Crystal Violet Contamination of Methyl Green and Purification of Methyl Green—a Historical Note

A method for evaluating the viability of mycobacterial cultures using fluorescein diacetate and ethidium bromide is described. Smears from 2-4 week old cultures of mycobacteria were stained with a 0.005% Dubos albumin broth dilution of fluorescein diacetate for thirty minutes at 37 C. The smears were counterstained with a 0.005% aqueous solution of ethidium bromide for ten minutes at room temperature and blotted dry. One drop of glycerol was placed on the smear and covered with a 22 × 40 mm coverslip. Stained smears were observed with fluorescence microscopy at 450 X. Viable organisms hydrolyzed the fluorescein diacetate and appeared yellow-green while dead organisms absorbed the ethidium bromide and appeared red-orange. Aliquots of material from which the slides were made were concurrently placed on Lowenstein-Jensen media and cultured for growth as a confirmation of viability. Investigation of 104 mycobacterial isolates using the described test showed that the viability of mycobacterial cultures can be determined by this method.     

The mechanism of action of “mordant” dyes — a study using preformed metal complexes

Summary For small basic dyes blocking or selective extraction of tissue sections can reduce staining (methylation, or trichloracetio acid extraction) or increase staining (acetylation or nitrous acid deamination). This is as predicted by a simple electrostatic model of dye binding. In contrast, the staining with both large basic dyes and with metal complex dyes was only slightly affected by these treatments. This is in keeping with the probable role of van der Waals attractions and hydrophobic bonding in the binding of large dyes.Since MCDs are all large, there is no need to invoke the traditional, special mechanism of mordanting (i.e. tissue-metal ion-dye covalencies) to explain the peculiarities of these MCDs. An apparent exception to this was the resistance of MCDs, unlike either small or large basic dyes, to the action of processing fluids. However, this was due to the insolubility of MCDs in alcoho, lsin contrast to the solubility of most basic dyes, irrespective of size, in these media.     

Green Islands — nutrition not predation —an alternative hypothesis

Summary Mountain birch trees are said to survive as green islands around nests of red ants in Finnish Lapland because the ants kill larvae which would defoliate trees during outbreaks of the moth O. autumnata. An alternative hypothesis says that because the ants will concentrate soil nutrients (and possibly ameliorate soil moisture and temperature) in and around their nests, they provide a more favourable site for trees growing nearby. These trees are therefore less stressed and a poorer source of food for defoliators at times of outbreaks. Few if any young O. autumnata larvae survive on the trees which then survive in green islands around ant nests.     

一种智能化的Y—型迷宫

本文介绍了一种智能化Ｙ－型迷宫的硬件、软件结构。它利用微机控制大鼠（或小鼠）分辨学习实验的全过程,利用红外光电传感器监测动物活动行为,判断准确,计时精确。由于以ＷＩＮＤＯＷＳ为工作平台,人机界面友好,操作简便。     

Determination of rarefaction effects on transport properties of nanoscale gas flows using Green–Kubo molecular dynamic simulation

This study aimed to investigate the rarefaction effects on thermal conductivity, viscosity, and density of Argon, Neon and Xenon gas flows in a Platinum nanochannel. Green–Kubo approach with Lenard Jones potential function are used for molecular dynamic simulation. Simulations showed that with decrease in number of atoms, density, viscosity and thermal conductivity decreases, while decrease in nanochannel width in same number of gas atoms leads to increase in viscosity and thermal conductivity.     

Towards a pathogenic Escherichia coli detection platform using multiplex SYBR®Green Real-time PCR methods and high resolution melting analysis

Escherichia coli is a group of bacteria which has raised a lot of safety concerns in recent years. Five major intestinal pathogenic groups have been recognized amongst which the verocytotoxin or shiga-toxin (stx1 and/or stx2) producing E. coli (VTEC or STEC respectively) have received a lot of attention recently. Indeed, due to the high number of outbreaks related to VTEC strains, the European Food Safety Authority (EFSA) has requested the monitoring of the "top-five" serogroups (O26, O103, O111, O145 and O157) most often encountered in food borne diseases and addressed the need for validated VTEC detection methods. Here we report the development of a set of intercalating dye Real-time PCR methods capable of rapidly detecting the presence of the toxin genes together with intimin (eae) in the case of VTEC, or aggregative protein (aggR), in the case of the O104:H4 strain responsible for the outbreak in Germany in 2011. All reactions were optimized to perform at the same annealing temperature permitting the multiplex application in order to minimize the need of material and to allow for high-throughput analysis. In addition, High Resolution Melting (HRM) analysis allowing the discrimination among strains possessing similar virulence traits was established. The development, application to food samples and the flexibility in use of the methods are thoroughly discussed. Together, these Real-time PCR methods facilitate the detection of VTEC in a new highly efficient way and could represent the basis for developing a simple pathogenic E. coli platform.     

