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Leaf spotting diseases commonly occur on spring wheat crops grown in Saskatchewan, causing yield losses of up to 15%, although greater losses have been documented during severe epidemics. In the past decade, Fusarium head blight (FHB) has become a major concern for growers resulting in extensive use of fungicide to mitigate the disease. The optimal fungicide timing for leaf spot control is generally at the flag-leaf stage, while the optimal timing for FHB is during anthesis. The objective of this study was to determine whether applying fungicide at anthesis timing can provide adequate control of leaf spots when compared to application at flag-leaf stage. Fungicide treatments applied at flag-leaf, anthesis, and both growth stages were evaluated on the cv. Carberry. Prothioconazole + tebuconazole and tebuconazole (only) applied at anthesis provided adequate control of leaf spots, although the severity of leaf diseases was slightly higher in this treatment than application at flag-leaf stage but yields were similar. Test weight and thousand kernel weight were improved with the application at anthesis relative to that at flag-leaf stage. Two applications of fungicide provided only a small incremental benefit to the anthesis application, and would not be economically justified in western Canada at this time. Anthesis fungicide application provided adequate leaf spot disease control and is the optimum timing for the control of FHB. [ABSTRACT FROM AUTHOR]

Wastewater treatment and recycling for offshore oilfield can bring economic and social benefits. This paper produced wastewater treatment and recycling technological process for offshore oilfield combining with engineering practice. Considering the complexity of internal flow in disc separator, VOF model and RNG k-ε turbulence model were used to numerically simulate the process of separating oil-water in the separator then the law of distribution and the efficiency of separating oil-water such as flow velocity, pressure, turbulent kinetic energy, turbulent flow, laminar flow and so on were obtained. The discrete phase model (DPM) was used to simulate the motion of particles, then obtained the motion process and separation efficiency of discrete phase particles. The test results show that, the separation efficiency of the calculation and actual measurements both meet the design requirements with the separation efficiency calculated slightly higher than that in the actual measurements. The relative error of oil-water separation efficiency and particle separation efficiency are 1.5% and 1.4% respectively. The data indicate that the numerical simulation method is reliable for predicting the separation performance of the separator, so wastewater treatment and recycling technological process meet the requirements of engineering application. [ABSTRACT FROM AUTHOR]

Concurrent chemoradiotherapy (CRT) with/without induction chemotherapy has been the standard therapy (ST) for locally advanced nasopharyngeal carcinoma (LA-NPC). However, most patients supporting these clinical trials were younger than 65 years of age. For the toxicity of CRT and the poor tolerance of elderly patients, it is still controversial whether ST could bring the most promising survival benefits for elderly NPC compared with individualized therapy (IT). Thus, in this real-world study we compared the survival and safety of ST with IT in elderly LA-NPC to explore an effective and tolerable treatment strategy for elderly LA-NPC. A total of 109 newly diagnosed elderly LA-NPC (>65 years old) from Jan. 2013-Jul. 2020 were retrospectively enrolled and divided into the ST group and IT group according to the original treatment tendency. ST refers to CRT with/without induction chemotherapy. IT group included patients not suitable for CRT and were given individualized treatment fully discussed by at least two oncologists from our head and neck team. A 1:1 propensity score matching (PSM) generated a matched cohort of ST and IT. The survivals and treatment related toxicities were compared between the two groups. There were 46 cases in the ST group and 63 cases in the IT group. The 5-year overall survival (OS) rate, cancer-specific survival (CSS) rate, progression- free survival (PFS) rate, local recurrence-free survival (LRFS) rate and distant metastasis-free survival (DMFS) rate were 68.64%, 76.42%, 73.69%, 85.67% and 86.82%, respectively. By 1:1PSM, 35 cases in each group were matched. No significant differences of OS, CSS, PFS, LRFS and DMFS were found between ST and IT groups in the PSM-matched cohorts (P = 0.87, P = 0.79, P = 0.51, P = 0.81 and P = 0.24, respectively). Compared with patients in the ST group, cases received IT were associated with less severe acute toxicities including anemia, leucopenia, neutropenia, and thrombocytopenia. For elderly LA-NPC, IT had similar survivals while less severe toxicities compared with ST, which revolutionarily challenged the role of ST for elderly LA-NPC. In the future, more studies are need to explore a less toxic treatment modality with noninferior efficacy for elderly LA-NPC. [ABSTRACT FROM AUTHOR]

