Synthesis,antifungal activity and in vitro mechanism of novel 1-substituted-5-trifluoromethyl-1H-pyrazole-4-carboxamide derivatives

Inspired by the wide application of amides in plant pathogens, a series of novel 1-substituted-5-trifluoromethyl?1H?pyrazole-4-carboxamide derivatives were designed and synthesized. Bioassay results indicated that some target compounds exhibited excellent and broad-spectrum in vitro and certain in vivo antifungal activities. Among them, the in vitro EC₅₀ values of Y₁₃ against G. zeae, B. dothidea, F. prolifeatum and F. oxysporum were 13.1, 14.4, 13.3 and 21.4 mg/L, respectively. The in vivo protective activity of Y₁₃ against G. zeae at 100 mg/L was 50.65%. SAR analysis revealed that the phenyl on the 1-position of the pyrazole ring was important for this activity. An antifungal mechanism study of Y₁₃ against G. zeae demonstrated that this compound may disrupt the cell membrane of mycelium, thus inhibiting the growth of fungi. These mechanistic study results were inconsistent with those for traditional amides and may provide a novel view for deep study of this series of pyrazole carboxamide derivatives.     

Structural, spectral and thermal studies of substituted N-(2-pyridyl)-N′-phenylthioureas

N-2-(3-picolyl)-N′-phenylthiourea, 3PicTuPh, monoclinic, P2₁/n, a=7.617(2) b=7.197(5), c=22.889(5) Å, β=94.63(4)°, V=1250.7(1) Å³ and Z=4; N-2-(4-picolyl)-N′-phenylthiourea, 4PicTuPh, triclinic, P-1, a=7.3960(5), b=7.9660(12), c=21.600(3) Å, α=86.401(4), β=84.899(8), γ=77.769(8)°, V=1237.5(3) Å³ and Z=4; N-2-(5-picolyl)-N′-phenylthiourea, 5PicTuPh, monoclinic, P2₁/c, a=14.201(1), b=4.905(3), c=17.689(3) Å, β=91.38(1)°, V=1231.8(7) Å³ and Z=4; N-2-(6-picolyl)-N′-phenylthiourea, 6PicTuPh, monoclinic, C2/c2, a=14.713(1), b=9.367(1), c=18.227(1) Å, β=92.88(1)°, V=2515.5(1) Å³ and Z=8 and N-2-(4,6-lutidyl)-N′-phenylthiourea, 4,6LutTuPh, monoclinic, C2/c, a=11.107(2), b=11.793(2), c=20.084(4) Å, β=96.10(3)°, V=2616(1) Å³ and Z=8. Intramolecular hydrogen bonding between N′H and the pyridyl nitrogen and intermolecular hydrogen bonding involving the thione sulfur are affected by substitution of the pyridine ring, as is the planarity of the molecule. ¹H NMR studies in CDCl₃ show the NH′ hydrogen resonance considerably downfield from other resonances in the spectrum for each thiourea.     

Enthalpies of solution of <Emphasis Type="Italic">n</Emphasis>-alkanes in mixtures of MeCN with alkan-1-ols at 298.15 K. Relations between the thermodynamic properties of binary and ternary systems

The solution enthalpies of n-hexane, n-nonane, and n-undecane in mixtures of MeCN with EtOH, PrOH, and BuOH were determined by calorimetric method at 298.15 K. Relations between the thermodynamic properties of ternary systems and the properties of the binary solvents and the solute are discussed. To predict the enthalpies of solution of hydrocarbons in mixed solvents whose components have strongly different molar volumes (V ₂/V ₁ > 1.5), it is proposed to use the values that are additive in the volume fraction scale. The solution enthalpies of hydrocarbons in mixtures characterized by close molar volumes of the components strongly depend on the excess properties of the binary solvent.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1578–1582, August, 2004.     

