bluuebunny/crossref_metadata_2025 huggingface dataset:
CO2 Capture by Calcined Dolomite in a Fluidized Bed: Experimental Data and Numerical Simulations
Authors: Di Felice Luca , Foscolo Pier U. , Gibilaro Larry
Published: April 2012

The capture of CO2 by particles of calcined dolomite in a gas-fluidized bed was investigated experimentally in a laboratory-scale reactor. Step-response experiments were performed to determine CaO conversion rates in the bed as a function of time and dolomite particle diameter. It was found that the CO2 capture dynamics in the fluidized bed itself could be extracted from the overall system response curves by making use of a blank testperformed under identical flow and temperature profile conditions but with no calcined dolomite present. A simple flow-with-reaction model of the process was proposed; it provided a good description of the transient behaviour in terms of an empirical transfer coefficient, which was found to depend linearly on dolomite particle diameter. A shrinking core model was then developed and applied, to evaluate the individual effect of chemical kinetics and pore diffusion on the global reaction rate. The chemical process was found to control the smallest particle size carbonation test, in very good agreement with the kinetic constant value proposed in literature (Bhatia and Perlmutter, 1983), whereas the diffusion coefficient, needed to describe CO2 uptake as particle grows, appeared to be a function of sorbent size: this points to the need of more sophisticated SRD (simultaneous reaction and diffusion) models to describe the real behaviour of systems at hand.
Investigation of Picolinic Acid Extraction by Trioctylamine
Authors: Tuyun Amaç Fatih , Uslu Hasan
Published: April 2012

Picolinic acid is a pyridine compound with a carboxyl side chain at the 2-position. It is an isomer of nicotinic acid, which has the carboxyl side chain at the 3-position. Picolinic acid acts as a chelating agent of elements such as chromium, zinc, manganese, copper, iron, and molybdenum in the human body. It is involved in phenylalanine, tryptophan, and alkaloid production, and for the quantitative detection of calcium. In this study, picolinic acids aqueous solution was extracted by a method reactive extraction. All experiments were reported on the extraction of picolinic acid by trioctylamine (TOA) dissolved in two different aliphatic hydrocarbons (n-octane and n-decane), two different alcohols (octan-1-ol and decan-1-ol), and two different ketones (diisobutyl ketone (DIBK) and octan-2-one), as well as single diluents. Experimental results of batch extraction experiments were calculated and reported as distribution coefficients (KD=C*PA/CPA ), loading factors (Z), and extraction efficiency (E). The highest synergistic extraction efficiency was found as 89.199 for TOA+ isoamyl alcohol extractant system with KD value of 8.259 and Z value of 0.530.
Intrinsic Mode Entropy Analysis of Tube-Wall Pressure Fluctuation Signals in the Kenics Static Mixer
Authors: Meng Hui-Bo , Liu Zhi-Qiang , Yu Yan-Fang , Xiong Qiang , Wu Jian-Hua
Published: April 2012

The multi-scale nonlinear hydrodynamics in Kenics Static Mixer (KSM) with 100 mm in diameter and 2 in aspect ratio was investigated in this work. The time series of tube-wall pressure fluctuation signals were measured at different flow rates ranged of 100~600 Lh-1 and at different axial positions in the range of 420~580 mm away from the cross-section of mixer inlet. It is difficult for composite signals to make an effective analysis by Sample Entropy (SampEn) based on a single scale. The complexity of tube-wall pressure fluctuation signals in a Kenics static mixer was investigated using Intrinsic Mode Entropy (IMEn) based on Sample Entropy algorithm and Empirical Mode Decomposition (EMD) method. Data sampling length and tolerance are optimized based on intrinsic mode entropy. Results of multi-scale analysis of pressure fluctuations indicated that the Sample entropy reaches maximum in the first scale and progressively decreases according to increase of the decomposed order. It is clear that the movement of high frequency component of the pressure signal is the most complicated and is rich in randomness. With the decomposition scales increasing, the complexity of signal decreases and approaches periodic motion eventually. The intrinsic mode entropy of the tube wall pressure signals in KSM has similar development tendencies in different flow rates. Besides, as the flow rates increased, the macro-scale vortexes play a more and more important role and guide the system to develop toward the stable state.
Sonochemical Degradation of Methylene Blue and P-Nitrophenol in Aqueous Medium
Authors: K. S Rajanandam , G.M Madhu , Thomas Ashly
Published: April 2012

The presence of dyes in aqueous system causes aesthetic pollution, hydrolysis or other chemical reactions leading to the formation of products which are non degradable, and accumulate in water. A number of methods have been devised for degradation of dyes in aqueous streams which can cater to the never ending necessities of water worldwide. The methods include biological treatment, chemical oxidation, electrochemical decomposition, photocatalytic and chemical coagulation, physical and physico-chemical treatment. These methods are successful to a certain extent. In the present work, an attempt was made towards the sonochemical degradation of azo dyes such as methylene blue and p-nitro phenol. Further sonication experiments were carried out in combination with advanced oxidation processes. Sonication was performed at 20 and 70 kW power ratings. Percentage degradation was found to increase with increase in power ratings. Degradation of azo dyes was improved in presence UV source. Maximum degradation was observed when sonication was carried out in presence of UV source and hydrogen peroxide which was used as an oxidant. Increase in dye concentration decreased degradation rate and decrease in pH (acid medium) increased the degradation rate.
Response Surface Methodology for Optimization of Epoxidized Trimethylolpropane Ester Synthesis from Palm Oil
Authors: Naidir Ferra , Yunus Robiah , Ramli Irmawati , Mohd. Ghazi Tinia I.
Published: April 2012

