Cadmium effects on embryo growth of pea seeds during germination: Investigation of the mechanisms of interference of the heavy metal with protein mobilization-related factors

2018 ◽  
Vol 226 ◽  
pp. 64-76 ◽  
Author(s):  
Khadija Jaouani ◽  
Inès Karmous ◽  
Maciej Ostrowski ◽  
Ezzedine El Ferjani ◽  
Anna Jakubowska ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Related Factors ◽  
Protein Mobilization ◽  
Pea Seeds

Effect of metal ions on pea alcohol dehydrogenase

1979 ◽  
Vol 44 (3) ◽  
pp. 799-803 ◽  
Author(s):  
Sylva Leblová ◽  
Noemi Nováková ◽  
Marie Stiborová
Keyword(s):  
Heavy Metal ◽  
Alcohol Dehydrogenase ◽  
Metal Ions ◽  
Mechanism Of Action ◽  
Heavy Metal Ions ◽  
Inhibitory Effect ◽  
Zinc Ions ◽  
Pea Seeds

The effect of Cu2+, Ag+, Zn2+, Cd2+ and Co2+ on alcohol dehydrogenase (ADH) isolated from germinating pea seeds was examined. The enzyme is inhibited approximately to the same degree if incubated 5 to 30 min with Ag+, Cu2+, and Cd2+; the same degree of inhibition can be brought about by zinc ions only if concentration by one order higher (10-4M) is used. Co2+-ions do not inhibit pea alcohol dehydrogenase even at 10-3M concentration. NAD and Zn2+ decrease the inhibitory effect of Cd2+ yet not the effect of Cu2+ or Ag+. The differences in the mechanism of action of individual heavy metal ions on plant ADH are discussed.

Practical Importance of Spatial Resolution and Analytical Sensitivity in AEM X-ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 432-433
Author(s):  
J. Zhang ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Spatial Resolution ◽  
Practical Importance ◽  
Beam Current ◽  
Specimen Thickness ◽  
Analytical Sensitivity ◽  
Related Factors ◽  
X Ray ◽  
Probe Size ◽  
Excitation Volume ◽  
Two Parameters

Analytical sensitivity and spatial resolution are important and closely related factors in x-ray microanalysis using the AEM. Analytical sensitivity is the ability to distinguish, for a given element under given conditions, between two concentrations that are nearly equal. The analytical sensitivity is directly related to the number of x-ray counts collected and, therefore, to the probe current, specimen thickness and counting time. The spatial resolution in AEM analysis is determined by the probe size and beam broadening in the specimen. A finer probe and a thinner specimen give a higher spatial resolution. However, the resulting lower beam current and smaller X-ray excitation volume degrade analytical sensitivity. A compromise must be made between high spatial resolution and an acceptable analytical sensitivity. In this paper, we show the necessity of evaluating these two parameters in order to determine the low temperature Fe-Ni phase diagram.A Phillips EM400T AEM with an EDAX/TN2000 EDS/MCA system and a VG HB501 FEG STEM with a LINK AN10 EDS/MCA system were used.

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.

Voice Therapy With Seniors: Attendance, Outcomes, and Associated Patient Characteristics

2019 ◽  
Vol 4 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Bonnie E. Smith ◽  
Ruth Huntley Bahr ◽  
Hector N. Hernandez
Keyword(s):  
Outcome Data ◽  
Voice Therapy ◽  
Similar Data ◽  
Success Rates ◽  
Reflux Symptom Index ◽  
Voice Change ◽  
Related Factors ◽  
Symptom Index ◽  
Younger Patients ◽  
Unsuccessful Treatment

Purpose The purpose of this study was to determine the attendance and success rates for seniors in voice therapy, identify any contributing patient-related factors, and compare results to existing findings for younger patients. Method This retrospective study included information from the voice records of 50 seniors seen by the same speech-language pathologist in a private practice. Analysis of attendance and outcome data divided participants into 6 groups. Outcomes for Groups 1–3 (64% of patients) were considered successful (positive voice change), while outcomes for Groups 4–6 (36% of patients) were considered unsuccessful. These data were compared to similar data collected for younger adults in a previous study. Results The attendance and success rates for seniors in this study were higher than those previously reported for younger patients. Further consideration of patient factors revealed that reports of increased stress, Reflux Symptom Index scores > 13, and higher Voice Handicap Index functional subscale scores were significant in distinguishing between patients in the successful and unsuccessful treatment outcome groups. Conclusions The relatively high attendance and success rates among this sample of seniors suggest the desire to achieve voice improvement does not diminish with age, and chances for success in voice therapy among nonfrail seniors may be greater than for younger patients.

Obstacles to Claiming Permanence and Injury-Relatedness for “Posttraumatic” Headache

2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth
Keyword(s):  
Complete Recovery ◽  
World Health ◽  
Related Factors ◽  
Posttraumatic Headache ◽  
Sixth Edition ◽  
Causative Relationship ◽  
Short Period ◽  
The One ◽  
Health Organization ◽  
Subjective Reports

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.

Heavy Metal Tales

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