Inter-laboratory validation of the fluorescent protein phosphatase inhibition assay to determine diarrhetic shellfish toxins: intercomparison with liquid chromatography and mouse bioassay

Toxic episodes of diarrhetic shellfish toxins (DSP) in shellfish harvesting areas have serious economic and public health implications, where fluorescent protein phosphatase inhibition assay (FPPIA) may be a highly useful tool for monitoring purposes. This paper presents results from the first inter-laboratory study to validate the assay. Three laboratories participated in the design and development of the inter-laboratory work. Standard solutions and spiked samples of the main toxin, okadaic acid, were used at the beginning of the validation exercise to avoid cross-inhibition of other toxins that would otherwise deteriorate the quantitative significance of the data. HPLC with fluorimetric detection of okadaic acid was also submitted to inter-laboratory validation to be subsequently used as a quantitative reference method. FPPIA results from spiked samples were free of systematic bias in any laboratory and determinations repeated over 3 days showed that the classic “repeatability” was the main within-laboratory source of variability (15-26% R.S.D. depending on the sample).After the inter-laboratory validation of both HPLC and FPPIA methods, 83 samples of mussel hepatopancreas collected during a toxic DSP episode were analyzed over 9 weeks. Toxic levels determined with FPPIA were in line with mouse bioassay results, highlighting the lack of false negative results of the FPPIA test: 98.7% of samples whose concentration of okadaic acid equivalents was over 0.8 μg/g hep., provided positive bioassay results within 24 h of observation time. The reliability and the quantitativeness of the FPPIA method in naturally contaminated samples was demonstrated by intercomparison with mouse bioassay and HPLC.     

Densities and Viscosities of Binary Mixtures of <Emphasis Type="Italic">m</Emphasis>-Cresol with Some Chlorohydrocarbons

Densities and viscosities of the binary mixtures of m-cresol with 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane and tetrachloroethylene were measured at 303.15, 313.15 and 323.15 K. The measured results are used to compute the excess volumes (V^E), deviations in viscosity (Δη) and excess Gibbs energy for activation of flow (ΔG^E). The excess volumes, deviations in viscosity, and Gibbs energies for activation of flow are fitted to a polynomial-type equation suggested by Scharlin et al. [J. Chem. Thermodyn. 34, 927 (2002)] and are discussed in general terms.     

Moderate Deviations for Empirical Measures of Markov Chains: Upper Bounds

We obtain upper bounds for moderate deviations of empirical measures of Markov chains with general state space in the -topology under the minimal assumption of geometric ergodicity. The regeneration-split chain method and a result on projective systems are employed in the proof.     

Variability in road traffic noise levels

Environmental noise levels can vary over a wide range as a result of the diversity of site conditions and activities occurring during field measurements. This variability, extremely important for a correct measurement interpretation, is often a source of disagreement when applying standards and regulations, as there is no consensus about how to estimate and present it. The paper contributes to this technical debate by investigating the statistical variability associated with a large measurement database acquired under field conditions. The database consists of 2 week’s noise recordings at each of 50 separate locations in residential areas affected mainly by road traffic noise. The results show increased variability (standard deviations) at the lower values of either logarithmic or arithmetic mean L_Aeq over the time periods investigated. It is anticipated that the observed relationships may be of assistance when estimating the noise level variability and the uncertainty associated with a noise measurement affected by road traffic or other environmental noise sources.     

Logarithmic Level Comparison for Small Deviation Probabilities

Log-level comparisons of the small deviation probabilities are studied in three different but related settings: Gaussian processes under the L² norm, multiple sums motivated by tensor product of Gaussian processes, and various integrated fractional Brownian motions under the sup-norm. An erratum to this article can be found at     

任意随机变量序列关于随机选择的一类强偏差定理

本文通过引进极限相对对数似然比,利用限制似然比给出了样本空间的一个子集,得到了任意实值随机变量序列关于随机选择的一类用不等式表示的强极限定理.并作为推论得到了任意整值随机变量序列的m元序组的强偏差定理.     

LARGE DEVIATION FOR THE EMPIRICAL CORRELATION COEFFICIENT OF TWO GAUSSIAN RANDOM VARIABLES

In this article,the author obtains the large deviation principles for the empir- ical correlation coefficient of two Gaussian random variables X and Y.Especially,when considering two independent Gaussian random variables X,Y with the means EX. EY (both known),wherein the author gives two kinds of different proofs and gets the same results.