bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction Kinetics of Simultaneous Removal of SO2 and NO from Flue Gas by NaClO2 Solution
Authors: Zhao Yi , Feng Liu , Tianxiang Guo , Yin Zhao
Published: April 2012

Experiments of simultaneous removal of SO2 and NO from simulated flue gas, using NaClO2 solution as the absorbent, were carried out in a self-designed bubble reactor, and removal efficiencies of 100 percent for SO2 and 95.2 percent for NO were obtained under the optimal experimental conditions. The mechanism of simultaneous removal of SO2 and NO using NaClO2 acid solutions was proposed by analyzing the removal products. The reaction kinetics for simultaneous desulfurization and denitrification were investigated, and the results indicated that the oxidation-absorption processes of SO2 and NO were divided into two zones, as the fast and slow reaction zones. In the slow reaction zones, both were zero order reactions, and in the fast reaction zones, the reaction order, rate constant and activation energy of SO2 removal reaction with absorbent were 1.4, 1.22 (mol L-1)-0.4 s-1 and 66.25 kJ mol-1, respectively, and 2, 3.15×103 (mol L-1)-1 s-1, and 42.50 kJ mol-1 for NO removal reaction, respectively.
Alkali Metal Exchanged Zeolite as Heterogeneous Catalyst for Biodiesel Production from Sunflower Oil and Waste Oil: Studies in a Batch/Continuous Slurry Reactor System
Authors: Borges M. E. , Brito A. , Hernández A. , Díaz L.
Published: April 2012

Biodiesel as an alternative fuel has become more important in recent times due to the increasing awareness of fossil fuel resources and the environmental benefits. The main disadvantages are its cost and availability of fats and oils resources. By collecting used frying oils and converting them to biodiesel fuel, the cost of biodiesel is significantly lowered and the negative impact of disposing used oil to environment reduced.The aim of this study was to analyse the performance of several alkali metal exchanged zeolites as heterogeneous catalysts for biodiesel production from sunflower oil and waste oil. Several catalysts studied showed a high activity for transesterification reaction with batch or continuous flow reactor operation conditions performed: temperature (100- 155°C), methanol/oil molar ratio (12:1- 72:1 mol/mol) and catalyst concentration (3-6 wt %). Results indicated that biodiesel production using waste oil as feedstock has good potential because it is an inexpensive and available feedstock.
Development of an All-in-One Type Adsorption Heat Pump for Heating Application
Authors: Dong Lihua , Huang Hongyu , Kobayashi Noriyuki
Published: April 2012

The present research of adsorption heat pump system for heating application mainly focuses on its miniaturization and high output. When the adsorption heat pump is downsized the heat energy is insufficient to meet heating application. In addition, a large amount of low-temperature heat energy in industry has not been utilized but discharged into the atmosphere as waste heat. To improve energy efficiency and reduce carbon dioxide emission, it is important to effectively utilize the low-temperature heat source which is usually discarded as waste heat. In order to solve the problem between the miniaturization and the high output, a miniature all-in-one type adsorption heat pump which can effectively utilize waste heat is designed. In this design, a heat exchanger coated with adsorption material is used as an adsorber or desorber, and another heat exchanger is used as an evaporator or condenser. A seal unit is formed by assembling two heat exchangers into a vacuum tight container and is connected to the surroundings only by hydraulic piping. Moreover, the adsorbent is a functional adsorbent material-zeolite (AQSOA FAM-Z02, Mitsubishi Plastics) which can be regenerated by utilizing the low-temperature heat energy between 75 and 100°C. In this paper the design and experimental performance of this all-in-one type adsorption heat pump are described.
Unsteady Flow Mixing Effect in Bionic Micro-Flow Channel
Authors: Wang Chin-Tsan , Chang C. T. , Hu Tzu-Yang , Leu Tzong-Shyng
Published: April 2012

Micro-mixers are studied extensively due to their high mixing efficiency. A periodic flow variation at the channel entrance will be used to drive fluids in this study to achieve a mixing effect. Numerical analysis is used and verified by experiment in the study to identify the group of operating factors, such as Reynolds number Re, the driving phase difference ? and the driving frequency ratio Fr, needed for the fluid to achieve the best mixing result for a bionic micro-mixer. It is found in this study that the mixing efficiency is related to the velocity period distribution; the more even the velocity period distribution becomes, the better the mixing efficiency and the best group of operating factors is found (Re2 = 1, Rer = 0.85, Fr = 1, F2 = 50 Hz, I/Am = 1, ? = 3/4 ?). Furthermore, a larger aspect ratio results in a better mixing efficiency. The influence of wall-effect on the flow mixing decreases with AR. It is found that there exists an optimal mixing efficiency at aspect ratio AR = 10. These research results could be used to improve the design of a bionic micro-mixer.
A Three-Dimensional Model Frame for Modelling Combustion and Gasification in Circulating Fluidized Bed Furnaces
Authors: Myöhänen Kari , Hyppänen Timo
Published: April 2012

