bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Behavior of Positronium Annihilation in Porous Silicon
Authors: Wang Bao Yi , Yu Run Sheng , Cao Xing Zhong , Li Zhuo Xin , Zhang Peng , Qin Xiu Bo , Wei Long , Kurihara Toshikazu
Published: November 2012

The annihilation behavior of positronium in N and P type porous silicon is investigated via positron annihilation lifetime (PAL) and positronium time-of-flight (Ps-TOF) measurements. The result shows the N type sample has smaller positronium annihilation fraction and more interconnected pores. The microstructure of Rapid Thermal Oxidation (RTO) treated N type porous silicon also studied using PAL spectroscopy, and the relationship between its photoluminescence properties and porous structure was discussed.
Positron Annihilation at Planar Defects in Oxides
Authors: Kuriplach Jan , Melikhova O. , Čížek Jakub , Procházka I. , Brauer G. , Anwand W.
Published: November 2012

Planar defects may exhibit free volumes which, in principle, are detectable using positron annihilation spectroscopy. In this contribution, we present a preliminary theoretical study of positron trapping at stacking faults in zinc oxide and at a grain boundary in zirconia. In particular, we calculate the positron lifetime and positron binding energy to such defects. In the case of the grain boundary in zirconia, the influence of the yttrium segregation on the GB structure and positron characteristics is also examined. Calculated structural and positron characteristics are critically compared with experimental and other calculated data.
Inhibition of Positronium Formation in Yttria Stabilized Zirconia Nanopowders Modified by Addition of Chromia
Authors: Melikhova Oksana , Čížek Jakub , Procházka Ivan , Konstantinova Tetyana E. , Yashchishyn Igor A.
Published: November 2012

The effect of chromia additive on defects in yttria stabilized zirconia (YSZ) nanopowders was investigated in this work. It was found that positrons are trapped at vacancy-like misfit defect at grain boundaries and at larger defects situated at triple points. Moreover, a long-lived ortho-positronium contribution was found in YSZ nanopowder without chromia. Addition of chromia prolongs the lifetime of positrons trapped at vacancy-like misfit defects which indicates segregation of Cr ions at grain interfaces and interaction of Cr with vacancy-like misfit defets. Moreover addition of chromia completely suppresses formation of positronium.
Defect Detection in Fe-Cr Alloys with Positron Annihilation Doppler Broadening Spectroscopy
Authors: Sabelová Veronika , Petriska Martin , Veterníková Jana , Slugeň Vladimir , Degmová Jarmila , Kilpeläinen Simo
Published: November 2012

Positron annihilation Doppler broadening spectroscopy (DBS) has been used for the detection of structural defects in Fe-9wt%Cr (Fe-9Cr) alloy in the as-prepared and implanted states. Defects were created by He and H ion implantation with a kinetic energy of 250 keV. DBS is a non-destructive method and is a unique tool for the observation of open volume defects like vacancies and vacancy clusters in solids. A positron beam with variable positron energy was used for the measurement of defect depth profiles up to 1.5 µm. The obtained results provide qualitative and semi-quantitative information about radiation induced defects and their chemical environment. Although the collision damage from helium implantation was one order of magnitude higher than for the case of hydrogen, the changes in S and W parameters are much less significant, probably due to considerably lower mobility of helium in the implanted materials, which results in helium capture by the created open volume defects.
Positron Annihilation Measurements Performed on Oxide-Dispersion Strengthened Steels
Authors: Veterníková Jana , Kilpeläinen Simo , Skarba M. , Tuomisto Filip , Slugeň Vladimir , Degmová Jarmila , Sabelová Veronika , Sojak Stanislav
Published: November 2012

This paper is focused on investigation of oxide-dispersion strengthened steels in a basic state (before an experimental treatment) by two positron annihilation techniques – positron annihilation lifetime spectroscopy and Doppler broadening spectroscopy. Three high chromium commercial steels – MA 956, MA 957 and PM 2000 were measured in order to identify and quantify defects in samples as well as to demonstrate defect depth profile in subsurface layers up to 1.6µm. Results indicate presence of di-vacancies in PM 2000, three-vacancies in MA 956 and six-vacancies together with dislocations in MA 957. Positron techniques were supplemented by scanning electron microscopy, which demonstrated also presence of larger defects as pores and different density of precipitates.
Scoring Analysis of Design, Verification and Optimization of High Intensity Positron Source (HIPOS)
Authors: Zeman Andrej , Tuček K. , Daquino G. , Debarberis L. , Hogenbirk A.
Published: November 2012

