bluuebunny/crossref_metadata_2025 huggingface dataset:
P-017 Balloon-Assisted Guide Catheter Positioning to Overcome Extreme Cervical Carotid Tortuosity: Technique and Case Experience
Authors: Fiorella D , Peeling L
Published: July 2013

Background and Significance

We describe a method by which to efficiently and atraumatically achieve distal positioning of a flexible guiding catheter beyond extreme cervical tortuosity using a hypercompliant temporary occlusion balloon.

Methods

A retrospective review of a prospective neuroendovascular database was used to identify cases in which a hypercompliant balloon catheter (Hyperform or Hyperglide, ev3/Covidien, Irvine, CA; Scepter or Scepter XC, MicroVention, Tustin, CA) was used to achieve distal positioning of a flexible guiding catheter (Navion, ev3/Covidien, Irvine, CA; Neuron, Penumbra Inc., Alameda, CA). After achieving a stable guiding sheath position within the proximal cervical carotid artery, a hypercompliant balloon catheter was manipulated beyond the tortuous cervical internal carotid segment into the distal carotid artery. The balloon was then inflated to anchor it distally within the cavernous segment of the ICA. Then the guiding catheter was advanced beyond the tortuous cervical segment, over the balloon catheter, as gentle counter traction was applied to the balloon.

Results

Balloon-assisted guiding catheter placement was used to perform endovascular treatments of twelve anterior circulation aneurysms. One patient underwent coiling alone. Five patients underwent balloon assisted coiling. One patient underwent balloon and stent assisted coil embolisation. Four patients with five carotid aneurysms (one with bilateral carotid aneurysms) underwent vascular reconstruction with the pipeline embolisation device. All patients had tortuosity of the carotid system. Three patients had findings consistent with cervical carotid fibromuscular dysplasia. The technique was successful each time it was attempted. No parent artery dissections or catheter-induced vasospasm were noted in any case.

Discussion

Hypercompliant balloon catheters can be reliably used to facilitate safe and rapid distal positioning of flexible guiding catheters beyond severe cervical tortuosisty.

Disclosures

D. Fiorella: 1; C; MicroVention, Siemens Med Systems. 2; C; ev3/Covidien, JNJ/Codman, CVSL. 6; C; Codman. L. Peeling: None
P-020 Preliminary Findings of Recanalisation and Stenting for Symptomatic Vertebrobasilar Artery Occlusion Lasting more than 24 hours: A Retrospective Analysis of 21 Cases
Authors: He Y , Wang Z , Li T
Published: July 2013

Introduction and Purpose

A subset of patients with vertebrobasilar artery occlusion (VBAO) lasting more than 24 hours still suffered recurrent ischaemic events and progressive disability despite intensive medical therapy. The prognosis of these patients is extremely poor, with a high incidence of catastrophic brainstem and cerebellar infarction. Optimal management for these patients remains unknown. Recurrent symptoms despite aggressive medical treatment may be an indication for endovascular revascularisation and stenting. This study was to evaluate the technical feasibility, safety and short-term effects of recanalisation and stenting.

Materials and Methods

Twenty-one consecutive patients with VBAO including 12 vertebral artery occlusion (VAO: occlusion not involving basilar artery) and 9 basilar artery occlusion (BAO) lasting more than 24 hours refractory to aggressive medical treatment were enrolled into this study and underwent recanalisation and stenting between February 2010 and November 2011. Data were retrospectively collected. The rate of recanalisation was evaluated radiographically and the functional outcome was examined using modified Rankin Scale (mRS) scores. Independent groups T-test, t’-test, Fisher Exact test or Nonparametric test were used according to the studied variables characteristics.

Results

The median time between onset of symptoms and recanalisation was 1.7 months (IR, 0.9–5.2), and the median time between imaging-documented occlusion and endovascular recanalisation was 10.5 days (IR, Interquartile Range: 6.5–18); Median NIH Stroke Scale (NIHSS) at admission was 8 (IR, 2–13). Technique success ratio of recanalisation was 95.2%. There were 3 periprocedural complications. Median mRS score was 4 (IR, 2.5–5) prior to procedure and 4 (IR, 1–5) at discharge (P<0.05). One stroke and one death occurred within 30 days postprocedure. Mean duration of clinical follow-up was 6.9 months. One transient ischaemic attack, one stroke and one death occurred beyond 30-day postprocedure. Mean angiographic follow-up was 8.9 months in 7 patients. Three patients developed in-stent restenosis or occlusion, and two of them were symptomatic. Subgroup analyses revealed patients got better functional recovery (lower mRS) at discharge in patients with VAO (P<0.05) compared with their respective preoperative mRS scores and there was no significant difference in patients with BAO.

Conclusions

Endovascular recanalisation and stenting for symptomatic VBAO lasting more than 24 hours was technically feasible and patients with VAO benefited from the treatment with significant functional recovery. However, the complexity of the procedure and high risk of complications should prompt extreme caution. Procedures should only be performed at high volume centres by experienced operators.

Disclosures

Y. He: 1; C; Zhengzhou University. Z. Wang: None. T. Li: None.
P-021 Should Ischaemic Stroke Patients with Aphasia or High NIHSS Score Undergo Pre-procedural Intubation Prior to Endovascular Treatment?
Authors: Hassan A , Adil M , Tekle W , Qureshi A
Published: July 2013

Background and purpose

Presence of aphasia or severe neurological deficits is considered an indication for pre-procedural intubation (PPI) for endovascular treatment (ET) of acute ischaemic stroke (AIS) patients although a critical analysis has not been performed. To compare outcomes in AIS patients undergoing ET with or without PPI in two groups of patients: those with presence of aphasia; and those with admission NIHSS score of ≥20.

