Waiting list mortality and the potential of donation after circulatory death heart transplantations in the Netherlands

BACKGROUND: With more patients qualifying for heart transplantation (HT) and fewer hearts being transplanted, it is vital to look for other options. To date, only organs from brain-dead donors have been used for HT in the Netherlands. We investigated waiting list mortality in all Dutch HT centres and the potential of donation after circulatory death (DCD) HT in the Netherlands. METHODS: Two different cohorts were evaluated. One cohort was defined as patients who were newly listed or were already on the waiting list for HT between January 2013 and December 2017. Follow-up continued until September 2018 and waiting list mortality was calculated. A second cohort of all DCD donors in the Netherlands (lung, liver, kidney and pancreas) between January 2013 and December 2017 was used to calculate the potential of DCD HT. RESULTS: Out of 395 patients on the waiting list for HT, 196 (50%) received transplants after a median waiting time of 2.6 years. In total, 15% died while on the waiting list before a suitable donor heart became available. We identified 1006 DCD donors. After applying exclusion criteria and an age limit of 50 years, 122 potential heart donors remained. This number increased to 220 when the age limit was extended to 57 years. CONCLUSION: Waiting list mortality in the Netherlands is high. HT using organs from DCD donors has great potential in the Netherlands and could lead to a reduction in waiting list mortality. Cardiac screening will eventually determine the true potential

Chemistry of desiccant properties of carbohydrate polymers as studied by near-infrared spectroscopy

The combination frequency of water molecule in near-infrared spectroscopy is very useful for studying water molecular adsorption on solid surfaces. The absorption is purely from water molecules, and the variation in the absorption bands reflects the change in the environment of the water molecules on a surface. This variation, in turn, reflects the nature of the functional groups on the surface. Recently, Christy used this information in combination with second-derivative techniques to probe the surface of hydrothermally treated silica gel samples (Ind. Eng. Chem. Res.2011, 50, 5543). In this work, a similar approach was used in studying the surface OH groups in carbohydrate polymers and their behavior toward water molecular adsorption. Not only second-derivative profiles but also fourth-derivative profiles of the near-infrared spectra were used in revealing the adsorption behavior of the OH groups on the polymer surface. Carbohydrate polymers such as amylose amylopectin, cellulose, and starch samples were used in this study. After being heated and evacuated at 120 °C, the samples were exposed to air, and the evolving changes on the surfaces of the samples were followed by near-infrared spectroscopy. Furthermore, the effectiveness of the samples in adsorbing water molecules was followed by monitoring the mass of water adsorbed. These investigations formed the basis for understanding how the OH groups on the carbohydrate polymers adsorb water molecules. The results clearly reveal that carbohydrate polymers such as amylose, amylopectin, and cellulose have three OH groups of different polarities and that the OH groups attached to C2 and C3 positions in the monomer glucose units adsorb water molecules faster than the C6-OH group. Furthermore, the adsorption of water molecules in amylose and amylopectin follows the same pattern during the first hour, irrespective of the variation in their structure