115 research outputs found
Profile Characteristics of Some Forest-Formed Soils Derived from Iowan Till
Three profiles were collected in Bremer and Floyd counties to represent the proposed Coggon series; detailed field and laboratory studies were conducted on these profiles. The Coggon soils have developed under forest vegetation from a two-story parent material consisting of a silty mantle-pebble band-glacial till sequence. Being formed from Iowan-age glacial till, the Coggon profiles exhibit an amount of development that is low compared to other Gray-Brown Podzolic soils of Iowa. Coarser parent material might possibly explain why Coggon is less developed than the Weller soils, which are formed from presumably younger, loessial parent material. On the other hand, the lack of development in Coggon could be explained by its youth if one considers the possibility that the present geomorphic surface of the Iowan till represents a rather young pedi-sedimented surface which is more recent than the last glaciation
Diffusion Of Color-Centers Generated By 2-Photon Absorption At 532-Nm In Cubic Zirconia
We have recently reported the formation of color centers in stabilized cubic zirconia (ZrO2, 18% Y2O3) by two‐photon absorption at 532 nm. Here we present the results of measurements of the transmission of the colored samples as a function of time at room temperature. The results are found to be in good agreement with theory that assumes the color centers diffuse out of the irradiated region. The initial distribution of centers is assumed to have a Gaussian profile. For this model, the diffusion equation was solved exactly and the diffusion constant obtained (∼3.4×10−8 cm2/s)
Laser-Induced Damage And The Role Of Self-Focusing
We review the influence of self-focusing on the measurement of bulk laser-induced-damage (LID) thresholds in normally transparent optical mate-rials. This role is experimentally determined by measuring the spot size and polarization dependence of LID and by observing beam distortion in the far field. Utilizing these techniques, we find that by using a tight focusing geometry in which the breakdown power is below P2, the effects of self-focusing can be practically eliminated in an LID experiment. P2 is the so-called second critical power for self-focusing, and P2 = 3.77P1, where P1 = cX2/327r2n2, where c is the speed of light in vacuum, X is the laser wavelength and n2 is the nonlinear index of refraction. This is in accordance with numerical calculations by J. H. Marburger [in Progress in Quantum Electronics, J. H. Sanders and S. Sten-holm, eds., Vol. 4, Part 1, pp. 35-110, Pergamon, Oxford (1975)]. With this knowledge we determine that damage is only partially explained by avalanche ionization and that the initiation of damage is strongly influenced by extrinsic processes. We therefore conclude that we are measuring extrinsic LID
Analysis of Clinical Records as a Means to Validate Non-Invasive Assessment of Intracranial Pressure Using the Cerebral and Cochlear Fluid Pressure (CCFP) Analyzer
No abstract availabl
Enhanced Damage-Resistant Optics for Spaceflight Laser Systems: Workshop findings and recommendations
NASA has defined a program to address critical laser-induced damage issues peculiar to its remote sensing systems. The Langley Research Center (LaRC), with input from the Goddard Space Flight Center (GSFC), has developed a program plan focusing on the certification of optical materials for spaceflight applications and the development of techniques to determine the reliability of such materials under extended laser exposures. This plan involves cooperative efforts between NASA and optics manufacturers to quantify the performance of optical materials for NASA systems and to ensure NASA's continued application of the highest quality optics possible for enhanced system reliability. A review panel was organized to assess NASA's optical damage concerns and to evaluate the effectiveness of the LaRC proposed program plan. This panel consisted of experts in the areas of laser-induced damage, optical coating manufacture, and the design and development of laser systems for space. The panel was presented information on NASA's current and planned laser remote sensing programs, laser-induced damage problems already encountered in NASA systems, and the proposed program plan to address these issues. Additionally, technical presentations were made on the state of the art in damage mechanisms, optical materials testing, and issues of coating manufacture germane to laser damage
Continuous subcutaneous foslevodopa/foscarbidopa infusion for the treatment of motor fluctuations in Parkinson's disease:Considerations for initiation and maintenance
