Liposomes loaded with quantum dots for ultrasensitive on-site determination of aflatoxin M1 in milk products

A quantitative fluorescence-labeled immunosorbent assay and qualitative on-site column tests were developed for the determination of aflatoxin M1 in milk products. The use of liposomes loaded with quantum dots as a label significantly increased the assay sensitivity by encapsulating multiple quantum dots in a single liposome and, therefore, amplifying the analytical signal. Two different techniques were compared to obtain aflatoxin-protein conjugates, used for further coupling with the liposomes. The influence of nonspecific interactions of the liposome-labeled conjugates obtained with the surface of microtiter plates and column cartridges was evaluated and discussed. The limit of detection for fluorescence-labeled immunosorbent assay was 0.014 mu g kg(-1). For qualitative on-site tests, the cutoff was set at 0.05 mu g kg(-1), taking into account the EU maximum level for aflatoxin M1 in raw milk, heat-treated milk, and milk for the manufacture of milk-based products. The direct addition of labeled conjugate to the milk samples resulted in an additional decrease of analysis time. An intralaboratory validation was performed with sterilized milk and cream samples artificially spiked with aflatoxin M1 at concentrations less than, equal to and greater than the cutoff level. It is shown that milk products can be analyzed without any sample preparation, just diluted with the buffer. The rates for false-positive and false-negative results were below 5 % (2.6 % and 3.3 %, respectively)

Development of Hydrometallurgical Process of Non-Ferrous and Rare Metals Recovery from Untraditional Mineral Raw Materials and Natural Brines

In connection with gradual lowering of supplies of tradit- ional ore raw materials involving non-ferrous and rare metals, winch is treated by well-known technologies, invo-lving into the production of untraditional, secondary and technogeneous raw materials appears to be actual task

Silkworm Thermal Biology: A Review of Heat Shock Response, Heat Shock Proteins and Heat Acclimation in the Domesticated Silkworm, Bombyx mori

Heat shock proteins (HSPs) are known to play ecological and evolutionary roles in this postgenomic era. Recent research suggests that HSPs are implicated in cardiovascular biology and disease development, proliferation and regulation of cancer cells, cell death via apoptosis, and several other key cellular functions. These activities have generated great interest amongst cell and molecular biologists, and these biologists are keen to unravel other hitherto unknown potential functions of this group of proteins. Consequently, the biological significance of HSPs has led to cloning and characterization of genes encoding HSPs in many organisms including the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae). However, most of the past investigations in B. mori were confined to expression of HSPs in tissues and cell lines, whereas information on their specific functional roles in biological, physiological, and molecular processes is scarce. Naturally occurring or domesticated polyvoltines (known to be the tropical race) are more resistant to high temperatures and diseases than bi- or univoltines (temperate races). The mechanism of ecological or evolutionary modification of HSPs during the course of domestication of B. mori - particularly in relation to thermotolerance in geographically distinct races/strains - is still unclear. In addition, the heat shock response, thermal acclimation, and hardening have not been studied extensively in B. mori compared to other organisms. Towards this, recent investigations on differential expression of HSPs at various stages of development, considering the concept of the whole organism, open ample scope to evaluate their biological and commercial importance in B. mori which has not been addressed in any of the representative organisms studied so far. Comparatively, heat shock response among different silkworm races/strains of poly-, bi-, and univoltines varies significantly and thermotolerance increases as the larval development proceeds. Hence, this being the first review in this area, an attempt has been made to collate all available information on the heat shock response, HSPs expression, associated genes, amino acid sequences, and acquired/unacquired thermotolerance. The aim is to present this as a valuable resource for addressing the gap in knowledge and understanding evolutionary significance of HSPs between domesticated (B. mori) and non-domesticated insects. It is believed that the information presented here will also help researchers/breeders to design appropriate strategies for developing novel strains for the tropics

Species Accumulation Curves and Incidence-Based Species Richness Estimators to Appraise the Diversity of Cultivable Yeasts from Beech Forest Soils

Background: Yeast-like fungi inhabit soils throughout all climatic zones in a great abundance. While recent estimations predicted a plethora of prokaryotic taxa in one gram of soil, similar data are lacking for fungi, especially yeasts. Methodology/Principal Findings: We assessed the diversity of soil yeasts in different forests of central Germany using cultivation-based techniques with subsequent identification based on rDNA sequence data. Based on experiments using various pre-cultivation sample treatment and different cultivation media we obtained the highest number of yeasts by analysing mixed soil samples with a single nutrient-rich medium. Additionally, several species richness estimators were applied to incidence-based data of 165 samples. All of them predicted a similar range of yeast diversity, namely 14 to 16 species. Randomized species richness curves reached saturation in all applied estimators, thus indicating that the majority of species is detected after approximately 30 to 50 samples analysed. Conclusions/Significance: In this study we demonstrate that robust species identification as well as mathematical approaches are essential to reliably estimate the sampling effort needed to describe soil yeast communities. This approach has great potential for optimisation of cultivation techniques and allows high throughput analysis in the future

Positive and Negative Regulation of Gli Activity by Kif7 in the Zebrafish Embryo

Loss of function mutations of Kif7, the vertebrate orthologue of the Drosophila Hh pathway component Costal2, cause defects in the limbs and neural tubes of mice, attributable to ectopic expression of Hh target genes. While this implies a functional conservation of Cos2 and Kif7 between flies and vertebrates, the association of Kif7 with the primary cilium, an organelle absent from most Drosophila cells, suggests their mechanisms of action may have diverged. Here, using mutant alleles induced by Zinc Finger Nuclease-mediated targeted mutagenesis, we show that in zebrafish, Kif7 acts principally to suppress the activity of the Gli1 transcription factor. Notably, we find that endogenous Kif7 protein accumulates not only in the primary cilium, as previously observed in mammalian cells, but also in cytoplasmic puncta that disperse in response to Hh pathway activation. Moreover, we show that Drosophila Costal2 can substitute for Kif7, suggesting a conserved mode of action of the two proteins. We show that Kif7 interacts with both Gli1 and Gli2a and suggest that it functions to sequester Gli proteins in the cytoplasm, in a manner analogous to the regulation of Ci by Cos2 in Drosophila. We also show that zebrafish Kif7 potentiates Gli2a activity by promoting its dissociation from the Suppressor of Fused (Sufu) protein and present evidence that it mediates a Smo dependent modification of the full length form of Gli2a. Surprisingly, the function of Kif7 in the zebrafish embryo appears restricted principally to mesodermal derivatives, its inactivation having little effect on neural tube patterning, even when Sufu protein levels are depleted. Remarkably, zebrafish lacking all Kif7 function are viable, in contrast to the peri-natal lethality of mouse kif7 mutants but similar to some Acrocallosal or Joubert syndrome patients who are homozygous for loss of function KIF7 alleles

Public Library Organization Systems in Taiwan, Republic of China

本文介紹我國臺灣地區公共圖書館行政組織體系之現況，分以下五部份陳述之：公共圖書館設置之法規依據、各層?公共圖書館之行政組織體系及其隸屬關係、公共圖書館組織結構、公共圖書館人員選用制度、以及公共圖書館輔導體系。This paper is a state report of the public library organizational systems in Taiwan, Republic of China, which is to study the following aspects: the founding regulations and the rules, the organizational hierarchies, the organizational structure and subordinate unites, librarian’s recruiting regulations and rules, as well as the library advisory systems