Hasse principle for classical groups over function fields of curves over number fields

In (Letter to J.-P. Serre, 12 June 1991) Colliot-Thélène conjectures the following: Let F be a function field in one variable over a number field, with field of constants k and G be a semisimple simply connected linear algebraic group defined over F. Then the map has trivial kernel, denoting the set of places of k.The conjecture is true if G is of type 1A∗, i.e., isomorphic to SL₁(A) for a central simple algebra A over F of square free index, as pointed out by Colliot-Thélène, being an immediate consequence of the theorems of Merkurjev-Suslin [S1] and Kato [K]. Gille [G] proves the conjecture if G is defined over k and F=k(t), the rational function field in one variable over k. We prove that the conjecture is true for groups G defined over k of the types 2A∗, B_n, C_n, D_n (D₄ nontrialitarian), G₂ or F₄; a group is said to be of type 2A∗, if it is isomorphic to SU(B,τ) for a central simple algebra B of square free index over a quadratic extension k′ of k with a unitary k′|k involution τ.     

Spectrophotometric determination of beryllium with carminic acid

Summary A new reagent has been proposed for the determination of beryllium. The method is based on the reaction between beryllium and carminic acid, forming a Be-carminic acid complex at pH 4. The absorption is measured at 580 nm. The molar absorptivity is 2.25×10³ mol^–1 cm^–1. Beer's law is obeyed from 0.4 ppm to 1.6 ppm of beryllium. The effects of pH, reagent concentration and interferences from foreign ions have been studied. The method has been applied to the determination of beryllium in polluted water and blood samples.

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Spektralphotometrische Bestimmung von Beryllium mit CarminsÄure

     

Phase Diagram Study of Succinonitrile-Vanillin Organic Alloy System

Phase diagram studies of succinonitrile-vanillin system show the formation of 2:1 congruent melting type compound. Crystallization velocities of pure components, succinonitrile-vanillin complex, and two eutectics have been determined at different undercoolings. On the basis of heat of fusion measurements, excess thermodynamic functions have been calculated. Microstructural studies revealed that impurities modify the morphology. FTIR spectral studies and computer simulation have shown the existence of hydrogen bonding in the eutectics and the congruent melting compound. On the basis of experimental results, the mechanism of formation of eutectics and its solidification behavior are discussed.     

Solvent free reactions

Reactions of nitrophenols have been studied in the eutectic melt of 8-hydroxyquinoline–benzoic acid, where it reacted with 8-hydroxyquinoline. The reactions were also carried out in solution. The reaction products obtained from both the methods were characterized by FT-IR, differential scanning calorimetry, X-ray diffraction technique and microstructural investigations. The reaction products obtained from eutectic melt were analyzed for C, H, N. The results showed that reaction products obtained from both the methods are same. An attempt has been made to propose the overall mechanism of the reaction in the eutectic melt.     

Molecular mechanism-based network-like similarity graphs reveal relationships between different types of receptor ligands and structural changes that determine agonistic, inverse-agonistic, and antagonistic effects

Receptor ligands might act as agonists, partial agonists, inverse agonists, or antagonists and it is often difficult to understand structural modifications that alter the mechanism of action. In order to compare ligands that are active against a given receptor but have different mechanisms of action, we have designed molecular networks that mirror similarity relationships and incorporate both mechanism of action information and mechanism-specific SAR features. These network representations make it possible to systematically evaluate relationships between different types of receptor ligands and identify communities of structurally very similar ligands with different mechanisms. From a series of such ligands, structural modifications can often be deduced that lead to "mechanism hops".     

A benzthiazole-based tripodal chemosensor for Ba recognition under biological conditions

We synthesized a benzthiazole-based chemosensor with mixed S,N donor sites. The binding units are incorporated in a highly flexible tripodal framework which facilitates the complexation of the binding of larger-sized metals. The chemosensor resulted in the sensitive and selective recognition of Ba²⁺ through the enhancement of the fluorescence intensity when studied in a THF/H₂O (8:2, v/v) solvent mixture. The sensor offers an interesting opportunity to monitor Ba²⁺ in biological samples including the cytoplasm of microbes such as Saccharomyces cerevisiae.     

