Synthesis and mechanochemical activation of copper(I)-bis(NHC) complexes with different architectures

Das Herbeiführen chemischer Reaktionen durch den Einfluss mechanischer Kraft ermöglicht eine direkte Umwandlung destruktiver Effekte, wie beispielsweise das Auftreten von Materialschäden aufgrund struktureller Schwachstellen, in produktive Applikationen und bietet somit Möglichkeiten potenzieller Anwendungen in Bereichen der Stress Sensorik oder der autonomen Materialreparatur. Zu diesem Zweck wurden verschiedene latente, hochmolekulare Kupfer-(I)-N-Heterozyklische-Carben (NHC) Komplexe hergestellt, die durch den Einfluss mechanischer Kraft ein aktives Kupfer(I)-Zentrum ausbilden und somit die Möglichkeit besitzen eine fluorogene „Klick“-Reaktion zu katalysieren. Die damit verbundene, kraft-induzierte Erzeugung eines optischen Signals bietet die Möglichkeit zur Untersuchung polymerarchitektonischer Einflüsse auf die Aktivierungseffizienz und ermöglicht zudem durch eine simple Modularität, ein leicht adaptierbares, stress-detektierendes Material zu generieren.Triggering chemical reactions by mechanical stimuli has become important as it enables the direct transformation of destructive effects, like structural damage or leaking material properties, to productive applications, usable for instance in the field of self-healing and stress-sensing materials. For this purpose, a series of macromolecular copper(I)-bis(N-heterocyclic carbene) (NHC) complexes were designed, inactive in their initial state, but turned to an active state upon cleavage of one shielding ligand solely by force. These catalysts are able to trigger a fluorogenic click reaction of initially non-fluorescent substrates forming a highly fluorescent reporter dye which offers the possibility to investigate the effects of different architectures in respect to the mechanophore activation. Thus, the potential for stress-sensing materials, easily tunable by structural variation could be proven highlighting their versatility and make them beneficial for a broad range of technical applications

Localized amyloidosis presenting with a penile mass: a case report

Amyloidosis is a disease characterized by the deposition of altered proteins in tissues. Amyloid deposition always occurs in the extracellular matrix and presents a fibrillary conformation. Local deposition of amyloid may occur in individual organs, without systemic involvement. We report here a rare case of localized penile shaft amyloidosis--an unusual location for amyloid deposition--presenting as a penile mass that resulted in a urethral stricture in 37-year old male patient. We have also comprehensively reviewed the literature regarding localized amyloidosis

Surgical removal of amyloid-laden lymph nodes: a possible therapeutic approach in a primary systemic AL amyloidosis patient with focal lymphadenopathy

We report a patient with primary systemic AL amyloidosis who suffered from remarkable bilateral cervical lymphadenopathy. Intensive chemotherapies, including two cycles of high-dose melphalan with autologous peripheral blood stem cell transplantation, were insufficiently effective for both the lymphadenopathy and amyloidogenic IgG lambda lambda-type M-protein in serum, but the patient showed complete haematological remission after extensive surgical removal of enlarged lymph nodes that had massive depositions of lambda lambda-type immunoglobulin light chain-derived amyloid. Lymphadenectomy may be a possible therapeutic approach with regard to both cosmetic and haematological aspects in primary systemic AL amyloidosis patients with focal lymphadenopathy.ArticleAMYLOID-JOURNAL OF PROTEIN FOLDING DISORDERS. 18(2):79-82 (2011)journal articl

Detection of stress in polymers: mechanochemical activation of CuAAC click reactions in poly(urethane) networks

We report on copper(i)-bis(N-heterocyclic carbene)s (NHC) for quantitative stress-sensing. This mechanophore is embedded within a polyurethane network, triggering a fluorogenic copper(i) azide alkyne cycloaddition (CuAAC) of 8-azido-2-naphtol and 3-hydroxy phenylacetylene.</p