Methods

All endovascular treated AIS patients were identified through a database maintained from two comprehensive stroke centres over an 8 year period. The rate of intra-procedural intubation in patients without PPI was ascertained. The rates of poor functional outcome at discharge (modified Rankin score [mRS] of ≥3) and intracerebral haemorrhage (ICH) were compared between those who did or did not undergo PPI in the two study groups.

Results

In the first analysis, 60 (50%) of 120 patients with aphasia underwent procedure without PPI; 6 of 60 patients required intra-procedural intubation. The odds of any ICH [OR 6.3, 95% CI 1.6–24.0] and in-hospital mortality [OR 9.3, 95% CI 2.7–31.0] were significantly higher among those who underwent PPI after adjusting for potential confounders. In the second analysis, 36 (39%) of 93 patients with NIHSS score ≥20 underwent ET without PPI; 6 of 57 patients required intra-procedural intubation. The risk of any ICH (OR 7.6, 95% CI 0.9–67.8) and in-hospital mortality [OR 5.0, 95% CI 0.9–27.5] were higher among patients who underwent PPI, after adjusting for potential confounders. The rates of good outcome at discharge were significantly lower among those patients with aphasia [OR 0.1, 95% CI 0.04–0.2, p=<0.0001] or those with NIHSS score ≥20 [OR 0.07, 95% CI 0.005–0.9, p=0.04] who underwent PPI.

Conclusions

Despite the risk of intra-procedural intubation among patients with either aphasia or admission NIHSS score ≥20 who undergo ET without PPI, the rates of poor outcomes, ICH, and death are prominently lower than those with PPI.

Disclosures

A. Hassan: None. M. Adil: None. W. Tekle: None. A. Qureshi: None.
P-024 Scepter C™ Balloon Occlusion Device use for Liquid Embolisation of Vascular Malformations, a Pilot Study
Authors: Grupke S , Alhajeri A , Fraser J
Published: July 2013

Objective

The Scepter C™ balloon occlusion catheter (Microvention, Tustin CA) is an endovascular device designed with a polyurethane balloon that elongates with inflation to allow it to conform to the lumen of the target vessel. The device has a double lumen, allowing passage over a 0.014-inch guidewire, and/or passage of Onyx embolisation distal to the balloon. We reviewed our initial use of this device as a conduit for liquid embolisation of vascular malformations as compared to the Marathon™ microcatheter (ev3, Plymouth, MN) alone, outlining indications for and outcomes with use.

Methods

We performed a retrospective review of patients who underwent Onyx embolisation of an arterovenous malformation or a dural A-V fistula from October 2011 to February 2013 at the University of Kentucky Hospital.

Results

14 Scepter C™ devices were used in 8 patients over the course of 10 endovascular interventions. We compared this to 8 patients treated with 11 embolisations over the course of 9 interventions without balloon assistance. Technical success was achieved in 13/14 (93%) deployments of the balloon. There were no complications related to Scepter C™ use. Scepter C™ permitted distal navigation, while facilitating faster Onyx injection with more extensive and distal casting. This led to a trend of decreased fluoro time per embolisation with Scepter C™, though not statistically significant (23.0 ± 8.8 min vs 34.0 ± 10.4 min). There were no cases of Onyx fixation of the device in the parent artery; no significant tension was required to remove the device after Onyx injection. This represents a significantly different experience from the typically used Onyx microcatheter (Marathon), which carries a known risk of tip-adhesion to the Onyx cast. We detail technical nuances used to maximise the benefits of the Scepter C™ for such applications.

Conclusions

The Scepter C balloon catheter has, thus far, proven to be a safe and effective device for the endovascular treatment of vascular malformations through Onyx embolisation. A larger prospective study should be undertaken to ascertain any potential advantages or disadvantages compared to the current standard delivery catheters.

Disclosures

S. Grupke: None. A. Alhajeri: None. J. Fraser: None.
E-007 Analysis of endovascular intervention on emergent postoperative bleeding control after Head & Neck cancer surgery
Authors: Kim S
Published: July 2013

Background

In clinical practice, endovascular intervention may be considered as a treatment option in managing patients with active bleeding following head and neck cancer surgery. This study aims to evaluate treatment outcome of patients undergone with selective endovascular embolisation as therapeutic alternative when surgery is not possible.

Material and Method

Retrospective chart review of cancer patients treated by the Head and Neck Service of Severance Hospital underwent endovascular embolisation for control of actual or threatened postoperative bleeding, from 2005.January to 2013.February. 10 patients underwent endovascular embolisation for control postoperative bleeding. Demographic variables, location of primary tumour, material for embolisation, and clinical outcomes including incidence of recurrent bleeding were recorded.

Results

10 patients received emblotherapy for acute bleeding after surgery. 9 of 10 cases has allowed patients to undergo successful embolisation. In 1 patient, the procedure failed due to diffuse bleeding without main bleeder and progression of disseminated intravascular coagulopathy. The most common cancerous lesion associated with wound bleeding was oral cavity and oropharynx. This was followed by nasopharynx, hypopharynx, respectively. The main bleeding focus was recorded as common carotid artery (4), bifurcation of CCA (1), branch of ECA (distal maxillary artery (2), superior thyroid artery (1)), and thyrocervical trunk (1). The patients underwent interventional embolisation using stent (3),coil (3),vascular plug and microparticles (NBCA)(3).

