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  • Author: Dan Liu x
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Statistical inference for microarray experiments usually involves the estimation of error variance for each gene. Because the sample size available for each gene is often low, the usual unbiased estimator of the error variance can be unreliable. Shrinkage methods, including empirical Bayes approaches that borrow information across genes to produce more stable estimates, have been developed in recent years. Because the same microarray platform is often used for at least several experiments to study similar biological systems, there is an opportunity to improve variance estimation further by borrowing information not only across genes but also across experiments. We propose a lognormal model for error variances that involves random gene effects and random experiment effects. Based on the model, we develop an empirical Bayes estimator of the error variance for each combination of gene and experiment and call this estimator BAGE because information is Borrowed Across Genes and Experiments. A permutation strategy is used to make inference about the differential expression status of each gene. Simulation studies with data generated from different probability models and real microarray data show that our method outperforms existing approaches.

Solubilities are measured for natural tocopherols and fatty acid methyl esters(FAMEs) under partly isothermal, isobaric and isochoric conditions in the range of temperature of 40-60deg.C and pressure of 9.7-16.2MPa based on soybean de-odorizer(DOD) pretreatment, the separation factors between FAMEs and tocopherols are 3.1-5.4 in this study. Furthermore, three different technology projects are analyzed qualitatively and quantitatively of single column extraction (SCE), extraction and fractionation (EF), two-column extraction (TCE).

Abstract

1-dodecylamine hydrobromide was synthesized. The crystal structure of the compound was determined by X-ray crystallography. Low-temperature heat capacities of the title compound were measured by an adiabatic calorimeter over the temperature range from 78 to 390 K. Three solid–solid phase transitions were observed at the peak temperatures of (329.278±0.234), (337.805±0.326), and (347.371±0.154) K. The molar enthalpies and entropies of the three phase transitions of the substance were calculated based on the analysis of heat capacity curves. Experimental values of heat capacities for the title compound were fitted to two polynomial equations. Three solid–solid phase transitions and a melting process of 1-dodecylamine hydrobromide were verified by DSC technique. In addition, the reversibility and repeatability of the three phase transitions were discussed.

Abstract

Synchrotron infrared (IR) and micro-Raman spectroscopic studies have been performed on zeolite natrolites as a function of the non-framework composition at ambient conditions. This establishes the spectroscopic characterization of the ion-exchanged natrolites in the alkali-metal series both in the as-prepared hydrated (M-NAT-hyd, M = Li, Na, K, Rb, and Cs) and some stable dehydrated forms (MNAT- deh, M = Rb and Cs). The former series exhibits non-framework cation-size dependent opening of the helical channels to span ca. 21° range in terms of the chain rotation angle, ψ (or ca. 45° range in terms of the chain bridging angle, T-O2-T). For these hydrated phases, both IR and Raman spectra reveal that the degree of the red-shifts in the frequencies of the helical 8-ring channel as well as the 4-ring unit is proportional to the ionic radius of the non-framework cations. Linear fits to the data show negative slopes of -55.7 from Raman and -18.3 from IR in the 8-ring frequencies and ionic radius relationship. The spectroscopic data are also used to identify the modes of the dehydration-induced “collapse” of the helical 8-ring channels as observed in the stable anhydrous Rb-NAT-deh and Cs- NAT-deh. In addition, we demonstrate that the spectroscopic data in the hydrated series can be used to distinguish different water arrangements along the helical channels based on the frequency shifts in the H-O-H bending band and the changes in the O-H stretching vibration modes.

Abstract

Objective: To identify the common sites and risk factors of community-associated infections in Chinese patients with diabetes. Materials and Methods: The Wanfang, CNKI, PUBMED and VIP databases restricting to Chinese patients with diabetes were queried without restriction to time period. Randomized controlled trials (RCTs) on the risk factors of community-associated infections in Chinese patients with diabetes were considered. Polled odd ratios (OR) and 95% confidence intervals (95% CI) were used for each factor in fixed or random-effect metaanalyses. Results: Twelve studies were identified that investigated seven risk factors of community-associated infections in Chinese patients with diabetes. The average infection incidence was 39.55%. The respiratory tract and urology tract were the predilection sites. Meta-analysis results are as follows: Diabetic patients with chronic complications (OR: 1.63; 95% CI 1.45-1.82), advanced age (OR: 1.30; 95% CI 1.19-1.42), longer duration (OR: 1.47; 95% CI 1.35-1.61) or ketoacidosis (OR: 1.37; 95% CI 1.13-1.66) were more prone to suffer from infections. Those with better glycemic control (OR: 0.68; 95% CI 0.61-0.76) or males (OR: 0.69; 95% CI 0.64-0.75) were less prone to suffer from infections. Conclusion: Chinese patients with diabetes had a high incidence of community-associated infections. We should highlight the risk factors that might provide a reference for the same.

Abstract

A linkage map for Betula platyphylla Suk was constructed based on RAPD, ISSR, AFLP and SSR markers by a pseudo-testcross mapping strategy. A F1 segregating population including 80 progenies was obtained from the cross between two superior trees selected from Qinghai and Wangqing provenance, respectively. The paternal map was constructed with 282 markers consisting of 14 major and 15 minor (5 triplets and 10 doublets) linkage groups and spanning 1131 cM at an average distance of 4.0 cM between adjacent markers. The maternal map has 277 markers consisting of 15 major and 8 minor (5 triplets and 3 doublets) groups covering 1288 cM at an average distance of 4.6 cM between adjacent markers. In the same pedigree we investigated association of genetic markers with seedling stem height and circumference. The composite interval mapping was used to detect the number of quantitative trait loci and their position on the genetic linkage maps. Three QTLs (one on the male map and two on the female map) were found explaining 13.4%, 17.5% and 18.8% of the trait variation, respectively.