Germinal vesicle chromatin configurations of bovine oocytes

A common feature in the configuration of germinal vesicle (GV) chromatin in most species is that diffuse chromatin condenses into a perinucleolar ring during follicular growth; however, no such ring was observed in goat oocytes. Reports on whether bovine GV chromatin condenses into a perinucleolar ring are controversial. Besides, it is not known whether the perinucleolar ring in an oocyte represents a step toward final maturation or atresia. Changes in GV chromatin configurations during growth and maturation of bovine oocytes were studied using a new method that allows a clearer visualization of both the nucleolus and the chromatin after Hoechst and chromomycin A(3) staining. On the basis of the degree of condensation and distribution, the GV chromatin of bovine oocytes were classified into five configurations: NSN with diffuse chromatin in the whole nuclear area, N with condensed netlike chromatin, C with clumped chromatin, SN with clumped chromatin surrounding the nucleoli, and F with floccular chromatin near the nucleoli and near the nuclear envelope. Most of the oocytes were at the NSN stage in the <1.4-mm follicles, but the NSN pattern disappeared completely in follicles larger than 1.5mm. The SN pattern began to emerge in 1.5-mm follicles, and the number of SN oocytes increased while the number of oocytes with N and C configurations decreased with follicular growth. During maturation in vivo, while the number of N, C, and SN oocytes decreased, that of the F oocytes increased and reached maximum at 51h post prostaglandin injection. After that, the number of F oocytes decreased significantly because of germinal vesicle breakdown (GVBD). During maturation in vitro, GV chromatin configurations changed in a similar manner as during maturation in vivo. Fewer oocytes were at N, C, and SN stages, but more were at F and GVBD stages in the atretic than in the healthy follicles. Serum starvation slowed the F-GVBD transition of the in vitro maturing oocytes. More oocytes were of the SN or C configuration when ovaries were transported at 45-40 degrees C than at 35-30 degrees C. Most of the heated oocytes were blocked at the SN stage during in vitro maturation. It is concluded that (i) bovine GV chromatin condenses into a perinucleolar ring during follicular growth; (ii) bovine oocytes were synchronized at the F stage before GVBD; (iii) oocyte GV chromatin configurations were affected by serum starvation, high temperature, and follicular atresia.     

Alpha-Tomatine Purification and Quantification in Tomatoes by HPLC

A high-performance liquid chromatographic procedure was developed for purification and quantification of α-tomatine from tomatoes. A crude preparation of glycoalkaloids from tomato fruits was fractionated on a column of Nucleosil NH₂ (10 μm), and eluted with a mixture of tetrahydrofuran/acetonitrile/0.02 M KH₂PO₄ (50/30/20, v/v/v). The column effluent was monitored at 205 run. Total analysis of α-tomatine was completed in < 10 min. It was present at highest concentrations in fruit at the mature-green stage but its level decreased rapidly as fruit approached full maturity. The technique should be useful for analysis of α-tomatine in biological samples.     

Determination of Total Charge Content of Whiskey by Polyelectrolyte Titration: Alteration of Polyphenols

ABSTRACT: Whiskeys with maturation periods of 1 to 26 y were analyzed by polyelectrolyte titration at various pH levels. The amounts of charge (polyelectrolyte concentration), which were mainly attributable to polyphenols which were extracted from wood casks during the maturation, were determined. The amounts of charge, namely polyphenols, increased with increasing periods of maturation. On the other hand, the ratio of amounts of charge in the alkaline region compared to those in the neutral region became smaller with longer storage. It was found that polyphenols were extracted over time from the wood cask by whiskey, but they were oxidized to alter the polyphenol compositions, which stabilized clusters (molecular association) between alcohol and water to make whiskeys mellow.     

Changes in the concentration of volatile oak compounds and esters in red wine stored for 18 months in re-used French oak barrels

Studies were made of changes in concentration of oak-wood-derived volatiles and the evolution of esters in red wine during storage in twice-used French oak barrels. Wine samples were taken after 8, 10, 12, 15, and 18 months maturation in the barrels. Results showed that most of the volatile compounds extracted from the wood (furanic compounds, volatile phenols, lactones) reached maximum concentration between 10 and 12 months of barrel storage. After 18 months of maturation many of the compounds showed concentrations similar to those found after 10 to 12 months. However, the concentrations of furfural, 5-methyl furfural, furfuryl alcohol, coniferaldehyde, acetovanillone and phenol in wines aged for 18 months were lower than those reached after 10 to 12 months. The concentration of the ethylphenols increased right up to 18 months of ageing, which can only have a negative impact on the quality of the wine. There were few modifications in the concentration of esters, except for ethyl lactate which reached peak concentration after 12 months maturation and decreased thereafter.     

Young adult identities and their pathways: A developmental and life course model.