In a large-scale circulating fluidized bed furnace, the local feeding of fuel, air, and other input materials, and the limited mixing rate of different reactants produce spatially non-uniform process conditions. To simulate the real conditions, the furnace should be modelled three-dimensionally or the three-dimensional effects should be accounted for. The fluidized beds can be studied by different model approaches, ranging from micro-scale particle models and meso-scale two-fluid models to macro-scale engineering models. The fundamentals-oriented micro- and meso-scale models are not yet capable for practical comprehensive calculations of industrial scale circulating fluidized bed units, including modelling of reactions, attrition of particles, and heat transfer. The following paper introduces a three-dimensional semi-empirical steady state model for modelling combustion and gasification in circulating fluidized bed processes. The incorporated submodels include fluid dynamics of solids and gases, fuel combustion and limestone reactions, comminution of solid materials, homogeneous reactions, heat transfer within suspension and to surfaces, models for separators and external heat exchangers, and a model for nitrogen oxide chemistry. The model structure and the main features together with a sample calculation are described. A review of the currently used model approaches for fluidized bed systems at different scales is included to relate the presented model to other modelling field and to justify the need for semi-empirical modelling approach.
Removal of Remazol Turquoise Blue (G-133) and Polyvinyl Alcohol (PVA) by Electrocoagulation using Monopolar and Bipolar Electrodes
Authors: Altin Sureyya
Published: April 2012

This study aims to investigate color and COD removal efficiencies of electrocoagulation (EC) process for dye solutions simulated by using polyvinyl alcohol (PVA) and reactive dyestuff of Remazol Turquoise Blue (G-133). The two different electrode configurations, namely monopolar and bipolar, were examined to find out the better alternative intensifying the performance of the process. The results obtained from these tests show that an EC cell with bipolar electrodes has produced slightly higher color and COD removal efficiencies than that of an EC cell with monopolar electrodes. The best removal efficiencies have been found for the both electrode configurations under the conditions that the time of electrolysis is 30 min, the constant direct current (DC) value 0.75 A and the initial pH value 3. Consequently, the bipolar electrode configuration (BPEC) has yielded 72.7 percent COD and 99.8 percent color removals while the monopolar electrode configuration (MPEC) producing 65.2 percent COD and 99.6 percent color removals.
Kinetic Modeling and Reactor Simulation and Optimization of Industrially Important Polymerization Processes: a Perspective
Authors: Ramteke Manojkumar , Gupta Santosh K.
Published: April 2012

The field of what is now referred to as polymer reaction engineering started in the early 1930s with Staudingers discovery of macromolecules. Though the earlier work was related primarily to synthesis and kinetics, the field started growing at increasing rates, possibly in the late 1950s or early 1960s. In the early years, this field provided a challenging area of research. It has evolved from the modeling of simple polymerizations to that of more complex systems, to experimentation for filling the gaps in our knowledge, to optimization. This mini-review summarizes a small sampling of the literature in polymerization reaction engineering over the last about four decades using a personal perspective. The concepts in this area are now being applied in a variety of specialized domains, e.g., polymerization at the nano scale, design and control of chain macrostructure and rapid optimal switch-over of grades being manufactured, molecular simulation and computational fluid dynamics, etc.
Asymptotic Analysis of Flow Processes at Drawing of Single Optical Microfibres
Authors: Luzi Giovanni , Epple Philipp , Scharrer Michael , Fujimoto Ken , Rauh Cornelia , Delgado Antonio
Published: April 2012

Microstructured optical fibres (i.e. fibres that contain holes) have assumed a high profile in recent years, and given rise to many novel optical devices. The problem of manufacturing such fibres by heating and then drawing a preform is considered for both the cases of annular microfibres and annular capillaries. A fluid-mechanics model suggested in literature that uses asymptotic analysis based on the small aspect ratio of capillaries is analysed and revised. The leading-order equations are examined in some asymptotic limits, many of which give valuable practical information about the control parameters that influence the drawing process. Additionally, the solution obtained for a single capillary provides a suitable basis for describing more complicated fibre structures.
The Influence of Boria and EDTA on the Hydrodesulfurization Activity on CoMoS Supported Catalysts
Authors: Parvari Matin , Moradi Peyman
Published: April 2012

The hydrodesulfurization of dibenzothiophene (HDS of DBT) in a high pressure batch reactor at 320°C was carried out over CoMo/Al2O3-B2O3 catalysts with different B2O3 contents (4, 10, and 16 wt%). Ethylenediaminetetraacetic acid (EDTA) with different EDTA/Co mole ratios (0.6, 1.2 and 1.8) was used as a chelating ligand during the preparation of CoMo/Al2O3-B2O3. XRD studies, FTIR, TPD of NH3, and BET experiments were used to investigate the catalyst samples. The results showed that the catalyst using the support with 4 wt% B2O3 and an EDTA/Co mole ratio of 1.2 had a hydrodesulfurization activity (in pseudo first order kinetic constant basis) value of ~2.96 times higher than that of the simple CoMo/Al2O3 catalyst.
Multicultural Education: Lessons from Teaching and Learning in the U.S. and Abroad
Authors: Reyes Xaé Alicia
Published: April 2012