As part of an exploratory research project at the Institute for Energy (Joint Research Centre of the European Commission), a feasibility assessment was performed for the design and construction of a high-intensity positron facility (HIPOS) in a neutron beam tube, HB9, at the High Flux Reactor (HFR) in Petten. The full model of reactor core, reflector and reactor instrumentation at the neutron beam line HB9 were modeled and full neutronic and photonic calculations were carried out by MCNP4C3. The source file was generated in two formats: SDEF and WESSA. Consequently, two different codes were used for scoring analysis for the optimization of the concept and geometry of positron generator. The main concept including key design parameters have been evaluated independently by two computer codes, in particular MCNP-X and GEANT4. The parametric design analysis including the optimization of positron generator at the pre-selected neutron beam line is reported in this paper. The detailed assessment of the critical design parameters, specifically from technological point of view is summarised. The results of independent analysis confirmed that the best approach is to combine two concepts of positron generation, which are based on the exploiting of neutron and gamma radiation. The results verified that the proposed concept can reach the defined threshold of the positron yield and the positron beam can reach an intensity of 1013 e+/sec (un-moderated). The details of completed work are reported in this paper.
Study of Unbound HePs Using Exact Diagonalization Technique
Authors: Zubiaga Asier , Tuomisto Filip , Puska Martti
Published: November 2012

The many-body wavefunction of the unbound He-Ps system has been studied by the exact diagonalization of a explicitly correlated gaussians basis optimized by a stochastic variational method. The nucleus-positron distance has been varied by constraining the parameters of the nucleus-positron correlated gaussian term. The constraining technique allows to describe He and Ps interacting at different distances. The calculated wavefunction can be approximated as composed by weakly perturbed He and Ps atoms. The electron forming the Ps tends to be farther from the nucleus than the positron due to the strong electron-electron Pauli repulsion with the electrons of He. The described technique gives accurate energy and wave functions for Ps interacting with atoms that can be used to calculate the interaction potential of Ps with molecular matter.
Study of Thin Nafion® Films for Fuel Cells Using Energy Variable Slow Positron Annihilation Spectroscopy
Authors: Mohamed Hamdy F.M. , Kuroda Seiti , Kobayashi Yoshinori , Tavernier Bruno , Suzuki Ryoichi , Ohira Akihiro
Published: November 2012

Nafion® is one of the most popular proton conducting membranes for polymer electrolyte fuel cells (PEFCs). For the integration of Nafion® to the catalyst layers, very thin layers of the polymer are often formed on the catalysts of PEFC from dilute solutions. We applied energy variable positron annihilation to characterizing the structure of thin Nafion® films prepared by spin and dip coating from ethanol/water solutions of Nafion® on Si substrates. Experimental data suggest that the nano-structure of 23 nm thick spin coated Nafion® film is different from 220 nm thick film and also from 26 and 227 nm thick dip coated films, possibly due to the preservation of the unique rod-like structure of Nafion® in the dilute solution.
Beyond the Point Ps Approximation
Authors: Stepanov Sergey V. , Zvezhinskiy Dmitry S. , Byakov Vsevolod M.
Published: November 2012

In application to positron annihilation spectroscopy, Ps atom is considered not as a point particle, but as a finite size e+e- pair localized in a bubble-like state in a medium. It is shown that during transition from quasifree to localized state, variation of the internal Coulombic e+-e- attraction energy (several eV) plays an important role, which may govern Ps localization process.
Motion of Molecules at Plateau Region: Case of Propylene Glycol
Authors: Majerník Viktor , Krištiak Jozef , Šauša Ondrej , Iskrová-Miklošovičová Martina
Published: November 2012

Positronium annihilation measurements on normal and deuterated propylene glycols have been performed at the temperature range (14-325) K. The so-called “plateau region” in the dependence of the ortho-positronium lifetime on temperature has been observed at temperatures T > 270 K. Free volume differences between normal and deuterated propylene glycols have been observed at ≈ 100 K and ≈ 225 K. Assuming a linear expansion of propylene glycol at T > 260 K, we can estimate the velocity of moving molecules or part of them that surround a free volume. It appears to be 2.5 cm/s (0.25 Å/ns) in average.
Modification of the Crystallographic Structure of Olanzapine during Solvation by PALS and X-Ray Diffraction Methods
Authors: Tydda Maciej , Jasińska Bożena , Kozioł Anna E. , Wawrzycka-Gorczyca Irena
Published: November 2012

