Daily variations in oligosaccharides of human milk determined by microfluidic chips and mass spectrometry

Human milk is a complex biological fluid that provides not only primary nourishment for infants but also protection against pathogens and influences their metabolic, immunologic, and even cognitive development. The presence of oligosaccharides in remarkable abundance in human milk has been associated to provide diverse biological functions including directing the development of an infant's intestinal microflora and immune system. Recent advances in analytical tools offer invaluable insights in understanding the specific functions and health benefits these biomolecules impart to infants. Oligosaccharides in human milk samples obtained from five different individual donors over the course of a 3 month lactation period were isolated and analyzed using HPLC-Chip/TOF-MS technology. The levels and compositions of oligosaccharides in human milk were investigated from five individual donors. Comparison of HPLC-Chip/TOF-MS oligosaccharides profiles revealed heterogeneity among multiple individuals with no significant variations at different stages of lactation within individual donors.     

Size-dependent lipid content in human milk fat globules

Human milk fat globules (HMFGs) are considered to constitute a triglyceride-rich source of fat and energy. However, milk contains lipid particles at different sizes ranging from tens of micrometers to less than 1 microm. In particular, the physical, chemical, and biological properties of submicron sized particles are poorly described. Individual HMFGs were analyzed using laser trapping confocal Raman spectroscopy, and their chemical signature was obtained and compared to 1, 5, and 10 microm globules. Significant differences in both lipid composition and relative lipid content were found between the classes of particles with different diameters. A strong Raman peak at 1742 cm(-1) corresponding to the triacylglycerol core was detected in the 5 and 10 microm diameter globules, whereas in the smaller HMFGs no detectable peak was found. In addition, the submicron particles produced Raman signals consistent with large quantities of unsaturated fatty acids. Moreover, cis and trans isomers of unsaturated fatty acids were found to be unequally distributed between large and small milk fat globules. Interestingly, trans unsaturated fatty acids were found only in 1 and 5 microm globules although more prominent in the 5 microm diameter range. This is the first evidence for size related differential lipid composition of various diameter classes of HMFGs. The results suggest that the milk fat globule size distribution determines milk lipid composition. In addition, large portions of the HMFGs are secreted into milk conspicuously not for fat delivery. Thus, small HMFGs may offer novel metabolic and nutritional functions.     

Echinosporins as new cell cycle inhibitors and apoptosis inducers from marine-derived Streptomyces albogriseolus

Bioassay-guided fractionation of the ethyl acetate extract from the fermentation broth of marine-derived Streptomyces albogriseolus A2002 led to the isolation of echinosporin (1) and 7-deoxyechinosporin (2). Compound 1 inhibited the proliferation of tsFT210, K562 and HCT-15 cancer cells (IC(50) 91.5 microM, 25.1 microM and 247 microM respectively) and 2 showed the same effect on K562 cells (IC(50) 143 microM). Flow cytometric analysis suggested that 1 and 2 exert their anti-proliferative effects on those cells through inhibiting cell cycle at the G(2)/M phase and inducing apoptosis.     

应用同位素（#+14）C和（#+15）N研究再生稻光合产物分配和氮素营养吸收的生理效应

再生稻的生长和发育是在头熟基础上进行的。研究头熟后期同化产物的分配及其在二熟生育期间被再利用的情况;研究再生稻头熟收割前后对氮素营养的吸收和转运规律,对制定再生稻的全苗技术和肥水技术具有一定的指导意义。本文报道应用同位素~()14C和~(15)N示踪技术,研究再生稻光合产物分配和氮素营养吸收的生理效应。     

New multiple-herbicide crop resistance and formulation technology to augment the utility of glyphosate

Glyphosate has performed long and well, but now some weed communities are shifting to populations that survive glyphosate, and growers need new weed management technologies to augment glyphosate performance in glyphosate-resistant crops. Unfortunately, most companies are not developing any new selective herbicides with new modes of action to fill this need. Fortunately, companies are developing new herbicide-resistant crop technologies to combine with glyphosate resistance and expand the utility of existing herbicides. One of the first multiple-herbicide-resistant crops will have a molecular stack of a new metabolically based glyphosate resistance mechanism with an active-site-based resistance to a broad spectrum of ALS-inhibiting herbicides. Additionally, new formulation technology called homogeneous blends will be used in conjunction with glyphosate and ALS-resistant crops. This formulation technology satisfies governmental regulations, so that new herbicide mixture offerings with diverse modes of action can be commercialized more rapidly and less expensively. Together, homogeneous blends and multiple-herbicide-resistant crops can offer growers a wider choice of herbicide mixtures at rates and ratios to augment glyphosate and satisfy changing weed management needs.     

Purpurogemutantin and purpurogemutantidin, new drimenyl cyclohexenone derivatives produced by a mutant obtained by diethyl sulfate mutagenesis of a marine-derived Penicillium purpurogenum G59

Two new drimenyl cyclohexenone derivatives, named purpurogemutantin (1) and purpurogemutantidin (2), and the known macrophorin A (3) were isolated from a bioactive mutant BD-1-6 obtained by random diethyl sulfate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. Structures and absolute configurations of 1 and 2 were determined by extensive spectroscopic methods, especially 2D NMR and electronic circular dichroism (ECD) analysis. Possible biosynthetic pathways for 1-3 were also proposed and discussed. Compounds 1 and 2 significantly inhibited human cancer K562, HL-60, HeLa, BGC-823 and MCF-7 cells, and compound 3 also inhibited the K562 and HL-60 cells. Both bioassay and chemical analysis (HPLC, LC-ESIMS) demonstrated that the parent strain G59 did not produce 1-3, and that DES-induced mutation(s) in the mutant BD-1-6 activated some silent biosynthetic pathways in the parent strain G59, including one set for 1-3 production.     