This article is a reflective essay that examines the experiences of a Multicultural Educator from a non-mainstream perspective. The author, of Latino descent, has attended schools in Puerto Rico and in the United States, and has taught at universities in both. Experiences teaching and learning within and outside of the United States are compared and contrasted. The challenges and opportunities to enrich worldviews and perspectives of students and colleagues are discussed in terms of how these experiences have shaped her teaching and learning. Issues confronted through different structural, cultural, and political dynamics at institutions of higher education are addressed.
Envelhecimento acelerado de sementes de pinhão-manso
Authors: Pereira Márcio Dias , Martins Filho Sebastião , Laviola Bruno Galvêas
Published: April 2012

O pinhão-manso (Jatropha curcas L.) é uma planta oleaginosa que têm se destacado por apresentar as qualidades necessárias à produção de biodiesel. O objetivo deste trabalho foi adequar a metodologia do teste de envelhecimento acelerado, para a avaliação do potencial fisiológico de sementes de pinhão-manso. Para isto, quatro lotes de sementes foram, inicialmente, caracterizados, por meio do teor de água, percentagem e primeira contagem de germinação, percentagem e índice de velocidade de emergência de plântulas, germinação a baixa temperatura e altura da parte aérea. Os tratamentos utilizados foram três temperaturas (41ºC, 42ºC e 45ºC) e quatro tempos de exposição das sementes (24, 48, 72 e 96 horas), em cerca de 100% de umidade relativa do ar. O teste de envelhecimento acelerado conduzido por 24 horas, a 41ºC, foi eficiente para avaliar o vigor de sementes de pinhão-manso, permitindo a classificação dos lotes em níveis de vigor, à semelhança dos testes de primeira contagem de germinação, emergência de plântulas, germinação a baixa temperatura, índice de velocidade de emergência e altura da parte aérea de plântulas.
Perceptions of Family Members of Children with Cleft Lip and Palate in Hyderabad, India, and Its Rural Outskirts regarding Craniofacial Anomalies: A Pilot Study
Authors: Naram Aparajit , Makhijani Sumeet N. , Naram Depack , Reddy Srinivas Gosla , Reddy Rajgopal R. , Lalikos Janice F. , Chao Jerome Donald
Published: April 2012

Objective

This pilot study aimed to understand cultural perspectives on cleft anomalies in the community of Hyderabad, India, and its rural outskirts.

Design

Interviews focusing on perceptions of cleft lip and palate were conducted using a 21-item interview guide approved by the director of the Gosla Srinivas Reddy Institute of Craniofacial Surgery (GSR).

Settings

Interviews were conducted at GSR, a specialty surgical center located in Hyderabad, India.

Patients and Participants

All patients who presented to GSR with either cleft lip, cleft palate, or cleft lip and palate at the time of this study were included.

Results

Of the 23 families interviewed, 12 mothers believed the cleft was caused by an eclipse, and two believed the scientific explanation their physician offered. Fourteen families were offered no explanation for the cleft lip and/or palate at the time of their first physician visit. No families practiced non-Western methods for treatment of the cleft. One family identified beliefs held in the community that their child with a cleft lip was bad luck.

Conclusion

A commonly held belief in this community in India is that cleft lip, cleft palate, or cleft lip and palate are caused by an eclipse. Physicians appear to be providing families with insufficient education on cleft impairments. Data generated from studies similar to this can be used to design educational protocols that address this gap in community understanding of orofacial clefting.
Influence of Monomer Structures on the High Temperature Properties of Poly[(Alkylamino)Borazine)]s Derived BN
Authors: Lei Yongpeng , Wang Yingde , Song Yongcai
Published: April 2012

Preceramic polymers to boron nitride (BN) have been synthesized by thermal condensation of different
(alkylamino)borazine monomers. Crystalline BN was obtained by pyrolysis of those polymeric precursors in NH3 and
then in Ar. The influence of monomer structure on the chemical composition, microstructure, oxidation resistance and
high temperature stability of BN was investigated by a combination of elemental analysis (EA), density measurement,
FTIR, XPS, XRD, HRTEM and TGA. With similar chemical composition, BN derived from symmetric monomer
exhibited a higher crystallinity, better oxidation resistance and higher temperature stability. This was because that the
structure of the precursor polymerized from symmetric molecular was close to that of hexagonal BN (h-BN).
A Novel Expression of Exercise Induced Pulmonary Hypertension in Human Immunodeficiency Virus Patients: A Pilot Study
Authors: Doukky Rami , Lee Won Y , Ravilla Mahindhar , Lateef Omar B , Pelaez Victor , French Audrey , Tandon Rajive
Published: April 2012

Background:

Patients with the human immunodeficiency virus (HIV) are at risk for multiple pulmonary complications including pulmonary hypertension. Exercise induced pulmonary hypertension (EIPH) has been previously described in patients with scleroderma, sickle cell disease and chronic obstructive pulmonary disease, yet has not been associated with the HIV population.

Methods:

A prospective case-control study design was implemented. Four HIV patients with unexplained dyspnea and four healthy controls underwent symptom-limited stationary bicycle exercise. Transthoracic Doppler Echocardiography was used to measure tricuspid regurgitation velocity which was used to calculate the right ventricular to right atrial pressure (RV-RA) gradient at rest and at peak exercise using the simplified Bernoulli’s equation. Change in RV-RA gradient between rest and peak exercise was calculated and considered to represent change in pulmonary arterial systolic pressure.