In this study a model based on the Bouc-Wen-Baber-Noori (BWBN) method was proposed to describe the distorted hysteretic behaviour of a self-constructed magneto-rheological (MR) damper whose mechanical performance was measured with an Instron test machine. The experimental results indicated that the MR damper exhibited a force-lag phenomenon. The parameters of the modified BWBN model were identified with the MATLAB SIMULINK Design and Optimisation toolbox. A comparison between the experimental results and modelling predictions revealed that the proposed model could well present the force-lag phenomenon. [ABSTRACT FROM AUTHOR]

Abstract: This study explored an effective method for repairing cranio-maxillofacial soft-tissue defects following radical craniofacial surgery in four patients with malignant tumours involving the skull base and frontal region. The large cranio-maxillofacial soft-tissue defects were reconstructed using an extended vertical lower trapezius island myocutaneous flap based on the transverse cervical artery. The flap was 8–12cm long and 5–7cm wide. No major flap failure occurred, and there was no shoulder dysfunction. The patients were followed for 3–12 months. One patient suffered a local recurrence, and another died of lung metastasis 12 months postoperatively. The extended vertical lower trapezius island myocutaneous flap is a simple, reliable and large flap. It is preferred for reconstructing cranio-maxillofacial soft-tissue defects when a pedicled flap is used following craniofacial surgery for cancer. [Copyright &y& Elsevier]

Based on investigations of metal–insulator transition temperature Tm on La2/3(Ca1−x′Srx′−x″Bax″)1/3MnO3, we point out that considerations based only on the mismatch effect or the strain-field effect cannot provide a reasonable description for the experimental observations. Including two contributions arising from the average A-cation size (〈rA〉) and the strain-field effect defined by a quantity S=〈(rA0−rA)2〉 gives Tm varying as Tm=Tm(〈rA〉,0)−pS, where Tm(〈rA〉,0) is the transition temperature in the absence of the strain-field effect and the parameter p is estimated to be ∼1.05×106 K nm−2. It is shown that the strain-corrected Tm shows a behavior expected by the double-exchange mechanism which monotonously increases towards ∼500 K with increasing 〈rA〉 towards rA0 (the A-cation size of an ideal cubic perovskite). [Copyright &y& Elsevier]

Naturally occurring N-glycoproteins exhibit glycoform heterogeneity with respect to N-glycan sequon occupancy (macroheterogeneity) and glycan structure (microheterogeneity). However, access to well-defined glycoproteins is always important for both basic research and therapeutic purposes. As a result, there has been a substantial effort to identify and understand the catalytic properties of N-glycosyltransferases, enzymes that install the first glycan on the protein chain. In this study we found that ApNGT, a newly discovered cytoplasmic N-glycosyltransferase from Actinobacillus pleuropneumoniae, has strict selectivitytowardthe residuesaroundtheAsnofN-glycosylation sequon by screening a small library of synthetic peptides. The inherent stringency was subsequently demonstrated to be closely associated with a critical residue (Gln-469) of ApNGT which we propose hinders the access of bulky residues surrounding the occupied Asn into the active site. Site-saturated mutagenesis revealed that the introduction of small hydrophobic residues at the site cannot only weaken the stringency of ApNGT but can also contribute to enormous improvement of glycosylation efficiency against both short peptides and proteins. We then employed the most efficient mutant (Q469A) other than the wild-type ApNGT to produce a homogeneous glycoprotein carrying multiple (up to 10) N-glycans, demonstrating that this construct is a promising biocatalyst for potentially addressing the issue of macroheterogeneity in glycoprotein preparation. [ABSTRACT FROM AUTHOR]

