Effects of NHC-Backbone Substitution on Efficiency in Ruthenium-Based Olefin Metathesis

series of ruthenium olefin metathesis catalysts bearing N-heterocyclic carbene (NHC) ligands with varying degrees of backbone and N-aryl substitution have been prepared. These complexes show greater resistance to decomposition through C−H activation of the N-aryl group, resulting in increased catalyst lifetimes. This work has utilized robotic technology to examine the activity and stability of each catalyst in metathesis, providing insights into the relationship between ligand architecture and enhanced efficiency. The development of this robotic methodology has also shown that, under optimized conditions, catalyst loadings as low as 25 ppm can lead to 100% conversion in the ring-closing metathesis of diethyl diallylmalonate

Motion primitives and 3D path planning for fast flight through a forest

This paper presents two families of motion primitives for enabling fast, agile flight through a dense obstacle field. The first family of primitives consists of a time-delay dependent 3D circular path between two points in space and the control inputs required to fly the path. In particular, the control inputs are calculated using algebraic equations which depend on the flight parameters and the location of the waypoint. Moreover, the transition between successive maneuver states, where each state is defined by a unique combination of constant control inputs, is modeled rigorously as an instantaneous switch between the two maneuver states following a time delay which is directly related to the agility of the robotic aircraft. The second family consists of aggressive turn-around (ATA) maneuvers which the robot uses to retreat from impenetrable pockets of obstacles. The ATA maneuver consists of an orchestrated sequence of three sets of constant control inputs. The duration of the first segment is used to optimize the ATA for the spatial constraints imposed by the turning volume. The motion primitives are validated experimentally and implemented in a simulated receding horizon control (RHC)-based motion planner. The paper concludes with inverse-design pointers derived from the primitives

The Incidence of Upper and Lower Extremity Surgery for Rheumatoid Arthritis Among Medicare Beneficiaries

Background: For elderly patients with rheumatoid arthritis, aggressive immunosuppression can be difficult to tolerate, and surgery remains an important treatment option for joint pain and deformity. We sought to examine the epidemiology of surgical reconstruction for rheumatoid arthritis among older individuals who were newly diagnosed with the disorder. Methods: We identified a 5% random sample of Medicare beneficiaries (sixty-six years of age and older) newly diagnosed with rheumatoid arthritis from 2000 to 2005, and followed these patients longitudinally for a mean of 4.6 years. We used univariate analysis to compare the time from the diagnosis of rheumatoid arthritis to the first operation among the 360 patients who underwent surgery during the study period. Results: In our study cohort, 589 procedures were performed among 360 patients, and 132 patients (37%) underwent multiple procedures. The rate of upper extremity reconstruction was 0.9%, the rate of lower extremity reconstruction was 1.2%, and knee arthroplasty was the most common procedure performed initially (31%) and overall (29%). Upper extremity procedures were performed sooner than lower extremity procedures (fourteen versus twenty-five months; p = 0.02). In multivariable analysis, surgery rates declined with age for upper and lower extremity procedures (p \u3c 0.001). Conclusions: Knee replacement remains the most common initial procedure among patients with rheumatoid arthritis. However, upper extremity procedures are performed earlier than lower extremity procedures. Understanding the patient and provider factors that underlie variation in procedure rates can inform future strategies to improve the delivery of care to patients with rheumatoid arthritis. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence

Variation in Rheumatoid Hand and Wrist Surgery among Medicare Beneficiaries: A Population-based Cohort Study

Objective. To examine the rate and variation in rheumatoid arthritis (RA)-related hand and wrist surgery among Medicare (elderly) beneficiaries in the United States, and to identify the patient and provider factors that influence surgical rates. Methods. Using the 2006–2010 100% Medicare claims data of beneficiaries with RA diagnosis, we examined rates of rheumatoid hand and wrist arthroplasty, arthrodesis, and hand tendon reconstruction in the United States. We used multivariate logistic regression models to examine variation in receipt of surgery by patient and regional characteristics (density of providers, intensity of use of biologic disease-modifying antirheumatic drugs). Results. Between 2006 and 2010, the annual rate of RA-related hand and wrist arthroplasty or arthrodesis was 23.1 per 10,000 patients, and the annual rate of hand tendon reconstruction was 4.2 per 10,000 patients. The rates of surgery varied 9-fold across hospital referral regions in the United States. Younger patient age, female sex, white race, higher socioeconomic status (SES), and rural residence were associated with a higher likelihood of undergoing arthroplasty and arthrodesis. We observed a significant decline in rate of arthroplasty and arthrodesis with increasing density of rheumatologists. Tendon reconstruction was not influenced by provider factors, but was correlated with age, race, SES, and rural status of the patients. Conclusion. Surgical reconstruction of rheumatoid hand deformities varies widely across the United States, driven by both regional availability of subspecialty care in rheumatology and individual patient factors