Results:

The mean age was 41.25 years (±8.7) for patients and 33.5 years (±6.0) for controls. The mean CD4 count of patients was 191.5 cells/μL (±136.2). Patients had a significantly higher increase in RV-RA gradient as compared to controls (180.2% vs. 27.5%, p = 0.03).

Discussion:

This pilot study suggests that it is feasible to use recumbent bicycle and transthoracic Doppler echocardiography for the evaluation of EIPH among HIV patients with dyspnea of unknown etiology. The study is too small to draw any broad conclusion. Further evaluation of this concept with a larger study is warranted.
An Assessment of Two-Wheeler CO and PM10 Exposures Along Arterial Main Roads in Bangalore City, India
Authors: Sabapathy Ashwin , V. Santhosh Ragavan K. , Saksena Sumeet
Published: April 2012

This study investigated 2-wheeler exposures to CO and PM along six standardized arterial main road
stretches in Bangalore city in India during morning peak (9:00-11:00) and afternoon non-peak hours (13:00-15:00) using
personal samplers. Background levels on a local street carrying no traffic and away from main roads were also monitored
to determine the actual contributions of vehicular traffic to exposure. Road stretches were selected to compare exposures
on two types of routes - inner arterials and outer arterials with different built form characteristics.

Results indicate that average background PM and CO concentrations were much lower than the respective averages of
the 2-wheeler exposures as expected. While PM exposures for inner arterials were higher than for outer arterials
(p=0.007), differences were much larger for CO (p<0.001). Since the average run speeds were comparable for the
stretches, the variations in PM and CO could be attributed to different vehicular compositions and built form
characteristics of the stretches, but this needs to be verified through further investigation. PM exposures during nonpeaks
were lower than during morning peaks (p=0.02). However, CO exposures were not very different between non-peak
hours and morning peak hours (p=0.138) despite comparable average run speeds and shows that even lower traffic
volumes during non-peak hours result in high exposures. Results of various bivariate models indicate that average run
speed is a good predictor of CO exposures (R=0.56) but is only a minor predictor of PM exposures (R=0.18) in
Bangalore.
Soluble ST2 as a Diagnostic and Prognostic Marker for Acute Heart Failure Syndromes
Authors: Henry-Okafor Queen , P. Collins Sean , A. Jenkins Cathy , F. Miller Karen , J. Maron David , J. Naftilan Allen , Weintraub Neal , J. Fermann Gregory , McPherson John , Menon Santosh , B. Sawyer Douglas , B. Storrow Alan
Published: April 2012

Objectives:

We investigated the association of sST2 with diagnostic and prognostic outcomes and assessed whether it aids B-natriuretic peptide (BNP) in diagnosing and predicting outcomes in emergency department (ED) patients with suspected AHFS.

Methods:

We recruited patients who presented to the ED of 3 tertiary hospitals with signs or symptoms of AHFS and met modified Framingham criteria for AHFS. Outcome measures were a final diagnosis of AHFS and 5-and 30-day adverse events.

Results:

In the 295 subjects with sST2 available, the median sST2 was 0.20 ng/ml (IQR=0.10, 0.34). Although unadjusted analyses indicated sST2 was significantly associated with the diagnosis of AHFS (p=0.02), this was not so in the adjusted analysis (p=0.33). Moderately low diagnostic utility was noted with an AUC of 0.62 (95% CI=0.56, 0.69). Similar sST2 test characteristics were seen when BNP was restricted between 100 and 500 pg/ml. While sST2 was associated with AHFS readmission at 30-days (p=0.04), in the adjusted analyses it was not associated with adverse events.

Conclusion:

In patients with signs or symptoms of AHFS, unadjusted analyses indicated that sST2 was significantly asso-ciated with the diagnosis of AHFS and with 30-day AHFS recidivism. However, the associations did not carry over to ad-justed analyses, and sST2 did not add significant information with regard to explaining the diagnostic and prognostic vari-ability of BNP.
Can value judgments guide choices?
Authors: Milevski Voin
Published: April 2012

According to R.M.Hare, the primary function of the value-words is to commend Also, in his opinion, whenever we commend something, it is always in order to, at least indirectly, guide choices. This thesis was very often questioned. In his article 'Objectivism and Mr. Hare's Language of Morals' professor Sidney Zink attempts to prove that Hare's central thesis is incorrect. My primary contention in this paper is to demonstrate that professor Zink's argumentation is quite unworkable. At the same time, this contention represents one step further in justification of internalism.
Kantian turn in the contemporary philosophy of science
Authors: Sindjelic Svetozar
Published: April 2012

The aim of this paper is twofold. First, to answer the question is it possible to speak about some kind of Kantian turn in the transition from the traditional philosophy of science to the contemporary one. Second, and more important, to describe the main points of the new philosophy of science just through the discussion of above question. The author is of the opinion that it is possible to speak about Kantian turn in the new philosophy of science (the philosophy which underlines the role of an a priori and conventional conceptual framework), but he also indicates certain important differences between Kantian original position and the new philosophy of science.
Will to power as physis: Nietzsche and Aristotle
Authors: Savic Mico
Published: April 2012

