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

Secret History: Return of the Black Death Channel 4, 7-8pm In 1348 the Black Death swept through London, killing people within days of the appearance of their first symptoms. Exactly how many died, and why, has long been a mystery. This Secret History documentary follows experts as they pick through the evidence and reveal why the plague killed on such a scale. And they ask, what might be coming next?

Medscape

The ability to control cell volume is pivotal for cell function. Cell volume perturbation elicits a wide array of signaling events, leading to protective (e.g., cytoskeletal rearrangement) and adap...

Physiology of cell volume regulation in vertebrates.

of antibiotics, whether there was an explicit note in the medical chart in which the physician diagnosed a true bacteremia, and the Centers for Disease Control surveillance criteria for primary bloodstream infection. Agreement between same-strain bacteremia and each definition was examined, based on the assumption that most true infections should be the result of a single strain. The study sample consisted of 42 patients and 106 isolates. Nineteen of the 42 bacteremias (45%) were the same strain. Classification of bacteremias as same-strain correlated poorly with all three clinical assessments (range of percentage agreement, 50%-57%; range of kappa statistic, 0.01-0.15). There were both false-positive and false-negative errors. Patients with three or more positive blood cultures were more likely to have same-strain bacteremia than those with only two positive cultures (11/15 [73%] vs 8/27 [30%], P=.006). Pulsed-field gel electrophoresis was more discriminating than AP PCR (percentage agreement, 83%; kappa, 0.67). The authors concluded that molecular typing correlated poorly with clinical criteria for true bacteremia, suggesting either that true bacteremias are frequently the result of multiple strains or that the commonly used clinical criteria are not accurate for distinguishing contamination from true bacteremia. Vancomycin treatment of clinically defined coagulase-negative staphylococcal bacteremia may frequently be unnecessary. FROM: Seo SK, Venkataraman L, DeGirolami PC, Samore MH. Molecular typing of coagulase-negative staphylococci from blood cultures does not correlate with clinical criteria for true bacteremia. Am J Med 2000;109:697-704.

/pdf/nasal-carriage-as-a-source-of-staphylococcus-aureus-40zkf0m446.pdf

Nasal Carriage as a Source of Staphylococcus aureus Bacteremia

There has been considerable interest in the development of novel compounds with anticonvulsant, antidepressant, analgesic, antiinflammatory, antiplatelet, antimalarial, antimicrobial, antimycobacterial, antitumoral, vasodilator, antiviral and antischistosomiasis activities. Hydrazones possessing an azometine -NHN=CH- proton constitute an important class of compounds for new drug development. Therefore, many researchers have synthesized these compounds as target structures and evaluated their biological activities. These observations have been guiding for the development of new hydrazones that possess varied biological activities.

/pdf/biological-activities-of-hydrazone-derivatives-267j4w5bkl.pdf

Biological activities of hydrazone derivatives.

The series of nine amides of substituted 8-hydroxyquinolines were prepared. The synthetic procedures of compounds are presented. All the prepared quinoline derivatives were analyzed using RP-HPLC method for the lipophilicity measurement and their lipophilicity were determined. The prepared compounds were tested for the reduction of chlorophyll content in Chlorella vulgaris Beij. Several compounds showed biological activity comparable with or higher than the standard 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). The relationships between the lipophilicity and the chemical structure of the studied compounds are discussed as well as structure-activity relationships (SAR) between the chemical structure and the biological activities of the evaluated compounds.

Substituted Amides of Quinoline Derivatives: Preparation and Their Photosynthesis-inhibiting Activity

Impact of Nanoparticles on Protozoa

The new series of single-crystalline chromium selenides, Ta-doped ZnCr2Se4, was synthesised by a chemical vapour transport method to determine the impact of a dopant on the structural and thermodynamic properties of the parent compound. We present comprehensive investigations of structural, electrical transport, magnetic, and specific heat properties. It was expected that a partial replacement of Cr ions by a more significant Ta one would lead to a change in direct magnetic interactions between Cr magnetic moments and result in a change in the magnetic ground state and electric transport properties of the ZnCr2−xTaxSe4 (x = 0.05, 0.06, 0.07, 0.08, 0.1, 0.12) system. We found that all the elements of the cubic system had a cubic spinel structure; however, the doping gain linearly increased the ZnCr2−xTaxSe4 unit cell volume. Doping with tantalum did not significantly change the semiconductor and magnetic properties of ZnCr2Se4. For all studied samples (0 ≤ x ≤ 0.12), an antiferromagnetic order (AFM) below TN~22 K was observed. However, a small amount of Ta significantly reduced the second critical field (Hc2) from 65 kOe for x = 0.0 (ZnCr2Se4 matrix) up to 42.2 kOe for x = 0.12, above which the spin helical system changed to ferromagnetic (FM). The Hc2 reduction can lead to strong competition among AFM and FM interactions and spin frustration, as the specific heat under magnetic fields H < Hc2 shows a strong field decrease in TN.

https://www.mdpi.com/1996-1944/14/11/2749/pdf

Study of the Structure, Magnetic, Thermal and Electrical Characterisation of ZnCr2Se4: Ta Single Crystals Obtained by Chemical Vapour Transport.

Preparation and Properties of New Co-crystals of Ibandronate

Based on the fact that alaptide is able to influence the creation and function of keratinocytes, it was supposed that alaptide could be used as a transdermal permeation modifier. Various APIs (bases, acids, salts, neutral molecules, small molecules, steroid-like molecules) were tested on their transdermal permeation in the mixture with micronized and/or nanonized alaptide as a transdermal permeation modifier. Also the influence of the type of formulation (ointment, cream, gel) on the effect of alaptide on skin was investigated intensively. It was observed that under specific conditions alaptide is able to suppress permeation/absorption of compounds through the skin, which can limit the site of action of potentially hazardous/toxic drugs to skin surface. The skin curative activity of alaptide can be helpful in reduction of possible skin irritant/injurious effects of permeating compounds. In transdermal application alaptide causes an increase or a decrease, in dependence on the used concentration, physical state and supporting medium (pharmaceutical formulation), in permeation/absorption of drugs into the skin and/or through the skin. The concentration of the used drug was increased at the place of administration, and/or the systemic concentration was increased, or it was ensured that drugs acted only on the skin surface/in the skin surface layer and did not penetrate into the deeper skin layers or did not have any systemic effect. Although alaptide was found in the 1980s of the twentieth century, even now it has great potential either as an active pharmaceutical ingredient or a permeation modifier.

Josef Jampilek

Papers

Substituted Amides of Quinoline Derivatives: Preparation and Their Photosynthesis-inhibiting Activity

Impact of Nanoparticles on Protozoa

Study of the Structure, Magnetic, Thermal and Electrical Characterisation of ZnCr2Se4: Ta Single Crystals Obtained by Chemical Vapour Transport.

Preparation and Properties of New Co-crystals of Ibandronate

Alaptide as Transdermal Permeation Modifier