Green plot ratio: an ecological measure for architecture and urban planning

Current research on sustainability of cities has favoured the implementation and conservation of greenery in the urban context. The benefits of plants are not just environmental but recreational, aesthetic and emotional. The full benefits of plants and the role they play in the ecology of cities remain to be mapped out but the general significance of plants appears to be uncontested. This paper proposes a new architectural and planning metric for greenery in cities and buildings. This new metric, the green plot ratio (GPR), is based on a common biological parameter called the leaf area index (LAI), which is defined as the single-side leaf area per unit ground area. The green plot ratio is simply the average LAI of the greenery on site and is presented as a ratio that is similar to the building plot ratio (BPR) currently in use in many cities to control maximum allowable built-up floor area in a building development. GPR allows more precise regulation of greenery on site without excluding a corresponding portion of the site from building development. It provides flexibility to the designer while simultaneously protecting the green quota in the design. This concept has been applied in a number of design competitions in which the author has collaborated with colleagues and various architectural practices. It has also been adopted as a planning requirement by the client authority for one of the competitions for which the author has entered. While seen as a fundamental and important metric, GPR is not in itself an indicator for all the ecological relationships between plants and cities. A larger set of related metrics need to be developed.     

Relationship between C14 urea breath test values and solid-phase gastric emptying time in non-ulcer dyspepsia patients

BACKGROUND: Non-ulcer dyspepsia (NUD) is a poorly understood syndrome often found with endoscopic evidence of gastritis; Helicobacter pylori (Hp) is a common and important cause of gastritis. In the recent literature, gastric hypomotility is thought to be a cause of NUD. Thus, this investigation studied the relationship between Hp and delayed gastric emptying in NUD patients. METHODS: Using a radionuclide-labelled solid meal to calculate gastric emptying time (GET) of 78 NUD patients. The carbon-14 urea breath test (C14 UBT) was used to quantitate Hp infection. RESULTS: The prevalence of Hp infection in patients with NUD reached 59%. There was a strong association of Hp infection with advanced age (p = 0.0091). There was no significant difference between solid-phase GET and C14 UBT values among three different age groups (young, middle, old) of NUD patients. There was no difference among sex, age, body weight and solid-phase GET between Hp-positive and Hp-negative NUD patients. However the solid-phase GET was significantly prolonged in patients with NUD, compared with the controls. CONCLUSIONS: Solid-phase GET is not correlated with the C14 UBT values, and Hp gastric colonization does not account for dyspeptic syndrome in NUD patients.     

Conductive Polymer-Coated 3D Printed Microneedles: Biocompatible Platforms for Minimally Invasive Biosensing Interfaces

Conductive polymeric microneedle (MN) arrays as biointerface materials show promise for the minimally invasive monitoring of analytes in biodevices and wearables. There is increasing interest in microneedles as electrodes for biosensing, but efforts have been limited to metallic substrates, which lack biological stability and are associated with high manufacturing costs and laborious fabrication methods, which create translational barriers. In this work, additive manufacturing, which provides the user with design flexibility and upscale manufacturing, is employed to fabricate acrylic-based microneedle devices. These microneedle devices are used as platforms to produce intrinsically-conductive, polymer-based surfaces based on polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). These entirely polymer-based solid microneedle arrays act as dry conductive electrodes while omitting the requirement of a metallic seed layer. Two distinct coating methods of 3D-printed solid microneedles, in situ polymerization and drop casting, enable conductive functionality. The microneedle arrays penetrate ex vivo porcine skin grafts without compromising conductivity or microneedle morphology and demonstrate coating durability over multiple penetration cycles. The non-cytotoxic nature of the conductive microneedles is evaluated using human fibroblast cells. The proposed fabrication strategy offers a compelling approach to manufacturing polymer-based conductive microneedle surfaces that can be further exploited as platforms for biosensing.     

Rapid characterization of lipids by MALDI MS. Part 1: Bacterial taxonomy and analysis of food oils

Several new methods have been developed recently that allow the direct detection of lipids without resorting to derivatization or chromatographic separation. The simplest of these is direct MALDI (matrix‐assisted laser desorption/ionization) mass spectrometry. This approach is most useful for mixtures that contain minimal amounts of ion‐suppressing interfering components. However, even when such components are present, their effects can often be minimized by using simple separation techniques beforehand, such as solid phase extraction or thin layer chromatography. For example, direct MALDI has been used for rapid screening of lipids and for taxonomic identification of the source organisms with no sample pretreatment. Fractions collected from solid phase extraction cartridges have also been used to avoid the most extreme effects of ion suppression from more complex lipid mixtures. More recently, direct MALDI has been applied to the analysis of TLC plates allowing the detection of TLC‐separated lipids from the complex lipidome. Herein, we briefly describe the application of rapid MALDI MS to some typical research problems involving the characterization of lipids. In Part 1 these include bacterial taxonomy by direct analysis of intact lipids in simple extracts rather than by conversion to fatty acid methyl esters. Food oils such as triacylglycerols can be characterized simply and easily by direct MALDI MS without resort to any sort of separation. Part 2 (in the next issue of Lipid Technology) will cover the spontaneous fragmentation of protonated lipids, ion suppression and the use of solid phase extraction and thin layer chromatography with MALDI MS to characterize complex biological samples.