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1.
BMJ Open ; 10(12): e039473, 2020 12 16.
Article in English | MEDLINE | ID: mdl-33328257

ABSTRACT

Introduction Transparent collaborations between patient organisations (POs) and clinical research sponsors (CRS) can identify and address the unmet needs of patients and caregivers. These insights can improve clinical trial participant experience and delivery of medical innovations necessary to advance health outcomes and standards of care. We share our experiences from such a collaboration undertaken surrounding the SENSCIS® clinical trial (NCT02597933), and discuss its impact during, and legacy beyond, the trial.Summary We describe the establishment of a community advisory board (CAB): a transparent, multiyear collaboration between the scleroderma patient community and a CRS. We present shared learnings from the collaboration, which is split into three main areas: (1) the implementation and conduct of the clinical trial; (2) analysis and dissemination of the results; and (3) aspects of the collaboration not related to the trial.1. The scleroderma CAB reviewed and provided advice on trial conduct and reporting. This led to the improvement and optimisation of trial procedures; meaningful, patient-focused adaptations were made to address challenges relevant to scleroderma-associated interstitial lung disease patients.2. To ensure that results of the trial were accessible to lay audiences and patients, written lay summaries were developed by the trial sponsor with valuable input from the CAB to ensure that language and figures were understandable.3. The CAB and the CRS also collaborated to co-develop opening tools for medication blister packs and bottles. In addition, to raise disease awareness among physicians, patients and caregivers, educational materials to improve diagnosis and management of scleroderma were co-created and delivered by the CAB and CRS.Conclusions This collaboration between POs and a CRS, in a rare disease condition, led to meaningful improvements in patient safety, comfort and self-management and addressed information needs. This collaboration may serve as a template of best practice for future collaborations between POs, research sponsors and other healthcare stakeholders.


Subject(s)
Delivery of Health Care , Rare Diseases , Humans , Rare Diseases/therapy
2.
Angew Chem Int Ed Engl ; 55(4): 1514-8, 2016 Jan 22.
Article in English | MEDLINE | ID: mdl-26663567

ABSTRACT

We show that, all other conditions being equal, bond cleavage in the middle of molecules is entropically much more favored than bond cleavage at the end. Multiple experimental and theoretical approaches have been used to study the selectivity for bond cleavage or dissociation in the middle versus the end of both covalent and supramolecular adducts and the extensive implications for other fields of chemistry including, e.g., chain transfer, polymer degradation, and control agent addition are discussed. The observed effects, which are a consequence of the underlying entropic factors, were predicted on the basis of simple theoretical models and demonstrated via high-temperature (HT) NMR spectroscopy of self-assembled supramolecular diblock systems as well as temperature-dependent size-exclusion chromatography (TD SEC) of covalently bonded Diels-Alder step-growth polymers.

3.
ACS Macro Lett ; 5(9): 1023-1028, 2016 Sep 20.
Article in English | MEDLINE | ID: mdl-35614639

ABSTRACT

We report an advanced analysis protocol that allows to quantitatively study the course of step-growth reactions by size exclusion chromatography on the example of the depolymerization of a Diels-Alder polymer based on a furane/maleimide couple at elevated temperatures. Frequently occurring issues of molar mass calibrations and overlap of monomer with solvent signals are addressed for determining reliable molar masses. Thereby, even kinetic parameters (e.g., rate coefficients) can be derived that otherwise would require performing additional spectroscopic experiments. Our results confirm first-order behavior of the rDA reaction with an activation energy of 33 kJ mol-1.

