Rank 2 ACM bundles on complete intersection Calabi–Yau threefolds

The aim of this paper is to classify indecomposable rank two arithmetically Cohen–Macaulay (ACM) bundles on general complete intersection Calabi–Yau threefolds and prove the existence of some of them. New geometric properties of the curves corresponding to rank two ACM bundles (by Serre correspondence) are obtained. These follow from minimal free resolutions of curves in suitably chosen fourfolds (containing Calabi–Yau threefolds as hypersurfaces). A strong indication leading to existence of bundles with \(c_1\,=\,2\) , \(c_2\,=\,13\) on a quintic conjectured in Chiantini and Madonna (Le Matematiche 55:239–258, 2000), and Mohan Kumar and Rao (Cent Eur J Math 10(4):1380–1392, 2012) is found.     

Control of Glycopolymer Nanoparticle Morphology by a One‐Pot,Double Modification Procedure Using Thiolactones

A copolymer from N‐isopropylacryl amide (NIPAAm) and N‐homocysteine thiolactone acrylamide (TlaAm), prepared by RAFT polymerization, is reacted with various amines, bearing alkyl residues of increasing length (n‐propylamine, n‐hexylamine, and n‐dodecylamine) to liberate the corresponding thiol, which is consequently reacted in situ with 2‐bromoethyl‐2′,3′,4′,6′‐tetra‐O‐acetyl‐α‐d ‐mannopyranoside. The resulting double‐modified graft copolymers show characteristic self‐assembly behavior due to their amphiphilic nature, affording glycopoly­mer‐based nanoparticles. While the n‐propylamine‐derived amphiphiles mainly lead to micelles (30 nm), the n‐hexylamine adducts give rise to larger vesicles (200–600 nm). Longer alkyl amines result in the formation of large compound micelles. The assembled nanoparticles are bioactive and interact effectively with Concanavalin A (ConA).

     

Laser cutting of silicon with the liquid jet guided laser using a chlorine-containing jet media

In this paper results for liquid media are presented, which are used the first time as liquid jet for cutting of silicon with laser chemical processing (LCP). The liquids contain a perfluoro-carbon compound as solvent and elemental chlorine as etching agent for silicon. Experiments were performed to investigate its influence on groove form and maximum achieved groove depth. It is shown that with the addition of low-concentration chlorine, the groove depth can already be significantly increased. The groove shape could be changed from a V-profile to a U-profile. Furthermore, an about four times greater groove depth was achieved by applying a saturated chlorine solution compared to groove depths without using chlorine. Finally, a theory is given and discussed to describe the phenomena observed.     

Polyurethane biocompatible silver bionanocomposites for biomedical applications

Journal of Nanoparticle Research - Bionanocomposite membranes based on polyurethane (PU), extracellular matrix (EM), and silver nanoparticles (AgNPs) were prepared by applying both solvent casting...     

Catalytic Three‐Component Domino Reaction for the Preparation of Trisubstituted Oxazoles

Multicomponent reactions are attractive for assembling functionalized heterocyclic compounds. To this end, an efficient gold‐catalyzed three‐component domino reaction to form oxazoles directly from imines, alkynes, and acid chlorides is presented. The reaction proceeds in a single synthetic step by using a gold(III)–N,N′‐ethylenebis(salicylimine) (salen) catalyst to give trisubstituted oxazoles in up to 96 % yield. The substrate scope, a mechanistic study exploring the role of the gold catalyst, and the synthetic applications of the oxazole products are discussed.     

Planar Chromatographic Systems in Pattern Recognition and Fingerprint Analysis

An overview of opportunities of contemporary planar chromatography in pattern recognition and fingerprint analysis is presented. The most used chemometric methods are highlighted and their main advantages and drawbacks are underlined. In addition a cross section of the application of planar chromatographic fingerprinting in food, pharmaceutical, environmental, and forensic analysis is given.