"Gravity" - a new simple negative pressure wound therapy self-build design for low income countries.

Negative Pressure Wound Therapy (NPWT) is prohibitively expensive at the moment and therefore not easily accessible in low-income countries. An additional problem is the requirement of consistent reliable electricity to power the devices. A new low-cost NPWT device was designed from low cost and simple materials and it can be built and operated following a simple set of instructions. The so-called Gravity device was made from parts costing just under £6 GBP (May 2016) and it creates a constant pressure of 125 mmHg. Gravity operated from 4 hours and 40 minutes up to 5 hours and 18 minutes before needing to be reset. This reset can be achieved without patient involvement. Gravity was taken to Kenya by a Doctor on 5 May 2016 to be evaluated. A NPWT device prototype was successfully made and positive feedback was received from Kenya.

Influence of the molecular structure and morphology of self-assembled 1,3,5-benzenetrisamide nanofibers on their mechanical properties.

The influence of molecular structure on the mechanical properties of self-assembled 1,3,5-benzenetrisamide nanofibers is investigated. Three compounds with different amide connectivity and different alkyl substituents are compared. All the trisamides form well-defined fibers and exhibit significant differences in diameters of up to one order of magnitude. Using nanomechanical bending experiments, the rigidity of the nanofibers shows a difference of up to three orders of magnitude. Calculation of Young's modulus reveals that these differences are a size effect and that the moduli of all systems are similar and in the lower GPa range. This demonstrates that variation of the molecular structure allows changing of the fibers' morphology, whereas it has a minor influence on their modulus. Consequently, the stiffness of the self-assembled nanofibers can be tuned over a wide range--a crucial property for applications as versatile nano- and micromechanical components.

Nanomechanical properties of supramolecular self-assembled whiskers determined by AFM force mapping.

In this Letter, we investigate the nanomechanical properties of self-assembled 1,3,5-benzenetrisamide whiskers with atomic force microscopy (AFM) bending experiments. We use force mapping to acquire spatially resolved force measurements over the full length of a whisker segment spanning a channel of a structured glass substrate. This allows validation of the experimental boundary conditions directly from the AFM data and a reliable determination of Young's modulus. The presented technique can be generalized for the mechanical characterization of other one-dimensional materials.