In this work, the technology of nano and micro-scale particle reinforcement concerning various polymeric fibre-reinforced systems including polyamides (PA), polyesters, polyurethanes, polypropylenes and high performance/temperature engineering polymers such as polyimide (PI), poly(ether ether ketone) (PEEK), polyarylacetylene (PAA) and poly p-phenylene benzobisoxazole (PBO) is reviewed. When the diameters of polymer fibre materials are shrunk from micrometers to submicrons or nanometers, there appear several unique characteristics such as very large surface area to volume ratio (this ratio for a nanofibre can be as large as 10 3 times of that of a microfibre), flexibility in surface functionalities and superior mechanical performance (such as stiffness and tensile strength) compared with any other known form of the material. However, nanoparticle reinforcement of fibre reinforced composites has been shown to be a possibility, but much work remains to be performed in order to understand how nanoreinforcement results in dramatic changes in material properties. The understanding of these phenomena will facilitate their extension to the reinforcement of more complicated anisotropic structures and advanced polymeric composite systems.

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As the COVID-19 pandemic unfolds, radiology imaging is playing an increasingly vital role in determining therapeutic options, patient management, and research directions. Publicly available data are essential to drive new research into disease etiology, early detection, and response to therapy. In response to the COVID-19 crisis, the National Cancer Institute (NCI) has extended the Cancer Imaging Archive (TCIA) to include COVID-19 related images. Rural populations are one population at risk for underrepresentation in such public repositories. We have published in TCIA a collection of radiographic and CT imaging studies for patients who tested positive for COVID-19 in the state of Arkansas. A set of clinical data describes each patient including demographics, comorbidities, selected lab data and key radiology findings. These data are cross-linked to SARS-COV-2 cDNA sequence data extracted from clinical isolates from the same population, uploaded to the GenBank repository. We believe this collection will help to address population imbalance in COVID-19 data by providing samples from this normally underrepresented population.

Background: Periprosthetic fractures are increasingly encountered in hip arthroplasty. The Vancouver classification system is widely used. Little knowledge exists regarding the association of the Vancouver classification with either cemented or uncemented stems. The aim was to analyse a series of fractures and determine associations. Methods: A series of consecutive patients over 8 years was identified including only post-operative fractures of primary hip arthroplasties. Baseline and radiographic characteristics were recorded including the type of stem fixation (cemented or uncemented) and Vancouver classification. Statistical analysis was performed to determine the association of the Vancouver classification between cemented and uncemented stems. Results: A total of 172 patients were identified (84 cemented stems, 88 uncemented stems). There were 30 Vancouver A fractures (12 cemented vs.18 uncemented, p > 0.05), 125 Vancouver B fractures (63 cemented vs. 62 uncemented, p > 0.05) and 17 Vancouver C fractures (9 cemented vs. 8 uncemented, p > 0.05). The Vancouver B2 fracture occurred most frequently (N = 95; 44 cemented vs. 51 uncemented, p > 0.05) and consists of four distinct fracture patterns: the previously described comminuted 'burst', clamshell and spiral patterns and the newly observed 'reverse' clamshell. The burst and spiral fracture patterns are significantly associated with cemented stems, and the clamshell pattern is significantly associated with uncemented stems. Conclusions: Vancouver A, B and C fractures occur equally in cemented and uncemented stems. Awareness of four distinct Vancouver B2 fracture patterns, including the newly observed reverse clamshell, will aid surgeons in predicting stem instability.

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Pernio is a commonly reported cutaneous manifestation of SARS‐CoV‐2 infection. 1 Our international registry of COVID‐19 dermatologic manifestations has collected 1,176 total cases of COVID‐19 skin manifestations, including 619 cases of pernio in suspected or confirmed COVID‐19 patients. 1 Most patients with new‐onset pernio were entered into the registry after the first pandemic wave (79% in March‐May 2020). Starting in September 2020, the registry received reports of a subset of these patients who developed recurrent pernio in the following months.

Polyurethane-functionalized starch nanoparticles (PUFSNPs) have been synthesized by chemical modification of polyhydroxylated starch nanocrystals (SNC) with aliphatic and aromatic diisocyanates. The covalent attachment of the diisocyanates to the backbone of SNC for the formation of starch-derived nanopolyurethane polymers was unambiguously determined by FTIR and NMR spectroscopy. PUFSNPs were entirely obtained from SNC with yields ranging from 41.5 to 86.0 wt % and their size distribution, size, porosity and morphology were determined by dynamic light scattering (DLS), high resolution transmission electron microscopy (HRTEM) and Brunauer-Emmett-Teller (BET) adsorption techniques. The size and surface area of the cyclic aliphatic-based PUFSNP (NPU4) is 27 nm and 52.64 m 2 g 21 , respectively, indicating one of the potential and promising biodegradable materials for the adsorption of acid impurities and contaminants that are found in crude biodiesel. The acid content of the biodiesel is remarkably reduced by 32-39% with PUFSNPs while 7-18% with their corresponding bulk materials.

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