Two selected solvents were incorporated into the olanzapine structure. Molecules located inside the voids in the structure caused the changing of the o-Ps lifetime and intensity. After removing the n-butanol●H2O molecules, the materials returned to its initial structure. Creating the complex with the methanol●H2O leads to the change of the crystallographic structure of the olanzapine.
Evolution of Iron Electronic State in the Solid Solutions Gd2-xSr1+xFe2O7-δ
Authors: Shilova Anastasya , Chislova Irina , Panchuk V. , Semenov V. , Zvereva Irina
Published: November 2012

The present study is devoted to the non-isovalent substitution of Gd+3 for Sr+2 in matrix of Gd2-xSr1+xFe2O7 with perovskite-type intergrowth structure and to the investigation of oxidation state of iron depending on the method of synthesis and the content of solid solutions. Mössbauer spectroscopy showed the difference in the structure of complex ferrite Gd2SrFe2O7 obtained by ceramic technology (iron in single Fe+3 magnetically ordered state) from oxides obtained by the sol - gel technology (Fe+3 in the three different surroundings and presence of Fe+4).
Crystallization and Thermal Behavior of 2MX·CuX2·2H2O (M+ = K, NH4, Rb, Cs; X- = Cl, Br)
Authors: Tepavitcharova Stefka , Kovacheva Antonina , Balarew Christo
Published: November 2012

The crystallization in the MX – CuX2 – H2O system (M+ = K, NH4, Rb, Cs; X- = Cl, Br) was studied and 2MX.CuX2.2H2O was found to be the predominant type of double salts. All of them are isostructural (tetragonal crystal system, sp. gr. P42/mnm) and the structure consists of discrete [Me(H2O)2X4] octahedra and separate M+ ions. The thermal behavior of 2MX.CuX2.2H2O was studied in the range 20-780°C. Ammonium salts showed analogous behavior but higher thermal stability (up to 100-120°C) than the other salts (up to 50-60°C). The first step of 2MX.CuX2.2H2O decomposition was dehydration to anhydrous double salts that occurred up to 100-210°C. The second step was the decomposition of the anhydrous double salts followed by CuX2 decomposition. Formal kinetic parameters (E*deh and A) were calculated and kinetic equations of the dehydration processes were derived from the TG curves using the differential method of non-isothermal decomposition. The results pointed to a diffusion-controlled dehydration process in all cases.
Calorimetric Study of the Hydrogen Interaction with Ce6Ni1.67Si3
Authors: Anikina E.Yu. , Verbetsky V.N. , Yaropolov Yuriy L.
Published: November 2012

In the present work at the first time the hydrogen interaction with Ce6Ni1.67Si3 at pressure up to 45 atm and temperature 51˚C has been investigated by means of the calorimetric method. The ΔHabs. – C dependence (ΔHabs. –the partial molar enthalpy of the reaction of the hydrogen interaction with IMC, C – hydrogen concentration, C=H/IMC) was obtained.
Comparison of Iron-Cluster Deformations of Troilite Phases with Non-Stoichiometry and Vanadium Impurity
Authors: Hayashi Koya , Sakane Genta , Miyata Yoshihisa , Tashima Youhei , Nakata Yukio , Katayama Yasuhiro
Published: November 2012

The Fe-deficient troilite phase of the composition range between FeS1.00 and FeS1.40 was investigated in terms of the phase equilibrium, the crystal structure, and the electronic states. The Fe-vacancy relaxes the Fe3-cluster in the troilite structure. The vanadium impurity closes the Fe3-clusters in face to face manner. The electronic state modification of the idealized troilite FeS by the Fe-vacancy formation and the vanadium impurity substitution are calculated by DV-Xαcluster method to discuss the deficient troilite phase.
Lattice and Magnetic Anisotropies in Uranium Intermetallic Compounds
Authors: Havela Ladislav , Maskova Silvie , Adamska Anna , Kolomiets Aleksandre V. , Kim-Ngan N.T.H. , Daniš Stanislav , Heathman Stephen , Kothapalli Karunakar , Nakotte Heinz , Bordallo Heloisa
Published: November 2012

