544 research outputs found
Patient Decision Making in Vestibular Schwannoma: A Survey of the Acoustic Neuroma Association.
Objective To assess the decision-making process of patients with vestibular schwannoma (VS). Study Design Patients with VS completed a voluntary survey over a 3-month period. Setting Surveys were distributed online through email, Facebook, and member website. Subjects and Methods All patients had a diagnosis of VS and were members of the Acoustic Neuroma Association (ANA). A total of 789 patients completed the online survey. Results Of the 789 participants, 474 (60%) cited physician recommendation as a significant influential factor in deciding treatment. In our sample, 629 (80%) saw multiple VS specialists and 410 (52%) sought second opinions within the same specialty. Of those who received multiple consults, 242 (59%) of patients reported receiving different opinions regarding treatment. Those undergoing observation spent significantly less time with the physician (41 minutes) compared to surgery (68 minutes) and radiation (60 minutes) patients ( P < .001). A total of 32 (4%) patients stated the physician alone made the decision for treatment, and 29 (4%) felt they did not understand all possible treatment options before final decision was made. Of the 414 patients who underwent surgery, 66 (16%) felt they were pressured by the surgeon to choose surgical treatment. Conclusion Deciding on a proper VS treatment for patients can be complicated and dependent on numerous clinical and individual factors. It is clear that many patients find it important to seek second opinions from other specialties. Moreover, second opinions within the same specialty are common, and the number of neurotologists consulted correlated with higher decision satisfaction
D3-D7 Holographic dual of a perturbed 3D CFT
An appropriately oriented D3-D7-brane system is the holographic dual of
relativistic Fermions occupying a 2+1-dimensional defect embedded in
3+1-dimensional spacetime. The Fermions interact via fields of
Yang-Mills theory in the 3+1-dimensional bulk. Recently, using internal flux to
stabilize the system in the probe limit, a number of solutions which
are dual to conformal field theories with Fermion content have been found. We
use holographic techniques to study perturbations of a particular one of the
conformal field theories by relevant operators. Generally, the response of a
conformal field theory to such a perturbation grows and becomes nonperturbative
at low energy scales. We shall find that a perturbation which switches on a
background magnetic field and Fermion mass induces a renormalization
group flow that can be studied perturbatively in the limit of small . We
solve the leading order explicitly. We find that, for one particular value of
internal flux, the system exhibits magnetic catalysis, the spontaneous breaking
of chiral symmetry enhanced by the presence of the magnetic field. In the
process, we derive formulae predicting the Debye screening length of the
Fermion-antiFermion plasma at finite density and the diamagnetic moment of the
ground state of the Fermion system in the presence of a magnetic field.Comment: 23 pages, two figures; typos corrected, some comments adde
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Association Between Vestibular Migraine and Migraine Headache: Yet to Explore.
ObjectivesTo evaluate if patients with a diagnosis of vestibular migraine (VM) by the International Classification of Headache Disorders (ICHD) criteria have meaningful differences in symptomatology and disease characteristics when compared to patients with concurrent vestibular symptoms and migraine that do not meet ICHD criteria.MethodsPatients who presented for the evaluation of vertigo were provided a detailed questionnaire about dizziness and migraine symptoms. Patients were assigned to either VM cohort (met ICHD criteria for VM) or migraine headache (MH) cohort (met ICHD criteria for migraine with or without aura but not VM). Disease characteristics, symptomatology, quality of life, and perceived stress score were compared between the cohorts.ResultsThe VM cohort demonstrated a shorter duration of vertigo episodes, 11 ± 22 hours versus 84 ± 146 hours in the MH cohort. In the VM cohort, 81% reported experiencing migraine headaches during episodes of vertigo, versus 61% in the MH cohort. All patients in the VM cohort reported a previous diagnosis of migraine headache, whereas 9% of the MH cohort had not been previously diagnosed by another physician. There was no difference in quality of life or perceived stress scores between the cohorts.ConclusionsA large proportion of vertigo patients with migrainous features do not meet the ICHD criteria for VM. The differences between cohorts represent selection bias rather than meaningful features unique to the cohorts. As such, VM and MH with vestibular symptoms may exist on a spectrum of the same disease process and may warrant the same treatment protocols
Distilling Knowledge from CNN-Transformer Models for Enhanced Human Action Recognition
This paper presents a study on improving human action recognition through the
utilization of knowledge distillation, and the combination of CNN and ViT
models. The research aims to enhance the performance and efficiency of smaller
student models by transferring knowledge from larger teacher models. The
proposed method employs a Transformer vision network as the student model,
while a convolutional network serves as the teacher model. The teacher model
extracts local image features, whereas the student model focuses on global
features using an attention mechanism. The Vision Transformer (ViT)
architecture is introduced as a robust framework for capturing global
dependencies in images. Additionally, advanced variants of ViT, namely PVT,
Convit, MVIT, Swin Transformer, and Twins, are discussed, highlighting their
contributions to computer vision tasks. The ConvNeXt model is introduced as a
teacher model, known for its efficiency and effectiveness in computer vision.
