scholarly journals Heavy Metal Distributions in Water of the Aras River, Ardabil, Iran

2012 ◽  
Vol 04 (02) ◽  
pp. 73-78 ◽  
Author(s):  
Fatemeh Nasehi ◽  
Amirhesam Hassani ◽  
Masoud Monavvari ◽  
Abdoreza Karbassi ◽  
Nematollah Khorasani ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Aras River

scholarly journals Trophic transfer, bioaccumulation and Health risk assessment of heavy metal in Aras river, Case study: Amphipoda- Zander - Human

2021 ◽  
Author(s):  
Amir Dehghani ◽  
Atabak Roohi Aminjan ◽  
Allaverdi Dehghani
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Health Risk ◽  
Food Chain ◽  
Hazard Quotient ◽  
Human Health Risk ◽  
Close Correlation ◽  
International Standards ◽  
Target Hazard Quotient ◽  
Aras River

Abstract This research investigates and traces heavy metals (As, Pb, Cd and Cu) in a model of the aqueous food chain in the Aras River, located in northwestern of Iran. The selected model includes the zander (Sander lucioperca L.) and crustacean species known as amphipods (Gammarus spp.) that belong to the food chain of this fish. A total of 172 samples (70 fish and 102 Amphipoda) were collected randomly from the stations and analyzed for heavy metals using an Atomic Absorption Spectrophotometry (AAS). The results showed that the accumulation of heavy metals in both Taxon are in the order of As > Pb > Cd > Cu and concentrations of heavy metals in fish body are higher than Gammarus spp. in every stations in different seasons. Specimens of station (1) due to industrial activities indicates the highest heavy metal content. The concentrations of As, Pb, and Cd exceedes the permissible limits. There is a close correlation between the concentration of heavy metals in the amphipod and zander. The target hazard quotient (THQ), Total target hazard quotient (TTHQ) and Carcinogenic Risk (CR) were calculated to assess human health risk. The average of THQ for As (1.43) exceedes the international standards and will endangere the consumers of this fish species. The TTHQ for heavy metals has been estimated highr than 1. and at all stations, the value of CRCd > 1×10− 3, which reveals the degree of evidence of carcinogenicity of this metal in all parts of the Aras River. Therefore, according to results, effective controls and regular monitoring should be established in this regions

Complementary Z-Contrast Imaging and Digital Image Processing

1985 ◽  
Vol 43 ◽  
pp. 304-305
Author(s):  
K. N. Colonna ◽  
G. Oliphant
Keyword(s):  
Image Processing ◽  
Heavy Metal ◽  
Digital Image Processing ◽  
Digital Image ◽  
Biological Tissue ◽  
Biological Imaging ◽  
Tissue Preparation ◽  
Contrast Imaging ◽  
Imaging Tool ◽  
Z Contrast

Harmonious use of Z-contrast imaging and digital image processing as an analytical imaging tool was developed and demonstrated in studying the elemental constitution of human and maturing rabbit spermatozoa. Due to its analog origin (Fig. 1), the Z-contrast image offers information unique to the science of biological imaging. Despite the information and distinct advantages it offers, the potential of Z-contrast imaging is extremely limited without the application of techniques of digital image processing. For the first time in biological imaging, this study demonstrates the tremendous potential involved in the complementary use of Z-contrast imaging and digital image processing.Imaging in the Z-contrast mode is powerful for three distinct reasons, the first of which involves tissue preparation. It affords biologists the opportunity to visualize biological tissue without the use of heavy metal fixatives and stains. For years biologists have used heavy metal components to compensate for the limited electron scattering properties of biological tissue.

Recent Progress In High-Resolution Shadowing For Biological Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 510-511 ◽  
Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann
Keyword(s):  
Heavy Metal ◽  
High Resolution ◽  
Freeze Drying ◽  
Atmospheric Conditions ◽  
Vacuum Equipment ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Gas Molecules ◽  
Residual Gas ◽  
Backing Layer

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.

Heavy Metal Tales

2008 ◽  
Vol 42 (2) ◽  
pp. 24
Author(s):  
WILLIAM G. WILKOFF
Keyword(s):  
Heavy Metal

Musik und Gesundheit

2010 ◽  
Vol 21 (1) ◽  
pp. 1-6
Author(s):  
Hans-Joachim Trappe
Keyword(s):  
Heavy Metal ◽  
Physiologische Parameter

Zusammenfassung. Musik (M) spielt im Leben eines jeden Menschen nicht nur eine wichtige Rolle, sondern hat auch Effekte auf Herzfrequenz (HF), Herzfrequenzvariabilität (HRV) und auf andere physiologische Parameter. Bei Musikern sind die Beeinflussungen von HF, HRV und autonomen Nervensystem größer als bei Musik-Zuhörern. Obgleich M als subjektives Empfinden zu interpretieren ist, zeigen Studien, dass objektive Parameter unter verschiedenen Umständen eindeutig durch Musik beeinflusst werden. Es wurde nachgewiesen, dass M als Prämedikation zu einer signifikant niedrigen Ängstlichkeitsrate führte als Midazolam (p < 0,001). M wird auch bei anderen Situationen eingesetzt, bei depressiven Menschen, alten Menschen, zur Schmerztherapie und im Rahmen der Intensiv- bzw. Palliativmedizin. M sollte jedoch individuell nach den Wünschen der Pt ausgewählt werden. Nur so lassen sich die gewünschten Effekte erreichen, Ängste vermeiden und führen zu einer Verbesserung der Lebensqualität (QoL). Die besten M-Effekte sind durch klassische oder meditative M zu erreichen, Heavy Metal or Techno-M ist ineffektiv oder gar schädlich und kann zu Stress oder lebensgefährlichen Arrhythmien führen. Es gibt viele Komponisten, deren M zu einer Verbesserung der QoL führt, besonders Bach, Mozart oder italienische Komponisten sind hier zu nennen.

Heavy metal binding by mycorrhizal fungi

1994 ◽  
Vol 92 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Ulrich Galli ◽  
Hannes Schuepp ◽  
Christian Brunold
Keyword(s):  
Heavy Metal ◽  
Metal Binding ◽  
Mycorrhizal Fungi ◽  
Heavy Metal Binding
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