Examples of UNiAlD2.1 and UCoGe illustrate that the soft crystallographic direction coincides quite generally with the shortest U-U links in U intermetallics. It leads to a simple rule, that the easy magnetization direction and the soft crystallographic direction (in the sense of highest compressibility under hydrostatic pressure) must be mutually orthogonal.
Effect of Denture Cleanser on Weight, Surface Roughness and Tensile Bond Strength of Two Resilient Denture Liners
Authors: Chandu GS , Huddar Dayanand Ashok , Hombesh MN , Nanjannawar Girish Shankar
Published: November 2012

Aim

Evaluating effects of a denture cleanser on weight, surface roughness and tensile bond strength on two resilient lining materials.

Materials and methods

Specimens of heat cure acrylic resin were prepared to verify weight change, surface roughness and tensile bond strength. Specimens were divided into four groups: Relined with resilient liner Visco-gel, soft liner immersed in Clinsodent denture cleanser and water and evaluated immediately, 24 hours, 7 and 15 days. Weight changes, roughness and tensile bond strength were determined and data submitted to statistical analysis.

Results

Visco-gel specimens immersed in water (group 1) have shown significant increased surface roughness than those immersed in Clinsodent (group 3) during 24 hours, 7 and 15 days. The soft liner specimens immersed in water (group 2) have shown increased surface roughness than those immersed in Clinsodent (group 4) during 24 hours and 7 days. Visco-gel specimens immersed in water have shown significant increased tensile bond strength during 7 and 15 days than those immersed in Clinsodent. The soft liner specimens immersed in water have shown increased tensile bond strength than those immersed in Clinsodent during immediately, 24 hours and 7 days.

Conclusion

Within limitations of this study, specimens immersed in Clinsodent demonstrated increased weight changes compared with water. Specimens immersed in water demonstrated lesser surface roughness and tensile bond strength compared with specimens immersed in Clinsodent.

Clinical significance

Resilient denture liners and denture cleansers are most commonly used materials in prosthodontics. Caution should be taken while selecting the materials which cause the detrimental changes on properties of the materials.

How to cite this article

Huddar DA, Hombesh MN, Sandhyarani B, Chandu GS, Nanjannawar GS, Shetty R. Effect of Denture Cleanser on Weight, Surface Roughness and Tensile Bond Strength of Two Resilient Denture Liners. J Contemp Dent Pract 2012;13(5):607-611.
In vitro Evaluation of Microleakage under Ceramic and Metal Brackets Bonded with LED and Plasma Arc Curing
Authors: Davari Abdolrahim , Yassaei Soghra , Karandish Mariam , Zarghami Fateme
Published: November 2012

Aim

The aim of the present study was to evaluate these two high intensity light curing units regarding microleakage beneath metal and ceramic brackets.

Materials and methods

A total of 60 freshly extracted human premolar teeth were randomly divided into four groups of 15 samples; group I: Metal bracket + LED cured, group II: Ceramic bracket + LED cured, group III: Metal bracket + plasma arc cured, group IV: Ceramic bracket + plasma arc cured.

After photopolymerization, the teeth were immersed in water and thermocycled (500 cycles between 5 and 55). Specimens were further sealed with nail varnish and stained with 5% basic fuchsin for 24 hours. All of the teeth were sectioned with two parallel longitudinal occlusogingival cuts and examined under a stereomicroscope. The microleakage was measured with a digital caliper and scored from 0 to 3 for marginal microleakage at the bracket-adhesive and adhesive-enamel interfaces from both the occlusal and gingival margins.

Results

Microleakage was detected in all groups. The plasma arc cured group showed less microleakage than light emitting diode (LED) cured in all samples at the enamel-adhesive interface at the gingival margin (ceramic brackets, p = 0.009 and metal brackets, p = 0.005). The plasma arc cured samples showed less microleakage than LED cured in metal brackets at the adhesive-brackets interface at the occlusal margin (p = 0.033). While curing with an LED unit, ceramic brackets displayed significantly less microleakage than metal ones at the gingival margin of adhesive-enamel interface (p = 0.013).

The gingival margin in all groups exhibited higher microleakage compared with those observed in occlusal sides in all sample groups (p < 0.001).

