Topology Driven Improvement of FDC Build Parameters

The likeliest failure origin for advanced ceramics parts, prepared by fused deposition, is a void from improper fill. Adequate filling of each cross-section is dependent upon the deposition toolpath. Cross-sectional spaces are conventionally filled with pre-defined parameters. We propose that adaptive build parameters will control variations in geometry and property of a part. Voids, overfilling, incomplete bonding and excess traversing can be suppressed by adjusting the fill parameters for cross-sectional areas. Improved build parameters and toolpath allows for faster build time and components ofj full density. Some implementations are discussed and presented.Mechanical Engineerin

EFFECT OF THONG STYLE FLIP-FLOPS AND SUPPORTIVE SHOES ON CHILDRENS BAREFOOT SIDESTEP KINEMATICS

Thongs and supportive have been shown to alter children’s barefoot motion. However, the effect of thongs on other types of activities such as sidestepping are unknown. The purpose of this study was to evaluate the effect thong style flip-flops and supportive have on childrens knee and foot motion during a jogging sidestep task when compared to barefoot. Eleven healthy children with no foot deformity (aged 8 to 13 years) were recruited. Motion and force capture was used to record knee and multisegment foot motion. Motion adaptations while thongs were worn were restricted to the hallux and while supportive were worn, occurred with knee, midfoot and hallux motion. All footwear conditions increased ankle inversion magnitude. Thongs had less effect on children’s barefoot sidestep motion than supportive shoes

Effect of thong style flip-flops on children’s midfoot motion during gait

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Mechanism, localization and cure of atrial arrhythmias occurring after a new intraoperative endocardial radiofrequency ablation procedure for atrial fibrillation

AbstractOBJECTIVESThe purpose of this study was to test a new pattern of radiofrequency ablation for atrial fibrillation (AFib) intended to optimize atrial activation, and to demonstrate the usefulness of catheter techniques for mapping and ablation of postoperative atrial arrhythmias.BACKGROUNDLinear radiofrequency lesions have been used to cure AFib, but the optimal pattern of lesions is unknown and postoperative tachyarrhythmias are common.METHODSA radial pattern of linear radiofrequency lesions (Star) was made using an endocardial open surgical approach in 25 patients. Postoperative arrhythmias were induced and characterized during electrophysiological studies in 15 patients.RESULTSThe AFib was abolished in most patients (91%), but atrial flutter (AFlut) occurred in 96% of patients postoperatively. At postoperative electrophysiological studies, 37 flutter morphologies were studied in 15 patients (46% spontaneous, cycle length [CL] 223 ± 25 ms). Seven mechanisms (lesions discontinuity, n = 6; focal mechanism, n = 1) of AFlut were characterized in six patients. In these cases, flutter was abolished using further catheter radiofrequency ablation. In the remaining cases, flutter was usually localized to an area involving the interatrial septum, but no critical isthmus was identified for ablation. After 16 ± 10 months, 15 patients (65%) were asymptomatic with (n = 3) or without (n = 12) antiarrhythmic medications. Eight (35%) patients had persistent arrhythmias. Postoperative atrial electrical activation was near physiological.CONCLUSIONSThe AFib may be abolished using a radial pattern of linear endocardial radiofrequency lesions, but postoperative AFlut is common even when lesions are made under optimal conditions. Endocardial mapping techniques can be used to characterize the flutter mechanisms, thus enabling subsequent successful catheter ablation

Surgical procedure for the cure of atrioventricular junctional (“AV node”) reentrant tachycardia: Anatomic and electrophysiologic effects of dissection of the anterior atrionodal connections in a canine model

