3,5-Dibromo-4-oxo-2,2,6,6-tetra­methyl­piperidin-1-yl oxide

In the title compound, C9H14Br2NO2, the substituted ring exhibits a chair conformation. A crystallographic mirror plane, passing through the N atom, the O atoms and the C atom in the 4-position, bis­ects the mol­ecule

ELISA and chemiluminescent enzyme immunoassay for sensitive and specific determination of lead (II) in water, food and feed samples

Lead is a heavy metal with increasing public health concerns on its accumulation in the food chain and environment. Immunoassays for the quantitative measurement of environmental heavy metals offer numerous advantages over other traditional methods. ELISA and chemiluminescent enzyme immunoassay (CLEIA), based on the mAb we generated, were developed for the detection of lead (II). In total, 50% inhibitory concentrations (IC50) of lead (II) were 9.4 ng/mL (ELISA) and 1.4 ng/mL (CLEIA); the limits of detection (LOD) were 0.7 ng/mL (ic-ELISA) and 0.1 ng/mL (ic-CLEIA), respectively. Cross-reactivities of the mAb toward other metal ions were less than 0.943%, indicating that the obtained mAb has high sensitivity and specificity. The recovery rates were 82.1%–108.3% (ic-ELISA) and 80.1%–98.8% (ic-CLEIA), respectively. The developed methods are feasible for the determination of trace lead (II) in various samples with high sensitivity, specificity, fastness, simplicity and accuracy.This research was funded by National Natural Science Foundation of China, grant numbers 31572556, 31873006; the Key Program for International S&T Cooperation Project of Shaanxi Province, grant number 2017KW-ZD-10; and the Incubation Project on State Key Laboratory of Biological Resources and Ecological Environment of Qinba Areas, grant number SLGPT2019KF04-04

A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

We established a method on measuring the \dzdzb mixing parameter $y$ for BESIII experiment at the BEPCII $e^+e^-$ collider. In this method, the doubly tagged $\psi(3770) \to D^0 \overline{D^0}$ events, with one $D$ decays to CP-eigenstates and the other $D$ decays semileptonically, are used to reconstruct the signals. Since this analysis requires good $e/\pi$ separation, a likelihood approach, which combines the $dE/dx$, time of flight and the electromagnetic shower detectors information, is used for particle identification. We estimate the sensitivity of the measurement of $y$ to be 0.007 based on a $20fb^{-1}$ fully simulated MC sample.Comment: 6 pages, 7 figure

PMeS: Prediction of Methylation Sites Based on Enhanced Feature Encoding Scheme

Protein methylation is predominantly found on lysine and arginine residues, and carries many important biological functions, including gene regulation and signal transduction. Given their important involvement in gene expression, protein methylation and their regulatory enzymes are implicated in a variety of human disease states such as cancer, coronary heart disease and neurodegenerative disorders. Thus, identification of methylation sites can be very helpful for the drug designs of various related diseases. In this study, we developed a method called PMeS to improve the prediction of protein methylation sites based on an enhanced feature encoding scheme and support vector machine. The enhanced feature encoding scheme was composed of the sparse property coding, normalized van der Waals volume, position weight amino acid composition and accessible surface area. The PMeS achieved a promising performance with a sensitivity of 92.45%, a specificity of 93.18%, an accuracy of 92.82% and a Matthew’s correlation coefficient of 85.69% for arginine as well as a sensitivity of 84.38%, a specificity of 93.94%, an accuracy of 89.16% and a Matthew’s correlation coefficient of 78.68% for lysine in 10-fold cross validation. Compared with other existing methods, the PMeS provides better predictive performance and greater robustness. It can be anticipated that the PMeS might be useful to guide future experiments needed to identify potential methylation sites in proteins of interest. The online service is available at http://bioinfo.ncu.edu.cn/inquiries_PMeS.aspx

Enhancing Abiotic Stress Tolerance in Cereals Through Breeding and Transgenic Interventions

The success of plant breeding in the 20th century led to new cultivars that, to date, have provided enough food for an increasing world population (Conway and Toenniessen 1999; Mifflin 2000). The results of the Green Revolution-led in the 1960s by Henry M. Beachell andNormanE. Dotlaug—resulted in a dramatic increase in rice and wheal grain yields (Milford and Runge 2007; Ortiz et al. 2007). However, abiotic stresses and climate change are becoming increasingly serious threats to crop production worldwide at a time when food staple supply will need to be significantly higher to meet the demand of the growing human population. Water scarcity (Rockstrom et al. 2007], salinity (Rengasamy 2006). and low soil fertility (Sanchez and Swaminathan 2005) rank among the moat important abiotic stresses worldwide. Similarly, increased climatic disturbances due to global warming are causing the major stresses that necessitate crop improvements to safeguard grain supply, particularly in the developing world (Kumar 2006). Hence, genetic enhancement of cereal crops with respect to abiotic stress tolerance will be essential far ensuring grain yields in water-limited, increasingly hotter agricultural zones, particularly If these conditions combine with poor and saline soils, conditions that prevail in parts of the developing world. Crop breeding for adaptation to abiotic stress-prone environments remains a challenging task, not least because of the complexity of the stress-adaptive mechanisms in plants and particularly cereal crops, which are the staple of most of the world's population (Reynolds et al. 2005}

