Involvement of Transit Peptide Aromatic Residues in Precursor Interaction(s) with the Chloroplast Import Apparatus

The import of nuclear-encoded preproteins into chloroplast is mediated by the transit peptide located in the N-terminus of the preproteins. A semi-conserved FGLK motif is identified in most of the transit peptides bioinformatically, despite the lack of homology in the primary sequence. To investigate the role of phenylalanines in the FGLK motifs of SStp in the interaction with outer envelope import apparatus, mutations were made on the two motifs found in prSSU from tobacco: F26TGLK and F35PVSRK. These mutations include F→W, F→S, and F→A in both of the motifs. The WT precursor (prSSU), 6 single prSSU mutants, 9 double prSSU mutants and mature protein were expressed and purified from E. coli. The activities of 13 out of 15 mutant proteins are then tested as compeptivie inhibitors of the import of 35S-prSSU. The increase in IC50 indicated that both phenylalanines at position 26th and 35th are important for the import process. Membrane disruption assay showed that all these mutants have slightly reduced membrane activity compared to wild type, suggesting that interaction with membrane lipid components is secondary to other interactions with proteinaceous component in the early event of the import process. Tryptophan fluorescence assay using the transit peptide mutants F26W-SStp and F35W-SStp demonstrated that the two loosely conserved FGLK motifs have different positions when exposed to a hydrophobic environment, indicative of different roles they might have in the recognition/binding process

A Fuzzy Bayesian Network Model for Quality Control in O2O e-Commerce

With the popularization of the online to offline (O2O) e-commerce on fresh food products, how to control the quality is becoming increasingly important. To adequately address this problem, this paper presents a fuzzy Bayesian network model for effectively controlling the quality in O2O ecommerce. Reasoning about uncertain events and incomplete data through an intelligent simulation with Bayesian networks provides a convenient and fast method of evaluation and analysis for e-commerce platforms to quickly select fresh food suppliers. Such a model is capable of appropriately modelling the uncertainty inherent in the fresh food product distribution process. It focuses on the identification of the critical factors that affect the food product quality along the supply chain. This leads to the development of a complete selection and evaluation system for the quality in O2O e-commerce. A simulation study is conducted that shows the proposed model is applicable for effectively controlling the quality in O2O e-commerce. Ultimately, the unloading level, warehouse inspection and warehouse monitoring are determined as the entry points for quality control, with corresponding degrees of influence of 44%, 37%, and 34%. The main points to protect the quality of food are introduced, which provides a theoretical basis for solving fresh food safety problems for business platforms

Observation of Spin Hall Effect in Weyl Semimetal WTe2 at Room Temperature

Discovery of topological Weyl semimetals has revealed the opportunities to realize several extraordinary physical phenomena in condensed matter physics. Specifically, these semimetals with strong spin-orbit coupling, broken inversion symmetry and novel spin texture are predicted to exhibit a large spin Hall effect that can efficiently convert the charge current to a spin current. Here we report the direct experimental observation of a large spin Hall and inverse spin Hall effects in Weyl semimetal WTe2 at room temperature obeying Onsager reciprocity relation. We demonstrate the detection of the pure spin current generated by spin Hall phenomenon in WTe2 by making van der Waals heterostructures with graphene, taking advantage of its long spin coherence length and spin transmission at the heterostructure interface. These experimental findings well supported by ab initio calculations show a large charge-spin conversion efficiency in WTe2; which can pave the way for utilization of spin-orbit induced phenomena in spintronic memory and logic circuit architectures

Finite-Time H

This paper addresses the problem of finite-time H∞ filtering for one family of singular stochastic systems with parametric uncertainties and time-varying norm-bounded disturbance. Initially, the definitions of singular stochastic finite-time boundedness and singular stochastic H∞ finite-time boundedness are presented. Then, the H∞ filtering is designed for the class of singular stochastic systems with or without uncertain parameters to ensure singular stochastic finite-time boundedness of the filtering error system and satisfy a prescribed H∞ performance level in some given finite-time interval. Furthermore, sufficient criteria are presented for the solvability of the filtering problems by employing the linear matrix inequality technique. Finally, numerical examples are given to illustrate the validity of the proposed methodology

Contraceptive practices of women visiting a gynecology clinic in Beijing, China

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135321/1/ijgo64.pd

Low efficiency roll-off phosphorescent organic light-emitting devices using thermally activated delayed fluorescence hosts materials based 1, 2, 4-triazole acceptor

The host in phosphrescent organic light emitting devices (PhOLEDs), showing the thermally activated delayed fluorescence (TADF) charateristic, can effectively overcome the efficiency roll-off. Herein, six bipolar compounds with donor-π-acceptor (D-π-A) and D-π-A-π-D structures have been synthesized using 1,2,4-triazole derivative (TAZ) as an acceptor and phenothiazine (PTZ), phenoxazine (PXZ), and 9, 9-dimethylacridane (DMAC) as donors. The molecular structures were confirmed by 1H NMR, 13C NMR and X-ray single-crystal diffractions. The large steric hindrance endows these molecules with typical TADF features, including the small singlet-triplet energy splitting (Delta E-ST) of 0.08–0.30 eV and completely spatially separate highest occupied molecular orbitals (HOMO) and the lowest unoccupied molecular orbitals (LUMO) electron densities. The PhOLEDs hosted by these novel TADF materials display excellent performances with low efficiency roll-off

Zhang, et al, Expression of iKIR-HLA-Cw in patients with inflammatory bowel disease Expression of iKIR-HLA-Cw in patients with inflammatory bowel disease

Abstract Objective. To investigate the distribution of inhibitory killer cell immunoglobulin-like receptor (iKIR) and its ligand human leukocyte antigen C locus (HLA-Cw) in patients with inflammatory bowel disease (IBD), and explore whether iKIR/HLA-Cw combinations are associated with IBD susceptibility. Methods. The iKIR in 100 patients with ulcerative colitis (UC), 52 patients with Crohn's disease (CD) and 106 randomly ethnically matched healthy controls was phenotyped by sequence-specific primer PCR (PCR-SSP). HLA-Cw was phenotyped by CLOCUS SSP UNITRAY ® . The combination of HLA-Cw and its corresponding iKIR in individual was analyzed subsequently. Results. The KIR2DL1 and KIR2DL3 gene phenotype frequencies in UC patients were 0.710 and 0.620 respectively, both significantly lower than those in healthy controls, and the KIR2DL1 gene phenotype frequency in CD patients was 0.731, significantly lower than that in healthy controls. KIR2DL1-HLA-C2 combination in patients with UC and CD were 0.380 and 0.404 respectively, both significantly lower than that in healthy controls. Conclusion. The susceptibility to IBD is associated with decreased KIR2DL1-HLA-C2 combination