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.

1: Magnetic Particles: Preparation, Properties and Applications: M. Ozaki. 2: Maghemite (gamma-Fe2O3): A Versatile Magnetic Colloidal Material C.J. Serna, M.P. Morales. 3: Dynamics of Adsorption and Oxidation of Organic Molecules on Illuminated Titanium Dioxide Particles Immersed in Water M.A. Blesa, R.J. Candal, S.A. Bilmes. 4: Colloidal Aggregation in Two-Dimensions A. Moncho-Jorda, F. Martinez-Lopez, M.A. Cabrerizo-Vilchez, R. Hidalgo Alvarez, M. Quesada-PMerez. 5: Kinetics of Particle and Protein Adsorption Z. Adamczyk.

Surface and Colloid Science

Recent advances in nanoscience and nanotechnology radically changed the way we diagnose, treat, and prevent various diseases in all aspects of human life. Silver nanoparticles (AgNPs) are one of the most vital and fascinating nanomaterials among several metallic nanoparticles that are involved in biomedical applications. AgNPs play an important role in nanoscience and nanotechnology, particularly in nanomedicine. Although several noble metals have been used for various purposes, AgNPs have been focused on potential applications in cancer diagnosis and therapy. In this review, we discuss the synthesis of AgNPs using physical, chemical, and biological methods. We also discuss the properties of AgNPs and methods for their characterization. More importantly, we extensively discuss the multifunctional bio-applications of AgNPs; for example, as antibacterial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anti-cancer agents, and the mechanism of the anti-cancer activity of AgNPs. In addition, we discuss therapeutic approaches and challenges for cancer therapy using AgNPs. Finally, we conclude by discussing the future perspective of AgNPs.

/pdf/silver-nanoparticles-synthesis-characterization-properties-1gs52z8tm7.pdf

Silver Nanoparticles: Synthesis, Characterization, Properties, Applications, and Therapeutic Approaches

Metal oxide-based resistive-type gas sensors are solid-state devices which are widely used in a number of applications from health and safety to energy efficiency and emission control. Nanomaterials such as nanowires, nanorods, and nanoparticles have dominated the research focus in this field due to their large number of surface sites facilitating surface reactions. Previous studies have shown that incorporating two or more metal oxides to form a heterojunction interface can have drastic effects on gas sensor performance, especially the selectivity. Recently, these effects have been amplified by designing heterojunctions on the nano-scale. These designs have evolved from mixed commercial powders and bi-layer films to finely-tuned core–shell and hierarchical brush-like nanocomposites. This review details the various morphological classes currently available for nanostructured metal-oxide based heterojunctions and then presents the dominant electronic and chemical mechanisms that influence the performance of these materials as resistive-type gas sensors. Mechanisms explored include p–n and n–n potential barrier manipulation, n–p–n response type inversions, spill-over effects, synergistic catalytic behavior, and microstructure enhancement. Tables are presented summarizing these works specifically for SnO2, ZnO, TiO2, In2O3, Fe2O3, MoO3, Co3O4, and CdO-based nanocomposites. Recent developments are highlighted and likely future trends are explored.

Nanoscale metal oxide-based heterojunctions for gas sensing: A review

Here, using first-principles calculations based on density-functional theory, we propose a novel member of the two-dimensional (2D) transitional metal dichalcogenide family known as a Janus CrSSe monolayer (denoted as CrSSe-ML). The 2D CrSSe-ML has a hexagonal crystal structure. The calculated phonon band structure suggests Janus CrSSe-ML is dynamically stable, and formation energy indicates thermodynamic stability. At the equilibrium lattice constant, it is reported that 2D Janus CrSSe-ML is a non-magnetic semiconductor with a direct bandgap of 0.93 eV (K–K). We found that compressive biaxial strain induces no local magnetic moment, while in contrast the tensile biaxial strain of 12% induces a magnetic moment of 2 μB and half-metallicity which is robust up to 20%. Furthermore, we studied the ferromagnetic (FM) and antiferromagnetic (AFM) coupling between Cr atoms in CrSSe-ML and found that the FM state is favorable over AFM by the amount of energy of 0.007 meV, which is less than 0.03 eV, so no room-temperature ferromagnetism is possible. At the end, we added the H atom at the most preferable Se top-site in a Janus CrSSe-ML and found that hydrogenated Janus CrSSe-ML is magnetic and half-metallic at the equilibrium lattice constant. We further studied FM and AFM calculation by considering fully hydrogenated 4 × 4 × 1 supercell of a Janus CrSSe-ML. We used quantum Monte Carlo simulations (MC) to estimate the Curie temperature (Tc) of hydrogenated CrSSe-ML under normal conditions. The calculated value of Tc is 553.96 K using the quantum MC simulations. Our calculations predicted that the 2D Janus CrSSe-ML material is a promising candidate for spintronic device applications above room temperature. 

Room Temperature Ferromagnetism in Hydrogenated Janus CrSSe Monolayer Using Quantum Monte Carlo Simulation

Anchoring Zero-Valent Cu and Ni Nanoparticles on Carboxymethyl Cellulose-Polystyrene–Block Polyisoprene–Block Polystyrene Composite Films for Nitrophenol Reduction and Dyes Degradation

Sher Bahadar Khan

Papers

Room Temperature Ferromagnetism in Hydrogenated Janus CrSSe Monolayer Using Quantum Monte Carlo Simulation

Anchoring Zero-Valent Cu and Ni Nanoparticles on Carboxymethyl Cellulose-Polystyrene–Block Polyisoprene–Block Polystyrene Composite Films for Nitrophenol Reduction and Dyes Degradation

Nanomaterials and Their Fascinating Attributes

Synthesis, characterization and fuel cell application of polyimides

Al doped Sr and Cd metal oxide nanomaterials for resistive response of humidity sensing