146 research outputs found

    Referred cutaneous allodynia in a migraine patient without simultaneous headache

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    Cutaneous allodynia is defined as the perception of pain when a non-noxious stimulus is applied to normal skin. This phenomenon has been demonstrated in migraine patients during an acute attack. It is thought to result from central sensitization of neurons in the trigemino-vascular system and may spread to areas beyond that of the referred head pain. In a recent study, migraine patients demonstrated increased temporal summation to painful mechanical stimuli in their referred head pain area between attacks. This suggests that changes in physiologic properties of nociceptive neurons may occur in migraine patients between attacks. We describe a migraine patient with interictal cutaneous allodynia contralateral to her usual head pain

    Comparison of dynamic (brush) and static (pressure) mechanical allodynia in migraine

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    Allodynia has been described in migraine but has not been fully investigated for the different sensory modalities. The aim of this study was to compare the prevalence of dynamic (brush) and static (pressure) mechanical allodynia in migraine patients and to suggest a practical method of testing them in a clinical setting. Patients with International Headache Society-defined episodic migraine (EM) or with transformed migraine (TM) as defined by Silberstein and Lipton were prospectively recruited from the Jefferson Headache Center out-patient clinic. A questionnaire of migraine features and symptoms of allodynia was administered. Brush allodynia (BA) was tested by cutaneous stimulation with a gauze pad and pressure allodynia (PA) was tested using von Frey hairs (VFH). The prevalence of BA and PA in all patients and in the different subgroups was calculated and correlated with migraine features. We recruited 55 migraine patients. Twenty-five had EM and 30 had TM. BA was present in 18 (32.7%) patients and PA in 18–24 (32.7–43.6%). Allodynia to both brush and pressure was found in 13–17 (23.6–30.9%) patients. If a patient had allodynia to one modality only, it was more likely to be PA than BA. Both BA and PA were more common in patients with TM compared with those with EM [BA 46.7% vs. 16.0%; PA (differences significant for the medium and thick VFHs) 50% vs. 20% and 50% vs. 12%, respectively]. Both types of allodynia were also more common in patients with migraine with aura compared with those with migraine without aura (BA 57.1% vs. 17.6%; PA 57.1–61.9% vs. 17.6–32.7%). There was a positive correlation between allodynia score (as obtained by examination) and allodynia index (as obtained by history) for both BA and PA. The incomplete, although considerable, overlap between BA and PA suggests that allodynia to different sensory modalities is associated with sensitization of different neuronal populations. Because PA was more common than BA, it may be a more sensitive indicator of allodynia in migraine. PA can be tested clinically in a practical and systematic manner

    Solvent nature effect in preparation of perovskites by flame pyrolysis: 2 : Alcohols and alcohols plus propionic acid mixtures

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    The effect of either pure alcohols or alcohols + propionic acid mixtures as solvents for the preparation by flame pyrolysis of a standard LaCoO3 catalyst, to be employed for the catalytic flameless combustion of methane, has been investigated. All the catalysts proved very active for the mentioned reaction. Low-MW pure alcohols showed however less suitable than alcohols-propionic acid mixtures, leading to lower perovskite phase purity, less particle size homogeneity and lower specific surface area. The high volatility of the solvent seems to be the major cause, together with the improper behaviour of nitrates (forced by solubility reasons) as perovskite metals precursors. However, the addition of propionic acid to the alcohols allowed to use the acetates as precursors and hence to obtain high perovskitic phase purity, high SSA and Uniform particle size. Moreover, the increase of combustion enthalpy of the solvent, through the addition of higher-MW alcohols, leading to progressively higher flame temperature, strongly improved the thermal resistance of the catalyst, without lowering catalytic performance

    Solvent nature effect in preparation of perovskites by flame pyrolysis: 1: carboxylic acids

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    The effect of a series of carboxylic acids (C(2)-C(8)), as solvents for the preparation by flame spray pyrolysis of LaCoO(3) catalyst for the flameless combustion of methane, has been investigated. Acetic acid showed to be unsatisfactory from several points of view: low phase purity of the catalyst, higher amount of unburnt carbonaceous residua, lower catalytic activity and low thermal stability. By increasing the carbon chain length of the solvent, the consequent increase of flame temperature led to an increase of crystal phase purity and of particle size and to a decrease of specific surface area of the catalyst. Catalytic activity showed only marginally affected by the last parameter, phase purity seeming more important. Thermal resistance showed directly related to flame temperature, i.e. to the combustion enthalpy of the solvent, but a relatively high amount of residual organic matter can negatively affect this property

    Visual Outcomes, Efficacy, and Surgical Complications Associated with Intracameral Phenylephrine 1.0%/Ketorolac 0.3% Administered During Cataract Surgery