Conclusion

This study demonstrates that selective embolisation was shown to be a feasible and effective method to control acute postoperative bleeding of head and neck cancer.

Disclosures

S. Kim: None.
E-012 Long-Term Follow-Up of Unruptured Cerebral Aneurysms without Treatment; Compared with Those Treated by Endovascular Surgery
Authors: Nemoto S
Published: July 2013

Purpose

Annual bleeding rate of unruptured cerebral aneurysms have been reported relatively low. Indication of treatment for these patients is controversial. Results of long-term follow-up of unruptured aneurysms without treatment are analysed in comparison with coiled unruptured aneurysms.

Material and Method

917 patients with unruptured cerebral aneurysm were included in this study. All the patients were referred to single physician over the past 12 years. Indication of endovascular treatment was decided according to aneurysm size, shape, location, and family history of SAH. 661 patients selected observation and 256 patients endovascular treatment. In observation group MRA was repeated every 6–12 months. When MRA disclosed aneurysm growth, treatment is considered. In treated group angiography was performed year after treatment and MRA was repeated every year afterwards.

Results

Follow-up was performed from 6–144 months, with average follow-up period 39.7 months (6-144) in observation group and 76.5 months in treated group respectively.

Aneurysm rupture occurred in 15 patients in observation group (2.1%). Final outcome of ruptured patients is GR 3 cases (20.0%), MD 2 (13.3%), SD 4 (26.7%), Dead 6 (40.0%). Annual bleeding rate is 0.7%. Rupture rate is higher (1.0%) in aneurysms over 10mm in diameter. In 7 patients aneurysm growth is observed in follow-up and aneurysms were treated with good results. In treated group results are GR 249 cases (97.3%), MD 3 (1.2%), SD 2 (0.8%), Dead 2 (0.8%) respectively. Kaplan- Meyer survival rate of both groups are similar without significant difference.

Conclusion

Observation has better outcome in unruptured small cerebral aneurysms. 2. Treatment is indicated when aneurysm growth is detected in follow-up.

Disclosures

S. Nemoto: None.
E-019 Clinical, Angiographic, and Radiographic Outcomes Differences Amongst Mechanical Thrombectomy Devices: Initial Experience of a Large-Volume Centre
Authors: Kass-Hout T , Kass-Hout O , Sun C , Gupta R , Nogueira R
Published: July 2013

Background and purpose

Early Reperfusion is critical for favourable outcome in patients with acute ischaemic stroke (AIS). There are limited data on the comparative performance of FDA approved devices for mechanical thrombectomy. Here, we compare the angiographic, radiographic, and clinical outcomes amongst the three device categories currently available in the U.S. when used in routine clinical practice.

Methods

Retrospective review of a prospective collected database of endovascularly treated large vessel AIS in a large academic centre. Data from all consecutive patients who underwent clot retrieval using Merci, Penumbra, or Stent-Retrievers from September 2010 to July 2012 were analysed. Baseline characteristics including age, gender, NIHSS, ASPECTS score, and co-morbidities were compared across the 3 groups. The outcome measures included the rates of recanalisation (TICI 2b-3), symptomatic intracebral haemorrhage (sICH, defined as any parenchymal haematoma e.g. PH-1/PH-2), final infarct volume, 90-day mortality, and independent functional outcomes (modified Rankin Scale, mRS 0–2) at 90 days.

Results

The entire cohort included 287 patients with a mean age of 65.5 ± 14.2 and median baseline NIHSS 20. Of the patients 49.38% were females. The median ASPECTS score was 8. There were no significant differences in terms of baseline characteristics amongst the 3 device groups. There were not statistically differences in the rate of sICH (7% vs 7% vs 6%, for Stent retrieval, Merci and Penumbra respectively, P-value = 0.921), and the volume of infarction (66.9, 69.5, and 59.8 cc for Stent retrieval, Merci and Penumbra respectively, P-value = 0.621). However, the rates of TICI 2b-3 reperfusion (86 % vs 70% vs 78 %, p=: 0.027) were significantly higher with Stent-Retrievers and Penumbra system as compared to Merci treatments. This effect remained significant when controlling, for time of stroke onset, ASPECTS score, infarction volume, and co-morbidities. There was no significant difference in the 90-day functional independence (33 % vs 25 % vs 41%, p=0.079) amongst the different devices (for Stent-Retriever, Merci, and Penumbra groups, respectively).

Conclusion

Our initial data confirms the superiority of the Stent-Retriever technology over the Merci device in achieving higher rates of reperfusion and better outcomes. No significant difference in near complete/complete reperfusion, final infarct volumes, or clinical outcomes could be established between Stent-Retrievers and Penumbra thromboaspiration. This supports the need for a randomised clinical trial comparing these two technologies.

Disclosures

T. Kass-Hout: None. O. Kass-Hout: None. C. Sun: None. R. Gupta: None. R. Nogueira: None.
E-024 Intra-arterial Vasodilator Therapy for Severe Vasospasm in Acute Bacterial Meningitis
Authors: Taqui A , Burgess R , Hui F , Toth G
Published: July 2013

Introduction and Purpose

Cerebrovascular complications of acute bacterial meningitis may include vasculitis, vasospasm, venous and arterial thrombosis, intracranial aneurysm formation and others. These complications have been shown to be important predictors of prognosis. The role of invasive endovascular therapies has not been well studied for meningitis-related vasospasm. We present a patient with acute bacterial meningitis who received intra-arterial (IA) vasodilator therapy to arrest worsening intracranial vasculopathy.

Materials and Methods

Case report and review of literature.

