2,156 research outputs found
Patient-reported outcome assessment of inflammatory arthritis patient experience with intravenously administered biologic therapy
Objective: To evaluate patient perspectives regarding utilization of intravenous (IV) therapy for inflammatory arthritis (IA). Methods: This was a single-center, non-interventional, patient questionnaire-based study of adult IA patients currently receiving IV biologics. At a single visit, patients completed the questionnaire comprising 30 questions centered on their experience receiving an intravenously administered therapy to treat their IA. The questionnaire included questions on patient demographics, disease characteristics, and previous biologic treatment for IA (subcutaneous [SC] and IV). Patients rated their level of agreement with statements regarding satisfaction with current IV biologic therapy and potential advantages and disadvantages of IV biologic therapy using a 5-point Likert scale (1= strongly disagree, 5= strongly agree). Results: One hundred patients were enrolled and completed the survey; 66% were female and the mean age was 58 years. Before IV treatment, 97% of patients received information regarding therapy options. Ninety patients ranked their satisfaction with current IV therapy as 4 or 5. The proportion of patients with an “extremely favorable” perception of IV therapy increased from 33% to 71% following initiation of their current medication. Thirty-one patients had previously received SC therapies to treat their IA. Conclusion: These results demonstrated an overall favorable perception of IV therapy among this patient population. Patients previously treated with SC therapy also had a positive shift in the perception of IV therapy after initiating IV therapy. Patients’ perception and preference for treatment options should be highly considered by the treating physician during or as part of a shared decision-making process. © 2017 Gaylis et al
On the nature of prominence emission observed by SDO/AIA
The Prominence-Corona Transition Region (PCTR) plays a key role in the
thermal and pressure equilibrium of solar prominences. Our knowledge of this
interface is limited and several major issues remain open, including the
thermal structure and, in particular, the maximum temperature of the detectable
plasma. The high signal-to-noise ratio of images obtained by the Atmospheric
Imaging Assembly (AIA) on NASA's Solar Dynamics Observatory clearly show that
prominences are often seen in emission in the 171 and 131 bands. We investigate
the temperature sensitivity of these AIA bands for prominence observation, in
order to infer the temperature content in an effort to explain the emission.
Using the CHIANTI atomic database and previously determined prominence
differential emission measure distributions, we build synthetic spectra to
establish the main emission-line contributors in the AIA bands. We find that
the Fe IX line always dominates the 171 band, even in the absence of plasma at
> 10^6 K temperatures, while the 131 band is dominated by Fe VIII. We conclude
that the PCTR has sufficient plasma emitting at > 4 10^5 K to be detected by
AIA.Comment: accepted Ap
Reciprocity-Enhanced Optical Communication Through Atmospheric Turbulence—Part II: Communication Architectures and Performance
Free-space optical (FSO) communication provides rapidly deployable, dynamic communication links that are capable of very high data rates compared with those of radio-frequency systems. As such, FSO communication is ideal for mobile platforms, for platforms that require the additional security afforded by the narrow divergence of a laser beam, and for systems that must be deployed in a relatively short time frame. In clear-weather conditions the data rate and utility of FSO communication links are primarily limited by fading caused by microscale atmospheric temperature variations that create parts-per-million refractive-index fluctuations known as atmospheric turbulence. Typical communication techniques to overcome turbulence-induced fading, such as interleavers with sophisticated codes, lose viability as the data rate is driven higher or the delay tolerance is driven lower. This paper, along with its companion [J. Opt. Commun. Netw. 4, 947 (2012)], present communication systems and techniques that exploit atmospheric reciprocity to overcome turbulence that are viable for high data rate and low delay tolerance systems. Part I proves that reciprocity is exhibited under rather general conditions and derives the optimal power-transfer phase compensation for far-field operation. Part II presents capacity-achieving architectures that exploit reciprocity to overcome the complexity and delay issues that limit state-of-the-art FSO communications.United States. National Aeronautics and Space Administration (Air Force Contract #FA8721-05-C-0002
Human immunodeficiency virus (HIV) in Washington, D.C.: Prevalence of antiretroviral resistance in treatment naĂŻve patients from 2007 to 2010
