杏仁提取条件的探讨

目的：研究苦杏仁中有效成分苦杏仁苷的最佳提取条件。方法：采用2次重复的正交实验法，以加水倍量，提取时间，提取次数3个因素，每个因素选取3个水平进行实验。结果：因素A（加水倍量）有显著影响，因素B（提取时间）和因素C（提取次数）对苦杏仁苷的含量有极显著影响。结论：最佳提取工艺A2B2C2，即用10倍量提取2次，每次1h。     

乳熟期鲜食玉米穗不同部位碳水化合物的变化

对乳熟期鲜食玉米穗不同部位碳水化合物的变化研究表明，籽粒中可溶性总糖（TSC）质量分数为先增加后降低，蔗糖（SUC）和TSC的变化趋势相似，淀粉质量分数逐渐增加，可溶性酸性蔗糖转化酶的活性先增加后降低．穗轴中SUC及TSC质量分数在授粉后任何时期总是高于籽粒，淀粉质量分数远低于籽粒．苞皮中TSC与SUC质量分数缓慢减少，在籽粒灌浆初期积累有大量的TSC，为籽粒迅速灌浆做出了贡献，淀粉质量分数远低于穗轴．鲜食玉米采收后应低温放置或及时加工，以抑制糖快速转化为淀粉，防止鲜食玉米品质下降．     

Multimodal analysis of functional and structural disconnection in Alzheimer's disease using multiple kernel SVM

Alzheimer's disease (AD) patients exhibit alterations in the functional connectivity between spatially segregated brain regions which may be related to both local gray matter (GM) atrophy as well as a decline in the fiber integrity of the underlying white matter tracts. Machine learning algorithms are able to automatically detect the patterns of the disease in image data, and therefore, constitute a suitable basis for automated image diagnostic systems. The question of which magnetic resonance imaging (MRI) modalities are most useful in a clinical context is as yet unresolved. We examined multimodal MRI data acquired from 28 subjects with clinically probable AD and 25 healthy controls. Specifically, we used fiber tract integrity as measured by diffusion tensor imaging (DTI), GM volume derived from structural MRI, and the graph‐theoretical measures ‘local clustering coefficient’ and ‘shortest path length’ derived from resting‐state functional MRI (rs‐fMRI) to evaluate the utility of the three imaging methods in automated multimodal image diagnostics, to assess their individual performance, and the level of concordance between them. We ran the support vector machine (SVM) algorithm and validated the results using leave‐one‐out cross‐validation. For the single imaging modalities, we obtained an area under the curve (AUC) of 80% for rs‐fMRI, 87% for DTI, and 86% for GM volume. When it came to the multimodal SVM, we obtained an AUC of 82% using all three modalities, and 89% using only DTI measures and GM volume. Combined multimodal imaging data did not significantly improve classification accuracy compared to the best single measures alone. Hum Brain Mapp 36:2118–2131, 2015. © 2015 Wiley Periodicals, Inc.     

Consanguinity and Late Fertility: Spatial Analysis Reveals Positive Association Patterns

The role of consanguinity on human complex traits is an important and controversial issue. In this work we focused on the Sardinian population and examined the effect of consanguineous unions on late female fertility. During the last century the island has been characterized by a high incidence of marriages between relatives, favoured by socio economic conditions and geographical isolation, and by high fertility despite a widespread tendency to delay reproduction. Through spatial analysis techniques, we explored the geographical heterogeneity of consanguinity and late fertility, and identified in Central–Eastern Sardinia a common area with an excess of both traits, where the traits are positively associated. We found that their association did not significantly affect women's fertility in the area, despite the expected negative role of both traits. Intriguingly, this critical zone corresponds well to areas reported by previous studies as being peculiar for a high frequency of centenarians and for lower risk in pregnancy outcome. The proposed approach can be generally exploited to identify target populations on which socioeconomic, biodemographic and genetic data can be collected at the individual level, and deeper analyses carried out to disentangle the determinants of complex biological traits and to investigate their association.     