Nietzsche's critique of metaphysics, as the way of the overcoming of the modern interpretation of being, is based on his doctrine of will to power, which evokes a certain kind of the return to the Greeks. Therefore, the paper points to the close relationship between Nietzsche's notion of the will to power and the Greek notion of physis, which is primarily stated in Aristotle's philosophy. For this reason, the relationship between Nietzsche's and Aristotle's philosophy is also explained. However, the fact that Nietzsche interprets the being by the notion of will is the sign that he succeeded to rid of modern metaphysics only partly, for the metaphysical concept of will is the modern interpretation of the Greek concept of physis. Subsequently, Nietzsche's metaphysics holds some ambivalence, which is reason for different interpretations of his undertaking.
Nomokanon of St. Sava concerning murder in the war
Authors: Grozdic Borislav
Published: April 2012

The paper deals with understanding of murder in the war in Nomokanon of St. Sava, original and unique nomocanon in the Orthodox world, different from all those previously known, which is prepared by Saint Sava on the basis of the Byzantine nomocanon and who put inside of it over one hundred canonical and Byzantine legal documents, translated into serbian-slovene language. Murder in the war in Nomokanon of Saint Sava is considered wilful, intentional murder or premeditated murder. It is interesting and significant that Saint Sava in Nomokanon omits attitude of St. Athanasius the Great, who claims that is not allowed to kill, but that it is legal and deserved to be decorated to kill enemies in war, so that is why those who stand in the war were highly honored and devoted monuments, which describe their glorious deeds. St. Sava introduce and points out attitude of St. Vasilije the Great, according to which the soldier who kill in the war for holy truth and real Christian Faith, is not allowed to receive Holy Communion for three years. Thus, as well for those who killed in war in the name of their deep belief and holy truth, and whose hands are unclean, epitimija - prohibition of the Holy Eucharist is recommended for three years because of their unclean hands. Priests, if they kill, whether in war or not, are to be degradated. With judgement that the murder in war is deliberate, that is intentional murder and that it means a sin to be followed by certain epitimija still does not mean that the Church absolutely denies war as such, and participation in the war. It just confirms how much the war is tragic situation for Christians, but situation that they can not reject, avoid, and pretend that they do not see it. The obligation of Christians is to participate in the war with high ideals of love, justice, duty and service if there is the need, but bravely and ready for all related consequences. In this difficult dilemma, which leaves them without a moral way-out with 'clean hands', but where they are forced to consciously acceptance of injustice, and acceptance of not only burden of death but also burden of murder. Insisting on a three-year epitimija demonstrate a care that Christians should not lose awareness of the fact that they (if they) killed a man, regardless of the circumstances of war, and due to that a certain period is necessary, at least three years, of repentance and abstinence from communion.
The Effect of Hedge Fund Activism on Corporate Tax Avoidance
Authors: Cheng C. S. Agnes , Huang Henry He , Li Yinghua , Stanfield Jason
Published: April 2012

This paper examines the impact of hedge fund activism on corporate tax avoidance. We find that relative to matched control firms, businesses targeted by hedge fund activists exhibit lower tax avoidance levels prior to hedge fund intervention, but experience increases in tax avoidance after the intervention. Moreover, findings suggest that the increase in tax avoidance is greater when activists have a successful track record of implementing tax changes and possess tax interest or knowledge as indicated by their Securities and Exchange Commission (SEC) 13D filings. We also find that these greater tax savings do not appear to result from an increased use of high-risk and potentially illegal tax strategies, such as sheltering. Taken together, the results suggest that shareholder monitoring of firms, in the form of hedge fund activism, improves tax efficiency.

JEL Classifications: G32; G34; H26.

Data Availability: Data are available from sources identified in the text.
Cerebral dural arteriovenous fistulas and aneurysms
Authors: Gross Bradley A. , Ropper Alexander E. , Du Rose
Published: April 2012

Object

The association of aneurysms and cerebral arteriovenous malformations is well established in the literature. Aside from a small number of case reports and small patient series, this association has not been well explored with cerebral dural arteriovenous fistulas (DAVFs). This study was designed to elucidate this relationship in the authors' own patient cohort with DAVFs.

Methods

Cerebral angiograms of 56 patients with 70 DAVFs were reviewed for the presence of cerebral aneurysms. Background patient demographics, mode of presentation, and DAVF and aneurysm angiographic characteristics were noted.

Results

Twelve patients (21%) had aneurysms in addition to their DAVF. Three patients had multiple aneurysms. Of a total of 15 aneurysms, 5 (33%) occurred on DAVF feeding arteries and 10 (67%) were in remote locations. These patients more commonly presented with hemorrhage (58% vs 20% for those without aneurysms). Aneurysms were associated with DAVFs in any location (feeding artery or remote), but flow-related feeding artery aneurysms were more likely to be associated with Borden Type III DAVFs.