This work demonstrated the high efficiency of a sub-milligram-synthesis based medicinal chemistry method. Totally 72 compounds, consisting a tri-substituted pyrrolidine core, were prepared. Around 0.1 mg of each compound was solid-phase synthesized. Based on the additive property of UV absorptions of unconjugated chromophores of a molecule, these compounds were quantified by UV measurement. A hit, whose IC 50 value was 1.2 μM in HDAC11 inhibition assays, highlights the applicability of the approach reported here in future optimization works. [ABSTRACT FROM AUTHOR]

β1–3- N -Acetylglucosaminyltransferases (β3GlcNAcTs) and β1–4-galactosyltransferases (β4GalTs) have been broadly used in enzymatic synthesis of N -acetyllactosamine (LacNAc)-containing oligosaccharides and glycoconjugates including poly-LacNAc, and lacto- N -neotetraose (LNnT) found in the milk of human and other mammals. In order to explore oligosaccharides and derivatives that can be synthesized by the combination of β3GlcNAcTs and β4GalTs, donor substrate specificity studies of two bacterial β3GlcNAcTs from Helicobacter pylori (Hpβ3GlcNAcT) and Neisseria meningitidis (NmLgtA), respectively, using a library of 39 sugar nucleotides were carried out. The two β3GlcNAcTs have complementary donor substrate promiscuity and 13 different trisaccharides were produced. They were used to investigate the acceptor substrate specificities of three β4GalTs from Neisseria meningitidis (NmLgtB), Helicobacter pylori (Hpβ4GalT), and bovine (Bβ4GalT), respectively. Ten of the 13 trisaccharides were shown to be tolerable acceptors for at least one of these β4GalTs. The application of NmLgtA in one-pot multienzyme (OPME) synthesis of two trisaccharides including GalNAcβ1–3Galβ1–4GlcβProN 3 and Galβ1–3Galβ1–4Glc was demonstrated. The study provides important information for using these glycosyltransferases as powerful catalysts in enzymatic and chemoenzymatic syntheses of oligosaccharides and derivatives which can be useful probes and reagents. [ABSTRACT FROM AUTHOR]

Probenecid has been used for decades to treat gout, and recent studies have revealed it is also a specific inhibitor of the pannexin-1 channel. It has been reported that the pannexin-1 channel is involved in ischemic injury. Here, we investigated the neuroprotective effect and the possible mechanisms of action of probenecid in global cerebral ischemia/reperfusion (I/R) injury in rats. Twenty minutes of transient global cerebral I/R injury was induced using the four-vessel occlusion (4-VO) method in male Sprague–Dawley rats. Different doses of probenecid were administered intravenously, intraperitoneally, or by gavage before or after reperfusion. Probenecid via all three routes protected against CA1 neuronal death when given before reperfusion. This protective effect continued when probenecid was given at 2 h after reperfusion, but not at 6 h. Interestingly, the protective effect regained if probenecid was given continuously for 7 days after reperfusion. The release of cathepsin B and overexpression of calpain-1 after reperfusion were inhibited, while the upregulation of Hsp70 was strengthened by probenecid pre-treatment. Furthermore, the activation and proliferation of microglia and astrocytes after I/R injury were suppressed by continuous given for 7 days, but only partly by a single dose at 6 h of reperfusion. Thus, our data indicate that probenecid protects against transient global cerebral I/R injury probably by inhibiting calpain–cathepsin pathway and the inflammatory reaction. [ABSTRACT FROM AUTHOR]

Human milk oligosaccharides (HMOs) are a family of structurally diverse unconjugated glycans that exhibit a wide range of biological activities. In this report, we describe an efficient, Multi-Enzyme One-Pot strategy to produce HMO mimics by the sialylation of galacto-oligosaccharides (GOSs), which are often added to infant formula as an inexpensive alternative to HMOs. In this system, the sialyltransferase donor, cytidine-5′-monophospho-N-acetylneuraminic acid (CMP-Neu5Ac), was generated in situ using a CMP-sialic acid synthetase. The sialylated GOSs were obtained by one-step purification after digesting CMP using the alkaline phosphatase PhoA to cytidine and inorganic phosphate. Although the synthesized α2,3-, α2,6- and α2,3/8-sialyl-GOSs exhibit different sialylation levels and patterns, all of these mixtures can be fermented by Bifidobacterium longum subsp. infantis ATCC 15697 but not by Bifidobacterium adolescentis ATCC 15703. The sialidase NanH2, which is unique to the former strain, hydrolyzed all of the synthesized HMO mimics. [ABSTRACT FROM AUTHOR]

