Relativistic Coupled-Channel Quark Model for Meson Resonances

We present results from a study of meson ground and resonant states within a relativistic coupled-channel constituent-quark model. Along such an approach in particular the resonance character of hadron excitations can be fully taken into account. Thus it becomes possible to describe the decay of a hadron resonance into a lower lying state more realistically than in usual single-channel approaches. In a simplified model we demonstrate the viability and the advantages of our method by producing relativistic invariant results for the finite decay width of a meson resonance.     

Structure–Solubility Relationship of 1,4-Dioxane Complexes of Di(hydrocarbyl)magnesium

Systematic variation of the 1,4-dioxane (dx) concentration during the precipitation of sparingly soluble [MgBr₂(dx)₂] from ethereal Grignard solutions of RMgBr has allowed the structural investigation of crystallized [R₂Mg(dx)_n] (n=1, 1.5, 2, and 3), which form during this dioxane method, depending on the bulkiness of R. The numbering of the complexes explored in this study is based on the number n of dioxane molecules per magnesium atom, followed by the substituent R; an apostrophe denotes coordination polymers. The following derivatives were studied by X-ray crystal-structure determination and NMR spectroscopy: n=1: [Me₂Mg(μ-dx)]_∞ ( 1′-Me ) and [nPr₂Mg(μ-dx)]_∞ ( 1′-nPr ); n=1.5: [{iPr₂Mg(dx)}₂(μ-dx)] ( 1.5-iPr ), [{oTol₂Mg(dx)}₂(μ-dx)] ( 1.5-oTol ), and [(Me₃Si-C≡C)₂Mg(dx)_1.5]_∞ ( 1.5′-C₂SiMe₃ ); n=2: [tBu₂Mg(dx)₂] ( 2-tBu ) and [oTol₂Mg(dx)₂] ( 2-oTol ); n=3: [Ph₂Mg(dx)₃] ( 3-Ph ). In the structure types 1′ , 1.5 , and 2 , the magnesium atom exhibits the coordination number 4, whereas pentacoordinate metal atoms are observed in types 3 and 1.5′ . The structure type 2′ is realized for [(Ph-C≡C)₂Mg(dx)₂]_∞ ( 2′-C₂Ph ), [MgCl₂(dx)₂]_∞ ( 2′-Cl ), and [MgBr₂(dx)₂]_∞ ( 2′-Br ) with hexacoordinate metal atoms. The solubility of the dioxane adducts in common organic solvents strongly depends on the degree of aggregation with the solubility decreasing from molecular to strand to layer structures.     

Monotonic convergent optimal control theory with strict limitations on the spectrum of optimized laser fields

We present a modified optimal control scheme based on the Krotov method, which allows for strict limitations on the spectrum of the optimized laser fields. A frequency constraint is introduced and derived mathematically correct, without losing monotonic convergence of the algorithm. The method guarantees a close link to learning loop control experiments and is demonstrated for the challenging control of nonresonant Raman transitions, which are used to implement a set of global quantum gates for molecular vibrational qubits.     

Researches on thiazolobenzodiazepines: Behavior of tetrahydro‐1,5‐benzodiazepinethiones with aromatic α‐haloketones

A number of 1‐substituted 4H,5H,6H‐[1,3]thiazolo[3,2‐a][1,5]benzodiazepinium‐11‐bromides and S‐(2‐oxo‐2‐phenyl‐X‐(p)‐ethyl)‐3‐(2‐methyl‐1H‐benzimidazol‐1‐yl) propane (or butane) thioate hydrobromides were obtained by direct reaction of the 5‐acetyl(or formyl, or anilinocarbonyl)‐substituted tetrahydro‐1,5‐benzodiazepine‐2‐thiones with aromatic α‐bromoketones. 2‐[(1‐Acetyl‐2(or 3)‐methyl‐2,3‐dihydro‐1H‐1,5‐benzodiazepin‐4‐yl) sulfanyl]‐1‐phenylethanones as intermediates of the formation of thiazolo [3,2‐a][1,5]benzodiazepine and N‐substituted 2‐methyl‐1H‐benzimidazole derivatives have been synthesized. Semiempirical AM1 calculations of a mechanism and energetic parameters for the heptatomic nucleus rearrangement to benzimidazole ring are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:72–81, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20414     

Generalized Bregman Envelopes and Proximity Operators

Journal of Optimization Theory and Applications - We study the implications of a well-known metric inequality condition on sets to the applicability of standard necessary optimality conditions for...     

Multifunctional Cationic PeptoStars as siRNA Carrier: Influence of Architecture and Histidine Modification on Knockdown Potential

RNA interference provides enormous potential for the treatment of several diseases, including cancer. Nevertheless, successful therapies based on siRNA require overcoming various challenges, such as poor pharmacokinetic characteristics of the small RNA molecule and inefficient cytosolic accumulation. In this respect, the development of functional siRNA carrier systems is a major task in biomedical research. To provide such a desired system, the synthesis of 3‐arm and 6‐arm PeptoStars is aimed for. The different branched polypept(o)idic architectures share a stealth‐like polysarcosine corona for efficient shielding and a multifunctional polylysine core, which can be independently varied in size and functionality for siRNA complexation‐, transport and intra cellular release. The special feature of star‐like polypept(o)ides is in their uniform small size (<20 nm) and a core–shell structure, which implies a high stability and stealth‐like properties and thus, they may combine long circulation times and a deep penetration of cancerous tissue. Initial toxicity and complement studies demonstrate well tolerated cationic PeptoStars with high complexation capability toward siRNA (N/P ratio up to 3:1), which can lead to potent RNAi for optimized systems. Here, the synthetic development of 3‐arm and 6‐arm polypept(o)idic star polymers, their modification with endosomolytic moieties, and first in vitro insights on RNA interference are reported on.     

The X-ray crystal structures of three bis(cyclopentadienyl)titanium(IV) derivatives

The X-ray crystal structures of (aqua)bis(cyclopentadienyl)chlorotitanium(IV) trifluoromethanesulfonate, bis(aqua)bis(cyclopentadienyl)titanium(IV) bis(trifluoromethanesul-fonate) and bis(cyclopentadienyl)bis(trifluoromethanesulfonato)titanium(IV) show a pseudo-tetrahedral array of Cp ring centroids and oxygen or oxygen and chloride donors around titanium, and varied long-range packing motifs dependent on the availability of hydrogen bond acceptors within the lattice.