Conclusion

1. LED units cause more microleakage than plasma arc units.

2. In all groups the microleakage at the gingival margin is greater than the occlusal margin.

Clinical significance

The microleakage formation permits the passage of bacteria and oral fluids initiating white spot lesions beneath the bracket base.

How to cite this article

Davari A, Yassaei S, Karandish M, Zarghami F. In vitro Evaluation of Microleakage under Ceramic and Metal Brackets Bonded with LED and Plasma Arc Curing. J Contemp Dent Pract 2012;13(5):644-649.
Glass Ionomer Cement as an Orthodontic Bonding Agent
Authors: Ali Hashim , Maroli Sasi
Published: November 2012

Aim

• To find an alternative to popular orthodontic bonding agent composite resin and elimination of acid etching.

• To assess GC Fuji Ortho as an orthodontic bonding agent under different enamel conditions and evaluate the shear bond strength.

• Enamel surfaces intentionally contaminated with saliva, conditioned enamel using Fuji dentin conditioner and conventional 37% phosphoric acid/60 seconds.

• To evaluate and compare shear bond strength to a ‘gold standard’ composite bonding agent—Rely-a-Bond.

Materials and methods

The sample consisted of 50 human premolar teeth collected and stored in formalin. Out of 50 samples, 38 were upper premolars and 12 were lower second premolars. The total sample divide into 10 each. Stainless steel contour bracket with bondable mesh measured about 3.42 mm in length and 3.31 mm in width. Each tooth sample was embedded in a cylindrical acrylic block of polymethyl methacrylate (PMMN). The buccal surfaces of all the samples were polished with fluoride-free pumice and rinsed thoroughly. Group 1 bonded with GC Fuji Ortho after getting etched with 37% phosphoric acid/60 seconds. Group 2 was contaminated with saliva. Group 3 was conditioned with Fuji dentin condition. Group 4 unetched, uncontaminated, and Group 5 was treated with rely bond composite resin after getting etched with 37% phosphoric acid. The shear bond strength was tested using Instron universal testing machine. The force at which bond failed was recorded on XY recorder as shear/peel bond strength of the material used for bonding. The reading obtained were statistically analyzed.

Result

Rely bond showed highest bond strength of 64.70 N (Newtons). The next highest value was that of Group 1. The lowest bond strength in the Group 4.

Conclusion

GC Fuji Ortho can be used as a bonding agent on etched enamel. Unetched, uncontaminated enamel surfaces were inadequate for bracket bonding.

Clinical significance

Potential benefits of glass ionomer cements can be utilized in orthodontic bonding.

How to cite this article

Ali H, Maroli S. Glass Ionomer Cement as an Orthodontic Bonding Agent. J Contemp Dent Pract 2012; 13(5):650-654.
A Cross-Sectional Study on the Relationship between Behavioral Variables and Economic Status in Periodontal Disease among Elderly Individuals
Authors: Prasanna HR , Chandan DN , Kripal Krishna , Hari KR , Adarsh CM , Reddy T Praveenkumar
Published: November 2012

Objectives

The objectives of this study were to examine the relationship between behavioral variables, such as smoking and level of income on the periodontal disease among older South Indian adults.

Materials and methods

Data pertaining to participants aged 55 years and above from the Outpatient Department of MR Ambedkar Dental College and Hospital were used. A total of 209 elderly subjects were selected by convenient sampling and a complete evaluation of their periodontal status was carried out.

Results

Our study showed that patients belonging to the lower income group and smokers had more severe disease compared to other groups. They were found to have higher plaque scores, higher calculus scores, deeper pockets and attachment loss compared to the subjects of the other groups.

Conclusion

Variables, such as smoking, gender and low income are associated with the severity of periodontal disease in older adults.

How to cite this article

Prasanna HR, Chandan DN, Kripal K, Hari KR, Adarsh CM, Reddy TP. A Cross-Sectional Study on the Relationship between Behavioral Variables and Economic Status in Periodontal Disease among Elderly Individuals. J Contemp Dent Pract 2012;13(5):699-702.
Dental Infection Control and Occupational Safety in the Russian Federation
Authors: Miller Kierste , Budnyak Marina A , Gurevich Konstantin G , Fabrikant Kate , Puttaiah Raghunath
Published: November 2012

Background

In the recent past, the Russian Federation has seen a considerable increase in HIV caseload. A high level committee was formed to assess the status of dental infection control and safety (IC&S) in Russia. This article is one of the outcomes to assess the status of IC&S and is the research of a doctoral student (PhD) in public health.