Uridine 5′-diphosphate-glucuronic acid (UDP-GlcA) and UDP-galacturonic acid (UDP-GalA), the unique carboxylic acid-formed sugar nucleotides, are key precursors involved in the biosynthesis of numerous cell components. Limited availability of those components has been hindering the development of efficient ways towards facile synthesis of bioactive glycans such as glycosaminoglycans. In current study, we biochemically characterized two UDP-sugar pyrophosphorylases from Arabidopsis thaliana (AtUSP) and Bifidobacterium infantis ATCC15697 (BiUSP), and compared their activities towards a panel of sugar-1-phosphates and derivatives. Both enzymes showed significant pyrophosphorylation activities towards GlcA-1-phosphate, and AtUSP also exhibited comparable activity towards GalA-1-phosphate. By combining with monosaccharide-1-phosphate kinases, we have developed an efficient and facile one-pot three-enzyme approach to quickly obtain hundreds milligrams of UDP-GlcA and UDP-GalA. [ABSTRACT FROM AUTHOR]

Among 18 human histone deacetylases (HDAC), HDAC11 is least studied. MS275, a benzamide HDAC inhibitor (HDACi), was stereotypically considered to selectively target Class I HDACs. We verified this slow-binding inhibitor also targeted HDAC11. In a traditional enzyme based assay, MS275 at low concentrations surprisingly behaved as an agonist. This was attributed to the poor stability of HDAC11 which lost 40% activity in 3 h at 37 °C. By adding 0.2 μM SAHA, HDAC11 activity was stabilized during the 3-h assay period. Since 0.2 μM SAHA inhibited 50% HDAC11 activity, the apparent IC 50 ′ of MS275 was adjusted to the true IC 50 = 0.65 μM. Finally, the new method demonstrated its superiority in one-dose-screening assays by decreasing false negative results. This work highlighted an optimized strategy to assay slow-binding inhibitors of unstable proteins with known fast-binding inhibitors. It should be especially useful in a hit-discovery stage to find moderate potent compounds. [ABSTRACT FROM AUTHOR]

Oligosaccharyltransferases (OTases) are enzymes that catalyze the transfer of an oligosaccharide from a lipid carrier to an acceptor molecule, commonly a protein. OTases are classified as N-OTases and O-OTases, depending on the nature of the glycosylation reaction. The N-OTases catalyze the glycan transfer to amide groups in asparagines in a reaction named N-linked glycosylation. The O-OTases are responsible for protein O-linked glycosylation, which involves the attachment of glycans to hydroxyl groups of serine or threonine residues. These enzymes exhibit a relaxed specificity and are able to transfer a variety of glycan structures to different protein acceptors. This property confers OTases with great biotechnological potential as these enzymes can produce glycoconjugates relevant to the pharmaceutical industry. Furthermore, OTases are thought to be involved in pathogenesis mechanisms. Several aspects of the functionality of OTases are not fully understood. In this work, we developed a novel approach to perform kinetic studies on PglL, the O-OTase from Neisseria meningitidis. We investigated the importance of the acyl moiety of the lipid glycan donor substrate on the functionality of PglL by testing the efficiency of glycosylation reactions using synthetic substrates carrying the same glycan structure but different acyl moieties. We found that PglL can function with many lipids as glycan donors, although the length and the conformation of the lipid moiety significantly influenced the catalytic efficiency. Interestingly, PglL was also able to transfer a monosaccharide employing its nucleotide-activated form, acting as a Leloir glycosyltransferase. These results provide new insights on the function and the evolution of oligosaccharyltransferases. [ABSTRACT FROM AUTHOR]

