Plant hormone-mediated regulation of stress responses

10.1186/s12870-016-0771-yBMC Plant Biology1618

Using a modified Delphi methodology to gain consensus on the use of dressings in chronic wounds management

Objective: Managing chronic wounds is associated with a burden to patients, caregivers, health services and society and there is a lack of clarity regarding the role of dressings in improving outcomes. This study aimed to provide understanding on a range of topics, including: the definition of chronicity in wounds, the burden of illness, clinical outcomes of reducing healing time and the impact of early interventions on clinical and economic outcomes and the role of matrix metalloproteinases (MMPs) in wound healing. Method: A systematic review of the literature was carried out on the role of dressings in diabetic foot ulcer (DFU), and venous leg ulcer (VLU) management strategies, their effectiveness, associated resource use/cost, and quality of life (QoL) impact on patients. From this evidence-base statements were written regarding chronicity in wounds, burden of illness, healing time, and the role of MMPs, early interventions and dressings. A modified Delphi methodology involving two iterations of email questionnaires followed by a face-to-face meeting was used to validate the statements, in order to arrive at a consensus for each. Clinical experts were selected, representing nurses, surgeons, podiatrists, academics, and policy experts. Results: In the first round, 38/47 statements reached or exceeded the consensus threshold of 80% and none were rejected. According to the protocol, any statement not confirmed or rejected had to be modified using the comments from participants and resubmitted. In the second round, 5/9 remaining statements were confirmed and none rejected, leaving 4 to discuss at the meeting. All final statements were confirmed with at least 80% consensus. Conclusion: This modified Delphi panel sought to gain clarity from clinical experts surrounding the use of dressings in the management of chronic wounds. A full consensus statement was developed to help clinicians and policy makers improve the management of patients with these conditions

Investigation of γ‐irradiated syndiotactic poly(2‐methylheptyl methacrylate) using NMR spectroscopy

Syndiotactic poly(2-methylheptyl methacrylate) which was gamma-irradiated at room temperature to a dose of 1600 kGy was investigated by NMR spectroscopy. The H-1 and C-13 resonances for the macromolecular chain were assigned by using the 2D and the DEFT (distortionless enhancement by polarization transfer) technique. The spin-echo modified 2D NMR pulse sequence was used to investigate the small molecules and new structures which were formed during gamma-irradiation. The radiation mechanisms for cleavage of the side chain from the main chain and formation of double bonds from both the main chain and the side chain have been formulated based upon the NMR analysis

The copolymerisation of tetrahydrofurfuryl methacrylate and methyl methacrylate

The bulk copolymerisations of tetrahydrofurfuryl methacrylate, THFMA, and methyl methacrylate, MMA, were carried to low conversion at 60 degrees C, using benzoyl peroxide, BPO, as the initiator. The compositions of the copolymers were determined using C-13 NMR spectroscopy. The glass transition temperatures of the copolymers were determined using differential scanning calorimetry

Effect of temperature and a crosslinking promoter on the gamma-radiolysis of a perfluoroelastomer

Methods of promoting the radiation-induced cross linking of poly(tetrafluoro-ethylene-co-perfluoromethyl vinyl ether) (TFE/PMVE) have been investigated. Greater control of the crosslinking and chain-scission reactions was achieved by varying the radiolysis temperature. This was attributed to temperature affecting the mobilities of reactive species such as polymeric free radicals. These reactive species are precursors to radiation-induced cross links and chain-ends. Analysis of the sol/gel behaviour, tensile properties and FTIR indicated that the optimum temperature for the radiation crosslinking of TFE/PMVE, at a dose of 150 kGy, was 263 K. This temperature was 10 K below the glass transition temperature. Incorporation of 1 wt% triallyl isocyanurate (TAIC) greatly amplified the radiation crosslinking of TFE/PMVE, The dose for gelation was decreased by 70%, and the additive imparted superior mechanical properties compared to the neat irradiated TFE/PMVE. Electron spin resonance (ESR) measurements showed higher radical yields at 77 K with the 1 wt% TAIC, indicating that the crosslinking promoter was acting as a radical trap. (C) 1999 Society of Chemical Industry

INVESTIGATION OF HIGH-TEMPERATURE RADIATION EFFECTS ON POLY(METHYL METHACRYLATE) OF SPECIFIC TACTICITY

The high-temperature radiation properties of isotactic and syndiotactic poly(methyl methacrylate) (PMMA) have been investigated by NMR spectroscopy. The tacticity changes for the isotactic PMMA during gamma-irradiation have been simulated by a model which allows for recombination of a scissioned bond and for the recombined bond to be in either the meso or racemic configuration with probability P-t. The calculated values of P-t were found to be consistent with the tacticity parameter P-m values for the free-radical polymerization of a methyl methacrylate monomer. The G-value of the temporary chain scission and then recombination, G(TCS), for the isotactic PMMA sample which was gamma-irradiated at 80 degrees C was found to be 18.6, which is much higher than the G-value of the permanent main-chain scission, G(S). A mechanism to explain the observed tacticity changes have been proposed