The Utility of Outcome Studies in Plastic Surgery

Summary: Outcome studies help provide the evidence-based science rationalizing treatment end results that factor the experience of patients and the impact on society. They improve the recognition of the shortcoming in clinical practice and provide the foundation for the development of gold standard care. With such evidence, health care practitioners can develop evidence-based justification for treatments and offer patients with superior informed consent for their treatment options. Furthermore, health care and insurance agencies can recognize improved cost-benefit options in the purpose of disease prevention and alleviation of its impact on the patient and society. Health care outcomes are ultimately measured by the treatment of disease, the reduction of symptoms, the normalization of laboratory results and physical measures, saving a life, and patient satisfaction. In this review, we outline the tools available to measure outcomes in plastic surgery and subsequently allow the objective measurements of plastic surgical conditions. Six major outcome categories are discussed: (1) functional measures; (2) preference-based measures and utility outcome scores; (3) patient satisfaction; (4) health outcomes and time; (5) other tools: patient-reported outcome measurement information system, BREAST-Q, and Tracking Operations and Outcomes for Plastic Surgeons; and (6) cost-effectiveness analysis. We use breast hypertrophy requiring breast reduction as an example throughout this review as a representative plastic surgical condition with multiple treatments available

Hostility Modifies the Association between TV Viewing and Cardiometabolic Risk

Background. It was hypothesized that television viewing is predictive of cardiometabolic risk. Moreover, people with hostile personality type may be more susceptible to TV-induced negative emotions and harmful health habits which increase occurrence of cardiometabolic risk. Purpose. The prospective association of TV viewing on cardiometabolic risk was examined along with whether hostile personality trait was a modifier. Methods. A total of 3,269 Black and White participants in the coronary artery risk development in young adults (CARDIA) study were assessed from age 23 to age 35. A cross-lagged panel model at exam years 5, 10, 15, and 20, covering 15 years, was used to test whether hours of daily TV viewing predicted cardiometabolic risk, controlling confounding variables. Multiple group analysis of additional cross-lagged panel models stratified by high and low levels of hostility was used to evaluate whether the association was modified by the hostile personality trait. Results. The cross-lagged association of TV viewing at years 5 and 15 on clustered cardiometabolic risk score at years 10 and 20 was significant (B=0.058 and 0.051), but not at 10 to 15 years. This association was significant for those with high hostility (B=0.068 for exam years 5 to 10 and 0.057 for exam years 15 to 20) but not low hostility. Conclusion. These findings indicate that TV viewing is positively associated with cardiometabolic risk. Further, they indicate that hostility might be a modifier for the association between TV viewing and cardiometabolic risk

Intramuscular myxoid lipoma in the proximal forearm presenting as an olecranon mass with superficial radial nerve palsy: a case report

<p>Abstract</p> <p>Background</p> <p>Extremity lipomas may occur in any location, including the proximal forearm. We describe a case of a patient with an intramuscular lipoma presenting as an unusual posterior elbow mass.</p> <p>Case presentation</p> <p>We discuss the case of a 57-year-old Caucasian man who presented with a tender, posterior elbow mass initially diagnosed as chronic olecranon bursitis. A minor sensory disturbance in the distribution of the superficial radial nerve was initially thought to be unrelated, but was likely caused by mass effect from the lipoma. No pre-operative advanced imaging was obtained because the diagnosis was felt to have already been made. At the time of surgery, a fatty mass originating in the volar forearm muscles was found to have breached the dorsal forearm fascia and displaced the olecranon bursa. Tissue diagnosis was made by histopathology as a myxoid lipoma with no aggressive features. Post-operative recovery was uneventful.</p> <p>Conclusion</p> <p>We present a case of an unusual elbow mass presenting with symptoms consistent with chronic olecranon bursitis, a relatively common condition. The only unexplained pre-operative finding was the non-specific finding of a transient superficial radial nerve deficit. We remind clinicians to be cautious when diagnosing soft tissue masses in the extremities when unexplained physical findings are present.</p

Motion primitives and 3D path planning for fast flight through a forest

This paper presents two families of motion primitives for enabling fast, agile flight through a dense obstacle field. The first family of primitives consists of a time-delay dependent 3D circular path between two points in space and the control inputs required to fly the path. In particular, the control inputs are calculated using algebraic equations which depend on the flight parameters and the location of the waypoint. Moreover, the transition between successive maneuver states, where each state is defined by a unique combination of constant control inputs, is modeled rigorously as an instantaneous switch between the two maneuver states following a time delay which is directly related to the agility of the robotic aircraft. The second family consists of aggressive turn-around (ATA) maneuvers which the robot uses to retreat from impenetrable pockets of obstacles. The ATA maneuver consists of an orchestrated sequence of three sets of constant control inputs. The duration of the first segment is used to optimize the ATA for the spatial constraints imposed by the turning volume. The motion primitives are validated experimentally and implemented in a simulated receding horizon control (RHC)-based motion planner. The paper concludes with inverse-design pointers derived from the primitives