The WaaL-mediated ligation of O-antigen onto the core region of the lipid A-core block is an important step in the lipopolysaccharide (LPS) biosynthetic pathway. Although the LPS biosynthesis has been largely characterized, only a limited amount of in vitro biochemical evidence has been established for the ligation reaction. Such limitations have primarily resulted from the barriers in purifying WaaL homologues and obtaining chemically defined substrates. Accordingly, we describe herein a chemical biology approach that enabled the reconstitution of this ligation reaction. The O-antigen repeating unit (O-unit) of Escherichia coli O86 was first enzymatically assembled via sequential enzymatic glycosylation of a chemically synthesized GalNAc-pyrophosphate-undecaprenyl precursor. Subsequent expression of WaaL through use of a chaperone co-expression system then enabled the demonstration of the in vitro ligation between the synthesized donor (O-unit-pyrophosphate-undecaprenyl) and the isolated lipid A-core acceptor. The previously reported ATP and divalent metal cation dependence were not observed using this system. Further analyses of other donor substrates revealed that WaaL possesses a highly relaxed specificity toward both the lipid moiety and the glycan moiety of the donor. Lastly, three conserved amino acid residues identified by sequence alignment were found essential for the WaaL activity. Taken together, the present work represents an in vitro systematic investigation of the WaaL function using a chemical biology approach, providing a system that could facilitate the elucidation of the mechanism of WaaL-catalyzed ligation reaction. [ABSTRACT FROM AUTHOR]

Abstract: Calf thymus DNA (ctDNA) has been shown to stimulate macrophages to produce cytokines both in vitro and in vivo when complexed with cationic liposomes. In addition, direct cytotoxicity of ctDNA has been found in tissue culture and in mice. In this study, ctDNA and folate receptor targeted cationic liposome complexes (ctDNA-F-CLs) were prepared and evaluated in FR (+) tumors. In addition, the underlying mechanism for the anti-cancer activity of ctDNA-F-CLs was investigated. Selective uptake of ctDNA-F-CLs was observed in FR (+) KB and L1210JF cells using flow cytometry. In RAW264.7 cells and DBA/2 mice, ctDNA-F-CLs and ctDNA-N-CLs significantly induced TNF-α and IL-6 production compared to free ctDNA. However, no significant difference in cytokine production was observed between ctDNA-N-CLs and ctDNA-F-CLs. In tumor bearing DBA/2 mice, ctDNA-F-CLs significantly increased INF-γ and IL-6 production compared to ctDNA-N-CLs. Furthermore in L1210JF cells, ctDNA-F-CLs had significantly increased cytotoxicity compared to ctDNA-N-CLs. Tumor cell apoptosis was also found in co-culture of RAW264.7 cells and ctDNA-F-CLs treated L1210JF cells. In L1210JF tumor bearing mice, ctDNA-F-CLs were found to significantly inhibit tumor growth and prolong the median survival time (MeST). In contrast, ctDNA-N-CLs and free ctDNA showed similar activities for tumor inhibition and animal survival. Moreover, the anti-cancer effect of ctDNA-F-CL was further enhanced by combination with anti-cancer drug doxorubicin. These results suggest that ctDNA-F-CLs are a promising agent for treatment of FR-positive tumors. [Copyright &y& Elsevier]

Abstract: It is well known that the saccharides forming the intricate sugar coat that surrounds the cells play important biological roles in intercellular communication and cell differentiation. Therefore, it is worthwhile developing saccharide-based hydrogels for cell culture study. In this study, three novel saccharide-based compounds were designed and synthesized. It was found that one of them could form hydrogels efficiently, while the other two precipitated from water. The stability of the resulting hydrogel was tested, and the supramolecular nanofiber with fiber diameters in the range of 80–300nm was characterized as the structural element by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fluorescence microscopy revealed that extensive hydrogen bonds between sugar rings assisted the formation of efficient π–π stacking between aromatic naphthalene groups, thus resulting in the formation of a stable hydrogel in aqueous solution. When the gel was applied for mouse embryonic fibroblast (NIH 3T3), human hepatocellular carcinoma (HepG2), AD293 and HeLa cells culture in two dimensional environments, all of them showed a very good adhesion and good proliferation rate on the top of the hydrogel. These results indicates that the biocompatible hydrogel reported here has a potential to be developed into useful materials for in vitro cell culture, drug delivery, and tissue engineering. [Copyright &y& Elsevier]

