To develop superior piston pump friction pair materials in harsh working conditions, the tribological properties of two novel copper-based composites, C93800 copper alloy casting material and 10-10 ...powder metallurgy copper steel bimetallic plate, as tribo-pairs of a piston pump were evaluated on an end-face tribometer. Their tribological behavior and extreme pressure x velocity (PV) values (PV value is an important indicator that reflects the performance of sliding bearings and is the product of the unit bearing load and the restricted linear speed) were analyzed. The results show that both the two copper-based composites had excellent antifriction and antiwear performances. The 10-10 powder metallurgy copper steel bimetallic plate shows better wear resistance and superior tribological performance due to its higher hardness. However, its extreme PV value is lower than the C93800 copper alloy casting material, since the latter can play a buffer during the loading process. In addition, the extreme PV value of the C93800 copper alloy casting material amounted to 40 MPa·m/s, showing promising potential for industrial application.
Despite their many important physiological functions, past work on the diverse sequences of human milk oligosaccharides (HMOs) has been focused mainly on the highly abundant HMOs with a relatively ...low degree of polymerization (DP) due to the lack of efficient methods for separation/purification and high-sensitivity sequencing of large-sized HMOs with DP ≥ 10. Here we established an ultrahigh-temperature preparative HPLC based on a porous graphitized carbon column at up to 145 °C to overcome the anomeric α/β splitting problem and developed further the negative-ion ESI-CID-MS/MS into multistage MS
using a combined product-ion scanning of singly charged molecular ion and doubly charged fragment ion of the branching Gal and adjacent GlcNAc residues. The separation and sequencing method allows efficient separation of a neutral fraction with DP ≥ 10 into 70 components, among which 17 isomeric difucosylated nona- and decasaccharides were further purified and sequenced. As a result, novel branched difucosyl heptaose and octaose backbones were unambiguously identified in addition to the conventional linear and branched octaose backbones. The novel structures of difucosylated DF-
-heptaose, DF-
-LNO I, and DF-
-LNnO I were corroborated by NMR. The various fucose-containing Lewis epitopes identified on different backbones were confirmed by oligosaccharide microarray analysis.
Despite their many important physiological functions, past work on the diverse sequences of human milk oligosaccharides (HMOs) has been focused mainly on the highly abundant HMOs with a relatively ...low degree of polymerization (DP) due to the lack of efficient methods for separation/purification and high-sensitivity sequencing of large-sized HMOs with DP ≥ 10. Here we established an ultrahigh-temperature preparative HPLC based on a porous graphitized carbon column at up to 145 °C to overcome the anomeric α/β splitting problem and developed further the negative-ion ESI-CID-MS/MS into multistage MSn using a combined product-ion scanning of singly charged molecular ion and doubly charged fragment ion of the branching Gal and adjacent GlcNAc residues. The separation and sequencing method allows efficient separation of a neutral fraction with DP ≥ 10 into 70 components, among which 17 isomeric difucosylated nona- and decasaccharides were further purified and sequenced. As a result, novel branched difucosyl heptaose and octaose backbones were unambiguously identified in addition to the conventional linear and branched octaose backbones. The novel structures of difucosylated DF-novo-heptaose, DF-novo-LNO I, and DF-novo-LNnO I were corroborated by NMR. The various fucose-containing Lewis epitopes identified on different backbones were confirmed by oligosaccharide microarray analysis.
How to achieve simultaneous and rapid detection of various mycotoxins in food has important practical significance in the field of food processing and safety. In this paper, a smartphone immunoassay ...system based on hydrogel microspheres has been constructed to quickly detect two mycotoxins at the same time. The rapid detection system was reflected in the following three processes: (1) rapid separation of free matter after direct competition reaction based on hydrogel solid-phase carrier particles; (2) rapid detection process based on efficient catalytic function of enzymes; (3) fast capture and analysis of images based on smartphone software. Ochratoxin A (OTA) and zearalenone (ZEN) are secondary toxic metabolites of fungi that can contaminate a wide range of foods and feeds. OTA and ZEN were used as detection model molecules to verify the feasibility of the intelligent rapid detection system. The entire detection process was within 30 min, and the results were analyzed in only 10 s. Detection limits of mycotoxins OTA and ZEN are 0.7711 ng L
−1
and 1.0391 ng L
−1
. The recoveries of both mycotoxins ranged from 76.72 to 122.05%. This study provides a universal rapid detection method for on-site application of large-scale food security testing.