To improve the oxidative stability of the palm oil-based biolubricant, the fatty acid double bonds in palm oil-based trimethylolpropane ester (TMP ester) was converted into an oxirane ring via an in-situ epoxidation method. The epoxidized TMP ester was produced from a reaction between TMP ester and peracetic acid which was prepared in-situ by reacting glacial acetic acid with hydrogen peroxide in the presence of concentrated sulphuric acid. The response surface methodology was applied using a central composite design technique to optimize the conditions of the epoxidation reaction to produce the epoxidized TMP ester. The effects of four independent variables namely concentration of acetic acid (0-2 mol), concentration of hydrogen peroxide (1.5-9.5 mol), temperature of reaction (30-110°C) and reaction time (0.5-26.5 h) on the three dependent variables; percentage of oxirane oxygen, iodine value, and hydroxyl value were studied. A second-order polynomial multiple regression model was employed to predict the three dependent variables under optimum conditions of 0.59 mol of glacial acetic acid, 7.5 mol of hydrogen peroxide concentration, at temperature of 50°C and reaction times of 7 h. The optimum values of percentage of oxirane oxygen, iodine value, and hydroxyl value were 4.01%, 1.94%, and 0.43% respectively. The analysis of variance yielded a high coefficient of determination value of 0.9395-0.9880, hence indicating the fitness of the second-order regression model to the experimental data.
Self-Cleaning Tests of Zn-Fe/Anatase-Coated Glass Plates under Direct and Diffuse Sunlight
Authors: Medina-Valtierra Jorge , Ramírez-Ortiz Jorge , Frausto-Reyes Claudio
Published: April 2012

Thin films of anatase (TiO2) doped with 1 wt. percent of zinc ferrite (ZnFe2O4) were formed on glass plates by deposition of a sol-gel mixture using an ultra-spinning technique. After the preparation, the TiO2 films with a thickness of 168-232 nm were investigated with respect to their UV absorption capability and photo-degradation of organic molecules. Microscope observations of the surface of TiO2 films showed that they exhibit a micro-granular surface. To test the self-cleaning properties of the doped TiO2 films, a layer of fluoranthene of around 6.5 mg was sprayed over the glass and then exposed to direct or diffuse solar radiation. While the coated-glass transparency was totally recovered at 88 h of direct solar exposure for the undoped anatase film, the covering of fluoranthene on the 1 wt. percent ZnFe2O4-doped TiO2 film was degraded totally at 52 h of exposure time. As complementary experiments, the same glass plates with metal oxide-doped anatase films, after spraying with a similar layer of the organic contaminant, were placed under diffuse sunlight. In a typical experiment, the covering of fluoranthene was degraded almost 100 percent at an exposure time of 48 days and the transparency of glass plates was recovered totally at 55 days of indirect solar exposure. A correlation was found between the weight losses of the solid contaminant and the intensity of the Raman vibration at 672 cm-1. It was found that under diffuse solar irradiation is possible to remove completely a fluoranthene layer generating an expected application of these active surfaces under extreme conditions.
Effects of Lanthanum on the Structure and the Catalytic Performance of Ni/Al2O3 Catalysts for the Hydrotreating of Crude 2-Ethylhexanol
Authors: Yang Renchun , Li Xiaogang , Wu Junsheng , Zhang Xin , Zhang Zhihua , Wang Luhai
Published: April 2012

To study the effects of La modifier on Ni/Î³-Al2O3 catalysts for the hydrotreating of crude 2-ethylhexanol, four samples with various La contents were prepared by the hydrothermal deposition method and characterized by ICPâAES, XRD, XPS, TPR, and H2 chemisorption. It was found that the number of catalytic active sites of the four samples with a similar Ni loading follows the order: Ni/La0/Al (13.2Î¼mol gcat-1) < Ni/La0.5/Al (15.1Î¼mol gcat-1) < Ni/La2.0/Al (15.8Î¼mol gcat-1) < Ni/La1.0/Al (17.1Î¼mol gcat-1). The results indicate that the catalyst modified by an appropriate La can obtain more active centers and higher hydrogenation performance because it possesses a higher surface Ni content and an appropriate Ni dispersion degree.
In Quest of Judicial Independence for Protecting Private Property: Evidence from Constitutional Review in South Korea
Authors: Miah Md. Dulal
Published: April 2012

The sanctity of private property is an essential requirement for economic prosperity of an economy. However, in some countries, the ruler who is supposed to ensure the supremacy of private property is sometimes seen expropriating private property. In this circumstance, judicial independence is vastly required to restrict grabbers from attenuating property rights. Because court plays an important role not only in interpreting the law but also bears the responsibility to ensure the rule of law. This paper first, looks for the judicial independence in South Korea through the lens of constitutional review. In relation to property rights, constitutional reviews were required if any clause in the existing laws goes subversive to private property. The paper then analyzes some widely cited cases relevant to property rights issue before and after the establishment of the Constitutional Court in Korea. The analysis shows that in the pre-democratic era the court’s activities were frequently intervened by the government and hence the court did not possess sufficient power to uphold the spirit of private property. However, in the post-democratic regime, the court has been bestowed with adequate discretion and therefore, property rights are better protected.
Law and Finance: What Matters? Hong Kong as a Test Case
Authors: Yeung Horace , Huang Flora Xiao
Published: April 2012