Conclusions

Twenty-one percent of patients with cerebral DAVFs also had aneurysms in this patient cohort. It is thus prudent to perform 6-vessel digital subtraction angiography on patients with DAVFs to rule out potential feeding artery and remote aneurysms. This association may be explained by flow-related phenomena, the initial inciting event leading to DAVF formation, as well as a potential genetic component or predisposition to develop these lesions.
Rotational angiography for diagnosis and surgical planning in the management of spinal vascular lesions
Authors: Ropper Alexander E. , Lin Ning , Gross Bradley A. , Zarzour Hekmat K. , Thiex Ruth , Chi John H. , Du Rose , Frerichs Kai U.
Published: April 2012

Object

The management of spinal vascular malformations has undergone significant evolution with the advent of advanced endovascular and angiographic technology. Three-dimensional rotational spinal angiography is an advanced tool that allows the surgeon to gain a better appreciation of the anatomy of these spinal vascular lesions and their relation to surrounding structures. This article describes the use of rotational angiography and 3D reconstructions in the diagnosis and management of spinal vascular malformations.

Methods

The authors present representative cases involving surgical treatment planning for spinal vascular malformations with focus on the utility and technique of rotational spinal angiography. They report the use of rotational spinal angiography for a heterogeneous collection of vascular pathological conditions.

Results

Eight patients underwent rotational spinal angiography in addition to digital subtraction angiography (DSA) for the diagnosis and characterization of various spinal vascular lesions. Postprocessed images were used to characterize the lesion in relation to surrounding bone and to enhance the surgeon's ability to precisely localize and obliterate the abnormality. The reconstructions provided superior anatomical detail compared with traditional DSA. No associated complications from the rotational angiography were noted, and there was no statistically significant difference in the amount of radiation exposure to patients undergoing rotational angiography relative to traditional angiography.

Conclusions

The use of rotational spinal angiography provides a rapid and powerful diagnostic tool, superior to conventional DSA in the diagnosis and preoperative planning of a variety of spinal vascular pathology. A more detailed understanding of the anatomy of such lesions provided by this technique may improve the safety of the surgical approach.
Deformation and energy of dry snow slabs prior to fracture propagation
Authors: Mcclung D.M. , Borstad C.P.
Published: April 2012

Snow slab avalanches primarily release by propagation of shear fractures within thin weak layers under thicker slabs. The weak layer is typically on the order of 1 mm thick and fails in mode II. In some cases, the weak layer is thicker and there may be a need to consider slope-normal deformation as part of the energy condition prior to rapid propagation. In this paper, field measurements from shear fracture initiation and high-speed films are combined to consider the effects of slope-normal deformation on bending of the slab prior to propagation and its relation to the propagation condition. Slab bending is modelled using two limiting cases: (1) a uniformly loaded beam supported by a deforming weak layer, analogous to a Winkler foundation, and (2) a uniformly loaded unsupported cantilevered beam. The experimental and analytical results suggest that slab bending prior to fracture initiation is small or negligible. Two previous approaches to modelling slab avalanche initiation involving slab bending are discussed. Both models proposed strong slab-bending effects prior to initiation, which conflicts with our results. Our field observations and modelling both show that strong bending is a dynamic effect following slope-parallel weak-layer fracture initiation.
A Postmortem Study on the Volume of the Human Thyroid Gland
Authors: Nurunnabi ASM , Ara S , Jahan MU
Published: April 2012

The present study was designed to find out the difference in volume of the thyroid gland of Bangladeshi people in relation to age and sex and to compare with previous local and foreign studies. It was a Cross-sectional descriptive type of study. The hospital based study was conducted in the Department of Anatomy, Dhaka Medical College, Dhaka, from January to December 2008. The present study was performed on 60 post mortem human thyroid gland (39 of male and 21 of female) collected from unclaimed dead bodies which were in the morgue under examination in the Department of Forensic Medicine, Dhaka Medical College, Dhaka. The samples were divided into three age-groups including group A (10-20 years), group B (21-50 years) & group C (>50 years) and the volume of the thyroid glands were measured by fluid displacement method and recorded. No difference was found in mean volume of the thyroid gland between male and female. However, significant difference was found in between age groups. The volume of the gland was found to increase from early childhood and puberty up to 50 years of age and then decreased.  DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10444  Bangladesh Med Res Counc Bull 2012; 38: 6-8
Elevated serum homocysteine level has a positive correlation with serum cardiac troponin I in patients with acute myocardial infarction
Authors: Alam N , Khan HILR , Chowdhury AW , Haque MS , Ali MS , Sabah KMN , Amin MG
Published: April 2012

The objective of the present study is to find out whether the increased serum homocysteine level is associated with the increased serum troponin I as a surrogate marker of extent of myocardial injury in acute myocardial infarction patients. Elevated homocysteine levels are associated with increased thrombosis. In patients presenting with Acute Coronary Syndrome (ACS), it is not known whether this association is reflected in the degree of myocardial injury. This was a cross sectional study conducted among the patients with acute myocardial infarction in the Department of Cardiology, Dhaka Medical College Hospital during the period of October 2009 to September 2010 and which included 194 consecutive patients with acute myocardial infarction. The mean (±SD) serum homocysteine level was 20.2±14.3 ?mol/L with range from 7.4 to 129.1 ?mol/L. Mean serum troponin-I level was classified according to normal (<15?mol/L) and high (?15?mol/L) levels of serum homocysteine values. The mean serum troponin-I level was 8.9±8.6 ng/ml in the patients having normal serum homocysteine level and 18.4±6.5 ng/ml in the patients having high serum homocysteine level. A significant positive correlation (r=0.273; p<0.001) was found between serum troponin-I level with homocysteine level. Patients with moderate hyperhomocysteinemia (?15 ?mol/L) was found to be 7.09 times more likely to have increased serum troponin-I (a surrogate marker of extent of myocardial injury). The main observation of the present study was that elevated serum homocysteine level has a positive correlation with serum cardiac troponin-I in patients with acute myocardial infarction. So serum homocysteine is associated with increased extent of myocardial injury as measured by serum cardiac troponin-I level, a surrogate marker in patients with acute myocardial infarction.  DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10445  Bangladesh Med Res Counc Bull 2012; 38: 9-13
Comparison between prostate volume and intravesical prostatic protrusion in detecting bladder outlet obstruction due to benign prostatic hyperplasia
Authors: Hossain AKMS , Alam AKMK , Habib AKMK , Rashid MM , Rahman H , Islam AKMA , Jahan MU
Published: April 2012