Background:As Parkinson's disease (PD) advances, management is challenged by an increasingly variable and inconsistent response to oral dopaminergic therapy, requiring special considerations by the provider. Continuous 24 h/day subcutaneous infusion of foslevodopa/foscarbidopa (LDp/CDp) provides steady dopaminergic stimulation that can reduce symptom fluctuation. Objective: Our aim is to review the initiation, optimization, and maintenance of LDp/CDp therapy, identify possible challenges, and share potential mitigations.Methods: Review available LDp/CDp clinical trial data for practical considerations regarding the management of patients during LDp/CDp therapy initiation, optimization, and maintenance based on investigator clinical trial experience. Results: LDp/CDp initiation, optimization, and maintenance can be done without hospitalization in the clinic setting. Continuous 24 h/day LDp/CDp infusion can offer more precise symptom control than oral medications, showing improvements in motor fluctuations during both daytime and nighttime hours. Challenges include infusion-site adverse events for which early detection and prompt management may be required, as well as systemic adverse events (eg, hallucinations) that may require adjustment of the infusion rate or other interventions. A learning curve should be anticipated with initiation of therapy, and expectation setting with patients and care partners is key to successful initiation and maintenance of therapy. Conclusion: Continuous subcutaneous infusion of LDp/CDp represents a promising therapeutic option for individuals with PD. Individualized dose optimization during both daytime and nighttime hours, coupled with patient education, and early recognition of certain adverse events (plus their appropriate management) are required for the success of this minimally invasive and highly efficacious therapy.</p
Prospective Home-use Study on Non-invasive Neuromodulation Therapy for Essential Tremor.
Highlights: This prospective study is one of the largest clinical trials in essential tremor to date. Study findings suggest that individualized non-invasive neuromodulation therapy used repeatedly at home over three months results in safe and effective hand tremor reduction and improves quality of life for many essential tremor patients.
Background: Two previous randomized, controlled, single-session trials demonstrated efficacy of non-invasive neuromodulation therapy targeting the median and radial nerves for reducing hand tremor. This current study evaluated efficacy and safety of the therapy over three months of repeated home use.
Methods: This was a prospective, open-label, post-clearance, single-arm study with 263 patients enrolled across 26 sites. Patients were instructed to use the therapy twice daily for three months. Pre-specified co-primary endpoints were improvements on clinician-rated Tremor Research Group Essential Tremor Rating Assessment Scale (TETRAS) and patient-rated Bain & Findley Activities of Daily Living (BF-ADL) dominant hand scores. Other endpoints included improvement in the tremor power detected by an accelerometer on the therapeutic device, Clinical and Patient Global Impression scores (CGI-I, PGI-I), and Quality of Life in Essential Tremor (QUEST) survey.
Results: 205 patients completed the study. The co-primary endpoints were met (p≪0.0001), with 62% (TETRAS) and 68% (BF-ADL) of \u27severe\u27 or \u27moderate\u27 patients improving to \u27mild\u27 or \u27slight\u27. Clinicians (CGI-I) reported improvement in 68% of patients, 60% (PGI-I) of patients reported improvement, and QUEST improved (p = 0.0019). Wrist-worn accelerometer recordings before and after 21,806 therapy sessions showed that 92% of patients improved, and 54% of patients experienced ≥50% improvement in tremor power. Device-related adverse events (e.g., wrist discomfort, skin irritation, pain) occurred in 18% of patients. No device-related serious adverse events were reported.
Discussion: This study suggests that non-invasive neuromodulation therapy used repeatedly at home over three months results in safe and effective hand tremor reduction in many essential tremor patients
Simulação da expectativa de perdas de solo em microbacia sob diferentes manejos florestais
Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease
BACKGROUND:
Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes.
METHODS:
We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization.
RESULTS:
During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events.
CONCLUSIONS:
Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)
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