This paper, using Hong Kong as a test case, challenges one conventional theory and confirms another one in law and finance study: (i) legal families in relation to stock market development; (ii) transplant effect of foreign laws. Economists, most notably La Porta and colleagues, allege that common law systems can offer superior investor protection and thereby facilitate the rise of financial markets. Undeniably, the legal system of Hong Kong, which was inherited from England, belongs to the common law family and is widely considered as one of Hong Kong’s advantages. Nonetheless, the high concentration of family ownership among Hong Kong companies implies that its system is not entirely Anglo-Saxon. Moreover, legal scholars, most notably Pistor and colleagues, claim that the import of laws from a developed system (legal transplantation) will have little impact unless there is such a demand in the first place. Interestingly, for Hong Kong, the transformation of a small fishing village in the mid-nineteenth century to a financial service-oriented economy nowadays is an illustration of the existence of demand in corporate and financial laws. By absorbing the nutrients from English legal traditions, American style of intense public enforcement and the flexibility of Chinese family businesses, Hong Kong has successfully established itself as one of the most crucial financial centers in the world.
Ethnically Diverse Faculty in Higher Ed: Belonging, Respect, and Role as Cultural Broker
Authors: Vázquez-Montilla Elia , Wilder Lynn K. , Triscari Robert
Published: April 2012

The authors have completed a pilot study of the state of diverse faculty in higher education in the United States. Inquiries included the areas of belonging (if and how they developed a sense of belonging), professional respect (how colleagues regarded their achievements), and the role of cultural broker (how they functioned as cultural brokers in positions of influence and with diverse students). Initial results suggest that some diverse faculty members believe that racism is alive and well in higher education today. Others emphasize the challenge of adapting and belonging in higher education while retaining their unique cultural voices and having those voices be heard and utilized in movement toward cultural pluralism in the institutional environment of higher education.
Estrutura metabólica e genética de comunidades bacterianas em solo de cerrado sob diferentes manejos
Authors: Souza Leandro Moraes de , Schlemmer Franciele , Alencar Priscila Martins , Lopes André Alves de Castro , Passos Samuel Ribeiro , Xavier Gustavo Ribeiro , Fernandes Marcelo Ferreira , Mendes Ieda de Carvalho , Reis Junior Fábio Bueno dos
Published: April 2012

O objetivo deste trabalho foi avaliar a estrutura metabólica e genética de comunidades bacterianas em Latossolo de cerrado sob vegetação nativa ou cultivado em sistema de rotação soja/milho sob preparo convencional e plantio direto. Foram utilizadas microplacas EcoPlate para determinar o perfil e a diversidade metabólica das comunidades bacterianas, e eletroforese em gel com gradiente desnaturante (DGGE) para avaliar a estrutura genética. O teste estatístico de Mantel foi utilizado para avaliar a relação entre a estrutura metabólica e a genética. A comunidade bacteriana sob vegetação nativa apresentou perfil metabólico diferente do encontrado em solos cultivados. No solo cultivado com soja sob preparo convencional, o padrão de utilização das fontes de carbono diferenciou-se dos demais tratamentos. Com base nos resultados de DGGE, a comunidade bacteriana sob vegetação nativa apresentou 35% de similaridade com as de áreas cultivadas. Foram formados grupos distintos de comunidades bacterianas do solo entre as áreas sob preparo convencional e plantio direto. Houve correlação significativa de 62% entre as matrizes geradas pelas microplacas EcoPlate e pela DGGE. Variações no perfil metabólico estão relacionadas às variações na estrutura genética das comunidades bacterianas do solo.
Psychiatric Symptoms and Quality of Life in Systemic Sclerosis
Authors: Mura G , Bhat Krishna M , Pisano A , Licci G , Carta MG
Published: April 2012

Introduction:

Systemic sclerosis (SSc) is a rare conjunctive tissue disorder characterized by fibrosis of the skin and internal organs, and vascular obliteration phenomena. Patients with SSc often experience elevated symptoms of psychological distress, determined by the disfiguration, the pain, the fatigue sensation, and the difficult in daily life occupations. The characteristics of the disease may influence the perceived quality of life (QoL) in people with SSc.

Methods:

This is a narrative review aiming to define the amount of impairment of Quality of Life in patients with Systemic Sclerosis and the component of this impairment due to depressive or other psychiatric symptoms. The search of the significant articles was carried out in PubMed for the key words “Psychiatric symptoms and Systemic Sclerosis”; “Quality of life and Systemic Sclerosis”; “Depressive Disorders and Systemic Sclerosis”.

Results:

Psychiatric symptoms are frequents in patients with SSc, but pain, fatigue, disability, body changes don’t appear to explain the high prevalence of psychiatric comorbidity in SSc. Many studies founded a significant impairment in SSc patients’ QoL, and despite the undeniable correlation between physical symptoms and SSc patients’ QoL, mental health was found significantly impaired.