The objectives of this study were to determine and compare the correlation of intravesical prostatic protrusion (IPP) and prostate volume (PV) with bladder outlet obstruction (BOO). This study was conducted in the department of urology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, between July 2009 to September 2010. Fifty benign prostatic hyperplasia (BPH) patients were included in the study. Their evaluation consisted of history along with International Prostate Symptoms Score (IPSS), digital rectal examination (DRE), transabdominal ultrasonography to measure prostate volume, intravesical prostatic protrusion & post voidal residual (PVR) urine and pressure-flow studies to detect bladder outflow obstruction (BOO). Statistical analysis included Unpaired t test, Chisquare test and Spearmans Rank correlation test. Receiver Operator Characteristic (ROC) curves were used to compare the correlation of PV and IPP with BOO. Mean prostate volume was significantly larger in bladder outlet obstructed patients (P<0.05). Mean IPP was significantly greater in obstructed patients (P<0.001). Area under ROC curve was 0.700 for PV and 0.821 for IPP. Prostate volume & intravesical prostatic protrusion measured through transabdominal ultrasonography are noninvasive and accessible method that significantly correlates with bladder outlet obstruction in patients with benign prostatic hyperplasia and the correlation of IPP is much more stronger than that of prostate volume. Introduction Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men. The prevalence of histological BPH increases with age and appears in approximately 40% of men aged 50- 60 years and in approximately 90% of men aged more than 80 years1. Benign prostatic hyperplasia may lead to prostatic enlargement, bladder outlet obstruction (BOO) and lower urinary tract symptoms (LUTS). But the symptoms and obstruction do not entirely depend on prostates size. In contrast, intravesical prostatic protrusion (IPP) has been found to correlate with BOO2. IPP is a morphological change due to overgrowth of prostatic median and lateral lobes into the bladder and may lead to diskinetic movement of bladder during voiding. This IPP would cause more obstruction than if there were no protrusion and just enlargement of lateral lobes, as the strong bladder contraction could force open a channel between the lobes3. Several studies have previously demonstrated that the ultrasonographic measurement of IPP is able to detect BOO in BPH patients quickly and non-invasively4. This study was designed to diagnose BOO through non-invasive methods and aimed to define the correlationDOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10446  Bangladesh Med Res Counc Bull 2012; 38: 14-17
Chronic Kidney Disease specific cardiovascular risk factors among non dialytic patients with Chronic Kidney Disease stage-VAn experience of a specialized hospital
Authors: Saha M , Faroque MO , Alam KS , Alam MM , Ahmed S
Published: April 2012

The study was carried out to see prevalence of Chronic Kidney Disease (CKD) specific cardiovascular risk factors and cardiovascular events among patients with Chronic Kidney Disease stage-V (CKD-V) before starting dialysis therapy in the department of Nephrology of National Institute of Kidney Diseases & Urology (NIKDU), Dhaka, Bangladesh. Among CKD specific cardiovascular risk factors, anemia showed the highest prevalence (96.7%) in study population. More than fifty percent of CKD-V patients had both hypocalcaemia and hyperphosphataemia. Calcium-Phosphate Product (CaXP) was elevated among 23 percent of the population. C-reactive protein, an acute phase protein was positive in 78% of CKD-V patients. Besides, among traditional risk factors, Hypertension and Diabetes Mellitus were present in 83.3% and 23% of the study population respectively. The prevalence of cardiovascular events among CKD-V patients showed that 18.3% had ischemic heart disease, 38% heart failure, 4.7% arrhythmia and 9% left ventricular hypertrophy. Females were significantly prone to develop cardiovascular events than their male counterpart (p=0.028). Diabetes was significantly higher in patients with cardiovascular complications than in patients without cardiovascular complications (p=0.021). DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10447 Bangladesh Med Res Counc Bull 2012; 38: 18-22
A simple biological marker to differentiate the types of Herpes Simplex Viruses in resource-limited settings
Authors: Akter T , Tabassum S , Nessa A , Jahan M
Published: April 2012