Results

A 38 year old male with history of recurrent ear infections presented to the hospital with depressed mental status and fever requiring intubation. He was diagnosed with diffuse cerebral oedema, hydrocephalus, left mastoiditis, and severe Streptococcus Pneumoniae meningitis and ventriculitis. He was administered antibiotics, steroids and seizure prophylaxis. An extraventricular drain was placed. The patient underwent mastoidectomy. MRI brain on day 5 showed acute infarcts in bilateral inferior cerebellar hemispheres. Noninvasive MRA study on day 7 was suggestive of only mild vasocontrictive segments in anterior and posterior circulations. He was started on nimodipine and triple-H therapy. On day 9, patient developed bradycardia, worsened mental status and motor deficits. A CTA brain demonstrated significant narrowing of the vertebrobasilar system with associated new scattered infarcts on MRI. An angiogram confirmed severe vasospasm in the distal vertebral arteries, basilar artery, and moderate vasospasm in bilateral supraclinoid internal carotid arteries. IA verapamil was infused in these vasospastic regions with improved vessel calibre and distal flow. The patient’s neurological exam also improved after the intervention. A followup angiogram on day 14 revealed further improvement in the intracranial vasospasm.

Conclusion

Vasospasm causing delayed ischaemic neurologic deficit is a rare, but severe cerebrovascular complication of acute bacterial meningitis. It can be a significant predictor of prognosis, and the disease may progress despite maximal medical therapy. Interventional therapy may be an important adjunctive treatment along with conservative medical modalities.

Disclosures

A. Taqui: None. R. Burgess: None. F. Hui: None. G. Toth: None.
E-025 Initial Multicentre Experience Using the Penumbra 5Max,4MAX and 3MAX Reperfusion Catheters in Acute Stroke Therapy
Authors: Farkas J , Arcot K , Kumar R , Delbrune J , Papamitsakis N , Margulis Y , Walzman D , Dash S , Levin K , Azhar S
Published: July 2013

Purpose

The Penumbra MAX System (5MAX, 4MAX, and 3MAX) refers to a new generation of reperfusion catheters with a larger, tapered lumen and new material composition in the distal end designed to enhance aspiration efficiency with improve trackability. Results from a retrospective multicentre study with the Penumbra System 5 MAX, 4MAX and 3MAX reperfusion catheters in acute stroke patients with large vessel occlusion are reported.

Methods

A retrospective case-review of 22 consecutive acute ischaemic stroke cases from July 2012 through March 2013 treated by the Penumbra System (5 MAX, 4MAX and 3MAX) was performed. The case experience from three institutions was collected in the initial months after the device was released. Results are reported from cases which involved occlusions in the ICA (n=6), proximal MCA M1 (n=10), distal MCA M2 (n=3) and vertebrobasilar arteries (n=3).

Results

Prior to intervention, all patients presented with TICI 0 or 1. Successful revascularisation was primarily achieved in 86.3% (Tici 2b & Tici 3 ) using the Penumbra System with 5 MAX, 4MAX and 3MAX reperfusion catheters. Mean age was 71.45 ± 14.4 years; median baseline NIHSS score was 20.5 ± 3.96. In 1 patient, embolisation of new territory was found and treated by IA rtPA. One case of intracerebral haemorrhage (ICH) was noted with haemorrhage in a previously unaffected region, possibly secondary to IV rtPA treatment.

Conclusion

Early clinical experience suggests that the 5 MAX, 4MAX and 3MAX appear to have improved aspiration efficiency and tracking. Follow-up data and additional cases are critical in confirming these initial results.

Disclosures

J. Farkas: None. K. Arcot: None. R. Kumar: None. J. Delbrune: None. N. Papamitsakis: None. Y. Margulis: None. D. Walzman: None. S. Dash: None. K. Levin: None. S. Azhar: None.
A review of diagnostic imaging of snakes and lizards
Authors: Banzato T. , Hellebuyck T. , Caelenberg A. Van , Saunders J. H. , Zotti A.
Published: July 2013

Snakes and lizards are considered ‘stoic’ animals and often show only non‐specific signs of illness. Consequently, diagnostic imaging – along with clinical examination and laboratory tests – is gaining importance in making a final diagnosis and establishing a correct therapy. The large number of captive snake and lizard species commonly kept as pets, together with the high inter‐ and intraspecific morphological variability that is innate in these animals, make the analysis of diagnostic images challenging for the veterinary practitioner. Moreover, a thorough knowledge of the anatomy, physiology and pathology of the species that are the object of clinical investigation is mandatory for the correct interpretation of diagnostic images. Despite the large amount of clinical and scientific work carried out in the past two decades, the radiographic features of snakes and lizards have not undergone systematic description, and therefore veterinarians often have to rely mostly on anatomical studies rather than radiological literature. The aim of this paper is to review the most commonly used diagnostic imaging modalities, as well as to provide an overview of the available international original studies and scientific reviews describing the normal and pathological imaging features in snakes and lizards.
Modified Korteweg – de Vries solitons in a dusty plasma with electron inertia and drifting effect of electrons
Authors: Das R. , Karmakar K.
Published: July 2013

The formation of dust ion acoustic solitons in an unmagnetized plasma with the electrons’ drift velocity has been investigated through the modified Korteweg – de Vries (mKdV) equation. In this case only compressive solitons are found to exist. The mKdV solitons are established to exist in two new ranges of drift velocity [Formula: see text] for [Formula: see text] and [Formula: see text].
Inverse analysis for the determination of heat transfer coefficient
Authors: Fguiri Ali , Daouas Naouel , Radhouani M-Sassi , Aissia Habib Ben
Published: July 2013

