Many exciting frontiers of science and engineering require understanding the spatiotemporal properties of sustained nonequilibrium systems such as fluids, plasmas, reacting and diffusing chemicals, ...crystals solidifying from a melt, heart muscle, and networks of excitable neurons in brains. This introductory textbook for graduate students in biology, chemistry, engineering, mathematics, and physics provides a systematic account of the basic science common to these diverse areas. This book provides a careful pedagogical motivation of key concepts, discusses why diverse nonequilibrium systems often show similar patterns and dynamics, and gives a balanced discussion of the role of experiments, simulation, and analytics. It contains numerous worked examples and over 150 exercises. This book will also interest scientists who want to learn about the experiments, simulations, and theory that explain how complex patterns form in sustained nonequilibrium systems.
In addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the ...economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States.
The Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee.
Using the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017.
Understanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA.
Background
Medicare is rapidly moving toward using patient-reported outcome measures (PROMs) for outcomes assessment and justification of orthopaedic and other procedures. Numerous measures have been ...developed to study knee osteoarthritis (OA); however, many of these surveys are long, disruptive to clinic flow, and result in incomplete data capture and/or low followup rates. The Knee injury and Osteoarthritis Outcome (KOOS) physical function short-form (KOOS-PS), while shorter, ignores pain, which is a primary concern of patients with advanced knee OA.
Questions/purposes
Our objective was to derive and validate a short-form survey focused on the patient with end-stage knee OA undergoing TKA.
Methods
Using our hospital’s knee replacement registry, we retrospectively identified 2291 patients with knee OA who underwent primary unilateral TKA and had completed preoperative and 2-year postoperative PROMs. We assessed 30 items from the 42-item KOOS that were quantitatively most difficult for patients to perform before TKA and qualitatively most relevant to patients with end-stage knee OA. Rasch analysis identified the KOOS, JR, a seven-item instrument, representing a single dimension, which we define as “knee health” because it reflects aspects of pain, symptom severity, and activities of daily living (ADL) including movements or activities that are directly relevant and difficult for patients with advanced knee OA. We assessed the internal consistency, external validity (versus KOOS and WOMAC domains), responsiveness, and floor and ceiling effects of the KOOS, JR. External validation was performed using calculated KOOS, JR scores in collaboration with a nationally representative joint replacement registry, the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR).
Results
Internal consistency for the KOOS, JR was high (Person Separation Index, 0.84; and 0.85 FORCE), external validity against other validated knee surveys was excellent (Spearman correlation coefficient, ρ 0.54–0.91), particularly for the KOOS pain (ρ 0.89 95% CI, 0.88–0.91 Hospital for Special Surgery HSS; and 0.91 95% CI, 0.90–0.93 FORCE) and KOOS ADL (ρ 0.87 95% CI, 0.85–0.88 HSS; and 0.84 95% CI, 0.81–0.87 FORCE). The KOOS, JR responsiveness (standardized response means, 1.79 95% CI, 1.70–1.88 HSS; and 1.70 95% CI, 1.54–1.86 FORCE) was high and floor 0.4–1.2%) and ceiling (18.8–21.8%) effects were favorable.
Conclusions
The new short knee PROM, the KOOS, JR, provides a single score representing “knee health” as it combines pain, symptoms, and functional limitations in a single score. This short-form PROM is patient-relevant and efficient.
Level of Evidence
Level III, diagnostic study.
Background:
The quality and state of satisfaction reporting after total knee replacement (TKR) is variable.
Questions/Purposes:
The purposes of this systematic review were (1) to examine the ...available literature on patient satisfaction after TKR, (2) to evaluate the quality of available evidence, and (3) to identify predictors of patient satisfaction after TKR.
Methods:
A systematic review of the MEDLINE database was performed. The initial search yielded 1219 studies. The inclusion criteria were English language, clinical outcome study with primary outcome related to TKR for osteoarthritis, and patient-reported satisfaction included as an outcome measure. Studies were assessed for demographics, methodology for reporting satisfaction, and factors influencing satisfaction.
Results:
Two hundred eight studies, including 95, 560 patients who had undergone TKR, met all inclusion and exclusion criteria; 112 (53.8%) of these studies were published in the past 3 years. Satisfaction was most commonly measured using an ordinal scale. Twenty-seven studies (13%) used a validated satisfaction survey. Eighty-three percent of studies reported more than 80% satisfaction. The most commonly reported predictor of satisfaction was post-operative patient-reported functional outcome. Pre-operative anxiety/depression was the most common pre-operative predictor of dissatisfaction.
Conclusion:
There are numerous studies reporting patient satisfaction after TKR, and publication on the topic has been increasing over the past decade. However, the majority of studies represent lower levels of evidence and use heterogeneous methods for measuring satisfaction, and few studies use validated satisfaction instruments. In general, the majority of studies report satisfaction rates ranging from 80 to 100%, with post-operative functional outcome and relief of pain being paramount determinants for achieving satisfaction.