4.
Angew Chem Int Ed Engl ; 54(35): 10284-8, 2015 Aug 24.
Article in English | MEDLINE | ID: mdl-26179164

ABSTRACT

A rapid and catalyst-free cycloaddition system for visible-light-induced click chemistry is reported. A readily accessible photoreactive 2H-azirine moiety was designed to absorb light at wavelengths above 400 nm. Irradiation with low-energy light sources thus enables efficient small-molecule synthesis with a diverse range of multiple-bond-containing compounds. Moreover, in order to demonstrate the efficiency of the current approach, quantitative ligation of the photoactivatable chromophore with functional polymeric substrates was performed and full conversion with irradiation times of only 1 min at ambient conditions was achieved. The current report thus presents a highly efficient method for applications involving selective cycloaddition to electron-deficient multiple-bond-containing materials.


Subject(s)
Click Chemistry , Light , Photochemistry , Polymers/chemistry , Catalysis
5.
Chem Sci ; 6(2): 1061-1074, 2015 Feb 01.
Article in English | MEDLINE | ID: mdl-29560194

ABSTRACT

We report the investigation of fundamental entropic chain effects that enable the tuning of modular ligation chemistry - for example dynamic Diels-Alder (DA) reactions in materials applications - not only classically via the chemistry of the applied reaction sites, but also via the physical and steric properties of the molecules that are being joined. Having a substantial impact on the reaction equilibrium of the reversible ligation chemistry, these effects are important when transferring reactions from small molecule studies to larger or other entropically very dissimilar systems. The effects on the DA equilibrium and thus the temperature dependent degree of debonding (%debond) of different cyclopentadienyl (di-)functional poly(meth-)acrylate backbones (poly(methyl methacrylate), poly(iso-butyl methacrylate), poly(tert-butyl methacrylate), poly(iso-butyl acrylate), poly(n-butyl acrylate), poly(tert-butyl acrylate), poly(methyl acrylate) and poly(isobornyl acrylate)), linked via a difunctional cyanodithioester (CDTE) were examined via high temperature (HT) NMR spectroscopy as well as temperature dependent (TD) SEC measurements. A significant impact of not only chain mass and length with a difference in the degree of debonding of up to 30% for different lengths of macromonomers of the same polymer type but - remarkably - as well the chain stiffness with a difference in bonding degrees of nearly 20% for isomeric poly(butyl acrylates) is found. The results were predicted, reproduced and interpreted via quantum chemical calculations, leading to a better understanding of the underlying entropic principles.

6.
ACS Macro Lett ; 4(7): 774-777, 2015 Jul 21.
Article in English | MEDLINE | ID: mdl-35596475

ABSTRACT

We report the transfer of entropic chain length effects into the realm of supramolecular chemistry and thereby demonstrate a macromolecular method to tune the reaction equilibria of hydrogen bonding motifs via the application of substituents of differing lengths and masses while not altering the actual recognition units to achieve a difference in the degree of association. The supramolecular adducts are characterized via temperature-dependent nuclear magnetic resonance (NMR) spectroscopy.

7.
Chem Commun (Camb) ; 50(99): 15681-4, 2014 Dec 25.
Article in English | MEDLINE | ID: mdl-25355650

ABSTRACT

A facile, fast and ambient-temperature avenue towards highly fluorescent polymers is introduced via polymerizing non-fluorescent photoreactive monomers based on light-induced NITEC chemistry, providing a platform technology for fluorescent polymers. The resulting polypyrazolines were analyzed in depth and the photo-triggered step-growth process was monitored in a detailed kinetic study.


Subject(s)
Polymers/chemistry , Cycloaddition Reaction , Fluorescence Resonance Energy Transfer , Fluorescent Dyes/chemistry , Imines/chemistry , Kinetics , Nitriles/chemistry , Polymerization , Pyrazoles/chemistry , Tetrazoles/chemistry , Ultraviolet Rays
8.
Adv Mater ; 26(33): 5758-85, 2014 Sep 03.
Article in English | MEDLINE | ID: mdl-24782412

ABSTRACT

Dynamic bonding materials are of high interest in a variety of fields in material science. The reversible nature of certain reaction classes is frequently employed for introducing key material properties such as the capability to self-heal. In addition to the synthetic effort required for designing such materials, their analysis is a highly complex--yet important--endeavor. Herein, we critically review the current state of the art analytical methods and their application in the context of reversible bonding on demand soft matter material characterization for an in-depth performance assessment. The main analytical focus lies on the characterization at the molecular level.


