Specific arrangements of membrane particles at sites of exo-endocytosis in the freeze-etched neurohypophysis

Summary Images have been obtained from freeze-etch replicas of neurohypophyses which are consistent with the view that orderly arranged aggregates of membrane particles occur in regions where fragments of membrane are being added to and taken away from the plasma membrane during secretion. Aggregates of particles included rosette-like and necklace-like patterns similar to those described by other authors at sites of exocytosis and endocytosis.Dedicated to Prof. W. Bargmann at the occasion of his 70th birthday. A short account has been presented at the 8th International Congress of Electron Microscopy (Dreifuss, Akert, Sandri and Moor, 1974).This work was supported by grants from the Swiss National Foundation for Scientific Research Nos. 3.257.74, 3.368.0.74, 3.774.72 and 3.045.73; the Hartmann-Müller Foundation for Medical Research in Zürich and the Dr. Eric Slack-Gyr Stiftung.     

Particulate and dissolved organic matter in a small partly forested Ontario stream

Weekly measurements during the open season at five stations on a small Ontario stream system showed that the size distribution of fine particles in the water varied irregularly. In general, rainfall increased their total amount and also the concentration of dissolved organic carbon. Clearly other local factors affect the supply of particles, and each reach behaves individually and may react differently to successive storms. The behaviour of dissolved material is more predictable, and it is clear that much is rapidly removed from solution. It was shown that high concentrations of particles are associated with high amounts of plant pigments, carbohydrate, and protein. Similarly dissolved carbohydrate and protein are raised when rain increases dissolved organic carbon. These findings suggest a series of mechanisms by which a woodland stream may trap woodland produced energy and cycle it through the aquatic system.This work was supported by a research grant from the National Research Council of Canada to H. B. N. Hynes.     

Utilization of calcium carbonate particles from eggshell waste as coating pigments for ink-jet printing paper

The effective treatment and utilization of biowaste have been emphasized in our society for environmental and economic concerns. Recently, the eggshell waste in the poultry industry has been highlighted because of its reclamation potential. This study presents an economical treatment process to recover useful bioproducts from eggshell waste and their utilization in commercial products. We developed the dissolved air floatation (DAF) separation unit, which successfully recovered 96% of eggshell membrane and 99% of eggshell calcium carbonate (ECC) particles from eggshell waste within 2 h of operation. The recovered ECC particles were utilized as coating pigments for ink-jet printing paper and their impact on the ink density and paper gloss were investigated. The addition of the ECC particles as coating pigments enhances the optical density of cyan, magenta and yellow inks while decreasing the black ink density and the gloss of the coated paper.     

Effects of Gamma Irradiation and Silver Nano Particles on Microbiological Characteristics of Saffron,Using Hurdle Technology

Saffron, a plant from the Iridaceae family, is the world’s most expensive spice. Gamma irradiation and silver nano particles whose uses are gradually increasing worldwide, have positive effects on preventing decay by sterilizing the microorganisms and by improving the safety without compromising the nutritional properties and sensory quality of the foods. In the present study combination effects of gamma irradiation and silver nano particles packaging on the microbial contamination of saffron were considered during storage. A combination of hurdles can ensure stability and microbial safety of foods. For this purpose, saffron samples were packaged by Poly Ethylene films that posses up to 300 ppm nano silver particles as antimicrobial agents and then irradiated in cobalt-60 irradiator (gamma cell Model: PX30, dose rate 0.55 Gry/Sec) to 0, 1, 2,3 and 4 kGy at room temperature. The antimicrobial activities against Total Aerobic Mesophilic Bacteria, Entrobacteriace, Escherichia Coli and Clostridium Perfringines were higher in the irradiated samples, demonstrating the inhibition zone for their growth. Irradiation of the saffron samples packaged by Poly Ethylene films with nano silver particles showed the best results for decreasing microbial contamination at 2 kGy and for Poly Ethylene films without silver nano particles; it was 4 kGy.     

Purification and partial characterization of a protease associated with photosystem II particles

A protease was extracted with 1 M NaCl from spinach ( Spinacia oleracea L.) photosystem II (PSII) particles and purified through gel filtration and anion-exchange chromatography. SDS-polyacrylamide gel electrophoresis of the protease revealed a polypeptide with a molecular mass of 43 kDa. The activity of the purified protease was assayed using a 24 kDa water-soluble protein as substrate, visualized through SDS-PAGE. The protease even remained active in the presence of 0.1 and 0.2 M NaCl, although the degradation pattern changed, which indicated that the protease was different from that reported earlier by another group. The presence of 0.3 M NaCl was shown to be inhibitory. The protease was inhibited by 1,10-phenanthroline and EGTA-NaOH (pH 7.0), indicating that the metal ions are essential for activity and that the enzyme is a metal-protease. FTIR spectroscopy was used to examine the conformationally sensitive amide I' bands of the protease. The protease was observed to undergo spectroscopic changes that reflect the conformational changes that take place when Ca²⁺ is bound, which further confirms that the protease is a metal-protease.     

Lipid molecular timeline profiling reveals diurnal crosstalk between the liver and circulation

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基于裸磁珠体系检测血清淀粉样蛋白A浓度方法的建立与效果评估

传统链霉亲和素磁珠体系及酶促发光体系中通常存在生物素干扰强、发光率低、特异性差的缺陷。基于此，以裸磁珠为载体偶联血清淀粉样蛋白A（serum amyloid A, SAA）抗体，以吖啶酯作为发光标记物，依据双抗夹心原理，建立了一种快速测定SAA的方法，并对该方法的检测性能（包括：空白限、检测限、线性范围、精密度验证、干扰试验、HOOK效应、方法学比较等）进行了评估。结果表明，SAA抗体与裸磁珠成功偶联；该方法空白限为0.6 mg·mL^-1，检出限为1.0 mg·mL^-1；线性范围为1~100 mg·mL^-1 （R²＞0.990）；在精密度方面，以CV表示的重复性、室内精密度均<10%；血红蛋白、胆红素、甘油三酯对临床样本的干扰检测结果相对偏差均<10%。Bland-Altman偏倚分析表明，该方法检测值与西门子试剂的测量值差异基本在95％CI的一致性界限内波动，回归分析结果显示有较好的相关性（R²=0.987）。上述结果表明，研究所建立的裸磁珠-吖啶酯发光检测体系性能参数可满足临床检测要求，适用于血清中SAA的快速检测。