Discussion:

The high rate of depression seems to strictly correlate with poor quality of life, and this finding needs more research to establish the cause of such a correlation. Patients’ point of view regarding their health-related QoL could help physicians to enlarge the knowledge about physical and mental correlates of the disease, and to fit therapies as patient required. Particular attention must be given to provide the patient with correct information, in order to mitigate the anxious state on disease course, and to enhance coping skills of the patients.
Editorial - Polymer-Derived Ceramics (PDCs)
Authors: Chu Zengyong
Published: April 2012

Polymer-derived ceramics (PDCs) are the ceramics
derived from preceramic polymers by a pyrolysis process,
which makes them much different from those by traditional
sintering techniques. The PDCs present a growing interest in the ceramic science for their much suitability in (i)
elaborating complex forms (fibers, films, porous ceramics,
etc...), (ii) developing ceramic micro/nanostructures, (iii)
controlling ultimate compositions and (iv) producing
amorphous ceramics stable at ultra-high temperatures. The
most attractive point of the PDCs lies in the tailoring the
complex microstructure and functional properties easily with
the aid of molecular design and polymer synthesis. To some
extent, their life energy is rooted in the polymers.

In this special issue, papers were organized from a
viewpoint of the effect of polymer structures on the
functional properties of the PDCs.
Synthesis and Electronical Property of Antimony-Substituted Polysilanes and Iron-Substituted Polysilanes
Authors: Xing Xin , Gguo Aiqing , Liu Lin , Li Xiaodong
Published: April 2012

Novel polysilanes, antimony-substituted polysilanes (APS) and iron-substituted polysilanes (IPS), were
synthesized and characterized in this paper. To prepare these new metal-containing polymers, high reactive polymers,
polymethylsilane (PMS) and polychloromethylsilane (PCMS) were used as mother polymers. The APS was synthesized
directly by the reaction of PMS with SbCl3, while IPS was obtained from the reaction of PCMS with Na2Fe(CO)4 in the
solvent of n-hexane. The polymers were characterized by elemental analysis, FT-IR, 1H-NMR, 29Si CP/MAS NMR, GPC,
and UV. The number average molecular weights of these two polymers are between 1400 and 1600. These polymers show
good semiconductive properties, whose intrinsic conductivities are in the range of 10-8~10-7S/cm, and can be increased
to10-5S/cm after being doped with iodine.
Antibiotic Prophylaxis with Quinolones in Afebrile Neutropenic Patients: Is there Enough Evidence for Mortality Effect?
Authors: Fernandes Cota Glaucia , Fereguetti Tatiani , Roberto de Sousa Marcos
Published: April 2012

Febrile neutropenia causes significant morbidity and mortality in patients receiving antineoplastic
chemotherapy. During the last decade, some trials have shown reduction in febrile episodes and bacteraemia with
antibiotic prophylaxis. On the other hand, the emergence of fluoroquinolone-resistant bacteria in units practicing
quinolones prophylaxis has been described and there is justified concern about the implications of this fact. Recent
published guidelines now recommend quinolones prophylaxis for patients with neutropenia expected to last as least 7
days. They are based in a meta-analysis of placebo-controlled or no treatment-controlled trials of quinolone prophylaxis,
which demonstrated risk reduction in mortality among drug treated recipients. In contrast, previous meta-analyses and the
two major trials with two thirds of the number of patients of the largest meta-analysis failed to show this survival
advantage. Using two sensitive tests, Egger's and Trim and Fill methods, we found a “small study effect” which acts
exaggerating and making the result positive when they are probably neutral. In spite of the considerable number of trials
and reviews involving prophylactic antibiotics for neutropenic patients, available evidence is hypothesis generator but not
sufficient to state there is mortality benefit.
Spatial Variation in Personal Exposure of Parking Attendants to Traffic Emissions in an Urban Conurbation
Authors: Tiwary A. , Namdeo A. , Pareira A.
Published: April 2012

This study presents temporal and spatial variations in personal exposure of parking attendants in a busy
conurbation in the northern part of the UK. Two traffic related pollutants - carbon monoxide (CO) and ultrafine
particulates (UFP), mainly associated with urban drives, have been considered for two distinct locations- one, in the city
centre and the other in a suburban area of Leeds, a prominent city in West Yorkshire. The monitoring of pollutants was
conducted while parking attendants carried out their duty along the streets during different times of the year to capture the
seasonal fluctuations.

Our results show a wide variation in exposure levels for both CO and UFP, marked both by seasonal and daily
characteristics. There seems to be considerable variations in exposure levels depending on the location of the parking
attendants with respect to traffic activity. Specifically, the level of exposure closer to market areas within the city centre,
despite located in open spaces but closer to congested streets were found to be much higher owing to frequent stopping,
stopping and idling of cars in search of parking spaces. This demonstrates the merit in setting up transport interchanges
and park-and-ride schemes away from busy streets to ameliorate the exposure levels.
Hajdegerova promena tradicionalnog razumevanja coveka - jezik i intencionalnost
Authors: Popovic Una
Published: April 2012