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    Aim: The purpose of this study was to compare visual outcomes, surgical time, and perioperative surgical complications after intracameral use of either phenylephrine/ketorolac (P/K) or epinephrine (Epi) during cataract surgery.Methods: This was a single-center, retrospective case review of patients undergoing cataract surgery from August to November 2015. Of the 641 eyes of 389 patients who underwent cataract surgery, 260 eyes were administered phenylephrine 1.0%/ketorolac 0.3% and 381 eyes received Epi in the irrigation solution intraoperatively. All patients received a topical nonsteroidal anti-inflammatory drug regimen (bromfenac 0.07%, nepafenac 0.3%, or ketorolac 0.5%) for 3 days before surgery and topical tropicamide 1.0%, cyclopentolate 1.0%, and phenylephrine 2.5% on the day of surgery.Results: Mean length of surgery (LOS) was 15.4±0.6 minutes. Although a positive correlation was noted between patient age and LOS (p\u3c0.001), P/K was associated with a decrease in the LOS, when controlled for age quartiles. A statistically significant lower incidence of complications (1.1%) was observed with P/K use than Epi (4.5%; p=0.018). Among surgeons who used mydriatic-assist devices more frequently, P/K use was associated with a reduction in the use of these devices (p\u3c0.001). When controlling for age quartile, patients of age groups 69–76 and 76–92 years who received P/K had significantly better uncorrected visual acuity at postoperative day 1 than those receiving Epi (p=0.003).Conclusion: Intracameral use of phenylephrine 1.0%/ketorolac 0.3% during cataract surgery may be effective in maintaining mydriasis. It appears to be superior to intracameral Epi at reducing intraoperative and postoperative complications, need for pupillary dilating devices, and surgical time

    Challenges in measuring angles between craniofacial structures

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    Objective: Three-dimensional (3D) angular measurements between craniofacial planes pose challenges to quantify maxillary and mandibular skeletal discrepancies in surgical treatment planning. This study aims to compare the reproducibility and reliability of two modules to measure angles between planes or lines in 3D virtual surface models. Methodology: Twenty oriented 3D virtual surface models de-identified and constructed from CBCT scans were randomly selected. Three observers placed landmarks and oriented planes to determine angular measurements of pitch, roll and yaw using (1) 3D pre-existing planes, (2) 3D planes created from landmarks and (3) lines created from landmarks. Inter- and intra-observer reproducibility and repeatability were examined using the Intra-Class Correlation (ICC) test. One observer repeated the measurements with an interval of 15 days. ANOVA was applied to compare the 3 methods. Results: The three methods tested provided statistically similar, reproducible and reliable angular measurements of the facial structures. A strong ICC varying from 0.92 to 1.00 was found for the intra-observer agreement. The inter-observer ICC varied from 0.84 to 1.00. Conclusion: Measurements of 3D angles between facial planes in a common coordinate system are reproducible and repeatable either using 3D pre-existing planes, created based on landmarks or angles between lines created from landmarks

    Study of quark fragmentation in e

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    An Agent-Based Distributed Decision Support System Framework for Mediated Negotiation

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    Implementing an e-market for limited supply perishable asset (LiSPA) products is a problem at the intersection of online purchasing and distributed decision support systems (DistDSS). In this dissertation, we introduce and define LiSPA products, provide real-world examples, develop a framework for a distributed system to implement an e-market for LiSPA products, and provide proof-of-concept for the two major components of the framework. The DistDSS framework requires customers to instantiate agents that learn their preferences and evaluate products on their behalf. Accurately eliciting and modeling customer preferences in a quick and easy manner is a major hurdle for implementing this agent-based system. A methodology is developed for this problem using conjoint analysis and neural networks. The framework also contains a model component that is addressed in this work. The model component is presented as a mediator of customer negotiation that uses the agent-based preference models mentioned above and employs a linear programming model to maximize overall satisfaction of the total market. DEDICATION I dedicate this work to my wife, Stacie, and to our sons, Frankie, Dominic, Vincent, and Joseph. Stacie, endeavoring upon this journey would have been impossible without your support, understanding, and adventurous nature. Your patience and belief in my abilities are the reasons for our success. Boys, your existence alone provides the daily motivation I need to be successful, and your individual and collective success continually inspires me to do the best work possible. ii

    Phacoemulsification for the treatment of diabetic cataracts in a Pug

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    Cataracts are a relatively common blinding complication of diabetes mellitus in dogs. The pathophysiology of diabetic cataracts involves a persistent hyperglycemia that overwhelms the lens’ glycolysis pathway, resulting in shunting of glucose into the sorbitol pathway via the enzyme aldose reductase. Sorbitol cannot diffuse out of the lens, thus creating a hyperosmotic effect that leads to swelling. This swelling is associated with alterations in lenticular electrolyte levels, increased membrane permeability, and the formation of water clefts and vacuoles. As this process continues, an irreversible cataract eventually forms. Since the cataracts are often rapid onset with increased lens volume, there is an increased risk of lens capsule leakage, which results in phacolytic uveitis (intraocular inflammation that is induced by lens proteins). Occasionally, the lens capsule can actually rupture, leading to another form of lens-induced uveitis called phacoclastic uveitis. Treatment of cataracts involves surgery, with the most commonly performed procedure being phacoemulsification followed by the implantation of artificial intraocular lenses. Prognosis for sight after treatment is overall very good with atraumatic surgery if there are no active pre-operative secondary complications (i.e. lens-induced uveitis) and if a strict post-operative treatment protocol is followed
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