35 research outputs found

    Control of polymorphism in coronene by the application of magnetic fields

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    Coronene, a polyaromatic hydrocarbon, has been crystallized for the first time in a different polymorph using a crystal growth method that utilizes magnetic fields to access a unit cell configuration that was hitherto unknown. Crystals grown in magnetic field of 1 T are larger, have a different appearance to those grown in zero field and retain their structure in ambient conditions. We identify the new form, beta-coronene, as the most stable at low temperatures. As a result of the new supramolecular configuration we report significantly altered electronic, optical and mechanical properties.Comment: 32 pages, 17 figure

    ANALYSIS OF THE TRUNK/SHOULDER COMPLEX MOTION DURING THE GOLF DRIVES USING A 5-SEGMENT TRUNK/SHOULDER MODEL

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    The purpose of this study was to quantify detailed trunk/shoulder complex motions during the golf drives using a new 5-segment trunk/shoulder model (pelvis, abdomen, thorax, and right/left shoulder girdles) and to describe the patterns of the relative motions of the trunk/shoulder segments. Fifteen male golfers were divided into two groups: skilled (n=8, 3-handicap or better) and less skilled (n=7, 13- to 18-handicap). The ranges of the orientation angles of the segments during the downswing were computed. In addition to the dominant rotation of the thorax, substantial frontal plane motions of the trunk segments (abdomen and thorax) and transverse plane motions of the shoulder girdles were observed. Only the frontal plane motion of the left shoulder girdle (elevation/depression) was identified as the factor which differentiated the groups

    Pilot and Controller Evaluations of Separation Function Allocation in Air Traffic Management

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    Two human-in-the-loop simulation experiments were conducted in coordinated fashion to investigate the allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). Ground-based separation was provided by air traffic controllers without automation tools, with tools, or by ground-based automation with controllers in a managing role. Airborne self-separation was provided by airline pilots using self-separation automation enabled by airborne surveillance technology. The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations, assuming the starting point of current-day operations and modeling an emergence of NextGen technologies and procedures. In the controller-focused experiment, the impact of mixed operations on controller performance was assessed at four stages of NextGen implementation. In the pilot-focused experiment, the limits to which pilots with automation tools could take full responsibility for separation from ground-controlled aircraft were tested. Results indicate that the presence of self-separating aircraft had little impact on the controllers' ability to provide separation services for ground-controlled aircraft. Overall performance was best in the most automated environment in which all aircraft were data communications equipped, ground-based separation was highly automated, and self-separating aircraft had access to trajectory intent information for all aircraft. In this environment, safe, efficient, and highly acceptable operations could be achieved for twice today's peak airspace throughput. In less automated environments, reduced trajectory intent exchange and manual air traffic control limited the safely achievable airspace throughput and negatively impacted the maneuver efficiency of self-separating aircraft through high-density airspace. In a test of scripted conflicts with ground-managed aircraft, flight crews of self-separating aircraft prevented separation loss in all conflicts with detection time greater than one minute. In debrief, pilots indicated a preference for at least five minute's alerting notice and trajectory intent information on all aircraft. When intent information on ground-managed aircraft was available, self-separating aircraft benefited from fewer conflict alerts and fewer required deviations from trajectory-based operations

    Effects of MDM2, MDM4 and TP53 Codon 72 Polymorphisms on Cancer Risk in a Cohort Study of Carriers of TP53 Germline Mutations