Purpose

To assess needs in Dental Infection Control and Occupational Safety in the Moscow Metropolitan Region of the Russian Federation.

Materials and methods

A survey with variables assessing knowledge, attitude and practice of IC&S was administered to dentists practicing and or teaching in Moscow city and suburban areas on a convenience sample of dental practitioners.

Results

The total number of completed questionnaires were 303. Over 67% had up to three significant exposures to blood and potentially infectious materials (OPIM), but less than 30% got tested for HIV in the previous 3 months. Use of personal protective equipment was not based on anticipated exposure. Less than 10% had an understanding of Spaulding's classification with respect to sanitization, disinfection and sterilization. Only about 34% stated that there was a potential for infectious disease transmission through a percutaneous route and about 61% double gloved while treating patients with infectious diseases. Only about 61% disinfected impressions and most (83%) used alcohol for disinfection purposes. While 34% still used glass-bead sterilizers, about 13% did not sterilize handpieces between patients.

Conclusion

Results from this study indicated a disparity in the practice of infection control and safety procedures requiring formulation of nationwide dental safety standards. Further, there is a need in implementation of a standardized dental safety curriculum for dental schools and continuing dental education requirements in dental safety for practicing dentists in the Russian Federation.

How to cite this article

Budnyak MA, Gurevich KG, Fabrikant K, Miller K, Puttaiah R. Dental Infection Control and Occupational Safety in the Russian Federation. J Contemp Dent Pract 2012;13(5):703-712.
Invasive Cervical Resorption: Etiology, Diagnosis, Classification and Treatment
Authors: Discacciati José Augusto César , de Souza Eduardo Lemos , Costa Sérgio Carvalho , Sander Herbert Haueisen , de Magalhães Barros Vinícius , Vasconcellos Walison Arthuso
Published: November 2012

Background

Invasive cervical resorption (ICR) is not well understood by the professional, being misdiagnosed, leading to inappropriate treatment and unnecessary loss of tooth.

Introduction

ICR is defined as a localized process of resorption, which begins in the cervical area of the tooth, just below the epithelial junction and above the ridge crest in the area of the connective tissue insertion. Possible predisposing factors include external trauma, orthodontic movement, surgical procedures, periodontal disease and its treatments, endogenous bleaching, pressure generated by wind instruments and herpes virus infection. Different approaches have been suggested for the treatment of ICR, depending on the extent of the lesion and its location. However, in some cases due to the severity of the injury, there is no alternative but to tooth extraction, followed by restoration of the edentulous area.

Aim and objective

Discuss etiology, diagnosis and classification of the ICR, as well as different treatment options. Also is presented a case in which extraction was carried out, installation of the implant and ceramic crown, subsequent to a treatment approach that resulted in failure in the short-term period.

Conclusion

Early diagnosis of the ICR is critical to proper treatment and favorable prognosis. Interdisciplinary treatment should be instituted as soon as possible, avoiding the loss of the affected tooth. In advanced cases, treatment involving the installation of osseointegrated implants should be considered the first choice of treatment.

Clinical significance

Early diagnosis of the ICR is critical do prevent unnecessary tooth loss, once the prognosis for advanced cases is doubtful.

How to cite this article

Discacciati JAC, de Souza EL, Costa SC, Sander HH, Barros VM, Vasconcellos WA. Invasive Cervical Resorption: Etiology, Diagnosis, Classification and Treatment. J Contemp Dent Pract 2012;13(5):723-728.
Orbital Abscess arising from an Odontogenic Infection
Authors: Vijayan Ajoy , Sreejith VP , LNU Ranjini , Ahamed Gufran
Published: November 2012

Aim

Presenting a rare complication of an odontogenic infection extending to the orbit.

Background

A 45-year-old male patient reported with periorbital swelling of eyelids, of the left eye, foul smelling nasal discharge and a pus draining sinus on the left lower eyelid area.

Case description

The patient gave history of pain in the left upper first molar tooth 1 week back. His intraoral examination showed poor oral hygiene with tenderness on percussion on the left maxillary first molar. Investigations showed possible extension of infection from left maxillary molar root to maxillary sinus and to the orbital floor.