Subject(s)
Manufactured Materials , Materials Testing/methods
9.
Adv Mater ; 26(21): 3561-6, 2014 Jun 04.
Article in English | MEDLINE | ID: mdl-24659414

ABSTRACT

A novel adaptable network based on the reversible hetero Diels-Alder reaction of a cyanodithioester and cyclopentadiene is presented. Reversible between 50-120 °C, the adjustable and self-healing features of the network are evidenced via temperature dependent rheology experiments and repetitive tensile tests whereas the network's chemical structure is explored by temperature dependent (1) H MAS-NMR spectroscopy.

10.
Anal Bioanal Chem ; 405(28): 8981-93, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23877179

ABSTRACT

Polymers capable of dynamic bonding/debonding reactions are of great interest in modern day research. Potential applications can be found in the fields of self-healing materials or printable networks. Since temperature is often used as a stimulus for triggering reversible bonding reactions, an analysis operating at elevated temperatures is very useful for the in situ investigation of the reaction mechanism, as unwanted side effects can be minimized when performing the analyses at the same temperature at which the reactions occur. A temperature-dependent size exclusion chromatographic system (TD SEC) has been optimized for investigating the kinetics of retro Diels-Alder-based depolymerization of Diels-Alder polymers. The changing molecular weight distribution of the analyzed polymers during depolymerization gives valuable quantitative information on the kinetics of the reactions. Adequate data interpretation methods were developed for the correct evaluation of the chromatograms. The results are confirmed by high-temperature dynamic light scattering, thermogravimetric analysis, and time-resolved nuclear magnetic resonance spectroscopy at high temperatures. In addition, the SEC system and column material stability under application conditions were assessed using thermoanalysis methods, infrared spectroscopy, nitrogen physisorption, and scanning electron microscopy. The findings demonstrate that the system is stable and, thus, we can reliably characterize such dynamically bonding/debonding systems with TD SEC.


Subject(s)
Polymers/chemistry , Chromatography, Gel , Kinetics , Molecular Structure , Temperature
11.
Angew Chem Int Ed Engl ; 52(2): 762-6, 2013 Jan 07.
Article in English | MEDLINE | ID: mdl-23090883

ABSTRACT

Making light work of RAFT conjugation: a non-activated RAFT agent at the end of RAFT polymers can readily be coupled with ortho-quinodimethanes (photoenols) in a photo-triggered Diels-Alder reaction under mild conditions without catalyst. The method is universal and opens the door for the conjugation of a large number of RAFT-prepared polymers with photoenol-functionalized (macro)molecules. (RAFT=reversible addition-fragmentation chain transfer.).

12.
Curr Microbiol ; 65(2): 202-6, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22614101

ABSTRACT

Ten phosphate solubilizing pseudomonads isolated from a partially recultivated potash tailings pile in Germany were characterized and tested for their potential to assist in the ongoing recultivation process. Despite fertilization, the plants which are grown for recultivation show phosphate deficiency symptoms, and therefore the isolates are intended to be used as biofertilizer inoculants. On agar plates incubated at five different temperatures, some of the strains showed a temperature-dependent ability to solubilize tricalcium phosphate, while others performed the same at any given temperature. In liquid medium, the isolates solubilized between 271 and 730 µg ml(-1) of phosphate from tricalcium phosphate. Both the weakest (designated S10) and the strongest solubilizing strain (S06) were further tested for their viability during solubilization. In an assay over the course of 1 week, both strains released their maximum amount of phosphate after 2-4 days. At that later point of time, however, viable cells of isolate S06 were no longer detectable, whereas the weaker strain S10 could be cultured after 1 week in broth. Taking all in vitro observations into account, the usability of the isolates as biofertilizers is critically discussed regarding both the in situ conditions on the tailings pile and the lowered viability due to the excess production of organic acids.


