Maxwell's equations-based dynamic laser–tissue interaction model

Since its invention in the early 1960s, the laser has been used as a tool for surgical, therapeutic, and diagnostic purposes. To achieve maximum effectiveness with the greatest margin of safety it is important to understand the mechanisms of light propagation through tissue and how that light affects living cells. Lasers with novel output characteristics for medical and military applications are too often implemented prior to proper evaluation with respect to tissue optical properties and human safety. Therefore, advances in computational models that describe light propagation and the cellular responses to laser exposure, without the use of animal models, are of considerable interest. Here, a physics-based laser–tissue interaction model was developed to predict the dynamic changes in the spatial and temporal temperature rise during laser exposure to biological tissues. Unlike conventional models, the new approach is grounded on the rigorous electromagnetic theory that accounts for wave interference, polarization, and nonlinearity in propagation using a Maxwell's equations-based technique.     

Transitional Care for Young People with Neurological Disorders: A Scoping Review with A Focus on Patients with Movement Disorders

Childhood-onset movement disorders represent a heterogenous group of conditions. Given the complexity of these disorders, the transition of care from pediatric to adult medicine is an important consideration. We performed a scoping review of the literature on transitional care in chronic neurological disease, exploring key transitional issues and proposed transitional care models. Our aim was to describe the current knowledge and gaps about the transition process of young adults with chronic neurological disorders, paying special attention to childhood onset movement disorders. A total of 64 articles were included in the qualitative synthesis; 56 articles reported on transitional care issues, and 8 articles reported on transitional care models. Only 2 articles included patients with movement disorders. The following 4 main transitional issues were identified following synthesis of the available literature: (1) inadequate preparation for the transition process, (2) inappropriate and inconsistent transition practices, (3) inadequate adult services, and (4) heightened emotional response surrounding transition. Of the reported transitional care models, multidisciplinary ambulatory care was the most common approach. In studies evaluating patient-related outcomes, positive health, educational, and vocational outcomes were found. The available literature provides insights on issues that can arise during transition that should be addressed to improve patient and caregiver comfort and satisfaction with care. Further research is needed to evaluate how transitional care programs affect outcomes and their cost effectiveness. More studies are required to determine the needs and outcomes specific to patients with childhood onset movement disorders. © 2020 International Parkinson and Movement Disorder Society     

SYNTAX Score and Outcomes of Coronary Revascularization in Diabetic Patients

Purpose of Review

This review describes the dynamic relationship between diabetes mellitus (DM) and coronary artery disease (CAD) with respect to different revascularization strategies and how angiographic tools such as the Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score can supplement clinical decision-making.

Recent Findings

The SYNTAX score characterizes the anatomical extent of CAD in terms of the number of lesions, functional importance, and complexity. Studies not limited to patients with DM suggest that percutaneous coronary intervention (PCI) is a reasonable alternative to coronary artery bypass grafting (CABG) in patients with low-medium SYNTAX scores, while patients with high SYNTAX scores should be revascularized with CABG if operable. Similar findings were also observed for diabetes patients with multivessel disease in retrospective pooled analysis. The SYNTAX II score combines anatomical and clinical risk to improve upon the decision regarding the optimal revascularization strategy. The SYNTAX II score can be applied to patients with DM.

Summary

The SYNTAX scores provide guidance to clinicians faced with determining the optimal revascularization strategy in patients with DM and advanced CAD. Using a heart team approach, the information can be considered along with other factors that influence PCI or CABG risk.

     

Cangrelor for patients undergoing percutaneous coronary intervention: evidence from a meta-analysis of randomized trials

Cangrelor is a new parenteral adenosine diphosphate P2Y12 receptor inhibitor with rapid, profound and reversible inhibition of platelet activity. The aim of this meta-analysis was to evaluate efficacy and safety of this new agent in patients undergoing percutaneous coronary intervention (PCI). We searched PubMed, Cochrane Library, EMBASE, Web of Science and CINAHL databases from the inception through April 2013. Randomized controlled trials (RCTs) comparing cangrelor with control (clopidogrel/placebo) were selected. We used the random-effects models to calculate the risk ratio. The primary efficacy outcome was risk of myocardial infarction, and the primary safety outcome was TIMI major bleeding at 48 h. Three RCTs included a total of 25,107 participants. Effects of Cangrelor were not different against comparators for myocardial infarction (MI) (Risk ratio [RR] 0.94, 95 % confidence interval [CI] 0.78–1.13) and all-cause mortality (RR 0.72, 95 % CI 0.36–1.43). However, cangrelor significantly reduced the risk of ischemia-driven revascularization (RR 0.72, 95 % CI 0.52–0.98), stent thrombosis (RR 0.60, 95 % CI 0.44–0.82) and Q wave MI (RR 0.53, 95 % CI 0.30–0.92) without causing extra major bleeding (Thrombolysis in Myocardial infarction criteria) and severe or life-threatening bleeding (Global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries criteria). Separate analysis against only clopidogrel also showed similar findings except Q wave MI outcome. Use of cangrelor during PCI might reduce the risk of ischemia-driven revascularization and stent thrombosis, without causing extra major bleeding.     

Concrete by Preplaced Aggregate Method Using Silica Fume and Polypropylene Fibres

Preplaced aggregate concrete (PAC) is prepared in two steps, with the coarse aggregate being initially laid down in the formwork, after which a specialised grout is injected into it. To enhance the properties of concrete and to reduce the emission of CO₂ produced during the production of cement, supplementary cementitious materials (SCMs) are used to partially substitute ordinary Portland cement (OPC). In this study, 100 mm × 200 mm (diameter x height) PAC cylinders were cast with 10 per cent of cement being substituted with silica fume; along with that, 1.5% dosage of Macro polypropylene fibres were also introduced into the coarse aggregate matrix. Compressive strength test, splitting tensile strength test, mass loss at 250 °C, and compressive strength at 250 °C were performed on the samples. PAC samples with 10% of cement replaced with Silica Fume (SPAC) were used as control samples. The primary objective of this study was to observe the effect of the addition of Polypropylene fibres to PAC having Silica fume as SCM (FRPAC). The aforementioned tests showed that FRPAC had a lower compressive strength than that of the control mix (SPAC). FRPAC had greater tensile strength than that of NPAC and SPAC. Mass loss at 250 °C was greater in SPAC compared to FRPAC. The compressive strength loss at 250 °C was significantly greater in FRPAC compared to SPAC. FRPAC exhibited a greater strain for the applied stress, and their stress-strain curve showed that FRPAC was more ductile than SPAC.     

CORR Insights®: Débridement and Reconstruction Improve Postoperative Sagittal Alignment in Kyphotic Cervical Spinal Tuberculosis

Clinical Orthopaedics and Related Research® -