Abstract: Herein we report the practical chemo enzymatic synthesis of trisaccharide and derivatives of iGb3 and Gb3, and a novel purification process using immobilized yeast to remove the monosaccharide from the reaction mixture. High purity oligosaccharide compounds were achieved in large scale. This study represents a facile enzymatic synthesis of and novel purification process of oligosaccharide. [Copyright &y& Elsevier]

Abstract: When iNKT cells are stimulated by the CD1d presented exogenous α-galactosylceramide, a myriad of cytokines are released that trigger a variety of immune responses. However, the invisibility and poor aqueous solubility of α-galactosylceramide during bioassays have rendered it difficult to study the aforementioned biological responses. Accordingly, a biotin-labelled α-galactosylceramide was prepared to facilitate detection of this antigen in the immune process. The problematic low solubility was also remedies via incorporation of a truncated acyl chain. [Copyright &y& Elsevier]

Abstract: Activation of innate immunity is critical for vaccine development and immunotherapy, through triggering antigen specific immune responses. Natural killer T (NKT) cells are a unique type of innate immune cells which exert potent anti-viral and anti-metastasis function, through producing interferon-γ and activating dendritic cells to present tumor antigens to CD8 T cells. alpha-Galactosylceramide, a synthetic antigen for NKT cells, is an adjuvant for protein antigens which can induce protective immunity against cancer and viral diseases, and has been proven to be safe and immune stimulatory in human cancer and hepatitis patients. Current existing problem for alpha-galactosylceramide is its induction of anergy of NKT cells, due to the non-selective presentation of alpha-galactosylceramide antigen by B cells. We hypothesized that nanoparticle formulated alpha-galactosylceramide may be selectively presented by dendritic cells and macrophages, but not B cells, thus avoiding anergy induction in NKT cells. We have prepared poly-lactic acid based nanoparticles conjugated with alpha-galactosylceramide, examined their stimulation of NKT cells in vitro and in vivo in mice, and showed that nanoparticle formulated alpha-galactosylceramide stimulates NKT cells. In contrast to soluble alpha-galactosylceramide, which caused NKT anergy after single stimulation, nanoparticle formulated alpha-galactosylceramide repeatedly stimulates NKT cells without inducing anergy. Mechanistic studies showed that nanoparticle formulated alpha-galactosylceramide is efficiently presented by mouse CD11c+population containing dendritic cells, and CD11b+population containing macrophages, but very poorly by B220+population containing B cells. Hence, nanoparticle formulated alpha-galactosylceramide is an attractive immunomodulator for immunotherapy and vaccine development. Future studies will be focused on its application as adjuvant for protein and/or peptide antigens. [Copyright &y& Elsevier]

Abstract: Valproic acid (VPA), a widely prescribed drug for seizures and bipolar disorder, has been shown to be an inhibitor of histone deacetylase (HDAC). Our previous study has demonstrated that VPA pretreatment reduces lipopolysaccharide (LPS)-induced dopaminergic (DA) neurotoxicity through the inhibition of microglia over-activation. The aim of this study was to determine the mechanism underlying VPA-induced attenuation of microglia over-activation using rodent primary neuron/glia or enriched glia cultures. Other histone deacetylase inhibitors (HDACIs) were compared with VPA for their effects on microglial activity. We found that VPA induced apoptosis of microglia cells in a time- and concentration-dependent manner. VPA-treated microglial cells showed typical apoptotic hallmarks including phosphatidylserine externalization, chromatin condensation and DNA fragmentation. Further studies revealed that trichostatin A (TSA) and sodium butyrate (SB), two structurally dissimilar HDACIs, also induced microglial apoptosis. The apoptosis of microglia was accompanied by the disruption of mitochondrial membrane potential and the enhancement of acetylation levels of the histone H3 protein. Moreover, pretreatment with SB or TSA caused a robust decrease in LPS-induced pro-inflammatory responses and protected DA neurons from damage in mesencephalic neuron–glia cultures. Taken together, our results shed light on a novel mechanism whereby HDACIs induce neuroprotection and underscore the potential utility of HDACIs in preventing inflammation-related neurodegenerative disorders such as Parkinson’s disease. [Copyright &y& Elsevier]