Conclusion

A case of periapical infection of a maxillary left molar resulting in an orbital abscess is presented. Identification of odontogenic source of infections, institution of drainage, removal of offending teeth and appropriate antimicrobial therapy are mandatory in preventing loss of vision and cerebral extensions. The pathways of spread of the infection, treatment aspects, are discussed and complications are reviewed.

How to cite this article

Vijayan A, Sreejith VP, Ranjini, Ahamed G. Orbital Abscess arising from an Odontogenic Infection. J Contemp Dent Pract 2012;13(5):740-743.
Investigating relationships between aerosol optical depth and cloud fraction using satellite, aerosol reanalysis and general circulation model data
Authors: Grandey B. S. , Stier P. , Wagner T. M.
Published: November 2012

Abstract. Strong positive relationships between cloud fraction (fc) and aerosol optical depth (τ) have been reported. Data retrieved from the MODerate resolution Imaging Spectroradiometer (MODIS) instrument show positive fc–τ relationships across most of the globe. However, these relationships are not necessarily due to cloud–aerosol interactions. Using state of the art Monitoring Atmospheric Composition and Climate (MACC) reanalysis-forecast τ data, which should be less affected by retrieval artifacts, it is demonstrated that a large part of the observedfc–τ signal may be due to cloud contamination of satellite-retrieved τ. For longer MACC forecast time-steps of 24 h, which likely contain less residual cloud contamination, some negative fc–τ relationships are found. ECHAM5-HAM general circulation model (GCM) simulations further demonstrate that positive fc–τ relationships may arise due to covariation with relative humidity. Widespread negative simulated fc–τ relationships in the tropics are shown to arise due to scavenging of aerosol by precipitation. Wet scavenging events are likely poorly sampled in satellite-retrieved data. Quantifying the role of wet scavenging, and assessing GCM representations of this important process, remains a challenge for future observational studies of aerosol–cloud–precipitation interactions.
Macrofauna community inside and outside of the Darwin Mounds SAC, NE Atlantic
Authors: Serpetti N. , Gontikaki E. , Narayanaswamy B. E. , Witte U.
Published: November 2012

Abstract. Over the past two decades, growing concerns have been raised regarding the effects of towed fishing gears, such as trawls and dredges, on deep-sea biodiversity and ecosystem functioning. Trawling disturbs the benthic communities both physically and biologically, and can eliminate the most vulnerable organisms and modify habitat structure; chronically disturbed communities are often dominated by opportunistic species. The European Union is under obligation to designate a network of offshore Special Areas of Conservation (SACs) and Marine Protected Areas (MPAs) by the end of 2012 based on the perceived expectation that these networks will help protect marine biodiversity and that within these areas, faunal abundance and diversity will be higher than the surrounding fished areas. The Darwin Mounds, only discovered in 1998, are located in the Rockall Trough, NE Atlantic at a depth of ~ 1000 m. Deep-water trawling regularly took place in the region of the Darwin Mounds; however in 2004 the mounds were designated as the first offshore SAC in UK and the area is now closed to bottom trawling. As part of the HERMIONE programme the influence of human impact on the Oceans was one of the key themes and in June 2011, an investigation of the macrofaunal community structure at comparable sites both inside and outside of the Darwin Mound SAC was undertaken. Macrofaunal communities were found to differ significantly, with the difference mostly driven by changes in the abundance of polychaetes, crustaceans and nematodes whilst no significant differences were seen for the other phyla. Whereas overall macrofaunal abundance was higher outside the SAC compared to within, this pattern varies considerably between phyla. Diversity indices showed no significant differences between protected and unprotected sites. This could indicate that a few years of preservation are not enough time to determine a recovery by the macrofaunal community of cold-water ecosystems and that a continued monitoring over a longer term is necessary to fully understand the impact of fishery closures.
Multifractal analysis of solar flare indices and their horizontal visibility graphs
Authors: Yu Z. G. , Anh V. , Eastes R. , Wang D.-L.
Published: November 2012