The paper presents performance results for human action recognition on the
Stanford 40 dataset, comparing the accuracy and mAP of student models trained
with and without knowledge distillation. The findings illustrate that the
suggested approach significantly improves the accuracy and mAP when compared to
training networks under regular settings. These findings emphasize the
potential of combining local and global features in action recognition tasks
Comparison the efficacy of pre-emptive oral celecoxib with acetaminophen in controlling post-operative pain and nausea after lower limb surgery under general anesthesia
IntroductionUp to now, there is no single opinion on how to control pain after surgeryand molecular and clinical research in this area has been continuing. This study aimed to compare the effect of premedication with oral administration of celecoxib and acetaminophen on postoperative pain relief in the lower extremity surgery under general anesthesia. Materials and methods:In a prospective, randomized, double-blinded, clinical trial study, 70 patients undergoing lower limb surgery under general anesthesia were distributed into two equal groups. In the first and second group, oral acetaminophen 1000 mg orcelecoxib 400 mg capsules were prescribed one hour before the operation, respectively. Postoperative painand nausea severity in both groups were evaluatedby VAS score and compared with each other. ResultsAssessment of pain intensity at 1, 2, 6, 12 and 24 hours after surgery revealed that acetaminophen group at the first hour had more intensity of postoperative pain (5.46±1.17) compared with celecoxib group(4.31±1.32)(P <0.001). In the rest of the time, there was no significant difference between the two groups. Analysis of variance with repeated observations showed, the trend of postoperative pain intensity during the study in both groups had a significant difference (p = 0.013). The intensity of nausea in the first hour after surgery was significantly more in acetaminophen group compared with celecoxib group (2.8±1.1 vs. 2.2±1.3, p<0.034). Conclusions:Celecoxib may be a better choice in reducing pain and nausea after surgery compared with acetaminophen. Considering no significant adverse effects in many studies, celecoxib may be used as a pre-emptive medication to reduce pain after lower extremity surgery.Key words: Premedication, Post-operative, PONV, pain, Celecoxib, Acetaminophe
The changing landscape of vestibular schwannoma diagnosis and management: A cross-sectional study.
