Bioaccumulation of Heavy Metal in Plants: Morphological and Physiological Changes

2020 ◽  
pp. 1-20
Author(s):  
V. Verma ◽  
G. Singhal ◽  
P. Singh ◽  
N. Srivastava
Author(s):  
K. N. Colonna ◽  
G. Oliphant

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.


Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann

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.


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

2010 ◽  
Vol 21 (1) ◽  
pp. 1-6
Author(s):  
Hans-Joachim Trappe

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.


2020 ◽  
Vol 34 (3) ◽  
pp. 192-201
Author(s):  
Melanie M. van der Ploeg ◽  
Jos F. Brosschot ◽  
Markus Quirin ◽  
Richard D. Lane ◽  
Bart Verkuil

Abstract. Stress-related stimuli may be presented outside of awareness and may ultimately influence health by causing repetitive increases in physiological parameters, such as blood pressure (BP). In this study, we aimed to corroborate previous studies that demonstrated BP effects of subliminally presented stress-related stimuli. This would add evidence to the hypothesis that unconscious manifestations of stress can affect somatic health. Additionally, we suggest that these findings may be extended by measuring affective changes relating to these physiological changes, using measures for self-reported and implicit positive and negative affectivity. Using a repeated measures between-subject design, we presented either the prime word “angry” ( n = 26) or “relax” ( n = 28) subliminally (17 ms) for 100 trials to a student sample and measured systolic and diastolic BP, heart rate (HR), and affect. The “angry” prime, compared to the “relax” prime, did not affect any of the outcome variables. During the priming task, a higher level of implicit negative affect (INA) was associated with a lower systolic BP and diastolic BP. No association was found with HR. Self-reported affect and implicit positive affect were not related to the cardiovascular (CV) activity. In sum, anger and relax primes elicited similar CV activity patterns, but implicit measures of affect may provide a new method to examine the relationship between (unconscious) stress and health.


1994 ◽  
Vol 92 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Ulrich Galli ◽  
Hannes Schuepp ◽  
Christian Brunold

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