Ceric ammonium nitrate-catalyzed azidation of 1,2-anhydro sugars: application in the synthesis of structurally diverse sugar-derived morpholine 1,2,3-triazoles and 1,4-oxazin-2-ones

Azidation of 1,2-anhydro sugars with NaN(3) in CH(3)CN by using a catalytic amount of ceric ammonium nitrate has been accomplished in a regio- and stereoselective manner. Various 1,2-anhydro sugars produced 2-hydroxy-1-azido sugars in good yields which, in turn, were converted to structurally diverse sugar-derived morpholine triazoles and sugar oxazin-2-ones. These sugar derivatives were tested against various commercially available glycosidases, and two of them were found to be active in the micromolar range.     

Free Vibration Analysis of RC Box-Girder Bridges Using FEM

The free vibration analysis of simply supported box-girder bridges is carried out using the finite element method. The fundamental frequency is determined in straight, skew, curved and skew-curved box-girder bridges. It is important to analyse the combined effect of skewness and curvature because skew-curved box-girder bridge behaviour cannot be predicted by simply adding the individual effects of skewness and curvature. At first, an existing model is considered to validate the present approach. A convergence study is carried out to decide the mesh size in the finite element method. An exhaustive parametric study is conducted to determine the fundamental frequency of box-girder bridges with varying skew angle, curve angle, span, span-depth ratio and cell number. The skew angle is varied from 0° to 60°, curve angle is varied from 0° to 60°, span is changed from 25 to 50 m, span-depth ratio is varied from 10 to 16, and single cell & double cell are used in the present study. A total of 420 bridge models are used for parametric study in the investigation. Mode shapes of the skew-curved bridge are also presented. The fundamental frequency of the skew-curved box-girder bridge is found to be more than the straight bridge, so, the skew-curved box-girder bridge is preferable. The present study may be useful in the design of box-girder bridges.     

N-methyl Benzimidazole Tethered Cholic Acid Amphiphiles Can Eradicate S. aureus-Mediated Biofilms and Wound Infections

Infections associated with Gram-positive bacteria like S. aureus pose a major threat as these bacteria can develop resistance and thereby limit the applications of antibiotics. Therefore, there is a need for new antibacterials to mitigate these infections. Bacterial membranes present an attractive therapeutic target as these membranes are anionic in nature and have a low chance of developing modifications in their physicochemical features. Antimicrobial peptides (AMPs) can disrupt the microbial membranes via electrostatic interactions, but the poor stability of AMPs halts their clinical translation. Here, we present the synthesis of eight N-methyl benzimidazole substituted cholic acid amphiphiles as antibacterial agents. We screened these novel heterocyclic cholic acid amphiphiles against different pathogens. Among the series, CABI-6 outperformed the other amphiphiles in terms of bactericidal activity against S. aureus. The membrane disruptive property of CABI-6 using a fluorescence-based assay has also been investigated, and it was inferred that CABI-6 can enhance the production of reactive oxygen species. We further demonstrated that CABI-6 can clear the pre-formed biofilms and can mitigate wound infection in murine models.     

EurJIC: Evolving with the Field of Inorganic Chemistry for 25 Years

There is much to celebrate in 2023, not least it is EurJIC's 25th Anniversary. Twenty-five years ago, the Dutch and German chemical societies (KNCV and GDCh) took the initiative to create strong European journals with a global reach. Cooperation with more European national chemical societies soon followed, and the amalgamation of their national journals led to the formation of EurJIC under the ownership of Chemistry Europe . With its strong European roots, EurJIC has since developed into a leading inorganic chemistry journal serving an international community.