ObjectivesTo assess the current state of the diagnosis and management of vestibular schwannoma (VS) as well as treatment trends, and to evaluate the role of treatment setting and various specialists in treatment plan.MethodsPatients diagnosed with VS completed a voluntary and anonymous survey. The questionnaires were distributed through Acoustic Neuroma Association website, Facebook page, and e-mail newsletters from January to March 2017.ResultsIn total, 789 VS patients completed the survey. Of those, 414 (52%) underwent surgery; 224 (28%) underwent radiotherapy; and 121 (15%) were observed. General otolaryngologists diagnosed 62% of responders, followed by primary care (11%) and neurotologists (10%). Patients who underwent surgery were significantly younger and had larger tumors compared to those treated with radiation or observation. The ratio of patients having nonsurgical versus surgical resection changed from 1:2 to 1:1 for the periods of 1979 through 2006 versus 2007 through 2017, respectively. Neurosurgeons (40%) and neurotologists (38%) were the most influential in treatment discussion. Neurotologists (P < 0.001) and general otolaryngologists (P = 0.04) were more influential than neurosurgeons for the decision process in patients with smaller tumors. Patients treated at academic versus nonacademic private institutions reported similar tumor sizes (P = 0.27), treatment decisions (P = 0.09), and decision satisfaction (P = 0.78).ConclusionThere is a continuing trend toward nonsurgical management, with approximately half of the patients opting for nonsurgical management. In this cohort, the patients commonly presented with otologic symptoms and otolaryngologists made the most diagnoses. Neurotologists and neurosurgeons were the most influential in treatment discussion.Level of evidenceNA Laryngoscope, 130:482-486, 2020
Enhanced thermal stability and lifetime of epoxy nanocomposites using covalently functionalized clay: Experimental and modelling
The present work aims at finding a relationship between kinetic models of thermal degradation process with the physiochemical structure of epoxy-clay nanocomposites in order to understand its service temperature. In this work, two different types of modified clays, including clay modified with (3-aminopropyl)triethoxysilane (APTES) and a commercial organoclay, were covalently and non-covalently incorporated into epoxy matrix, respectively. The effect of different concentrations of silanized clay on thermal behaviour of epoxy nanocomposites were first investigated in order to choose the optimum clay concentration. Afterwards, thermal characteristics of the degradation process of epoxy nanocomposites were obtained by TGA analysis and the results were employed to determine the kinetic parameters using model-free isoconversional and model-fitting methods. The obtained kinetic parameters were used to model the entire degradation process. The results showed that the incorporation of the different modified clay into epoxy matrix change the mathematical model of the degradation process, associating with different orientations of clay into epoxy matrix confirming by XRD results. The obtained models for each epoxy nanocomposite systems were used to investigate the dependence of degradation rate and degradation time on temperature and conversion degree. Our results provide an explanation as to how the life time of epoxy and its nanocomposites change in a wide range of operating temperatures as a result of their structural changes
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Dosimetric Analysis of Neural and Vascular Structures in Skull Base Tumors Treated with Stereotactic Radiosurgery.
Objective To examine the relationship between the prescribed target dose and the dose to healthy neurovascular structures in patients with vestibular schwannomas treated with stereotactic radiosurgery (SRS). Study Design Case series with chart review. Setting SRS center from 2011 to 2013. Subjects Twenty patients with vestibular schwannomas treated at the center from 2011 to 2013. Methods Twenty patients with vestibular schwannomas were included. The average radiation dose delivered to healthy neurovascular structures (eg, carotid artery, basilar artery, facial nerve, trigeminal nerve, and cochlea) was analyzed. Results Twenty patients with vestibular schwannomas who were treated with fused computed tomography/magnetic resonance imaging-guided SRS were included in the study. The prescribed dose ranged from 10.58 to 17.40 Gy over 1 to 3 hypofractions to cover 95% of the target tumor volume. The mean dose to the carotid artery was 5.66 Gy (95% confidence interval [CI], 4.53-6.80 Gy), anterior inferior cerebellar artery was 8.70 Gy (95% CI, 4.54-12.86 Gy), intratemporal facial nerve was 3.76 Gy (95% CI, 3.04-4.08 Gy), trigeminal nerve was 5.21 Gy (95% CI, 3.31-7.11 Gy), and the cochlea was 8.70 Gy (95% CI, 7.81-9.59 Gy). Conclusions SRS for certain vestibular schwannomas can expose the anterior inferior cerebellar artery (AICA) and carotid artery to radiation doses that can potentially initiate atherosclerotic processes. The higher doses to the AICA and carotid artery correlated with increasing tumor volume. The dose delivered to other structures such as the cochlea and intratemporal facial nerve appears to be lower and much less likely to cause immediate complications when shielded
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