Graphical abstract
Schematic diagram of the construction of the smartphone detection system: The system is divided into three parts: detection, image capture and analysis, and result.
Shengyu Decoction (SYD), a classical Chinese medicine formula, is good at nourishing blood, promoting blood circulation, and soothe the nerves. SYD can improve cognitive ability. This decoction is ...suitable for treating vascular cognitive impairment (VCI). however, its active ingredients and possible mechanism have not been investigated.
This study was conducted to observe the effects of SYD on improving the cognitive abilities of rats with VCI, to explore its active ingredients and mechanism.
The rats with VCI model were established by bilateral common carotid artery occlusion (BCCAO), and the effects of SYD (5, 2.5 g/kg) on the cognitive abilities of VCI rats were evaluated using the Morris water maze (MWM) and neurological assessment. The pathological changes of hippocampal CA1 were observed by H &E and Nissl staining. The effect of SYD on cerebral blood flow (CBF) was evaluated by Laser Speckle Contrast Imager. The expression of CD31 in the cerebral cortex was measured by immunofluorescence (IF) to evaluate the number of cerebral micro vessels. The levels of IL-6, IL-1β, and TNF-α in the hippocampus were determined using an ELISA kit, and the active components in the plasma and brain tissues of rats after SYD administration were analyzed using UPLC-Q-TOF-MS/MS. The interaction network of the compound-target pathway was established using the SWISS Target, GO, and DAVID databases. The expression of AKT/HIF-1α/VEGF and p38 MAPK signaling pathway in the brain tissues was determined using western blotting (WB).
SYD (2.5, 5 g/kg) significantly improved the cognitive abilities of VCI rats in the MWM and neurological assessment. H&E and Nissl staining showed that SYD significantly ameliorated the pathological hippocampal CA1 area and increased the number of Nissl bodies. The Laser Speckle Contrast Imager showed that the cortical CBF of VCI rats in the SYD group was significantly increased, and the IF results showed that CD31 expression was significantly increased in the SYD group. The ELISA results showed that the contents of IL-6, IL-1β, and TNF-α in SYD were significantly reduced. A total of 29 compounds were found in the plasma and brain tissues of the rats treated with SYD. Network pharmacology revealed 99 targets for the treatment of VCI. Pathway enrichment analysis showed that the HIF-1 and MAPK signaling pathways might be important for SYD to ameliorate VCI. WB showed that the expressions of AKT, HIF-1α, and VEGF in the brain tissues of rats were significantly increased; in addition, NF-κB and p38 MAPK were significantly reduced in the SYD group.
SYD can improve the cognitive abilities of VCI rats. The mechanism of action of its active ingredients improves cognitive impairment by affecting the AKT/HIF-1α/VEGF and p38 MAPK/NF-κB signaling pathways, promoting cerebrovascular generation, and ameliorating neuroinflammation.
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A new glucose-responsive polymer made from carbopol and 3-phenylboronic acid was developed with condensation reaction. The resulting polymer possesses a pKa of 6.86 ± 0.38 at a proper feedstock ratio ...of 1:2 (
w
/
w
), which approached the physiological pH. The hydrogel made of the corresponding polymer exhibited good features in response to changes of glucose concentration and solution pH value. The sensitive feature of glucose was elevated owing to the addition of ammoniated ZnO nanoparticles, and be related to the structure morphology of hydrogel converted into irregular sheet along with porous structure from initial regular lamellar. Two types of microneedles containing insulin were also made and demonstrated their enough piercing abilities by mechanical compression test. Transdermal release tests of insulin in vitro displayed well responsive release performances, and then the pulsatile releases ensued since glucose concentration alternated between 400 and 100 mg/dL, indicating that the developed micronedle system can realize the controlled release of insulin, i.e. the constructed smart carbopol polymer have potential application in the field of biomedicine.