桃胶改良前后的溶胀性能分析

目的:阐明溶剂、盐浓度、温度及p H对桃胶改良前后溶胀性能的影响,为阐明其缓释性能提供实验依据。方法:采用称重法测定原桃胶和改良桃胶辅料溶胀前后的干重、湿重,计算平衡溶胀率。结果:在不同溶剂中,改良桃胶的平衡溶胀率普遍明显高于原桃胶;桃胶改良前后的平衡溶胀率为二甲基亚砜水无水乙醇;在不同盐浓度中,桃胶改良前后的平衡溶胀率基本相同,均不受盐浓度影响,但显著小于水;在不同温度中,温度越高,桃胶改良前后的溶胀性能均越大,且改良桃胶更优;在不同p H溶液中,原桃胶易受酸碱度影响,而改良桃胶的平衡溶胀率不受其影响,且表现出更佳的溶胀性能。结论:改良桃胶的溶胀性能显著优于原桃胶;桃胶改良前后的溶胀性能受溶剂、温度的影响显著,而对盐浓度和p H(原桃胶易受影响)则不敏感。     

Bayesian semiparametric regression models for evaluating pathway effects on continuous and binary clinical outcomes

Many statistical methods for microarray data analysis consider one gene at a time, and they may miss subtle changes at the single gene level. This limitation may be overcome by considering a set of genes simultaneously where the gene sets are derived from prior biological knowledge. Limited work has been carried out in the regression setting to study the effects of clinical covariates and expression levels of genes in a pathway either on a continuous or on a binary clinical outcome. Hence, we propose a Bayesian approach for identifying pathways related to both types of outcomes. We compare our Bayesian approaches with a likelihood‐based approach that was developed by relating a least squares kernel machine for nonparametric pathway effect with a restricted maximum likelihood for variance components. Unlike the likelihood‐based approach, the Bayesian approach allows us to directly estimate all parameters and pathway effects. It can incorporate prior knowledge into Bayesian hierarchical model formulation and makes inference by using the posterior samples without asymptotic theory. We consider several kernels (Gaussian, polynomial, and neural network kernels) to characterize gene expression effects in a pathway on clinical outcomes. Our simulation results suggest that the Bayesian approach has more accurate coverage probability than the likelihood‐based approach, and this is especially so when the sample size is small compared with the number of genes being studied in a pathway. We demonstrate the usefulness of our approaches through its applications to a type II diabetes mellitus data set. Our approaches can also be applied to other settings where a large number of strongly correlated predictors are present. Copyright © 2012 John Wiley & Sons, Ltd.     

柱前衍生化HPLC法测定薏苡非种仁部位中丙氨酸的含量

目的:建立柱前衍生化反相高效液相色谱法测定薏苡非种仁部位中氨基酸含量的方法。方法:采用Shim-pack CLC-ODS(4.6 mm)色谱柱,流动相A为0.1 mol/L乙酸钠溶液(pH=6.5)-乙腈(93∶7),流动相B为乙腈-水(4∶1),梯度洗脱,柱温为40℃,检测波长为254 nm。结果:丙氨酸进样量在0.01296～0.2851μg范围内,线性关系良好,r=0.9998(n=7),平均加样回收率为98.01%,RSD为2.2%。结论:方法准确、可靠,具有良好的重复性和稳定性,可用于薏苡非种仁部位中氨基酸的含量测定。     

BCYB代数的理想和同构定理

本文使用一种新的方法引入了BCYB代数的理想的概念,并由此引入了BCYB代数的商代数,进而又定义了BCYB代数的同态、同构、同态的核等术语,最终导出了BCYB代数的第一同构定理和双商定理。     

Quantitative magnetic resonance spectroscopy: semi-parametric modeling and determination of uncertainties.

A semi-parametric approach for the quantitative analysis of magnetic resonance (MR) spectra is proposed and an uncertainty analysis is given. Single resonances are described by parametric models or by parametrized in vitro spectra and the baseline is determined nonparametrically by regularization. By viewing baseline estimation in a reproducing kernel Hilbert space, an explicit parametric solution for the baseline is derived. A Bayesian point of view is adopted to derive uncertainties, and the many parameters associated with the baseline solution are treated as nuisance parameters. The derived uncertainties formally reduce to Cramér-Rao lower bounds for the parametric part of the model in the case of a vanishing baseline.The proposed uncertainty calculation was applied to simulated and measured MR spectra and the results were compared to Cramér-Rao lower bounds derived after the nonparametrically estimated baselines were subtracted from the spectra. In particular, for high SNR and strong baseline contributions the proposed procedure yields a more appropriate characterization of the accuracy of parameter estimates than Crémer-Rao lower bounds, which tend to overestimate accuracy.