Herpes simplex viruses (HSV) multiply readily on the chorioallantoic membrane (CAM) of embryonated hens egg and produce easily visible foci or pocks on this membrane. In the present study, pocks produced by the two antigenic types of HSV (1 & 2) were compared to evaluate the effectiveness of typing HSV isolates by pock size on CAMs. A total of 57 HSV isolates from both non-genital and genital samples were typed by the pock size produced on the CAMs of fertile hens eggs. Twenty two HSV isolates yielded visible pocks on CAM, of which 9 (40.9%) produced small pocks, while 13 (59.1%) produced large pocks. All pocks produced on CAM were confirmed by antigenic typing by the Direct Fluorescent Antibody (DFA) method. HSV isolates which produced small pocks were in complete (100%) concordance with HSV type-1, while those producing larger pocks were in full (100%) concordance with HSV type-2. Thus, the pock size on CAM of embryonated fertile hens egg may be used as a simple and relatively inexpensive biological marker for the differentiation of HSV types 1 & 2. DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10448 Bangladesh Med Res Counc Bull 2012; 38: 23-26
What cannot be measured cannot be done; risk factors for childhood tuberculosis: a case control study
Authors: Karim MR , Rahman MA , Mamun SAA , Alam MA , Akhter S
Published: April 2012

Childhood tuberculosis is one of the major causes of childhood mortality and morbidity though much neglected within our National Tuberculosis Control Program. This case control study was carried out to identify the risk factors for tuberculosis among children. Cases (n=95) and controls (n=94) were selected from Directly Observed Treatment Short Course (DOTS) centers of four upazillas of Dhaka and Gazipur districts. Cases were childhood tuberculosis patient, who were test positive by sputum microscopy from January to May, 2011 and controls were children who visited DOTS laboratory suspecting tuberculosis infection but were sputum negative. Both cases and controls were selected from the sputum examination registers and were traced at home for exposure data. The study showed more girls were infected than boys. Several socio demographic and environmental factors were found to be associated with the development of childhood tuberculosis. Logistic regression model was constructed to find out the important predictors which revealed age, education of the respondents, indoor environment and contact pattern were significantly associated with childhood tuberculosis. Children more than 14 years of age had 6.25 times higher risk of developing childhood tuberculosis; (Odds ratio=6.25; 95% CI for OR=2.00 to 19.55), Children completed primary education had 3.12 times lower risk of developing childhood tuberculosis, (Odds ratio=.32; 95% CI for OR=.10 to 1.00). Those who resided in better in-house environment had 4.35 times lower risk of developing childhood tuberculosis (Odds ratio=.23; 95% CI for OR=.06 to .95) and children came in contact with source tuberculosis cases who were their relatives or neighbors were 5.26 times lower risk of developing childhood tuberculosis than being in contact with family members with TB (Odds ratio=.19; 95% CI for OR=.07 to .49). Contact Screening should be incorporated in National TB program for early detection and effective treatment of tuberculosis. Improvement of indoor environment and ventilation status of the bedroom might reduce the risk of developing childhood tuberculosis. DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10449 Bangladesh Med Res Counc Bull 2012; 38: 27-32
Symptomatic overlap in patients with diarrhea predominant irritable bowel syndrome and microscopic colitis in a sub group of Bangladeshi population
Authors: Rahman MA , Raihan ASMA , Ahamed DS , Masud H , Safiullah ABM , Khair KB , Salimullah ASM , Islam MMS
Published: April 2012

Microscopic Colitis (MC) and diarrhea predominant irritable bowel syndrome (IBS-D) has almost similar clinical feature but MC is diagnosed by histologic criteria and IBS is diagnosed by symptombased criteria. There is ongoing debate about the importance of biopsies from endoscopically normal colonic mucosa in the investigation of patients with IBS-D. Aim of this study was to assess the prevalence of MC in patient with IBS-D and to determine the distribution of MC in the colon. This observational study was conducted in department of Gastroenterology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2008 to December 2009. Patients were evaluated thoroughly & who meet RomeII criteria with normal routine laboratory tests, were included in the study. Colonoscopy was done and biopsies were taken from the caecum, transverse colon, descending colon, and rectum. Out of total 60 patients, 22 had Lymphocytic Colitis (LC), 28 had nonspecific microscopic colitis (NSMC) and 10 had irritable bowel syndrome noninflamed (IBSNI). The distribution of LC was restricted to proximal colon in 15 patients, in the left colon in 2 patients and diffuses throughout the colon in 5 patients. There is considerable symptom overlap between the patients of IBS-D and patients with microscopic colitis. Without colonoscopic biopsy from multiple sites, possibility of MC cannot be excluded in patients with IBS-D and it can be said that clinical symptom based criteria for irritable bowel syndrome are not sufficient enough to rule out the diagnosis of microscopic colitis. DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10450 Bangladesh Med Res Counc Bull 2012; 38: 33-38
Congenital absence of one tonsil without any other congenital abnormality: a rare presentation
Authors: Datta PG , Saha KL , Roy JS , Biswas AK , Das PP
Published: April 2012

DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10451Bangladesh Med Res Counc Bull 2012; 38: 39-40
Back Pain: An Unusual Presentation of Castlemans Diseases
Authors: Kabir AL , Irshadullah NM , Aziz A , Begum M , Rahman F
Published: April 2012

DOI: http://dx.doi.org/10.3329/bmrcb.v38i1.10452 Bangladesh Med Res Counc Bull 2012; 38: 40-41