The immature phenotype of stem cell derived cardiomyocytes is a significant barrier to their use in translational medicine and pre-clinical in vitro drug toxicity and pharmacological analysis. Here ...we have assessed the contribution of non-myocyte cells on the contractile function of co-cultured human embryonic stem cell derived cardiomyocytes (hESC-CMs) in spheroid microtissue format. Microtissues were formed using a scaffold free 96-well cell suspension method from hESC-CM cultured alone (CM microtissues) or in combination with human primary cardiac microvascular endothelial cells and cardiac fibroblasts (CMEF microtissues). Contractility was characterized with fluorescence and video-based edge detection. CMEF microtissues displayed greater Ca(2+ )transient amplitudes, enhanced spontaneous contraction rate and remarkably enhanced contractile function in response to both positive and negative inotropic drugs, suggesting a more mature contractile phenotype than CM microtissues. In addition, for several drugs the enhanced contractile response was not apparent when endothelial cell or fibroblasts from a non-cardiac tissue were used as the ancillary cells. Further evidence of maturity for CMEF microtissues was shown with increased expression of genes that encode proteins critical in cardiac Ca(2+ )handling (S100A1), sarcomere assembly (telethonin/TCAP) and β-adrenergic receptor signalling. Our data shows that compared with single cell-type cardiomyocyte in vitro models, CMEF microtissues are superior at predicting the inotropic effects of drugs, demonstrating the critical contribution of cardiac non-myocyte cells in mediating functional cardiotoxicity.
Vascular endothelial growth factors (VEGFs) regulate vascular development, angiogenesis and lymphangiogenesis by binding to a number of receptors. VEGFR-1 is required for the recruitment of ...haematopoietic stem cells and the migration of monocytes and macrophages, VEGFR-2 regulates vascular endothelial function and VEGFR-3 regulates lymphatic endothelial cell function. Over the last decade, considerable progress has been made in delineating the VEGFR-2 specific intracellular signalling cascades leading to proliferation, migration, survival and increased permeability, each of which contributes to the angiogenic response. Furthermore, therapeutic inhibition of VEGFR-2 action is now having an impact in the clinic for the treatment of a number of diseases.
Transforming Universities in South Africa: Pathways to Higher Education Reform responds to the pressing need to comprehensively review the post-apartheid experience and assess where South Africa's ...higher education stands across the continent and globally, particularly within the country's efforts to overcome decades of socio-economic imbalances.
Purpose
Unicompartmental knee arthroplasty (UKA) has a faster short-term recovery than total knee arthroplasty (TKA). The purpose of this study was to determine the feasibility and safety of ...performing outpatient UKAs in a consecutive group of patients presenting with unicompartmental knee osteoarthritis.
Methods
A total of 105 consecutive patients underwent unicompartmental arthroplasty before noon with the intention of being discharged as an outpatient. All patients followed an established rapid recovery pathway to facilitate a same-day discharge. Post-operative complications and hospital readmissions were retrospectively recorded for all patients at one week and at three months after surgery.
Results
All of the 105 patients (100 %) indicated for outpatient UKA could be discharged home on the same day of surgery. No patients required readmission within the first week post-operatively, while one patient required readmission between week one and week 12. The single patient who required readmission developed a post-operative infection requiring irrigation/debridement with polyethylene liner exchange and intravenous antibiotics.
Conclusion
Using an established, multidisciplinary, rapid recovery protocol, outpatient UKA is safe and feasible in the vast majority of patients.
Abstract Background Obesity is frequently associated with complications following total hip arthroplasty (THA), and is often concomitant with malnutrition. The purpose of this study was to ...investigate the independent morbidity risk of malnutrition relative to obesity. Methods The National Surgical Quality Improvement Program from 2005-2013 was queried for elective primary THA cases. Malnutrition was defined as albumin <3.5 g/dL. Propensity scores for having preoperative albumin data were determined from demographics, body mass index (BMI), and overall comorbidity burden. Patients were classified as non-obese (BMI 18.5-29.9), obese I (30-34.9), obese II (35-39.9), or obese III (≥40). Complications were compared across nutritional and obesity classes. Multivariable propensity-adjusted logistic regressions were used to examine associations between obesity and malnutrition with thirty-day outcomes. Results 40,653 THA cases were identified, of which 20,210 (49.7%) had preoperative albumin measurements. Propensity score adjustment successfully reduced potential selection bias, with p >0.05 for differences between those with and without albumin data. Malnutrition incidence increased from 2.8% in obese I to 5.7% in obese III patients. With multivariable propensity-adjusted logistic regression, malnutrition was a more robust predictor than any obesity class for any postoperative complication(s) (odds ratio OR 1.61, 95% confidence interval CI 1.25-2.08), major complications (OR 1.63, 95% CI 1.21-2.19), respiratory complications (OR 2.35, 95% CI 1.27-4.37), blood transfusions (OR 1.71, 95% CI 1.44-2.03), and extended length of stay (OR 1.35, 95% CI 1.14-1.59). Conclusion Malnutrition incidence increased significantly from obese I to obese III patients, and was a stronger and more consistent predictor than obesity of complications following THA.
We report the first catalytic use of a divalent lanthanide in visible-light-promoted bond-forming reactions. Our new precatalyst uses europium in the +2 oxidation state and is active in the presence ...of blue light from light-emitting diodes. The use of low-energy visible light reduces the occurrence of potential side reactions that might be induced by higher-energy UV light. The system described here uses zinc metal as a sacrificial reductant and is tolerant to wet, protic solvents. The catalyst can be made
from relatively inexpensive and air-stable EuCl
·6H
O, and the ligand can be synthesized in large quantities in two steps. With 0.5% loading of precatalyst, an average of 120 turnovers was observed in six hours for reductive coupling of benzyl chloride. We expect that the results will initiate the study of visible-light-promoted photoredox catalysis using divalent europium in a variety of reactions.
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