Developmental and life course studies of young adult identities have focused on 2 dimensions: subjective age and psychosocial maturity. This study examines the developmental synchrony of these 2 processes. In a longitudinal sample of young adults from Add Health (ages 18–22), a person-centered analysis of indicators of these dimensions identified 4 identity profiles. Two depict early and late patterns of identity; the others represent contrasting types of discordance: pseudo-adult, with subjective age more advanced than maturation level, and anticipatory, with subjective age less advanced than maturational level. The profiles vary by gender, socioeconomic status, and race–ethnicity, as well as by adolescent (ages 12–16) pubertal maturation, psychosocial adjustment, and family context. These results provide support for a more holistic, interdisciplinary understanding of adult identity and show that young adult identities in the Add Health sample follow differentiated paths into the adult years, with largely unknown consequences for the subsequent life course. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Biochemical and morphological alterations of the extracellular matrix of chicken calcaneal tendon during maturation

The region in tendons that surrounds bone extremities adapts to compression forces, developing a fibrocartilaginous structure. During maturation, changes occur in the amount and organization of macromolecules of the extracellular matrix of tendons, changing the tissue morphology. To study the effect of maturation on tendons, Pedrês chickens were sacrificed at 1, 5, and 8 months old and had the calcaneal tendon (CT) divided into proximal region, submitted to tension/compression forces ( p ), and distal region submitted to tension force ( d ). Morphological analysis of the p region showed the presence of fibrocartilage in all ages. In the central part of the fibrocartilage, near a diminishment of the metachromasy, there was also a development of a probable fat pad that increased with the maturation. The activity of MMP‐2 and MMP‐9 was higher at 5 and 8 months old, in both regions, compared with 1‐month‐old animals. In SDS‐PAGE analysis, components with electrophoretic migration similar to decorin and fibromodulin increased with maturation, particularly in the d region. The Western blotting confirmed the increased amount of fibromodulin with maturation. In conclusion, our results show that process of maturation leads to the appearance of a probable fat pad in the center of the fibrocartilage of CT, with a reduced amount of glycosaminoglycans and an increased activity of MMPs. Microsc. Res. Tech. 78:949–957, 2015. © 2015 Wiley Periodicals, Inc.     

Changes in lipid class and fatty acid composition during maturation of mesocarp of oil palm (Elaeis guineensis) variety dura

The deposition of oil, major lipid classes, and the constituent fatty acids of the oil palm fruit mesocarp were investigated to gain a better insight into the accumulation of these components. The oils were extracted with chloroform-methanol 1:2 (v/v) and were fractionated by silicic acid column chromatography into classes. Fatty acids were analysed by gas-liquid chromatography. Shortly after anthesis, lipids, mainly phospho- and glyco-lipids, were a small proportion of the mesocarp. With time the lipid content increased, until at maturity it accounted for about 60% of fresh mesocarp weight. Approximately 97% of the lipid at maturity was neutral lipid, essentially triacylglycerol. Maximum oil quantity was obtained at 22 weeks after anthesis. The active lipid accumulation period was from weeks 18 to 22 after pollination. Contrary to previously published data, palmitic, oleic and linoleic acids were characteristically present at all stages of oil accumulation. Linolenic acid was present in the neutral lipids from immature mesocarp of the oil palm fruit, but was probably diluted out in mature palms. Appreciable amounts of linolenic acid were present in the polar lipid fractions.     

善酿酒的生产工艺及质量控制

该文主要介绍了善酿酒的生产工艺、操作规程及产品质量控制。提出了从原辅料开始各道工序都要严格把关,才能确保生产出优质的产品。     

ETHYL CARBAMATE FORMATION IN GRAIN BASED SPIRITS: PART I: POST-DISTILLATION ETHYL CARBAMATE FORMATION IN MATURING GRAIN WHISKY

Distilled spirits are subject to post-distillation ethyl carbamate formation in the presence of appropriate precursors. Freshly distilled grain whisky, produced by the continuous distillation Coffey still process, normally contains ethyl carbamate concentrations not exceeding 20 ppb (normalized to 43% v/v alcoholic strength). Further ethyl carbamate formation, dependent upon the presence of trace anionic precursors such as cyanate, cyanide, and copper cyanide complexes, may take place during normal maturation in oak casks. Related but different mechanisms may induce ethyl carbamate formation under normal daylight and artificial light in the laboratory. Ethyl carbamate precursors convert into ethyl carbamate during the initial three months of maturation and are not detectable in the final bottled product. Thus the final ethyl carbamate concentration in spirit is dependent upon the initial ethyl carbamate level measured after distillation plus ethyl carbamate formed from precursors. It is important during process control to monitor not only the ethyl carbamate level in freshly distilled spirit but also the spirit's potential to form ethyl carbamate from precursors with the objective of minimizing these components in the freshly distilled and maturing spirit. A scheme for predicting final ethyl carbamate concentrations from precursor concentrations in freshly distilled spirit is presented.     

Individual and interactive effects of cultivar maturation time, nitrogen regime and temperature level on accumulation of wheat grain proteins

BACKGROUND: Background and reasons for differences in wheat grain protein accumulation and polymerization are not fully understood. This study investigated individual and interactive effects of genetic and environmental factors on wheat grain protein accumulation and amount and size distribution of polymeric proteins (ASPP). RESULTS: Individual factors, e.g. maturation time of a cultivar, nitrogen regime and temperature level, influenced grain protein accumulation and ASPP, although interaction of these factors had a greater influence. Early maturation time and long grain maturation period (GMP) in a cultivar resulted in high amounts of sodium dodecyl sulphate (SDS)‐extractable proteins (TOTE) and low percentage of SDS‐unextractable polymeric proteins in total polymeric proteins (%UPP). Cultivars with late maturation time and short GMP resulted in low TOTE and high %UPP. Late versus early nitrogen application regime resulted in low %UPP versus low TOTE and high %UPP, respectively. High versus low temperature resulted in high %UPP and low %UPP, respectively. Differences in ASPP at maturity started as changes in protein accumulation from 12 days after anthesis. CONCLUSION: Length of GMP, especially in relation to length until maturity, governs gluten strength (%UPP) and grain protein concentration (TOTE). Length of GMP is determined by cultivar, temperature during GMP and late nitrogen availability. Copyright © 2011 Society of Chemical Industry