AbstractObjectives. This study was undertaken to examine the electrophysiologic and anatomic efects of a surgical procedure that cures the anterior (common) type of atrioventricular (AV) junciional reentrant tachycardia.Background. The procedure was designed to interrupt the reentrant circuit at the point of earliest atrial activation during AV junctional reentrant tachycardia, the anterior atrionodal connections.Methods. Atrioventricular node function and the sequence of electrical excitation of Koch's triangle were examined in 18 dogs. Excitation of Koch's triangle was mapped using a 60-channel mapping system. Surgical dissection was performed in 10 dogs and a sham procedure in 8. After 28 to 35 days, AV node function and the atrial excitation pattern were reassessed. The AV junction was examined using light microscopy.Results. Some degree of AV node damage was visible in all dogs in the dissection group, but it was minor in 40% of cases. The anterior part of the AV node was disconnected from the anterior atrionodal connections in all cases. Anterograde AV node function was mildly impaired. The median AH interval was increased (62 vs. 76 ms [interquartile ranges 48 to 72 and 64 to 104, respectively], P = 0.05), and the AV Wenckebach cycle length was increased (210 vs. 245 ms [interquartile ranges 200 to 230 and 210 to 260, respectively], p = 0.02). The degree of impairment of conduction was directly proportional to the length of dissection (p < 0.05) but not to the degree of damage to the AV node. Ventriculoatrial (VA) conduction was destroyed in 50% of dogs undergoing dissection but in none of those with a sham operation (p < 0.04). The AV node remained responsive to autonomic blocking drugs, and atrial mapping during ventricular pacing revealed that the site of exit from the AV node had been altered.Conclusions. The atrionodal connections closest to the His bundle are the preferred route of conduction through the AV node during normal AV or VA conduction. Destruction of these connections modifies AV node conduction. The surgical procedure selectively interrupts these connections, and this interruption is likely to be the mechanism of cure

Effect of thong style flip-flops on children’s barefoot walking and jogging kinematics

BACKGROUND: Thong style flip-flops are a popular form of footwear for children. Health professionals relate the wearing of thongs to foot pathology and deformity despite the lack of quantitative evidence to support or refute the benefits or disadvantages of children wearing thongs. The purpose of this study was to compare the effect of thong footwear on children’s barefoot three dimensional foot kinematics during walking and jogging. METHODS: Thirteen healthy children (age 10.3 ± 1.6 SD years) were recruited from the metropolitan area of Sydney Australia following a national press release. Kinematic data were recorded at 200 Hz using a 14 camera motion analysis system (Cortex, Motion Analysis Corporation, Santa Rosa, USA) and simultaneous ground reaction force were measured using a force platform (Model 9281B, Kistler, Winterthur, Switzerland). A three-segment foot model was used to describe three dimensional ankle, midfoot and one dimensional hallux kinematics during the stance sub-phases of contact, midstance and propulsion. RESULTS: Thongs resulted in increased ankle dorsiflexion during contact (by 10.9°, p; = 0.005 walk and by 8.1°, p; = 0.005 jog); increased midfoot plantarflexion during midstance (by 5.0°, p; = 0.037 jog) and propulsion (by 6.7°, p; = 0.044 walk and by 5.4°, p;= 0.020 jog); increased midfoot inversion during contact (by 3.8°, p;= 0.042 jog) and reduced hallux dorsiflexion during walking 10% prior to heel strike (by 6.5°, p; = 0.005) at heel strike (by 4.9°, p; = 0.031) and 10% post toe-off (by 10.7°, p; = 0.001). CONCLUSIONS: Ankle dorsiflexion during the contact phase of walking and jogging, combined with reduced hallux dorsiflexion during walking, suggests a mechanism to retain the thong during weight acceptance. Greater midfoot plantarflexion throughout midstance while walking and throughout midstance and propulsion while jogging may indicate a gripping action to sustain the thong during stance. While these compensations exist, the overall findings suggest that foot motion whilst wearing thongs may be more replicable of barefoot motion than originally thought

