activates the SS bond leading to the final cleavage of SS bond to give the product (tBu)3P(SiPr)(iPrS)B(C6F5)3 (PR). The computed kinetics and thermodynamics suggest that the reaction can take place reversibly under ambient conditions, which accounts well for the experimental observations. Furthermore, the mechanism is compared with that of the HH bond cleavages by same FLP. Contrast to the HH bond cleavage, a weak donor–acceptor complex IM1 between iPrSSiPr and B(C6F5)3 could be located before SS bond cleavage. Nonetheless, the complete SS bond cleavage essentially is still due to the synergistic catalytic Lewis acid/base effects of FLP (tBu)3P/B(C6F5)3.
Enabling precise gene integration is important for installing traits in the plants. One of the practical methods of achieving precise gene integration is by using the yeast FLP-FRT recombination ...system that is efficient in directing DNA integration into the "engineered" genomic sites. The critical parameters of this method include the use of the thermostable version of FLP protein and the promoter trap design to select site-specific integration clones. The resulting transgenic plants display stable expression that is transmitted to the progeny. Therefore, FLP-mediated site-specific integration method could be used for trait engineering in the crop plants or testing gene functions in the model plants.
PDF