Subject(s)
Complex Mixtures , Phosphates/metabolism , Plant Development , Plants/microbiology , Pseudomonas/isolation & purification , Pseudomonas/metabolism , Culture Media/chemistry , Germany , Pseudomonas/growth & development , Temperature
13.
Syst Appl Microbiol ; 34(7): 482-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21612883

ABSTRACT

A novel, pink-pigmented aerobic, facultatively methylotrophic bacterial strain (F3.2(T)) isolated from the phyllosphere of Funaria hygrometrica, was analyzed using a polyphasic approach. Cells were Gram-negative, motile rods, strictly aerobic and non-spore-forming and exhibited surface structures varying in quantity, distribution and morphology. The isolate grew at 10-33°C over a pH range of 5.5-8.0 and in the presence of less than 1.0% NaCl. Strain F3.2(T) shared less than 70% DNA-DNA binding to the next type strain of the genus Methylobacterium (M. adhaesivum DSM 17169(T)). In addition to the major cellular fatty acid C(18:1)ω7c (81.7%), present in all Methylobacterium species (and also members of the genus Alphaproteobacteria), a high value (11.7%) of the fatty acids (summed feature) C(16:1)ω7c and/or iso-C(15:0)2OH was determined. Phylogenetic analyses based on 16S rDNA and methanol dehydrogenase gene sequences, DNA-DNA hybridization values, chemotaxonomic and phenotypic characteristics indicate that the strain F3.2(T) represents a novel species within the genus Methylobacterium. We propose the name Methylobacterium bullatum sp. nov. for this species. The type strain is the strain F3.2(T) (DSM 21893(T)=LMG 24788(T)).


Subject(s)
Bryopsida/microbiology , Methylobacterium/classification , Methylobacterium/isolation & purification , Alcohol Oxidoreductases/genetics , Bacteria, Aerobic/classification , Bacteria, Aerobic/genetics , Bacteria, Aerobic/isolation & purification , Bacteria, Aerobic/physiology , Bacteria, Aerobic/ultrastructure , Bacterial Typing Techniques , Base Composition , Biofilms , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Fatty Acids/metabolism , Genes, Bacterial , Hydrogen-Ion Concentration , Methylobacterium/genetics , Methylobacterium/physiology , Methylobacterium/ultrastructure , Microscopy, Electron , Phenotype , Phylogeny , Pigmentation , Ribosomes/genetics , Salt Tolerance
14.
Curr Microbiol ; 59(2): 206-11, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19459002

ABSTRACT

An Enterococcus faecalis mutant strain with a reduced ability for biofilm formation and primary attachment when compared to the high biofilm-forming wild-type strain was characterized by molecular biological and proteomic approaches. A point mutation in the srt-1 gene, which encodes a sortase-type enzyme and is part of the recently described bee (biofilm enhancer in Enterococcus) gene cluster, could be identified in the mutant strain. The Srt-1 deficiency resulted in a loss of the Bee-2 protein within a high molecular weight complex in cell surface protein extracts, as determined by mass spectrometry. These findings strongly suggest a specific linkage of Bee-2 to Bee-1 and Bee-3 within a complex by Srt-1. Furthermore, the identification of specific pilin motifs conserved in surface proteins of gram-positive bacteria indicated a possible involvement of the bee genes in the formation of pili structures, and may thus play a role in enhancing biofilm formation in Enterococcus faecalis.


Subject(s)
Biofilms/growth & development , Enterococcus faecalis/genetics , Fimbriae, Bacterial/genetics , Multigene Family , Adult , Bacterial Adhesion , Bacterial Proteins/analysis , Enterococcus faecalis/chemistry , Enterococcus faecalis/isolation & purification , Enterococcus faecalis/physiology , Female , Humans , Point Mutation , Proteome/analysis , Vagina/microbiology
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