(nemacki) In diesem Versuch ist der Begriff des Menschens in Martin Heideggers Philosophie in der Perspektive seiner ?berwindung bearbeitet. Der Mensch ist erstens als Begriff verstanden, weil solche Weise der Bearbeitung spezifische M?glichkeiten bietet, die Grundmotive und Grundlinien dieser Philosophie im kurz zu umfassen. Der spezifischen Ver?nderung dieser Begriff von Mensch ins Dasein ist mit dem Ziel akzentuiert, die Wandlung der Weisen des Denkens, und nich nur des Begriffs als solcher darzulegen. Im Vergleich mit den Begriffen der Selbstbewu?tsein und Reflexion, die seit Neuzeit Philosophie markiert, ist dieses Verstehen und Denken des Subjekts mit Hilfe der Intentionalit?t verweitert und konzeptiert. Metapher der Kehre ist das zentrale Punkt dieser Vergleichung. Gleichzeitig untersuchen wir die Stellung der Sprache, als einer der wichtigsten Motiven Heideggers Philosophie und auch als Mittel der Erleuterung der Erkentnissm?glichkeiten ?berhaupt.
Rationality and deliberative democracy
Authors: Milojevic Miljana
Published: April 2012

In this paper I will give a short description of deliberative democracy, its advantages over the aggregative model of democracy and its strategies for overcoming the obstacles which the social choice theory puts before the defenders of democracy. I will continue with the argument that the aim of deliberative democracy should not be reaching the consensus or unanimity, but obtaining preference single-peakedness. For, there is a practical impossibility of consensus reaching and the single-peakedness criterion is sufficient for prevention against the 'paradoxes of democracy'. Through the analysis of the given explanations of the ways in which deliberation can lead to the realization of single-peakedness, I will make an attempt to defend the position which holds that acquiring singlepeakedness, in the impartial conditions of deliberation, is a goal that is as equally unreachable as is reaching of the consensus because of the multidimensionality of the alternative evaluation criterion. However, I will show that even if deliberation does not necessarily lead to a preference single-peakedness, which would prevent Condorcet's paradox from happening, in accordance with Arrow's ethical conditions of democratic choice, it nevertheless reveals why these paradoxes are created in the first place, and it is providing us with an insight into how we can redefine the alternatives so that we can obtain a true single-peakedness of our preferences.
Two harmonizers of the epoch: Hegel and Tocqueville: And constitutioning of wide civil political centre
Authors: Cveticanin Neven
Published: April 2012

The text is elaborating the work of two philosophers - Hegel and Tocqueville in context of assembling of political liberal centre. Both of them will take the role of synthesizers of epochal movements, as well as 'harmonizers' of the Epoch, hereafter they will adjust some of the ideas brought by French Revolution to some of the conservative values pre-dating it. Both of them will take part in project of constituting of wide civil political centre by enriching the classical Locke-Kant's liberal centre with certain values (Hegel by adding the concept of bureaucratic state, Tocqueville by adding the concept of intermediate democracy) which will cause it to transform in wide medium that will soon absorb parts of Left and Right, making them to be left and right centre. This wide civil political centre, which will include the left and right centre in itself, will become truly dominant nowadays so Hegel and Tocqueville can be understood as ideological precursors of modern political actions.
Pionirski rad Mihaila Markovica
Authors: Maric Ilija
Published: April 2012

nema
The figures of (a)symmetry: 'Pirates' and the world as a closed commercial state
Authors: Bojanic Petar
Published: April 2012

My intention is not to simply evoke Schmitt's critique of Kant's ideas concerning preemptive war and the unjust enemy - as we all know, these ideas were not Kant's nor is their critique original; after all, both Kant and Schmitt are simply brilliant compilers in international law - rather, I want to preliminarily demonstrate that every project concerning the constitution of an empire, league of nations or world government (or world governance) implies a paradoxical existence of an ambiguous 'exterior' (outside, without). It seems that the existence (or nonexistence) of something 'outside' of the world or 'outside' of borderless sovereignty, is a precondition for any theory of empire. .
Form as an expression of function
Authors: Draskic-Vicanovic Iva
Published: April 2012

The paper offers an analysis of the aesthetic category to prepon, suitability, from an early antique period to contemporary revitalization of the same notion under the new name - function. The twentieth century architecture is the place of rebirth of the aesthetic category that gave intonation to the concept of beauty in pre - philosophical antique Greece, as well as to the philosophy of Socrates, Plato and Xenophon. Author's main theses are that the architecture is natural and logical birthplace of to prepon, that two main streams in contemporary architecture: organicism and geometrical rationalism have the same key notion in common - function and that suitability, or function as aesthetic category can be treated as a prysm for the central currents in contemporary art.
Unintended Consequences of LIFO Repeal: The Case of the Oil Industry
Authors: Guenther David A. , Sansing Richard C.
Published: April 2012

This study examines the effect on firm value of repealing the last-in, first-out (LIFO) inventory method for tax purposes. Our model extends prior literature by determining quantities and prices in equilibrium, rather than specifying them exogenously. We find that LIFO repeal could increase the future after-tax cash flows of firms that had used LIFO, because the higher tax costs associated with FIFO result in lower equilibrium quantities and higher equilibrium output prices, which increase pretax cash flows. We illustrate our model by examining inventory methods used by firms in the oil industry.
Curative Onyx embolization of tentorial dural arteriovenous fistulas
Authors: Puffer Ross C. , Daniels David J. , Kallmes David F. , Cloft Harry J. , Lanzino Giuseppe
Published: April 2012

Object

The authors conducted a study to review their experience with tentorial dural arteriovenous fistulas (DAVFs) treated with transarterial endovascular embolization in which Onyx was used.

Methods

The authors reviewed prospectively collected data in 9 patients with tentorial DAVFs treated with Onyx embolization between 2008 and 2011. Information reviewed included clinical presentation, angiographic features, treatment, and clinical and radiologically documented outcome. Clinical follow-up was available in every patient. Radiological follow-up studies were available in 8 of 9 patients (mean follow-up 4.6 months).