Development of sustainable dye adsorption system using nutraceutical industrial fennel seed spent—studies using Congo red dye

Fennel seed spent (FSS)—an inexpensive nutraceutical industrial spent has been used as an efficient biosorbent for the removal of Congo red (CR) from aqueous media. Results show that the conditions for maximum adsorption would be pH 2-4 and 30°C were ideal for maximum adsorption. Based on regression fitting of the data, it was determined that the Sips isotherm (R² = 0.994, χ² = 0.5) adequately described the mechanism of adsorption, suggesting that the adsorption occurs homogeneously with favorable interaction between layers with favorable interaction between layers. Thermodynamic analysis showed that the adsorption is favorable (negative values for ΔG°) and endothermic (ΔH° = 12–20 kJ mol^?1) for initial dye concentrations of 25, 50, and 100 ppm. The low ΔH° value indicates that the adsorption is a physical process involving weak chemical interactions like hydrogen bonds and van der Waals interactions. The kinetics revealed that the adsorption process showed pseudo-second-order tendencies with the equal influence of intraparticle as well as film diffusion. The scanning electron microscopy images of FSS show a highly fibrous matrix with a hierarchical porous structure. The Fourier transform infrared spectroscopy analysis of the spent confirmed the presence of cellulosic and lignocellulosic matter, giving it both hydrophilic and hydrophobic properties. The investigations indicate that FSS is a cost-effective and efficient biosorbent for the remediation of toxic CR dye.     

SH—SY5Y细胞的钙缓冲研究

目的：研究SH－SY5Y神经杂交瘤细胞的钙缓冲能力。方法：通过膜片钳手段,测量未分化的SH－SY5Y细胞钙离子通道电流;并应用显微荧光测量游离钙离子浓度和高钾去极化的方法,研究胞内Ca^2 浓度上升后浓度恢复的动力学过程。结果：未分化的SH－SY5Y细胞存在钙离子通道电流,在刺激时间间隔较短时（＜150s）,胞内钙浓度的恢复过程会由于缓冲机制的饱和而变慢;而时间间隔＞150s时,缓冲物质则可以基本恢复使得胞内钙的恢复过程基本保持不变。结论：钙缓冲蛋白在细胞内钙浓度的调节中起重要作用。     

Detection of RHD zygosity in China: using Syber Green Ⅰ real-time polymerase chain reaction based on high-resolution melting curve analysis

Due to relatively higher mutation frequencies in Chinese individuals with the RHD-negative phenotype[25% for 1227 G>A RHD elution and 5% for RHD1-RHCE(2-9)-RHD10], Rhesus box analysis is rarely used in China. Here, quantitative real-time polymerase chain reaction (qPCR) with a high-resolution melting curve mode and a matrix mix containing Syber Green Ⅰ were used to sequence specific primers of 1227 G>A and RHD exons 1, 5, and 10 in two families, consisting of two parents and two children per family (n = 8). The samples with RHD gene dele- tion homozygous/heterozygous, 1227 G>A heterozygous with RHD gene deletion and normal RHD, normal RHD homozygous/heterozygous, and RHD1-RHCE(2-9)-RHD10 homozygous/heterozygous status were all included. All samples were screened using RHD exon genotyping, Sanger sequencing, and Rhesus box analysis. DNA sample quality was maintained at 68~72 ng/μL, and OD_260/280 at 1.7~1.9. The Tm ratio of RHD exon 1 (87 ℃ ) to internal control (77℃ ) was 2.49~2.67 and 2.09~2.35 in subjects with RHD exon 1 homozygous and heterozygous, respectively; the Tm ratio of RHD exon 10 (81℃ ) to internal control (77℃ ) was 5.01~6.11 and 3.34~4.31 in subjects with RHD exon 10 homozygous and heterozygous, respectively; the Tm ratio of RHD exon 5 (83℃ ) to internal control (77℃ ) was 3.98~4.75, 3.02~3.45, and 0.03 in subjects with RHD exon 5 homozygous, heterozygous, and deletion homozygous, respectively; the Tm ratio of 1227A (87℃ ) to internal control (77℃ ) was 1.11, 0.51, and <0.03 in subjects with 1227A heterozygous, 1227A homozygous (exon 9 deletion), and wild type, respectively. The results suggest that using the primers of Tm ratio in comparison with an internal control is an effective way to detect RHD gene deletion or RHD-RHCE hybrid variant allele carrier. The method can also be used to calculate the mother-newborn RHD phenotype proportion and assist pedigree analysis.     

