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This study examined the application of slim‐hole nuclear magnetic resonance (NMR) tools to estimate hydraulic conductivity (KNMR) in an unconsolidated aquifer that contains a range of grain sizes (silt to gravel) and high and variable magnetic susceptibilities (MS) (10−4 to 10−2 SI). A K calibration dataset was acquired at 1‐m intervals in three fully screened wells, and compared to KNMR estimates using the Schlumberger‐Doll research (SDR) equation with published empirical constants developed from previous studies in unconsolidated sediments. While KNMR using published constants was within an order of magnitude of K, the agreement, overprediction, or underprediction of KNMR varied with the MS distribution in each well. An examination of the effects of MS on NMR data and site‐specific empirical constants indicated that the exponent on T2ML (n‐value in the SDR equation, representing the diffusion regime) was found to have the greatest influence on KNMR estimation accuracy, while NMR porosity did not improve the prediction of K. KNMR was further improved by integrating an MS log into the NMR analyses. A first approach detrended T2ML for the effects of MS prior to calculating KNMR, and a second approach introduced an MS term into the SDR equation. Both were found to produce similar refinements of KNMR in intervals of elevated MS. This study found that low frequency NMR logging with short echo times shows promise for sites with moderate to elevated MS levels, and recommends a workflow that examines parameter relationships and integrates MS logs into the estimation of KNMR. Article impact statement: Hydraulic conductivity estimates from nuclear magnetic resonance data are refined when using a workflow that integrates magnetic susceptibility logs. [ABSTRACT FROM AUTHOR]

Highly dynamic mitotic spindle microtubules are superb therapeutic targets for a group of chemically diverse and clinically successful anticancer drugs. Microtubule-targeted drugs disrupt microtubule dynamics in distinct ways, and they are primarily classified into two groups: microtubule destabilizing agents (MDAs), such as vinblastine, colchicine, and combretastatin-A4, and microtubule stabilizing agents (MSAs), such as paclitaxel and epothilones. Systematic discovery and development of new MSAs have been aided by extensive research on paclitaxel, yielding a large number of promising anticancer compounds. This review focuses on the natural sources, structural features, mechanisms of action, structure-activity relationship (SAR) and chemical synthesis of MSAs. These MSAs mainly include paclitaxel, taccalonolides, epothilones, FR182877 (cyclostreptin), dictyostatin, discodermolide, eleutherobin and sarcodictyins, zampanolide, dactylolide, laulimalides, peloruside and ceratamines from natural sources, as well as small molecular microtubule stabilizers obtained via chemical synthesis. Then we discuss the application prospect and development of these anticancer compounds. [ABSTRACT FROM AUTHOR]

The lead-free ceramics 0.92Na0.5Bi0.5TiO3-0.06BaTiO3-0.02K0.5Na0.5NbO3and 0.92Na0.5Bi0.5TiO3-0.06BaTiO3-0.02K0.5Na0.5NbO3with the addition of 0.2 wt% Co2O3were prepared by using a solid state reaction method. The ceramics were sintered in O2and N2atmospheres, respectively. The rhombohedral-tetragonal morphotropic phase boundary exists in all samples, with the relative amount of tetragonal phase varying with the sintering atmospheres which does not affect grain size of the ceramics. In the dielectric constant-temperature curves for all samples, two dielectric anomalies appear. The phase transition temperatures and maximum values of dielectric constant are closely related to the sintering atmospheres. The mechanism was also discussed. [ABSTRACT FROM AUTHOR]

The article offers information on a study which evaluates the acaricidal effects of four herbal monomers as experimental medication through in vitro observation, which include measurement of matrine, daphnetin, tuberostemonine.

The regioselective demethylations of two C19-diterpenoid alkaloids, 2 and 3, have been achieved with HBr-HOAc, trimethylsilyl iodide, or BBr3. It was observed that HBr-HOAc is an optimal demethylating agent for these two C19-diterpenoid alkaloids because it could provide different O-demethylation products by using different reaction temperature and reaction time. Especially, 1-O-methyl group in 2 and 3, one of the most difficult ones to be demethylated, could be removed by the treatment with HBr-HOAc at an elevated temperature and a prolonged reaction time. [ABSTRACT FROM AUTHOR]

Based on previous studies about microflora regulation and immunity enhancement activities of polysaccharides from Codonopsis pilosula Nannf. var. modesta (Nannf.) L. T. Shen (CPP), there is little study on intestinal mucosal immunity, which is a possible medium for contacting microflora and immunity. In the present study, the BALB/c mice were divided into five groups (eight mice in each group), including a normal group (Con), a model control group (Model), and model groups that were administered CPP (50, 100, 200 mg/kg/d) orally each day for seven days after intraperitoneal injection of 60 mg/kg BW/d cyclophosphamide (CP) for three days. CPP recovered the spleen index and restored the levels of IFN-γ, IL-2, IL-10, as well as serum IgG. In addition, it elevated ileum secretory immunoglobulin A (sIgA), the number of Lactobacillus and acetic acid content in cecum. These results indicated that CPP plays an important role in the protection against immunosuppression, especially mucosa immune damage, and the inhibition of pathogenic bacteria colonization, which could be considered a potential natural source of immunoregulator. [ABSTRACT FROM AUTHOR]

In an attempt to obtain dense lead metaniobate-based ceramics with improved dielectric and piezoelectric properties, the (Pb1.06−x Ba x )(Nb0.94Ti0.06)2O6 (x = 0, 0.04, 0.08, 0.12) piezoelectric ceramics were prepared separately from the two kinds of calcined powders, i.e., the powders with the rhombohedral phase and orthorhombic phase. For obtaining the calcined powders with the different phases, two different calcination temperatures of 900 °C and 1250 °C were chosen. The calcined powders were characterized using X-ray diffraction, scanning electron microscope, laser particle size analyzer and differential scanning calorimetry. Effects of the phase structures of the calcined powders on crystallite structure, microstructure, dielectric and piezoelectric properties of the ceramics were studied in detail. The lattice parameters and grain size of the ceramics are related to the phase structures of the calcined powders. The doping of Ba2+ has an influence on the dielectric and piezoelectric properties of the ceramics. The ceramics with x = 0.08 fabricated from the calcined powders with the orthorhombic phase demonstrate the optimum dielectric and piezoelectric properties. [ABSTRACT FROM AUTHOR]

Abstract: The ColR–ColS two-component signal transduction system was originally characterized as a regulatory system involved in the capacity of root-colonizing biocontrol bacterium Pseudomonas fluorescens to colonize plant roots. There are three pairs of putative colR–colS two-component regulatory systems annotated in the phytopathogen Xanthomonas campestris pathovar campestris. Mutational studies revealed that one of them, named colRXC1049 and colSXC1050 , is a global regulatory system involved in various cellular processes, including virulence, hypersensitive response and stress tolerance. Growth rate determination showed that, although the colRXC1049 and colSXC1050 mutants are not auxotrophic, colRXC1049 and colSXC1050 are required for the pathogen to proliferate well in standard media and host plants. Assays of β-glucuronidase activities of plasmid-driven promoter-gusA reporters and/or semi-quantitative RT-PCR demonstrated that colRXC1049 and colSXC1050 positively regulate expression of hrpC and hrpE operons, and that expression of colRXC1049 and colSXC1050 is not controlled by key hrp regulators HrpG and HrpX. [Copyright &y& Elsevier]