Results

Six of 9 patients had complete angiographic obliteration (in 5 this was confirmed by a follow-up angiogram obtained 3–6 months later), and 2 patients had near-complete obliteration (faint filling of the venous drainage in the late venous phase). One patient had partial obliteration and required surgical disconnection. In all patients with complete obliteration, transarterial embolization was performed through the posterior branch of the middle meningeal artery. There were no procedural complications, and no morbidity or mortality resulted from Onyx embolization.

Conclusions

Transarterial Onyx embolization is a valid, effective, and safe alternative to surgical disconnection in many patients with tentorial DAVFs. The presence of an adequate posterior branch of the middle meningeal artery is critical to achieve a microcatheter position distal enough to increase the likelihood of complete obliteration.
Surgical treatment of Type I spinal dural arteriovenous fistulas
Authors: Ropper Alexander E. , Gross Bradley A. , Du Rose
Published: April 2012

Object

Type I spinal dural arteriovenous fistulas (SDAVFs) are low-flow vascular shunts fed by radicular arteries in patients who most often present with myelopathy. Although some fistulas are amenable to endovascular embolization, nearly all can be treated with direct microsurgical obliteration.

Methods

The authors reviewed their experience in treating 214 craniospinal arteriovenous malformations and/or fistulas over the last 8 years. Of these, 19 were spinal (9%), of which 15 (79%) were Type I SDAVFs. The authors reviewed the patients' epidemiological characteristics, presenting symptoms, and SDAVF angioarchitecture in all cases. They subsequently analyzed surgical obliteration rates and outcomes of all 11 patients who underwent fistula microsurgical obliteration.

Results

In all patients who underwent microsurgical treatment, complete angiographic obliteration of the fistula was achieved. At follow-up, 10 (91%) of 11 patients exhibited improvement, 1 patient (9%) was the same, and no patients were worse. Specifically, 8 (73%) of 11 patients had improvement in strength and sensation, 5 (71%) of 7 had improvement of bowel/bladder function, and 3 (60%) of 5 had improvement of preoperative paresthesias. There were no wound infections, CSF leaks, or permanent neurological deficits.

Conclusions

Microsurgical treatment of SDAVF provides direct access to the fistula point, allowing for high obliteration rates with excellent long-term improvement of preoperative deficits and limited periprocedural complications.
Management of tandem occlusion stroke with endovascular therapy
Authors: Dababneh Haitham , Guerrero Waldo R. , Khanna Anna , Hoh Brian L. , Mocco J
Published: April 2012

Object

Approximately 25% of patients with middle cerebral artery (MCA) occlusion will have a concomitant internal carotid artery (ICA) occlusion, and 50% of patients with an ICA occlusion will have a proximal MCA occlusion. Cervical ICA occlusion with MCA embolic occlusion is associated with a low rate of recanalization and poor outcome after intravenous thrombolysis. The authors report their experience with acute ischemic stroke patients who suffered tandem ICA/MCA (TIM) occlusions and underwent intravenous thrombolysis followed by extracranial ICA angioplasty and intracranial MCA mechanical thrombectomy.

Methods

In a retrospective analysis of their stroke database (2008–2011), the authors identified 2 patients with TIM occlusion treated with intravenous thrombolysis followed by extracranial ICA angioplasty and intracranial mechanical thrombectomy. They examined early neurological improvement defined by a greater than 10-point reduction of National Institutes of Health Stroke Scale (NIHSS) score and an improved modified Rankin Scale (mRS) score at 60 days. Successful recanalization based on thrombolysis in cerebral infarction (TICI) score of 2 or 3 was also evaluated.

Results

In both patients a TICI score of 2b or 3 was achieved, signifying successful recanalization. In addition, both patients had a reduction in the NIHSS score by greater than 10 points and an mRS score of 0 at 60 days.

Conclusions

Tandem occlusions of the cervical ICA and MCA may be successfully treated using the multimodality approach of intravenous thrombolysis followed by extracranial ICA angioplasty and intracranial mechanical thrombectomy.
Clinical presentation and prognostic factors of spinal dural arteriovenous fistulas: an overview
Authors: Fugate Jennifer E. , Lanzino Giuseppe , Rabinstein Alejandro A.
Published: April 2012

Spinal dural arteriovenous fistulas (AVFs), the most common type of spinal cord vascular malformation, can be a challenge to diagnose and treat promptly. The disorder is rare, and the presenting clinical symptoms and signs are nonspecific and insidious at onset. Spinal dural AVFs preferentially affect middle-aged men, and patients most commonly present with gait abnormality or lower-extremity weakness and sensory disturbances. Symptoms gradually progress or decline in a stepwise manner and are commonly associated with pain and sphincter disturbances. Surgical or endovascular disconnection of the fistula has a high success rate with a low rate of morbidity. Motor symptoms are most likely to improve after treatment, followed by sensory disturbances, and lastly sphincter disturbances. Patients with severe neurological deficits at presentation tend to have worse posttreatment functional outcomes than those with mild or moderate pretreatment disability. However, improvement or stabilization of symptoms is seen in the vast majority of treated patients, and thus treatment is justified even in patients with substantial neurological deficits. The extent of intramedullary spinal cord T2 signal abnormality does not correlate with outcomes and should not be used as a prognostic factor.
Magnetic resonance imaging/magnetic resonance angiography fusion technique for intraoperative navigation during microsurgical resection of cerebral arteriovenous malformations
Authors: Bekelis Kimon , Missios Symeon , Desai Atman , Eskey Clifford , Erkmen Kadir
Published: April 2012