Intellectual Property Rights, Parallel Imports and Strategic Behavior

The existence of parallel imports (PI) raises a number of interesting policy and strategic questions, which are the subject of this survey article. For example, parallel trade is essentially arbitrage within policy-integrated markets of IPR-protected goods, which may have different prices across countries. Thus, we analyze fully two types of price differences that give rise to such arbitrage. First is simple retail-level trade in horizontal markets because consumer prices may differ. Second is the deeper, and more strategic, issue of vertical pricing within the common distribution organization of an original manufacturer selling its goods through wholesale distributors in different markets. This vertical price control problem presents the IPR-holding firm a menu of strategic choices regarding how to compete with PI. Another strategic question is how the existence of PI might affect incentives of IPR holders to invest in research and development (R&D). The global research-based pharmaceutical firms, for example, strongly oppose any relaxation of restrictions against PI of drugs into the United States, arguing that the potential reduction in profits would diminish their ability to innovate. There is a close linkage here with price controls for medicines, which are a key component of national health policies but can give rise to arbitrage through PI. We also discuss the complex economic relationships between PI and other forms of competition policy, or attempts to limit the abuse of market power offered by patents and copyrights. Finally, we review the emerging literature on how policies governing PI may affect international trade agreements

Scleroderma and related disorders: 223. Long Term Outcome in a Contemporary Systemic Sclerosis Cohort

Background: We have previously compared outcome in two groups of systemic sclerosis (SSc) patients with disease onset a decade apart and we reported data on 5 year survival and cumulative incidence of organ disease in a contemporary SSc cohort. The present study examines longer term outcome in an additional cohort of SSc followed for 10 years. Methods: We have examined patients with disease onset between years 1995 and 1999 allowing for at least 10 years of follow-up in a group that has characteristics representative for the patients we see in contemporary clinical practice. Results: Of the 398 patients included in the study, 252 (63.3%) had limited cutaneous (lc) SSc and 146 (36.7%) had diffuse cutaneous (dc) SSc. The proportion of male patients was higher among the dcSSc group (17.1% v 9.9%, p = 0.037) while the mean age of onset was significantly higher among lcSSc patients (50 ± 13 v 46 ± 13 years ± SD, p = 0.003). During a 10 year follow-up from disease onset, 45% of the dcSSc and 21% of the lcSSc subjects developed clinically significant pulmonary fibrosis, p < 0.001. Among them approximately half reached the endpoint within the first 3 years (23% of dcSSc and 10% of lcSSc) and over three quarters within the first 5 years (34% and 16% respectively). There was a similar incidence of pulmonary hypertension (PH) in the two subsets with a steady rate of increase over time. At 10 years 13% of dcSSc and 15% of lcSSc subjects had developed PH (p=0.558), with the earliest cases observed within the first 2 years of disease. Comparison between subjects who developed PH in the first and second 5 years from disease onset demonstrated no difference in demographic or clinical characteristics, but 5-year survival from PH onset was better among those who developed this complication later in their disease (49% v 24%), with a strong trend towards statistical significance (p = 0.058). Incidence of SSc renal crisis (SRC) was significantly higher among the dcSSc patients (12% v 4% in lcSSc, p = 0.002). As previously observed, the rate of development of SRC was highest in the first 3 years of disease- 10% in dcSSc and 3% in lcSSc. All incidences of clinically important cardiac disease developed in the first 5 years from disease onset (7% in dcSSc v 1% in lcSSc, p < 0.001) and remained unchanged at 10 years. As expected, 10-year survival among lcSSc subjects was significantly higher (81%) compared to that of dcSSc patients (70%, p = 0.006). Interestingly, although over the first 5 years the death rate was much higher in the dcSSc cohort (16% v 6% in lcSSc), over the following years it became very similar for both subsets (14% and 13% between years 5 and 10, and 18% and 17% between years 10 and 15 for dcSSc and lcSSc respectively). Conclusions: Even though dcSSc patients have higher incidence for most organ complications compared to lcSSc subjects, the worse survival among them is mainly due to higher early mortality rate. Mortality rate after first 5 years of disease becomes comparable in the two disease subsets. Disclosure statement: The authors have declared no conflicts of interes