The parallel hot wire technique is considered an effective and accurate means of experimental measurement of thermal conductivity. However, the assumptions of infinite medium and ideal infinitely thin and long heat source lead to some restrictions in the applicability of this technique. To make an effective experiment design, a numerical analysis should be carried out a priori, which requires a precise specification of the heating source strength and the heat transfer coefficient on the external surface. In this work, a more accurate physical and mathematical modeling of an experimental setup based on the parallel hot wire method is considered to estimate the two above-mentioned parameters from noisy temperature histories measured inside the material. Based on a sensitivity analysis, the heating source strength is estimated first using early time measurements. With such estimated value, determination of the heat transfer coefficient using temperatures measured at later times is then considered. The Levenberg–Marquardt (LM) method is successfully applied using a single experiment for the inverse solution of the two present parameter estimation problems. Estimates of this gradient-based deterministic method are validated with a stochastic method (Kalman filter). The effects of the measurement location, the heating duration, the measurement time step, and the LM parameter on the estimates and their associated confidence bounds are investigated. Used in the traditional fitting procedure of the parallel hot wire technique, the estimated heating source power provides a reasonable agreement between fitted and exact values of the thermal conductivity and the thermal diffusivity.
The effects of fish oil consumption on cardiovascular remodeling in ApoE deficient mice
Authors: Cleverley Kelby , Du Xiaozhou , Premecz Sheena , Le Khuong , Zeglinski Matthew , Nicholson Tiffany , Goh Chun Y. , Lu Yan , Anderson Hope D. , Moghadasian Mohammed H. , Jassal Davinder S.
Published: July 2013

Owing to their spontaneous development of atherosclerosis, apolipoprotein E knockout mice (ApoEKO) are one of the best studied animal models for this disease. Little is known about the utility of various omega-3 fatty acid regimens, in particular fish oils, in preventing cardiac disease in ApoEKO mice. The purpose of this study was to determine the cardiovascular effects of omega-3 fatty acid supplementation with either safflower oil (control), fish oil, flaxseed oil, or designed oil in ApoEKO mice fed a high-fat diet for a total of 16 weeks. In-vivo cardiac function was assessed weekly using murine echocardiography. Blood pressure, plasma lipid levels, and brain natriuretic peptide (BNP) were serially measured. The results show that ApoEKO mice fed fish oil demonstrated an increase in left ventricular wall thickness as a result of increased afterload. Despite chronic treatment with fish oil over 16 weeks, blood pressure increased in ApoEKO mice by 20% compared with the baseline. Both echocardiographic evidence of left ventricular hypertrophy and biochemical increase in BNP levels confirmed diastolic dysfunction in ApoEKO mice fed fish oil. This suggests that high-fat diet supplemented with fish oil may lead to adverse cardiovascular effects in ApoE deficient mice.
MICROSCOPIC FOUNDATIONS OF THE MEIßNER EFFECT: THERMODYNAMIC ASPECTS
Authors: BRU J.-B. , DE SIQUEIRA PEDRA W.
Published: July 2013

We analyze the Meißner effect from first principles of quantum mechanics. We show in particular the existence of superconducting states minimizing the magnetic free-energy of BCS-like models and carrying surface currents which annihilate the total magnetic induction inside the bulk in the thermodynamic limit. This study is a step towards a complete explanation of the Meißner effect from microscopic models. It remains indeed to prove that those states are dynamically stable, i.e. quasi-stationary at low temperatures. Note that our analysis shows that the Meißner effect is not necessarily related to an effective magnetic susceptibility equal to -1.
FACTOR UNIQUENESS IN THE S&P 500 UNIVERSE: CAN PROPRIETARY FACTORS EXIST?
Authors: FOCARDI SERGIO M. , FABOZZI FRANK J.
Published: July 2013

In this paper, we analyze factor uniqueness in the S&P 500 universe. The current theory of approximate factor models applies to infinite markets. In the limit of infinite markets, factors are unique and can be represented with principal components. If this theory would apply to realistic markets such as the S&P 500 universe, the quest for proprietary factors would be futile. We find that this is not the case: in finite markets of the size of the S&P 500 universe different factor models can indeed coexist. We compare three dynamic factor models: a factor model based on principal component analysis, a classical factor model based on industry, and a factor model based on cluster analysis. Dynamic behavior is represented by fitting vector autoregressive models to factors and using them to make forecasts. We analyze the uniqueness of factors using Procrustes analysis and correlation analysis. Forecasting performance of the factor models is analyzed by forming active portfolio strategies based on the forecasts for each model using sample data from the S&P 500 index in the 21-year period 1989–2010. We find that one or two factors which we can identify with global factors are common to all models, while the other factors for the factor models we analyzed are truly different. Models exhibit significant differences in performance with principal component analysis-based factor models appearing to behave better than the sector-based factor models.
CREDIT MODELING UNDER JUMP DIFFUSIONS WITH EXPONENTIALLY DISTRIBUTED JUMPS — STABLE CALIBRATION, DYNAMICS AND GAP RISK
Authors: HELLMICH MARTIN , KASSBERGER STEFAN , SCHMIDT WOLFGANG M.
Published: July 2013