Protein binding events on RNA are highly related to RNA secondary structure, which affects post-transcriptional regulation and translation. However, it remains challenging to describe the association ...between RNA secondary structure and protein binding events. Here, we present Structure Motif Analysis tool (SMAtool), a pipeline that integrates RNA secondary structure and protein binding site information to profile the binding structure preference of each protein. As an example of applying SMAtool, we extracted the RNA-structure and binding site information respectively from the DMS-seq and eCLIP-seq data of the K562 cell-line, and used SMAtool to analyze the structure motif of each RNA binding protein (RBP). This new approach provided results consistent with X-ray crystallography data from the protein data bank (PDB) database, demonstrating that it can help researchers investigate the structure preference of RBP, and understand the role of RNA secondary structure in gene expression. Availability and implementation: https://github.com/QuKunLab/SMAtool.
•Integrating RNA secondary structure and protein binding site information.•Profiling the RNA structure preference of the binding sites of each RBP.•Providing structure motifs of RBPs in K562 cell-line.•Presenting the role of RNA secondary structure in the process of RBP binding RNA.
A novel calcium-dependent protein kinase gene (designated as IiCPK2) was cloned from tetraploid Isatis indigotica. The full-length cDNA of IiCPK2 was 2585 bp long with an open reading frame (ORF) of ...1878 bp encoding a polypeptide of 625 amino acid residues. The predicted IiCPK2 polypeptide included three domains: a kinase domain, a junction domain (or autoinhibitory region), and a C-terminal calmodulin-like domain (or calcium-binding domain), which presented a typical structure of plant CDPKs. Further analysis of IiCPK2 genomic DNA revealed that it contained 7 exons, 6 introns and the length of most exons was highly conserved. Semi-quantitative RTPCR revealed that the expression of IiCPK2 in root, stem and leaf were much higher in tetraploid sample than that in diploid progenitor. Further expression analysis revealed that gibberellin (GA3), NaCl and cold treatments could upregulate the IiCPK2 transcription. All our findings suggest that IiCPK2 might participate in the cold, high salinity and GA3 responsive pathways.
IPEC Solver is a Windows program designed to analyze the stability of core–shell inter-polyelectrolyte complexes formed by complexation of oppositely charged block copolymers. The two-dimensional ...size distribution of the complexes composed by different numbers of positively or negatively charged polyelectrolytes is calculated based on the scaling model of block copolymer aggregation and Poisson–Boltzmann theory for electrostatic interactions V.A. Baulin, E. Trizac, Self-assembly of spherical inter-polyelectrolyte complexes from oppositely charged polymers, Soft Matter 8 (25) (2012) 6755–6766. Salt effects, charge distribution and distributions of labile cations and anions around the complexes are calculated numerically as a function of chain composition and solvent properties.
Program title: IPEC Solver
Catalogue identifier: AEPM_v1_0
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEPM_v1_0.html
Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland
Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html
No. of lines in distributed program, including test data, etc.: 53802
No. of bytes in distributed program, including test data, etc.: 4582576
Distribution format: tar.gz
Programming language: C++ (VS.10)
Computer: PC
Operating system: WinXP, Win7
Has the code been vectorized or parallelized?: Supports parallel computation through OpenMP
RAM: 1 GB
Classification: 16.11
Nature of problem:
This free software is designed to illustrate physical mechanisms of self-assembly of inter-polyelectrolyte complexes in the presence of salt. It can suggest an optimal structure of the aggregates as a function of the structure of block copolymers.
Solution method:
The distribution of the complexes composed by a different number of positively or negatively charged polyelectrolytes is calculated based on a scaling model of block copolymer aggregation and Poisson–Boltzmann theory for electrostatic interactions V.A. Baulin, E. Trizac, Self-assembly of spherical inter-polyelectrolyte complexes from oppositely charged polymers, Soft Matter, 8 (25) (2012) 6755–6766. Salt effects, charge distribution and distributions of labile ions around the complexes are provided.
Restrictions:
IPEC complex is assumed to have a core–shell structure: a spherical core containing charged polymers is surrounded by a neutral corona. To insure stability of the solution, salt concentration, ka>0.2
Additional comments:
Solves the Poisson–Boltzmann equation in a broad range of parameters.
Running time:
From seconds to several hours.
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