The Surfer's Shoulder: A Systematic Review of Current Literature and Potential Pathophysiological Explanations of Chronic Shoulder Complaints in Wave Surfers.

BACKGROUND: Wave surfing will debut in the next Olympic Games and is increasingly popular as a sport. Chronic shoulder complaints are frequently reported amongst surfers, though literature researching its pathophysiology and prevention is scarce. This article provides an overview of the current literature, proposes a potential pathogenesis and a potential physiotherapeutic prevention program for surf-induced shoulder complaints. METHODS: A systematic review was performed considering the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for articles regarding kinematic analysis of the surf paddling movement. Data sources were Embase, MEDLINE (PubMed) and Research gate. We included case series and cohort studies that originally studied or described the paddle movement made by wave surfers, studies that reported on kinesiologic analysis with nerve conduction studies and studies on 3D motion analysis of the shoulder while paddling. RESULTS: Eight original articles were included that analysed the shoulder movement in paddling surfers. Muscles that are active during paddling are mainly internal rotators and muscles that are involved in shoulder flexion. Internal rotators are active in propelling the surfer through the water, though external rotator strength is only used while the arm is out of the water. DISCUSSION: In surfers with shoulder complaints, external rotation range of motion and external rotation strength are impaired. Scapulothoracic dyskinesis may occur and subacromial pain syndrome may coincide. Further research should address potential pectoralis minor shortening, which may lead to aberrant scapular tilt and lateral rotation of the scapula. The surfer's shoulder is characterised by external rotation deficit, as opposed to internal rotation deficit in the thrower's shoulder, and it differs substantially from shoulder complaints in swimmers. Therefore, a specific prevention or rehabilitation protocol for surfers is required. Decreased thoracic extension may thereby alter the risk of scapular dyskinesis and hence increase the risk of impingement around the shoulder joint. A potential physiotherapeutic prevention programme should address all these aspects, with the main goal being to increase external rotator strength and to stretch the internal rotators. CONCLUSION: There is a high incidence of chronic surf-induced shoulder complaints in surfers. Symptoms may arise due to imbalanced training or scapular dyskinesis, which may subsequently trigger subacromial pain. Physiotherapeutic prevention should include stretching of the internal rotators, external rotator training and optimisation of thoracic extension and scapulothoracic movement.

In Vivo Evaluation of Bioabsorbable Fe-35Mn-1Ag: First Reports on In Vivo Hydrogen Gas Evolution in Fe-Based Implants.

This work investigates the influence of Ag (1 wt%) on the mechanical properties, in vitro and in vivo corrosion, and biocompatibility of Fe-35Mn. The microstructure of Fe-35Mn-1Ag possesses a uniform dispersion of discrete silver particles. Slight improvements in compressive properties are attributed to enhanced density and low porosity volume. Fe-35Mn-1Ag exhibits good in vitro and in vivo corrosion rate of Fe-35Mn due to an increase in microgalvanic corrosion. Gas pockets, which originate from an inflammatory response to the implants, are observed in the rats after 4 weeks implantation but are undetectable after 12 weeks. No chronic toxicity is observed with the Fe-35Mn-1Ag, suggesting acceptable in vivo biocompatibility. The high corrosion rate of the alloy triggers an increased level of nonadverse tissue inflammatory responses 4 weeks after implantation, which subsequently subsides at 12 weeks. The Fe-35Mn-1Ag displays properties that are suitable for orthopedic applications.

Microbial biosurfactant research: time to improve the rigour in the reporting of synthesis, functional characterization and process development.

The demand for microbially produced surface-active compounds for use in industrial processes and products is increasing. As such, there has been a comparable increase in the number of publications relating to the characterization of novel surface-active compounds: novel producers of already characterized surface-active compounds and production processes for the generation of these compounds. Leading researchers in the field have identified that many of these studies utilize techniques are not precise and accurate enough, so some published conclusions might not be justified. Such studies lacking robust experimental evidence generated by validated techniques and standard operating procedures are detrimental to the field of microbially produced surface-active compound research. In this publication, we have critically reviewed a wide range of techniques utilized in the characterization of surface-active compounds from microbial sources: identification of surface-active compound producing microorganisms and functional testing of resultant surface-active compounds. We have also reviewed the experimental evidence required for process development to take these compounds out of the laboratory and into industrial application. We devised this review as a guide to both researchers and the peer-reviewed process to improve the stringency of future studies and publications within this field of science.

Genome-wide CRISPR screen reveals host genes that regulate SARS-CoV-2 infection

Identification of host genes essential for SARS-CoV-2 infection may reveal novel therapeutic targets and inform our understanding of COVID-19 pathogenesis. Here we performed a genome-wide CRISPR screen with SARS-CoV-2 and identified known SARS-CoV-2 host factors including the receptor ACE2 and protease Cathepsin L. We additionally discovered novel pro-viral genes and pathways including the SWI/SNF chromatin remodeling complex and key components of the TGF-{beta} signaling pathway. Small molecule inhibitors of these pathways prevented SARS-CoV-2-induced cell death. We also revealed that the alarmin HMGB1 is critical for SARS-CoV-2 replication. In contrast, loss of the histone H3.3 chaperone complex sensitized cells to virus-induced death. Together this study reveals potential therapeutic targets for SARS-CoV-2 and highlights host genes that may regulate COVID-19 pathogenesis.

The Prospects for Biodegradable Zinc in Wound Closure Applications.

Zinc is identified as a promising biodegradable metal along with magnesium and iron. In the last 5 years, considerable progress is made on understanding the mechanical properties, biodegradability, and biocompatibility of zinc and its alloys. A majority of these studies have focused on using zinc for absorbable cardiovascular and orthopedic device applications. However, it is likely that zinc is also suitable for other biomedical applications. In this work, the prospects for zinc in the fabrication of wound closure devices such as absorbable sutures, staples, and surgical tacks are critically assessed, with the aim of inspiring future research on biodegradable Zn for this medical application.

The Dependence of Isothermal ω Precipitation on the Quenching Rate in a Metastable ß-Ti Alloy.

The precipitation behavior of the α strengthening phase in metastable ß-Ti alloys is highly dependent on heat treatment parameters such as quenching rate, heating rate and ageing temperature. In this paper we have investigated the influence of quenching rate on the formation of isothermal ω precipitates that have been regarded as potent nucleant sites for α precipitation. The results show that the ß-solutionized alloy contains a ß matrix with a layer structured morphology. Regular atomic movement of the (002)ß plane along the <002> direction was observed in the alloy. The increase in quenching rate refines the thickness of layers, subsequently influencing the nucleation and growth of isothermal ω precipitates after ageing treatment. The high quenching rate promotes the occurrence of ω precipitation, broadens the stage of ω precipitation and increases the number density of ω precipitates. Since the isothermal ω phase provides a heterogeneous nucleation site for α precipitates, it is inferred that the quenching rate may indirectly influence the mechanical properties of metastable ß-Ti alloy.