This paper investigates a structural credit default model that is based on a hyper-exponential jump diffusion process for the value of the firm. For credit default swap prices and other quantities of interest, explicit expressions for the corresponding Laplace transforms are derived. The time-dynamics of the model are studied, particularly the jumps in credit spreads, the understanding of which is crucial e.g. for the pricing of gap risk. As an application of our findings, the model is calibrated to credit default swap spreads observed in the market.
RESOLUTION OF AN INVERSE PROBLEM BY HAAR BASIS AND LEGENDRE WAVELET METHODS
Authors: POURGHOLI REZA , ESFAHANI AMIN , FOADIAN SAEDEH , PAREHKAR SONA
Published: July 2013

In this paper, two numerical methods are presented to solve an ill-posed inverse problem for Fisher's equation using noisy data. These two methods are the Haar basis and the Legendre wavelet methods combined with the Tikhonov regularization method. A sensor located at a point inside the body is used and u(x, t) at a point x = a, 0 < a < 1 is measured and these methods are applied to the inverse problem. We also show that an exponential rate of convergence of these methods. In fact, this work considers a comparative study between the Haar basis and the Legendre wavelet methods to solve some ill-posed inverse problems. Results show that an excellent estimation of the unknown function of the inverse problem which have been obtained within a couple of minutes CPU time at Pentium(R) Dual-Core CPU 2.20 GHz.
SCALE-INVARIANT V-TRANSFORM AND ITS APPLICATION TO SIGNAL DE-NOISING
Authors: LIANG YANYAN , CAI ZHANCHUAN , QI DONGXU , TANG ZESHENG
Published: July 2013

An aporia of signal de-noising is that the local signal reconstruction at the singular points. Based on the analysis for the signal singular points, combining signal scaling and orthogonal transform, This paper present a novel method called Scale-Invariant V-Transform (SIVT) for signal de-noising based on V-System, which is polynomial multi-wavelets in invariant set. SIVT employs multiple redundant basis of various scale to suppress the artifacts appearing in the singular points of denoised signal. The test results reveal the SIVT reconstructions exhibit higher visual quality and numerical measurement of SNR than wavelet-based reconstructions. Existing theory of SIVT suggests that these new approaches can perform significantly better than wavelet methods in certain signal reconstruction problems.
ANALYTIC SAMPLING APPROXIMATION BY PROJECTION OPERATOR WITH APPLICATION IN DECOMPOSITION OF INSTANTANEOUS FREQUENCY
Authors: LI YOUFA , QIAN TAO
Published: July 2013

A sequence of special functions in Hardy space [Formula: see text] are constructed from Cauchy kernel on unit disk 𝔻. Applying projection operator of the sequence of functions leads to an analytic sampling approximation to f, any given function in [Formula: see text]. That is, f can be approximated by its analytic samples in 𝔻s. Under a mild condition, f is approximated exponentially by its analytic samples. By the analytic sampling approximation, a signal in [Formula: see text] can be approximately decomposed into components of positive instantaneous frequency. Using circular Hilbert transform, we apply the approximation scheme in [Formula: see text] to Ls(𝕋2) such that a signal in Ls(𝕋2) can be approximated by its analytic samples on ℂs. A numerical experiment is carried out to illustrate our results.
DISCRETELY MODULATED CONTINUOUS-VARIABLE QUANTUM KEY DISTRIBUTION WITH A NONDETERMINISTIC NOISELESS AMPLIFIER
Authors: FANG JIAN , LU YUAN , HUANG PENG , HE GUANGQIANG , ZENG GUIHUA
Published: July 2013

In this paper, we first study a generalized protocol of discrete modulation for continuous-variable quantum key distribution with N coherent states in a Gaussian lossy and noisy channel and investigate its performance against collective attacks. We find that discrete modulation protocols with more than eight states do not perform better than the eight-state protocol. Then, we study the improvement of this protocol by using a nondeterministic noiseless linear amplifier (NLA) on Bob's detection stage. Results indicate that a NLA with gain g can extend the maximum transmission distance by 50 log10g2km and can increase the maximal tolerable excess noise. With the reconciliation efficiency β, we find the gain of NLA has a maximal value defined as gmaxand by adjusting the gain to about βgmaxone can have the best improvement on secret key rate.
Nonlinear optical behavior of metal octaphenoxy phthalocyanines: effect of distortion caused by the central metal
Authors: Sanusi Sikiru O. , Antunes Edith , Nyokong Tebello
Published: July 2013

In this work, we investigated the nonlinear optical absorption properties of chloroaluminum, chlorogallium, chloroindium, zinc and lead octaphenoxy phthalocyanines in a dimethyl sulphoxide solution using 5 ns pulses at 532 nm. Using the Z-scan technique, the nonlinear optical properties and the excited state absorption cross-sections were determined by fitting the Z-scan data. The k value was the highest for Pb derivative at 211, making it the best nonlinear optical material. In terms of hyperpolarizability, Pb derivative (containing a larger central metal) also gave the largest value followed by aluminum derivative (containing a small central metal). The distortion of the ring caused by the central metal is used to explain the hyperpolarizability values. Large nonlinear absorption coefficient values, β eff , in the range of 3.558–4.763 × 10-9 cm.W-1 and low saturation fluence values, F sat between 21.5–38.5 mJ.cm-2, were obtained for these samples.
The Glycosylation of AGP and Its Associations with the Binding to Methadone
Authors: Behan Jennifer L. , Cruickshank Yvonne E. , Matthews-Smith Gerri , Bruce Malcolm , Smith Kevin D.
Published: July 2013