HIV treatment has been greatly impacted by transmitted resistance to antiretrovirals (ARV). Several studies have documented resistance in naĂŻve individuals and estimates of transmitted drug resistance mutations range from \u3c5% to as high as 25%. Washington, D.C. has one of the highest human immunodeficiency virus (HIV) prevalence rates in the United States (3.2% in 2009), but local data regarding the frequency of major mutations and antiretroviral (ARV) resistance has been limited. Medical records of HIV positive, ARV-naĂŻve adults at two facilities in Washington, D.C., The George Washington University Medical Center and the Veterans Affairs Medical Center, were retrospectively analyzed in subjects who had genotypic resistance testing from 2007 to 2010. Of 407 ARV-naĂŻve patients, at least one transmitted drug resistance mutation was detected in 17% of our patients, with non-nucleoside reverse transcriptase (NNRTI) mutations observed in 15%. Among patients with at least one reverse transcriptase (RT) or major protease region (Pr) resistance mutation, 85% had resistance against a single ARV class. Dual and triple class resistance mutations were seen in 8 patients (2%) and 3 patients (0.7%), respectively. Most of the multiple class resistance was seen in 2010. A gradual increase in NNRTI resistance was noted during 2008 to 2010. Our prevalence of transmitted RT, major Pr mutations (17.4%) and ARV resistance (8.6%) were high but similar to rates reported by others within the United States. Given the high HIV prevalence in the District of Columbia, this has important implications for treatment of these ARV-naĂŻve patients
Improved models of upper-level wind for several astronomical observatories
An understanding of wind speed and direction as a function of height are
critical to the proper modeling of atmospheric turbulence. We have used
radiosonde data from launch sites near significant astronomical observatories
and created mean profiles of wind speed and direction and have also computed
Richardson number profiles. Using data from the last 30 years, we extend the
1977 Greenwood wind profile to include parameters that show seasonal variations
and differences in location. The added information from our models is useful
for the design of adaptive optics systems and other imaging systems. Our
analysis of the Richardson number suggests that persistent turbulent layers may
be inferred when low values are present in our long term averaged data.
Knowledge of the presence of these layers may help with planning for adaptive
optics and laser communications.Comment: 21 pages, 15 Figures, 8 table
Understanding olive oil stability using filtration and high hydrostatic pressure
Veiled extra virgin olive oil (VEVOO) is very attractive on the global market. A study was performed to highlight the role of different amounts of water and microorganisms on the evolution of VEVOO quality during storage, using the selective effects of the application of individual or combined filtration and high hydrostatic pressure (HHP) treatments. Four oil processing trials were carried out in four replicates, resulting in a full factorial design with two independent fixed factors: filtration and HPP treatments. The turbidity of all the olive oil samples was characterized. Furthermore, all the olive oil samples were analysed for legal parameters, volatile organic compounds and phenolic compounds during the storage tests. The microbial contamination in the presence of a high level of water activity (>0.6 Aw) was related to the formation of volatile aroma compounds, which were responsible for the \u201cfusty\u201d sensory defect. Furthermore, high water activity values were related to an increase in the hydrolytic degradation rate of the phenolic compounds. The oil turbidity has to be planned and controlled, starting from adjustment of the water content and application of good manufacturing practices
Filtration scheduling: Quality changes in freshly produced virgin olive oil
Filtration is the most widespread stabilisation operation for extra virgin olive oil, preventing microbial and enzymatic changes. However, during the harvest, the workload of olive mills is at its peak. This results in two approaches to filtration: (i) delays it until after harvesting, increasing the risk of degraded oil quality, and (ii) filters it immediately, increasing the workload. The aim of our experiment is to assess the risk of delaying filtration and establish a safe delay time. Changes in the sensory profile and volatile compound contents were evaluated during 30 days in filtered and unfiltered samples. Significant differences were related to filtration: both turbidity grade and microbial contamination; no differences for the legal parameters were found. Two, contrasting, results were obtained with respect to oil quality: (i) the fusty defect, appearing in less than five days in unfiltered oils, leading to the downgrade of the oil\u2019s commercial category, and (ii) filtration removing some lipoxygenase volatile compounds. Consequently, a fruity attribute was more pronounced in unfiltered samples until day five of storage; it seems that, from this point, the fusty defect masked a fruity attribute. Hence, filtering within a few days strongly reduced the risk of degraded oil quality compared to a delayed filtration
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