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    Previous studies have shown that MDM2 SNP309 and p53 codon 72 have modifier effects on germline P53 mutations, but those studies relied on case-only studies with small sample sizes. The impact of MDM4 polymorphism on tumor onset in germline mutation carriers has not previously been studied.We analyzed 213 p53 germline mutation carriers including 168(78.9%) affected with cancer and 174 who had genotypic data. We analyzed time to first cancer using Kaplan-Meier and Cox proportional hazards methods, comparing risks according to polymorphism genotypes. For MDM2 SNP309, a significant difference of 9.0 years in the average age of cancer diagnosis was observed between GG/GT and TT carriers (18.6 versus 27.6 years, P = 0.0087). The hazards ratio was 1.58 (P = 0.03) comparing risks among individuals with GG/GT to risk among TT, but this effect was only significant in females (HR = 1.60, P = 0.02). Compared to other genotypes, P53 codon 72 PP homozygotes had a 2.24 times (P = 0.03) higher rate for time to develop cancer. We observed a multiplicative joint effect of MDM2 and p53 codon72 polymorphism on risk. The MDM4 polymorphism had no significant effects.Our results suggest that the MDM2 SNP309 G allele is associated with cancer risk in p53 germline mutation carriers and accelerates time to cancer onset with a pronounced effect in females. A multiplicative joint effect exists between the MDM2 SNP309 G allele and the p53 codon 72 G allele in the risk of cancer development. Our results further define cancer risk in carriers of germline p53 mutations

    A randomized, double-blind, placebo-controlled trial of coenzyme Q10 in Huntington disease

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    Objective: To test the hypothesis that chronic treatment of early-stage Huntington disease (HD) with high-dose coenzyme Q10 (CoQ) will slow the progressive functional decline of HD. Methods: We performed a multicenter randomized, double-blind, placebo-controlled trial. Patients with early-stage HD (n = 609) were enrolled at 48 sites in the United States, Canada, and Australia from 2008 to 2012. Patients were randomized to receive either CoQ 2,400 mg/d or matching placebo, then followed for 60 months. The primary outcome variable was the change from baseline to month 60 in Total Functional Capacity score (for patients who survived) combined with time to death (for patients who died) analyzed using a joint-rank analysis approach. Results: An interim analysis for futility revealed a conditional power of <5% for the primary analysis, prompting premature conclusion in July 2014. No statistically significant differences were seen between treatment groups for the primary or secondary outcome measures. CoQ was generally safe and well-tolerated throughout the study. Conclusions: These data do not justify use of CoQ as a treatment to slow functional decline in HD

    An unforeseen polymorph of coronene by the application of magnetic fields during crystal growth

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    The continued development of novel drugs, proteins, and advanced materials strongly rely on our ability to self-assemble molecules in solids with the most suitable structure (polymorph) in order to exhibit desired functionalities. The search for new polymorphs remains a scientific challenge, that is at the core of crystal engineering and there has been a lack of effective solutions to this problem. Here we show that by crystallizing the polyaromatic hydrocarbon coronene in the presence of a magnetic field, a polymorph is formed in a β-herringbone structure instead of the ubiquitous γ-herringbone structure, with a decrease of 35° in the herringbone nearest neighbour angle. The β-herringbone polymorph is stable, preserves its structure under ambient conditions and as a result of the altered molecular packing of the crystals, exhibits significant changes to the optical and mechanical properties of the crystal

    Management of rhabdomyolysis: A practice management guideline from the Eastern Association for the Surgery of Trauma

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    BACKGROUND: The treatment of rhabdomyolysis remains controversial. Although there is no question that any associated compartment syndrome needs to be identified and released, debate persists regarding the benefit of further therapy including aggressive intravenous fluid resuscitation (IVFR), urine alkalization with bicarbonate, and the use of mannitol. The goal of this practice management guideline was to evaluate the effects of bicarbonate, mannitol, and aggressive intravenous fluids on patients with rhabdomyolysis. METHODS: A systematic review and meta-analysis comparing treatments in patients with rhabdomyolysis was performed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was applied to assess the quality of evidence and to create evidence-based recommendations regarding the use of bicarbonate, mannitol, and aggressive IVFR in patients with rhabdomyolysis. RESULTS: A total of 12 studies were identified for analysis. On quantitative analysis, IVFR decreased the incidence of acute renal failure (ARF) and need for dialysis in patients with rhabdomyolysis. Neither bicarbonate nor mannitol administration improved the incidence of acute renal failure and need for dialysis in patients with rhabdomyolysis. Quality of evidence was deemed to be very low, with the vast majority of the literature being retrospective studies. CONCLUSION: In patients with rhabdomyolysis, we conditionally recommend for aggressive IVFR to improve outcomes of ARF and lessen the need for dialysis. We conditionally recommend against treatment with bicarbonate or mannitol in patients with rhabdomyolysis
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