Methadone remains the most common form of pharmacological therapy for opioid dependence; however, there is a lack of explanation for the reports of its relatively low success rate in achieving complete abstinence. One hypothesis is thatin vivobinding of methadone to the plasma glycoprotein alpha-1-acid glycoprotein (AGP), to a degree dependent on the molecular structure, may render the drug inactive. This study sought to determine whether alterations present in the glycosylation pattern of AGP in patients undergoing various stages of methadone therapy (titration < two weeks, harm reduction < one year, long-term > one and a half years) could affect the affinity of the glycoprotein to bind methadone. The composition of AGP glycosylation was determined using high pH anion exchange chromatography (HPAEC) and intrinsic fluorescence analysed to determine the extent of binding to methadone. The monosaccharides galactose and N-acetyl-glucosamine were elevated in all methadone treatment groups indicating alterations in AGP glycosylation. AGP from all patients receiving methadone therapy exhibited a greater degree of binding than the normal population. This suggests that analysing the glycosylation of AGP in patients receiving methadone may aid in determining whether the therapy is likely to be effective.
Antifungal Applications of Ag‐Decorated Hydroxyapatite Nanoparticles
Authors: Zamperini C. A. , André R. S. , Longo V. M. , Mima E. G. , Vergani C. E. , Machado A. L. , Varela J. A. , Longo E.
Published: July 2013

Pure hydroxyapatite (HA) and hydroxyapatite decorated with silver (HA@Ag) nanoparticles were synthesized and characterized. The antifungal effect of HA@Ag nanoparticles in a distilled water solution was evaluated against Candida albicans. The origin of the antifungal activity of the HA@Ag is also discussed. The results obtained showed that the HA nanorod morphology remained the same with Ag ions decorations on the HA structure which were deposited in the form of nanospheres. Interaction where occurred between the structure and its defect density variation in the interfacial HA@Ag and intrafacial HA region with the fungal medium resulted in antifungal activity. The reaction mechanisms involved oxygen and water adsorption which formed an active complex cluster. The decomposition and desorption of the final products as well as the electron/hole recombination process have an important role in fungicidal effects.
Affine-Invariant Feature Extraction for Activity Recognition
Authors: Sadek Samy , Al-Hamadi Ayoub , Krell Gerald , Michaelis Bernd
Published: July 2013

We propose an innovative approach for human activity recognition based on affine-invariant shape representation and SVM-based feature classification. In this approach, a compact computationally efficient affine-invariant representation of action shapes is developed by using affine moment invariants. Dynamic affine invariants are derived from the 3D spatiotemporal action volume and the average image created from the 3D volume and classified by an SVM classifier. On two standard benchmark action datasets (KTH and Weizmann datasets), the approach yields promising results that compare favorably with those previously reported in the literature, while maintaining real-time performance.
Alcohol-Attributable Fraction of Ischemic Heart Disease Mortality in Russia
Authors: Razvodovsky Y. E.
Published: July 2013

Objective. The aim of the present study was to estimate the premature ischemic heart disease (IHD) mortality attributable to alcohol abuse in Russia on the basis of aggregate-level data of mortality and alcohol consumption. Method. Age-standardized sex-specific male and female IHD mortality data for the period 1980–2005 and data on overall alcohol consumption were analyzed by means of autoregressive integrated moving average (ARIMA) time series analysis. Results. The results of the analysis suggest that 41.1% of all male deaths and 30.7% of female deaths from IHD in Russia could be attributed to alcohol. The estimated alcohol-attributable fraction for men ranged from 24.0% (75+ age group) to 62.0% (15–29 age group) and for women from 20.0% (75+ age group) to 64.0% (30–44 age group). Conclusions. The outcomes of this study provide indirect support for the hypothesis that the high rate of IHD mortality in Russia may be related to alcohol, as indicated by a close aggregate-level association between number of deaths from IHD and overall alcohol consumption per capita.
Osteosarcoma: A Comparison of Jaw versus Nonjaw Localizations and Review of the Literature
Authors: van den Berg H. , Schreuder W. H. , de Lange J.
Published: July 2013

Purpose. It is assumed that osteosarcomas of the jaws mainly occur at older ages, whereas the most prominent sites, that is, the long bones, are more affected at ages <20. Jaw-localized tumors are less malignant and have lower metastatic spread rates.Patients and Methods. This study analyses the nationwide data of the Dutch Cancer Registry on osteosarcoma during the period from 1991 to 2010. Age-corrected incidence rates were calculated.Results. In 949, 38 patients had tumors in the maxilla and in 58 in the mandible. Median age for maxilla, mandible, and other localizations was 45.5, 49, and 23 years, respectively. Age-corrected incidence for osteosarcomas increased after a steep decline for the age cohorts from 20 to 60 years to nearly the same level as the younger patients. The incidence for maxillary lesions showed a steady increase from 0.46 to 1.60 per million over all age ranges; the highest incidence for mandibular lesions was found in the age cohort from 60 to 79 years. In respect to histology, no shifts for age were found, except for Paget’s disease-related osteosarcoma. In older patients, chemotherapy was omitted more often. Overall survival was similar for all age groups, except for extragnatic tumor patients in the age range of 60–79 years.Conclusions. Osteosarcomas have comparable incidences below the age of 20 as compared with ages >60 years. Poorer outcome in older people is likely due to refraining from chemotherapy.
Spectral Functions and Properties of Nuclear Matter
Authors: Danilenko V. A. , Gridnev K. A. , Kondratyev A. S.
Published: July 2013

