Revisiting NMR Through-Space <i>J</i>_FF Spin–Spin Coupling Constants for Getting Insight into Proximate F‑-‑F Interactions

At present times it is usual practice to mark biological compounds replacing an H for an F atom to study, by means of ¹⁹F NMR spectroscopy, aspects such as binding sites and molecular folding features. This interesting methodology could nicely be improved if it is known how proximity interactions on the F atom affect its electronic structure as gauged through high-resolution ¹⁹F NMR spectroscopy. This is the main aim of the present work and, to this end, differently substituted <i>peri-</i>difluoronaphthalenes are chosen as model systems. In such compounds are rationalized some interesting aspects of the diamagnetic and paramagnetic parts of the ¹⁹F nuclear magnetic shielding tensor as well as the transmission mechanisms for the PSO and FC contributions to ⁴<i>J</i>_F1F8 indirect nuclear spin–spin coupling constants

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially