Photodegradation of polypropylene thermal bonded non-woven fabric

Samples of thermal bonded polypropylene non-woven fabrics were exposed to light from two TUV 30W G30T8 Philips lamps (λ = 253.7 nm) in a covered open-air chamber at room temperature (25 °C and 55% relative humidity) for different periods of time. In order to determine the state of degradation, the samples were examined by optical microscopy, scanning electron microscopy, staining with an isopropanol solution of methylene blue and Sudan III, colourimetry, Fourier transform infrared (FTIR) spectroscopy and density measurements. Although the bonded areas formed under complex thermal and mechanical deformations during the fabric production, no localized staining was observed. The colour of the irradiated and stained fabrics changed uniformly due to the even production of polar groups in the process of irradiation. It was found that the change of redness and blueness of degraded and stained samples can be correlated linearly with the evolution of POOH groups as determined by FTIR spectroscopy. Products containing carbonyl (CO), hydroxyl and/or hydroperoxide (POOH) groups increase with time of degradation with a non-linear relation. It was also observed that the density and 997 cm⁻¹/972 cm⁻¹ FTIR absorbance ratio increases with degradation time. Density fluctuation and the build up of degradation products caused fibre cracks and embrittlement.     

Investigation of chemical activity,SCHIFF base reactions and staining effects of some amino acids by spectrophotometric and theorical methods

In this study, the staining properties of selected amino acids with Brassica oleraceae extract in alum and alum-free media were investigated. Basic, acidic and neutral amino acids (arginine, glutamic acid and glycine) were used to investigate the effect of staining. It was determined that all amino acids were stained in alum media. In the second step, the R group of amino acids found in the proteins of the cell nucleus was reacted with salicyl aldehyde. This reaction was successful only with Arginine. The staining properties of the newly formed compound were also investigated in alum and alum-free environments. Evaluation of the results was done using FT-IR and ¹H NMR methods. All compounds were optimized with the Gaussian G09 program (DFT/B3LYP/6.311 ?G(d.p) basic set. HOMO, LUMO and HOMO-LUMO gap values were determined. Chemical reaction capabilities of amino acids were discussed with the help of HOMO-LUMO gap values.     

酸性染料用于木材染色的研究

选择酸性染料对低质阔叶材单板进行染色研究，发现此类染料对滇杨木，滇桤木，西南桦有较好的易染性，通过试验得到几例常见木材颜色的染料配比，并对染色工艺进行了初步探讨，结果表明温度在70-80℃，pH=4及助染剂量1.5(wt)%时，染色效果最佳。     

一种考马斯亮蓝G-250快速染色法在SDS-PAGE中的应用

对SDS聚丙烯酰胺凝胶电泳中一种仅加入3mmol/L盐酸的考马斯亮蓝G-250染色液配合微波加热的快速染色方法的具体条件进行了研究.该方法能在1h内完成,比常规考马斯亮蓝R-250染色法短得多.同时未加入有机溶剂和其他酸,对人体几乎无害,对环境污染小.而其灵敏度与常规考马斯亮蓝R-250染色法相近,适于在实验教学和科研方面进行推广应用.     

Classifying Human Haptoglobin Phenotypes on Native‐PAGE Using a Modified Coomassie Brilliant Blue R 250 Staining

There are three types of human Haptoglobin, Hp 1‐1, Hp 2‐1, and Hp 2‐2, each characterized by a distinct combination of the two α chains of the holoprotein. A modified Coomassie Brilliant Blue R 250 (mCBB‐R250) staining method for detecting the phenotypes of human blood haptoglobin molecules is presented. Addition of excess hemoglobin to the sample allowed specific formation of different haptoglobin‐hemoglobin complexes, which, in turn can be separated into distinctive migration pattern on native‐PAGE and stained by CBB‐R250. The typing results are consistent with that using Western blotting. In comparison to the existing methods for haptoglobin typing, our method is comparable in accuracy, and is easier to carry out. The results on typing of 29 plasma samples from Taipei Blood Center were also presented.     

