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Disruption risks in supply chain management have a great negative influence on the performance of supply chain members. Therefore, the field of supply chain disruption (SCD) has received increasing attention on mitigating the risks and improving the supply chain performance. This paper presents a comprehensive bibliometric overview and visualisation of the field of SCD based on 1,310 publications derived from the core collection of the Web of Science. The influential authors, organisations, and SCD keywords are discussed in detail based on some visualisation tools. Then, the leading publications and main clusters of SCD are identified to find out the key research topics based on citation analysis and reference co-citation analysis. The paper will be a helpful resource for researchers and practitioners who are interested in the field of SCD to capture the current research hotspots and potential research directions.

Citric acid-based polymer/hydroxyapatite composites (CABP-HAs) are a novel class of biomimetic composites that have recently attracted significant attention in tissue engineering. The objective of this study was to compare the efficacy of using two different CABP-HAs, poly (1,8-octanediol citrate)-click-HA (POC-Click-HA) and crosslinked urethane-doped polyester-HA (CUPE-HA) as an alternative to autologous tissue grafts in the repair of skeletal defects. CABP-HA disc-shaped scaffolds (65 wt.-% HA with 70% porosity) were used as bare implants without the addition of growth factors or cells to renovate 4 mm diameter rat calvarial defects (n = 72, n = 18 per group). Defects were either left empty (negative control group), or treated with CUPE-HA scaffolds, POC-Click-HA scaffolds, or autologous bone grafts (AB group). Radiological and histological data showed a significant enhancement of osteogenesis in defects treated with CUPE-HA scaffolds when compared to POC-Click-HA scaffolds. Both, POC-Click-HA and CUPE-HA scaffolds, resulted in enhanced bone mineral density, trabecular thickness, and angiogenesis when compared to the control groups at 1, 3, and 6 months post-trauma. These results show the potential of CABP-HA bare implants as biocompatible, osteogenic, and off-shelf-available options in the repair of orthopedic defects.

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Power-law-distributed species counts or clone counts arise in many biological settings such as multispecies cell populations, population genetics, and ecology. This empirical observation that the number of species c k represented by k individuals scales as negative powers of k is also supported by a series of theoretical birth-death-immigration (BDI) models that consistently predict many low-population species, a few intermediate-population species, and very high-population species. However, we show how a simple global population-dependent regulation in a neutral BDI model destroys the power law distributions. Simulation of the regulated BDI model shows a high probability of observing a high-population species that dominates the total population. Further analysis reveals that the origin of this breakdown is associated with the failure of a mean-field approximation for the expected species abundance distribution. We find an accurate estimate for the expected distribution c k by mapping the problem to a lower-dimensional Moran process, allowing us to also straightforwardly calculate the covariances c k c ℓ . Finally, we exploit the concepts associated with energy landscapes to explain the failure of the mean-field assumption by identifying a phase transition in the quasi-steady-state species counts triggered by a decreasing immigration rate.

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