Learning-style profiles of 150 veterinary medical students

Awareness of student learning-style preferences is important for several reasons. Understanding differences in learning styles permits instructors to design course materials that allow all types of learners to absorb and process information. Students who know their own learning style are better able to help themselves in courses taught in a non-preferred method by developing study strategies in line with their preferred learning method. We used the Felder and Solomon Index of Learning Styles to assess the learning-style profiles of 150 veterinary students in three consecutive years. Students were predominantly active (56.7%), sensing (79.3%), visual (76.7%), and sequential (69.3%). Most were balanced on the active-reflective (59.3%) and global-sequential (50%) dimensions, and 61.3% and 54% were moderately to strongly sensing and visual, respectively. Small but significant numbers of students were moderately to strongly intuitive (8.7%), verbal (13%), and global (12%). The most common patterns were active-sensing-visual-sequential (26%), reflective-sensing-visual-sequential (19.3%), active-sensing-visual-global (8.7%), and active-sensing-verbal-sequential (8.7%). Although most students (65.3%) were balanced on one to two dimensions, 77.3% had one or more strong preferences. Our results show that although people have dominant learning-style preference and patterns, they have significant minor preferences and patterns across all dimensions with moderate to strong preferences on each scale. These results indicate that a balanced approach to teaching is essential to allow all students to learn optimally.     

The widespread impact of mammalian MicroRNAs on mRNA repression and evolution

Thousands of mammalian messenger RNAs are under selective pressure to maintain 7-nucleotide sites matching microRNAs (miRNAs). We found that these conserved targets are often highly expressed at developmental stages before miRNA expression and that their levels tend to fall as the miRNA that targets them begins to accumulate. Nonconserved sites, which outnumber the conserved sites 10 to 1, also mediate repression. As a consequence, genes preferentially expressed at the same time and place as a miRNA have evolved to selectively avoid sites matching the miRNA. This phenomenon of selective avoidance extends to thousands of genes and enables spatial and temporal specificities of miRNAs to be revealed by finding tissues and developmental stages in which messages with corresponding sites are expressed at lower levels.     

Honey characterization and adulteration detection by pattern recognition applied on HPAEC-PAD profiles. 1. Honey floral species characterization

An improved COFRAC (COmité FRan?ais d'ACréditation) method for the analysis and evaluation of the quality of honey by high-performance anion-exchange chromatography of sugar profiles is proposed. With this method, both minor and major sugars are simultaneously analyzed and the technique is integrated in a new chemometric approach, which uses the entire chromatographic sugars profile of each analyzed sample to characterize honey floral species. Sixty-eight authentic honey samples (6 varieties) were analyzed by high-performance anion-exchange chromatography-pulsed amperometric detection. A new algorithm was developed to create automatically the corresponding normalized data matrix, ready-to-use in various chemometric procedures. This algorithm transforms the analytical profiles to produce the corresponding calibrated table of the surfaces or intensities according to retention times of peaks. The possibility of taking into account unknown peaks (those for which no standards are available) allows the maximum chemical information provided by the chromatograms to be retained. The parallel application of principal component analysis (PCA)/linear discriminant analysis (LDA) and artificial neural networks (ANN) shows a high capability in the classification of the analyzed samples (LDA, 93%; ANN, 100%) and a very good discrimination of honey groups. This work is the starting point of the elaboration of a new system designed for the automatic pattern recognition of food samples (first application on honey samples) from chromatographic analyses for food characterization and adulteration detection.     

Controlled-atmosphere effects on postharvest quality and antioxidant activity of cranberry fruits

The effects of controlled-atmosphere (CA) storage on the firmness, respiration rate, quality, weight loss, total phenolics and flavonoids contents, and total antioxidant activities of the Pilgrim and Stevens cultivars of cranberries (Vaccinium macrocarpon Aiton) have been studied during storage in atmospheres of 2, 21, and 70% O(2) with 0, 15, and 30% CO(2) (balance N(2)); and 100% N(2) at 3 degrees C. Elevated CO(2) concentrations decreased bruising, physiological breakdown, and decay of berries, thereby reducing fruit losses. Respiration and weight loss of fruits decreased, but fruit softening increased, at higher CO(2) concentrations. Accumulations of acetaldehyde, ethanol, and ethyl acetate varied by cultivar and storage atmosphere but were generally highest in the 2 and 70% O(2) and 100% N(2) atmospheres and increased in response to elevated CO(2) concentrations. Overall, the 30% CO(2) plus 21% O(2) atmosphere appeared optimal for the storage of cranberries. Sensory analysis is required, however, to confirm that accumulations of fermentation products at this atmosphere are acceptable for consumers. Stevens fruits had a higher phenolics content and total antioxidant activity than Pilgrim fruits. The storage atmosphere did not affect the content of total phenolics or flavonoids. However, the total antioxidant activity of the fruits increased overall by about 45% in fruits stored in air. This increase was prevented by storage in 30% CO(2) plus 21% O(2).