Bioremediation of multi-metal contaminated soil using biosurfactant — a novel approach

An unconventional nutrient medium, distillery spent wash (1:3) diluted) was used to produce di-rhamnolipid biosurfactant by Pseudomonas aeruginosa strain BS2. This research further assessed the potential of the biosurfactant as a washing agent for metal removal from multimetal contaminated soil (Cr-940 ppm; Pb-900 ppm; Cd-430 ppm; Ni-880 ppm; Cu-480 ppm). Out of the treatments of contaminated soil with tap water and rhamnolipid biosurfactant, the latter was found to be potent in mobilization of metal and decontamination of contaminated soil. Within 36 hours of leaching study, di-rhamnolipid as compared to tap water facilitated 13 folds higher removal of Cr from the heavy metal spiked soil whereas removal of Pb and Cu was 9–10 and 14 folds higher respectively. Leaching of Cd and Ni was 25 folds higher from the spiked soil. This shows that leaching behavior of biosurfactant was different for different metals. The use of wastewater for production of biosurfactant and its efficient use in metal removal make it a strong applicant for bioremediation.     

Green synthesized nanoparticles in the fight against mosquito-borne diseases and cancer—a brief review

Nanobiomedicine and parasitology are facing a number of key challenges, which mostly deal with the paucity of effective preventive and curative tools against mosquito-borne diseases and cancer. In this scenario, the employ of botanical and invertebrate extracts as reducing, stabilizing and capping agents for the synthesis of nanoparticles is advantageous over chemical and physical methods, since it is one-pot, cheap, and does not require high pressure, energy, temperature, or the use of highly toxic chemicals. Considering the overlooked connection between mosquito vector activity and the spread of cancer in USA, this review focused on the current knowledge available about green synthesized nanoparticles with efficacy against mosquito-borne diseases and cancer. Green fabricated metal nanoparticles showed antiplasmodial activity that often encompasses the efficacy of currently marked drugs for malaria treatment. They have been also reported as growth inhibitors against dengue virus (serotype DEN-2), with moderate cytotoxicity on mammalian cells. However, this feature is strongly dependent to the botanical agents employed during nanosynthesis. In addition, green nanoparticles have been successfully used to reduce mosquito young instar populations in the field. The final section focuses on some issues for future research, with special reference to the chemical standardization of the botanical extracts used for nanosynthesis and the potential effects on green fabricated nanoparticles on non-target organisms.     

Atlantic Cod Trypsin Y—Member of a Novel Trypsin Group

A unique trypsinogen complementary DNA has been isolated from an Atlantic cod (Gadus morhua) cDNA library. Its predicted amino acid sequence contains 249 residues with a putative polypeptide of 227 residues. The distinctive features of this polypeptide, referred to as trypsin Y, are its low number of hydrogen-bond-forming residues, high content of Met and Pro residues, and lack of one conserved disulfide bond. Alignments show that cod trypsinogen Y has only approximately 45% identity to the two Atlantic cod trypsinogens I and X and most vertebrate trypsinogens. However, it has more than 70% identity to three other fish trypsinogens from two Pleuronectes and an Antarctic Notothenia species. These four trypsinogens share some unique characteristics and form a novel group, here referred to as group III. Received April 26, 1999; accepted June 29, 1999     

Y—box结合蛋白对mRNA的隐敝作用

本文介绍了Y-box结合蛋白与RNA的结合特征、影响因素以及mRNA隐蔽作用的调节等,分析了Y-box结合蛋白翻译抑制作用的原理和意义。由于Y-box结合蛋白特殊的、高度保守的结构,决定了它们与RNA(或DNA)的结合特征。任何影响Y-box结合蛋白结构的因素都将不同程度地影响其功能。Y-box结合蛋白被认为是生殖细胞和早胚细胞中含量最丰富的蛋白质之一,为“母系”和“父系”mRNP颗粒中的主要成分,在隐蔽mRNA中起重要作用。因而,对Y-box结合蛋白的研究,将对生殖细胞的成熟、早胚发育的分子机制以及母型向合子型过渡等一系列问题的解释都会有帮助。另外,研究范围若扩展到体细胞领域,也将对相关的研究有促进作用。