There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

I read this book the same weekend that the Packers took on the Rams, and the experience of the latter event, obviously, colored my judgment. Although I abhor anything that smacks of being a handbook (like, \"How to Earn a Merit Badge in Neurosurgery\") because too many volumes in biomedical science already evince a boyscout-like approach, I must confess that parts of this volume are fast, scholarly, and significant, with certain reservations. I like parts of this well-illustrated book because Dr. Sj6strand, without so stating, develops certain subjects on technique in relation to the acquisition of judgment and sophistication. And this is important! So, given that the author (like all of us) is somewhat deficient in some areas, and biased in others, the book is still valuable if the uninitiated reader swallows it in a general fashion, realizing full well that what will be required from the reader is a modulation to fit his vision, propreception, adaptation and response, and the kind of problem he is undertaking. A major deficiency of this book is revealed by comparison of its use of physics and of chemistry to provide understanding and background for the application of high resolution electron microscopy to problems in biology. Since the volume is keyed to high resolution electron microscopy, which is a sophisticated form of structural analysis, but really morphology in a modern guise, the physical and mechanical background of The instrument and its ancillary tools are simply and well presented. The potential use of chemical or cytochemical information as it relates to biological fine structure , however, is quite deficient. I wonder when even sophisticated morphol-ogists will consider fixation a reaction and not a technique; only then will the fundamentals become self-evident and predictable and this sine qua flon will become less mystical. Staining reactions (the most inadequate chapter) ought to be something more than a technique to selectively enhance contrast of morphological elements; it ought to give the structural addresses of some of the chemical residents of cell components. Is it pertinent that auto-radiography gets singled out for more complete coverage than other significant aspects of cytochemistry by a high resolution microscopist, when it has a built-in minimal error of 1,000 A in standard practice? I don't mean to blind-side (in strict football terminology) Dr. Sj6strand's efforts for what is \"routinely used in our laboratory\"; what is done is usually well done. It's just that …

Methods in Enzymology.

The first part of this two-part review focused on the fundamental and diagnostics aspects of laser-induced plasmas, only touching briefly upon concepts such as sensitivity and detection limits and largely omitting any discussion of the vast panorama of the practical applications of the technique. Clearly a true LIBS community has emerged, which promises to quicken the pace of LIBS developments, applications, and implementations. With this second part, a more applied flavor is taken, and its intended goal is summarizing the current state-of-the-art of analytical LIBS, providing a contemporary snapshot of LIBS applications, and highlighting new directions in laser-induced breakdown spectroscopy, such as novel approaches, instrumental developments, and advanced use of chemometric tools. More specifically, we discuss instrumental and analytical approaches (e.g., double- and multi-pulse LIBS to improve the sensitivity), calibration-free approaches, hyphenated approaches in which techniques such as Raman and fluorescence are coupled with LIBS to increase sensitivity and information power, resonantly enhanced LIBS approaches, signal processing and optimization (e.g., signal-to-noise analysis), and finally applications. An attempt is made to provide an updated view of the role played by LIBS in the various fields, with emphasis on applications considered to be unique. We finally try to assess where LIBS is going as an analytical field, where in our opinion it should go, and what should still be done for consolidating the technique as a mature method of chemical analysis.

https://journals.sagepub.com/doi/pdf/10.1366/11-06574

Laser-induced breakdown spectroscopy (LIBS), part II: review of instrumental and methodological approaches to material analysis and applications to different fields.

Nanoparticles (NPs) of copper oxide (CuO), zinc oxide (ZnO) and especially nanosilver are intentionally used to fight the undesirable growth of bacteria, fungi and algae. Release of these NPs from consumer and household products into waste streams and further into the environment may, however, pose threat to the ‘non-target’ organisms, such as natural microbes and aquatic organisms. This review summarizes the recent research on (eco)toxicity of silver (Ag), CuO and ZnO NPs. Organism-wise it focuses on key test species used for the analysis of ecotoxicological hazard. For comparison, the toxic effects of studied NPs toward mammalian cells in vitro were addressed. Altogether 317 L(E)C50 or minimal inhibitory concentrations (MIC) values were obtained for algae, crustaceans, fish, bacteria, yeast, nematodes, protozoa and mammalian cell lines. As a rule, crustaceans, algae and fish proved most sensitive to the studied NPs. The median L(E)C50 values of Ag NPs, CuO NPs and ZnO NPs (mg/L) were 0.01, 2.1 and 2.3 for crustaceans; 0.36, 2.8 and 0.08 for algae; and 1.36, 100 and 3.0 for fish, respectively. Surprisingly, the NPs were less toxic to bacteria than to aquatic organisms: the median MIC values for bacteria were 7.1, 200 and 500 mg/L for Ag, CuO and ZnO NPs, respectively. In comparison, the respective median L(E)C50 values for mammalian cells were 11.3, 25 and 43 mg/L. Thus, the toxic range of all the three metal-containing NPs to target- and non-target organisms overlaps, indicating that the leaching of biocidal NPs from consumer products should be addressed.

https://link.springer.com/content/pdf/10.1007%2Fs00204-013-1079-4.pdf

Toxicity of Ag, CuO and ZnO nanoparticles to selected environmentally relevant test organisms and mammalian cells in vitro: a critical review