Object

Microsurgical resection of arteriovenous malformations (AVMs) is facilitated by real-time image guidance that demonstrates the precise size and location of the AVM nidus. Magnetic resonance images have routinely been used for intraoperative navigation, but there is no single MRI sequence that can provide all the details needed for characterization of the AVM. Additional information detailing the specific location of the feeding arteries and draining veins would be valuable during surgery, and this detail may be provided by fusing MR images and MR angiography (MRA) sequences. The current study describes the use of a technique that fuses contrast-enhanced MR images and 3D time-of-flight MR angiograms for intraoperative navigation in AVM resection.

Methods

All patients undergoing microsurgical resection of AVMs at the Dartmouth Cerebrovascular Surgery Program were evaluated from the surgical database. Between 2009 and 2011, 15 patients underwent surgery in which this contrast-enhanced MRI and MRA fusion technique was used, and these patient form the population of the present study.

Results

Image fusion was successful in all 15 cases. The additional data manipulation required to fuse the image sets was performed on the morning of surgery with minimal added setup time. The navigation system accurately identified feeding arteries and draining veins during resection in all cases. There was minimal imaging-related artifact produced by embolic materials in AVMs that had been preoperatively embolized. Complete AVM obliteration was demonstrated on intraoperative angiography in all cases.

Conclusions

Precise anatomical localization, as well as the ability to differentiate between arteries and veins during AVM microsurgery, is feasible with the aforementioned MRI/MRA fusion technique. The technique provides important information that is beneficial to preoperative planning, intraoperative navigation, and successful AVM resection.
Absence of abnormal vessels in the subarachnoid space on conventional magnetic resonance imaging in patients with spinal dural arteriovenous fistulas
Authors: Miller Timothy R. , Eskey Clifford J. , Mamourian Alexander C.
Published: April 2012

Spinal dural arteriovenous fistula (DAVF) is an uncommon condition that can be difficult to diagnose. This often results in misdiagnosis and treatment delay. Although conventional MRI plays an important role in the initial screening for the disease, the typical MRI findings may be absent. In this article, the authors present a series of 4 cases involving patients with angiographically proven spinal DAVFs who demonstrated cord T2 prolongation on conventional MRI but without abnormal subarachnoid flow voids or enhancement. These cases suggest that spinal DAVF cannot be excluded in symptomatic patients with cord edema based on conventional MRI findings alone. Dynamic Gd-enhanced MR angiography (MRA) was successful in demonstrating abnormal spinal vasculature in all 4 cases. This limited experience provides support for the role of spinal MRA in patients with abnormal cord signal and symptoms suggestive of DAVF even when typical MRI findings of a DAVF are absent.
Comparative analysis of spinal extradural arteriovenous fistulas with or without intradural venous drainage: a systematic literature review
Authors: Takai Keisuke , Taniguchi Makoto
Published: April 2012

Object

Spinal arteriovenous malformations (AVMs) are classified into types according to anatomical characteristics: dural arteriovenous fistulas (AVFs), intramedullary AVMs, perimedullary AVFs, and extradural AVFs. Spinal extradural AVFs are much rarer than other types of spinal AVMs, and the available literature on this clinical entity has been based only on case reports or small case series. To investigate the clinical characteristics of patients with spinal extradural AVFs, the authors systematically reviewed the associated literature in the MRI era.

Methods

The PubMed database was searched for all relevant English-language case reports and case series published from 1990 to 2011. The clinical differences between Type A with and Type B without intradural venous drainage were statistically compared, especially regarding clinical features and angiographic and MRI findings.

Results

Forty-five cases of spinal extradural AVFs were found. Type A spinal extradural AVFs were diagnosed in patients with a significantly older age (mean 63.5 years) as compared with Type B AVFs (mean 34.3 years, p < 0.0001). Most cases of Type A spinal extradural AVFs exhibited a diffuse high signal intensity of the spinal cord on T2-weighted MR images and no mass effect (p < 0.0001), and they commonly occurred in the thoracolumbar and lumbar regions (p < 0.0001). On the other hand, cases of Type B lesions exhibited a normal signal intensity of the cord with severe mass effect due to an enlarged extradural venous plexus, and they commonly occurred in the cervical and upper thoracic regions (p < 0.0001), frequently in patients with neurofibromatosis Type 1 (p = 0.049). Because Type B AVFs consisted of high-flow, multiple complex anastomoses between arteries and the epidural venous plexus, patients with these lesions tended to undergo multisession treatments, and the rate of partial AVF occlusion was significantly higher than for Type A AVFs (p = 0.018), although there was no difference in symptom outcomes between the 2 groups.