The staining efficiency of cyanine dyes for single‐stranded DNA is enormously dependent on nucleotide composition

The staining of nucleic acids with fluorescent dyes is one of the most fundamental technologies in relevant areas of science. For reliable and quantitative analysis, the staining efficiency of the dyes should not be very dependent on the sequences of the specimens. However, this assumption has not necessarily been confirmed by experimental results, especially in the staining of ssDNA (and RNA). In this study, we found that both SYBR Green II and SYBR Gold did not stain either homopyrimidines or ssDNA composed of only adenine (A) and cytosine (C). However, these two dyes emit strong fluorescence when the ssDNA contains both guanine (G) and C (and/or both A and thymine (T)) and form potential Watson‐Crick base pairs. Interestingly, SYBR Gold, but not SYBR Green II, strongly stains ssDNA consisting of G and A (or G and T). Additionally, we found that the secondary structure of ssDNA may play an important role in DNA staining. To obtain reliable results for practical applications, sufficient care must be paid to the composition and sequence of ssDNA.     

Intra-layer flow in fouling layer on membranes

The structure of fouling layer determines the pressure drop across the fouling layer. Three-dimensional distributions of nucleic acids, proteins, α-d-glucopyranose polysaccharides, β-d-glucopyranose polysaccharides and lipids in the biofouling layer that is formed on a mixed cellulose ester membrane were determined using a six-fold staining protocol combined with confocal laser scanning microscopy (CLSM). Based on the three-dimensional volumetric grid model of the fouling layer structure observed from the series of CLSM images, the intra-layer flow field during filtration was simulated using commercial software. The effective permeability of the fouling layer was estimated to be 2.65 × 10⁻¹² m², which determines the upper estimate on the permeability of the fouling layer. The pores were categorized according to their diameters, using the maximum convex perimeter approach, and then the effects of the blocking pores on the permeability of the fouling layer were investigated. Blocking the large pores that accounted for 15% of the porosity reduced the mean permeability by 58%.     

全同立构聚丙烯的晶片形态

本文应用光学显微镜,扫描和透射电子显微镜从三种不同层次的结构水平上研究了α和β两种晶型的全同立构聚丙烯的球晶和晶片形态结构,特别是应用四氧化钌染色技术直接观察到两种不同晶型聚丙烯球晶中单独分离的晶片形态.结果表明,不同晶型聚丙烯球晶的形态是不同的,其所呈现的性质与其内部晶片结构的排列特征相对应.同时研究了两种晶型聚丙烯在熔体拉伸结晶条件下生成的晶片形态,倾向于相同的取向晶片结构.电子衍射数据证明了,β型聚丙烯在拉伸取向结晶时将转变为α晶型.     

Understanding otolith biomineralization processes: new insights into microscale spatial distribution of organic and mineral fractions from Raman microspectrometry

It is generally accepted that the formation of otolith microstructures (L- and D-zones) and in particular the organic and mineral fractions vary on a daily basis. Raman microspectrometry provides a nondestructive technique that can be used to provide structural information on organic and mineral compounds. We applied it to thin otolith sections of hake in order to address the following issues: (1) the simultaneous characterization of variations in the organic and mineral fractions both in the core area and along successive otolith microstructures; (2) elucidation of significant differences between these fractions; (3) quantification of the effects of etching and staining protocols on otolith structures. The primordium appeared as a punctual area depicting higher luminescence and greater concentrations in organic compounds containing CH groups. Sulcus side showed similar composition suggesting that the contact of the otolith with the macula and its orientation in otosac occur rapidly (about 10 days). The characterization of L- and D-zones in the opaque zones indicated that both structures contained organic and aragonitic fractions with cyclic and synchronous variations. Contrary to the results obtained after EDTA etching, L-zones depicted greater concentrations in organic compounds containing CH groups, whereas D-zones appear richer in aragonite. This organic fraction seemed to be revealed by Mutvei’s staining and was affected by EDTA etching which suggests that it corresponds to the soluble fraction of organic matrix. Such results indicate that L- and D-zones differ in their respective organic constituents. Raman microspectrometry thus appears as a powerful technique to acquire quantitative information that is required for a better understanding of otolith biomineralization. Figure Raman microspectrometry is a powerful technique for studying otolith biomineralization