■ CONTENTS General Information: Books, Reviews, and Conferences 640 Fundamentals 641 Interaction of Laser Beam with Matter 641 Factors Affecting Laser Ablation and LaserInduced Plasma Formation 642 Influence of Target on the Laser-Induced Plasmas 642 Influence of Laser Parameters on the LaserInduced Plasmas 643 Laser Wavelength (λ) 643 Laser Pulse Duration (τ) 643 Laser Pulse Energy (E) 645 Influence of Ambient Gas on the Laser-Induced Plasmas 645 LIBS Methods 647 Double Pulse LIBS 647 Femtosecond LIBS 651 Resonant LIBS 652 Ranging Approaches 652 Applications 654 Surface Inspection, Depth Profiling, and LIBS Imaging 654 Cultural Heritage 654 Industrial Analysis 655 Environmental Monitoring 656 Biomedical and Pharmaceutical Analysis 658 Security and Forensics 659 Analysis of Liquids and Submerged Solids 660 Space Exploration and Isotopic Analysis 662 Space Exploration 662 Isotopic Analysis 662 Conclusions and Future Outlook 663 Author Information 664 Corresponding Author 664 Notes 664 Biographies 664 Acknowledgments 664 References 664

Laser-induced breakdown spectroscopy.

catalyze the synthesis of heavy metal-binding PCs3, 4. PCs, cysteine-rich peptides, are produced from glutamine, cysteine and glycine. Unlike commonmetal-binding structures, MT and GSH, PCs are not gene-encoded, but enzymatically synthesized peptides5. PCs have been identified in a wide variety of plant species, microorganisms and some invertebrates6-10. They are structurally related to glutathione (GSH) and were presumed to be the products of a biosynthetic pathway. Numerous physiological, biochemical and genetic studies have confirmed GSH as the substrate for PCs biosynthesis11,12. The general structure of PCs is (c-Glu-Cys)n-Gly, with increasing repetitions of the dipeptide Glu-Cys linked through a c-carboxylamide bond (Fig 1), where n varies from 2 to 11, but typically reaching not further than five13. Except glycine, also other amino acid residues can be found on C-terminal end of (γ-Glu-Cys)n peptides. Examples of which, like Ser, Glu, Gln and Ala are often found at The role of phytochelatins in plant and animals: A review Miguel Angel Merlosa,b, Petr Michaleka,b, Olga Krystofovaa,b, Ondřej Zitkaa,b, Vojtěch Adama,b, Rene Kizeka,b

/pdf/the-role-of-phytochelatins-in-plant-and-animals-a-review-42g7e4ec4e.pdf

The role of phytochelatins in plant and animals: A review

Protein p53 is a transcriptional factor, which is routinely
attendant in a cell at low concentrations. Alzheimer's disease,
Parkinson's disease, cystic fibrosis, prion diseases, and many
types of cancer are considered to be protein p53 conformation
diseases. Most of them are also known as amyloidogenic diseases
due to the occurrence of pathological accumulation of insoluble
aggregates with fibrillar conformation. Some neuroblastomas,
carcinomas, and myelomas show an abnormal accumulation of the
wild-type tumor suppressor protein p53 either in the cytoplasm
or in the nucleus of the cell. Electrochemical methods could be
a suitable tool for study of very low protein p53 intracellular
concentrations. In our work, protein p53 was analyzed by flow
injection analysis coupled with electrochemical detector. The
optimized method was rapid (less then five minutes) and
sensitive (protein p53 detection limit was 45 amol). The
sensitive detection method was applied to the study structural
changes of protein p53 (denaturation and aggregation).
Considerable changes in electrochemical responses of individual
protein p53 forms were observed. That is why the denatured and
aggregated protein p53 form could be easily differentiated from
the native form of protein p53. The described method brings a
new effective tool for the study of normal and tumorous cells.

Fast and sensitive electrochemical detection of native,denatured, and aggregated forms of tumor supressor protein p53

In this contribution, Trolox equivalent antioxidant capacity (TEAC) was determined in various berries using carbon paste tyrosinase biosensor with multi-walled carbon nanotubes (MWCNTs), coated with Nafion® layer. Electrochemical behaviour of the biosensor and influence of MWCNTs on carbon paste surface were studied with respect to the sensitive amperometric detection of total content of phenolic compounds in berries, expressed as concentration equivalent of Trolox. After optimization of key instrumental and electroanalytical parameters, the biosensor was used for determination of TEAC in blackberries, blueberries, cranberries, raspberries and strawberries by method of multiple standard additions. Electrochemical TEAC assays corresponded well with results obtained by spectrophotometric 1,1-diphenyl-2-picrylhydrazyl radical method, known as DPPH assay. Obtained values were compared with those listed in the National Nutrient Database for additional antioxidant capacity assays as well.

Determination of trolox equivalent antioxidant capacity in berries using amperometric tyrosinase biosensor based on multi-walled carbon nanotubes

http://web2.mendelu.cz/af_239_nanotech/data/pub/y-Fe2O3%20Magnetic%20Core%20Functionalized%20with%20Tetraethyl%20Orthosilicate%20and%203-Aminopropyl%20Triethoxysilane%20for%20an%20Isolation%20of%20H7N7%20Influenza%20Serotype%20Virions.pdf

Vojtěch Adam

Papers

The role of phytochelatins in plant and animals: A review

Fast and sensitive electrochemical detection of native,denatured, and aggregated forms of tumor supressor protein p53

Determination of trolox equivalent antioxidant capacity in berries using amperometric tyrosinase biosensor based on multi-walled carbon nanotubes

y-Fe2O3 Magnetic Core Functionalized with TetraethylOrthosilicate and 3-Aminopropyl Triethoxysilane for anIsolation of H7N7 Influenza Serotype Virions

Kinetic analysis of human metallothionein and CdTe quantum dot complexes using fluorescence and voltammetry techniques.