Conclusions

To the best of the authors' knowledge, a comparative analysis of the clinical differences in patients with extradural AVFs with or without intradural venous drainage has yet to be described in the literature. They concluded that in the diagnosis of spinal extradural AVF, evaluation of intradural venous drainage is important because the cause of myelopathy determines the treatment goals.
Spinal dural arteriovenous fistulas: outcome and prognostic factors
Authors: Cenzato Marco , Debernardi Alberto , Stefini Roberto , D'Aliberti Giuseppe , Piparo Maurizio , Talamonti Giuseppe , Coppini Matteo , Versari Pietro
Published: April 2012

The aim of this study is to review the clinical outcome of patients treated for spinal dural arteriovenous malformations and investigate the presence of pretreatment indicators of outcome after short- and midterm follow-up. The authors retrospectively reviewed the records of 65 consecutive patients treated either surgically or endovascularly in 3 neurosurgery departments between 1989 and 2009. After treatment, 80% of patients reported improvement of at least 1 symptom. Motor symptoms improved more than sensory disorders, pain, or sphincter impairment. Spinal dural arteriovenous fistulas at the thoracic level, and in particular at the lower level, responded better than those in other spinal areas. Spinal dural arteriovenous fistula is a rare pathology with a malignant course that should be treated aggressively. This study appears to confirm that neurological status before treatment, anatomical location of the fistula, and symptoms at presentation are all factors that can predict outcome. Early diagnosis of spinal dural arteriovenous malformations in the lower thoracic area in patients with an Aminoff scale score < 3 was associated with the most favorable outcome.
Carotid-cavernous fistulas
Authors: Ellis Jason A. , Goldstein Hannah , Connolly E. Sander , Meyers Philip M.
Published: April 2012

Carotid-cavernous fistulas (CCFs) are vascular shunts allowing blood to flow from the carotid artery into the cavernous sinus. The characteristic clinical features seen in patients with CCFs are the sequelae of hemodynamic dysfunction within the cavernous sinus. Once routinely treated with open surgical procedures, including carotid ligation or trapping and cavernous sinus exploration, endovascular therapy is now the treatment modality of choice in many cases. The authors provide a review of CCFs, detailing the current classification and clinical management of these lesions. Therapeutic options including conservative management, open surgery, endovascular intervention, and radiosurgical therapy are presented. The complications and treatment results as reported in the contemporary literature are also reviewed.
Recurrence of “cured” dural arteriovenous fistulas after Onyx embolization
Authors: Adamczyk Peter , Amar Arun Paul , Mack William J. , Larsen Donald W.
Published: April 2012

Endovascular embolization with Onyx has been increasingly used to treat intracranial and spinal dural arteriovenous fistulas (DAVFs). Several case series have been published in recent years reporting high DAVF cure rates with this technique. Although it is seldom reported, DAVF recurrence may occur despite initial “cure.” The authors present 3 separate cases of a recurrent DAVF after successful transarterial Onyx embolization. Despite adequate Onyx penetration into the fistula and draining vein, these cases demonstrate that DAVF recanalization may reappear with filling from previous or newly recruited arterial feeders. Other published reports of DAVF recurrence are examined, and potential contributory factors are discussed. These cases highlight the need for awareness of this possible phenomenon and suggest that follow-up angiography should be considered in patients treated with catheter embolization.
Iatrogenic dural arteriovenous fistula and aneurysmal subarachnoid hemorrhage
Authors: Vadivelu Sudhakar , Xin Xin , Loven Tina , Restrepo Guillermo , Chalif David J. , Setton Avi
Published: April 2012

The authors present the case of a patient who presented acutely with aneurysmal subarachnoid hemorrhage (SAH) and a contralateral iatrogenic dural arteriovenous fistula (DAVF). Diagnostic angiography was performed, revealing a right-sided middle cerebral artery (MCA) aneurysm and a left-sided DAVF immediately adjacent to the entry of the ventriculostomy and bur hole site. A craniotomy was performed for clipping of the ruptured MCA aneurysm, and the patient subsequently underwent endovascular obliteration of the DAVF 3 days later. The authors present their treatment of an iatrogenic DAVF in a patient with an aneurysmal SAH, considerations in management options, and a literature review on the development of iatrogenic DAVFs.
T-Cell Mediated Immune Responses Induced in ret Transgenic Mouse Model of Malignant Melanoma
Authors: Abschuetz Oliver , Osen Wolfram , Frank Kathrin , Kato Masashi , Schadendorf Dirk , Umansky Viktor
Published: April 2012

Poor response of human malignant melanoma to currently available treatments requires a development of innovative therapeutic strategies. Their evaluation should be based on animal models that resemble human melanoma with respect to genetics, histopathology and clinical features. Here we used a transgenic mouse model of spontaneous skin melanoma, in which the ret transgene is expressed in melanocytes under the control of metallothionein-I promoter. After a short latency, around 25% mice develop macroscopic skin melanoma metastasizing to lymph nodes, bone marrow, lungs and brain, whereas other transgenic mice showed only metastatic lesions without visible skin tumors. We found that tumor lesions expressed melanoma associated antigens (MAA) tyrosinase, tyrosinase related protein (TRP)-1, TRP-2 and gp100, which could be applied as targets for the immunotherapy. Upon peptide vaccination, ret transgenic mice without macroscopic melanomas were able to generate T cell responses not only against a strong model antigen ovalbumin but also against typical MAA TRP-2. Although mice bearing macroscopic primary tumors could also display an antigen-specific T cell reactivity, it was significantly down-regulated as compared to tumor-free transgenic mice or non-transgenic littermates. We suggest that ret transgenic mice could be used as a pre-clinical model for the evaluation of novel strategies of melanoma immunotherapy.