A Dynamic Approach to Measuring China’s Provincial Energy Supply Security along “the Belt and Road”

Using a dynamic model from 2005 to 2015, this study assessed China’s energy supply security in the provinces along “the Belt and Road”. Energy supply security was conceptualized across four dimensions: availability, affordability, acceptability, and energy technology and efficiency. A dynamic model was used to calculate the dynamic weights for each indicator and to examine the variation laws. It was found that the acceptability dimension indicator weights had rapidly increased, indicating that energy supply security had been widely accepted. Smooth weights were found for the availability dimension indicators, indicating that the resources needed to protect basic energy supplies were available. A synthetical energy supply security evaluation index was also analyzed for each “Belt and Road” province using a “quadratic weighting” method, which showed that the index was different in the same provinces in different years and different for different provinces in the same year. For 14 “Belt and Road” provinces, the overall energy supply security was found to have a “V” shape and a general dynamic upward trend, with the trends in the northwest and southeast provinces and along the whole “Belt and Road” found to be consistent. The energy supply security differences between these provinces were analyzed deeply in this paper; it will help us to understand the strengths and weaknesses of energy supply security levels in these provinces. The result will make it easier to cooperate with other provinces or countries along the “Belt and Road” in energy supply

Influence of virgin aggregate content and curing time to performance of emulsion cold recycled asphalt mixtures

Paper presented at the 31st Annual Southern African Transport Conference 9-12 July 2012 "Getting Southern Africa to Work", CSIR International Convention Centre, Pretoria, South Africa.Cold recycling technologies utilizing emulsion as binder demonstrates a number of high environmental advantages and thus it is widely applied worldwide. There are many factors influencing the performance of emulsion recycled asphalt mixture, such as components, curing, aging etc. This study investigates the influence of proportion of virgin aggregate and curing time on the performance of recycled mixture. The mixture formulation design at three levels of virgin aggregate addition (0%, 10% and 20%) and one dosage of cement (1.5%) has been conducted. The performance of emulsion recycled asphalt mixture including splitting failure load, splitting failure strength and Freeze-thaw splitting strength has been measured at four curing times (0 day, 7 days, 14 days and 28 days). The effect of proportion of virgin aggregate and curing time on the performance of recycled mixture has been quantified accordingly. The research has manifested that the increment of the proportion of virgin aggregate and the curing time will enhance the performance of the emulsified asphalt cold recycled mixture up to 26%.This paper was transferred from the original CD ROM created for this conference. The material was published using Adobe Acrobat 10.1.0 Technology. The original CD ROM was produced by Document Transformation Technologies Postal Address: PO Box 560 Irene 0062 South Africa. Tel.: +27 12 667 2074 Fax: +27 12 667 2766 E-mail: nigel@doctech URL: http://www.doctech.co.zadm201

SiCl4-catalyzed/PR3-mediated beta-C(sp(3))-H functionalization of nitrones to alpha,beta-unsaturated imines and aromatic heterocycles

A novel method of SiCl4-catalyzed/PR3-mediated beta-C(sp(3))-H functionalization of nitrones with aldehydes/ketones to alpha,beta-unsaturated imines was developed. The synthesis of 4-unsaturated imines mainly invovles deoxygenation and aldol condensation, each proceeding under a cooperation effect between Lewis acid and Lewis base. In addition, both the acidity and hydrolytic stability of the weak SiCl4 were supposed to be enhanced by coordination with phosphine oxide (R = Et) or phosphoric triamide (R = NMe2) that originated from deoxygenation of nitrones by PR3. In the case of 6-membered nitrone, a [1,3]-hydride shift within the resulted alpha,beta-unsaturated imines renders the aromatization leading to 3,5-dialkylpyridines. (C) 2018 Elsevier Ltd. All rights reserved.</p

Cobalt-catalyzed intermolecular hydroacylation of aldehydes: initiation of hydride transfer enables turnover

Intermolecular hydroacylation of aldehydes catalyzed by an in situ generated low-valent cobalt system was developed. Mechanistic studies disclosed that the desired hydroacylation was impeded by poor hydride donation by the respective Co(III)-H phosphine complex formed by the oxidative addition of Co(I) to the formyl C-H bond. Surprisingly, the reaction rate was significantly promoted in the presence of Lewis base N,N-diisopropylethylamine (iPr(2)NEt) functioning as an initiator of hydride transfer, thereby offering an excellent reaction efficiency with high substrate tolerance