The Green’s function method in the Kadanoff-Baym version provides a basic theory for nuclear dynamics which is applicable also to nonzero temperature and to nonequilibrium systems. At the same time, it maintains the basic many-body techniques of the Brueckner theory that makes reasonable a comparison of the numerical results of the two methods for equilibrium systems. The correct approximation to the spectral function which takes into account the widths of energy levels is offered and discussed, and the comparison of the values of binding energy in the two methods is produced.
Combining Electronic Tongue Array and Chemometrics for Discriminating the Specific Geographical Origins of Green Tea
Authors: Xu Lu , Yan Si-Min , Ye Zi-Hong , Fu Xian-Shu , Yu Xiao-Ping
Published: July 2013

The feasibility of electronic tongue and multivariate analysis was investigated for discriminating the specific geographical origins of a Chinese green tea with Protected Designation of Origin (PDO). 155 Longjing tea samples from three subareas were collected and analyzed by an electronic tongue array of 7 sensors. To remove the influence of abnormal measurements and samples, robust principal component analysis (ROBPCA) was used to detect outliers in each class. Partial least squares discriminant analysis (PLSDA) was then used to develop a classification model. The prediction sensitivity/specificity of PLSDA was 1.000/1.000, 1.000/0.967, and 0.950/1.000 for longjing from Xihu, Qiantang, and Yuezhou, respectively. Electronic tongue and chemometrics can provide a rapid and reliable tool for discriminating the specific producing areas of Longjing.
A Patient with Systemic Lupus Erythematosus Complicated by Neurological Symptoms of Toluene Poisoning
Authors: Isoda Kentaro , Takeuchi Tohru , Makino Shigeki , Hanafusa Toshiaki
Published: July 2013

We report a patient with systemic lupus erythematosus complicated by toluene poisoning. She had erythema, alopecia, arthralgia, and various neurological symptoms. Laboratory findings showed leukocytopenia, low levels of complements, and anti-dsDNA antibody. However, normal interleukin-6 level and IgG index of cerebrospinal fluid and brain magnetic resonance imaging and single photon emission computed tomography findings suggested that her neurological symptoms were caused by metabolic disorder but not neuropsychiatric systemic lupus erythematosus. Erythema, alopecia, and arthralgia improved rapidly after administration of prednisolone and tacrolimus, whereas neurological symptoms improved only gradually. Because of a history of exposure to toluene, her neurological symptoms were considered to be due to toluene poisoning. The differentiation of toluene poisoning from neuropsychiatric systemic lupus erythematosus based on symptoms is difficult because both induce various neuropsychiatric disorders. Laboratory findings of cerebrospinal fluid, radiological findings, and medical interview were useful for differentiation of toluene poisoning from neuropsychiatric systemic lupus erythematosus.
Concerted Action of ANP and Dopamine D1-Receptor to Regulate Sodium Homeostasis in Nephrotic Syndrome
Authors: Fernandes-Cerqueira Cátia , Sampaio-Maia Benedita , Quelhas-Santos Janete , Moreira-Rodrigues Mónica , Simões-Silva Liliana , Blazquez-Medela Ana M. , Martinez-Salgado C. , Lopez-Novoa Jose M. , Pestana Manuel
Published: July 2013

The edema formation in nephrotic syndrome (NS) is associated with a blunted response to atrial natriuretic peptide (ANP). The natriuretic effects of ANP have been related to renal dopamine D1-receptors (D1R). We examined the interaction between ANP and renal D1R in rats with puromycin aminonucleoside-induced NS (PAN-NS). Urinary sodium, cyclic guanosine monophosphate (cGMP) excretion, and D1R protein expression and localization in renal tubules were evaluated in PAN-NS and control rats before and during volume expansion (VE). The effects of zaprinast (phosphodiesterase type 5 inhibitor), alone or in combination with Sch-23390 (D1R antagonist), were examined in both groups. The increased natriuresis and urinary cGMP excretion evoked by acute VE were blunted in PAN-NS despite increased levels of circulating ANP. This was accompanied in PAN-NS by a marked decrease of D1R expression in the renal tubules. Infusion of zaprinast in PAN-NS resulted in increased urinary excretion of cGMP and sodium to similar levels of control rats and increased expression of D1R in the plasma membrane of renal tubular cells. Combined administration of Sch-23390 and zaprinast prevented natriuresis and increased cGMP excretion induced by zaprinast alone. We conclude that D1R may play a major role in the ANP resistance observed in PAN-NS.
Sensory Response Patterns in Nonverbal Children with ASD
Authors: Patten Elena , Ausderau Karla K. , Watson Linda R. , Baranek Grace T.
Published: July 2013

We sought to examine concurrent and longitudinal associations between sensory response patterns (i.e., hyperresponsiveness, hyporesponsiveness, and sensory seeking) and verbal status of young children with autism spectrum disorder (ASD) as a potential factor influencing the development of verbal communication. Seventy-nine children with ASD (verbal,n=29; nonverbal,n=50) were assessed using cross-sectional analyses (Study 1), and 14 children with ASD (verbal,n=6; nonverbal,n=8) were assessed using prospective longitudinal analyses (Study 2). Data were collected regarding sensory response patterns and verbal ability. Hyporesponsiveness and sensory seeking behaviors were associated with verbal status in both cross-sectional and longitudinal analyses; nonverbal children were more likely to demonstrate higher hyporesponsive and sensory seeking patterns. Hyperresponsiveness did not significantly differ between verbal and nonverbal groups in either design. Sensory hyporesponsiveness and seeking behaviors may be important factors hindering the development of functional verbal communication in children with ASD. Unusual sensory responsiveness can often be observed before the onset of speech and may yield important prognostic capabilities as well as inform early interventions targeting verbal communication or alternative communication options in young children with ASD.