Abstract. The multifractal properties of the daily solar X-ray brightness, Xl and Xs, during the period from 1 January 1986 to 31 December 2007 which includes two solar cycles are examined using the universal multifractal approach and multifractal detrended fluctuation analysis. Then we convert these time series into networks using the horizontal visibility graph technique. Multifractal analysis of the resulting networks is performed using an algorithm proposed by us. The results from the multifractal analysis show that multifractality exists in both raw daily time series of X-ray brightness and their horizontal visibility graphs. It is also found that the empirical K(q) curves of raw time series can be fitted by the universal multifractal model. The numerical results on the raw data show that the Solar Cycle 23 is weaker than the Solar Cycle 22 in multifractality. The values of h(2) from multifractal detrended fluctuation analysis for these time series indicate that they are stationary and persistent, and the correlations in the time series of Solar Cycle 23 are stronger than those for Solar Cycle 22. Furthermore, the multifractal scaling for the networks of the time series can reflect some properties which cannot be picked up by using the same analysis on the original time series. This suggests a potentially useful method to explore geophysical data.
On the multi-scale nature of large geomagnetic storms: an empirical mode decomposition analysis
Authors: De Michelis P. , Consolini G. , Tozzi R.
Published: November 2012

Abstract. Complexity and multi-scale are very common properties of several geomagnetic time series. On the other hand, it is amply demonstrated that scaling properties of geomagnetic time series show significant changes depending on the geomagnetic activity level. Here, we study the multi-scale features of some large geomagnetic storms by applying the empirical mode decomposition technique. This method, which is alternative to traditional data analysis and is designed specifically for analyzing nonlinear and nonstationary data, is applied to long time series of Sym-H index relative to periods including large geomagnetic disturbances. The spectral and scaling features of the intrinsic mode functions (IMFs) into which Sym-H time series can be decomposed, as well as those of the Sym-H time series itself, are studied considering different geomagnetic activity levels. The results suggest an increase of dynamical complexity and multi-scale properties for intermediate geomagnetic activity levels.
Hepatic Dysfunction in Hospitalized Patients with Acute Thyrotoxicosis: A Decade of Experience
Authors: Elias Richard M. , Dean Diana S. , Barsness Gregory W.
Published: November 2012

Thyroid disease is a common condition, and thyroid hormone excess or deficiency is known to have wide-ranging effects on a variety of organ systems. Our objective is to describe the magnitude, biochemical features, and clinical characteristics of hepatic abnormalities in patients with acute thyrotoxicosis. We performed a retrospective review of all patients admitted to our institution between January 1, 1998 and December 31, 2008 with a discharge diagnosis of acute thyrotoxicosis excluding iatrogenic causes. The records of these patients were reviewed and data extracted regarding demographic, biochemical, and clinical data particularly relevant to liver function. Fourteen patients were identified of which eleven had liver studies performed. The majority (90.9%) had Graves disease. Nine of eleven patients (81.8%) had some degree of hepatic abnormality. Seven patients (63.6%) had an elevation in one or both transaminases, and two (18.2%) had isolated synthetic dysfunction as manifested as an elevated INR and/or decreased albumin without transaminitis. The mean magnitude of deviation from the normal range was greater in the transaminases as compared to bilirubin, INR, or albumin. Definitive treatment was radioiodine ablation in six cases (54.5%) and surgical thyroidectomy in two cases (18.2%). Noniatrogenic acute thyrotoxicosis requiring hospitalization is a rare condition which is most frequently caused by Graves disease. The majority of patients have disordered liver tests of a highly variable nature, making the recognition of this association important in the care of patients presenting with acute thyrotoxicosis.
Obesity Prevention and National Food Security: A Food Systems Approach
Authors: Finney Rutten Lila , Yaroch Amy Lazarus , Patrick Heather , Story Mary
Published: November 2012

Interventions that cultivate sustainable food systems to promote health, prevent obesity, and improve food security have the potential for many large-scale and long-lasting benefits including improvements in social, environmental, health, and economic outcomes. We briefly summarize findings from previous research examining associations between obesity and food insecurity and discuss the need for greater synergy between food insecurity initiatives and national obesity prevention public health goals in the United States. The common ground between these two nutrition-related public health issues is explored, and the transformation needed in research and advocacy communities around the shared goal of improving population health through individual, environmental, and policy level changes to promote healthy sustainable food systems is discussed. We propose an ecological framework to simultaneously consider food insecurity and obesity that identifies levers for change to promote sustainable food systems to improve food security and prevent obesity.
Parametric Study of Entropy Generation in a Fluid with Internal Heat Generation between Two Rotating Cylinders Subjected to Convective Cooling at the Surface
Authors: El Haj Assad M. , Oztop Hakan F.
Published: November 2012

Entropy generation analysis of a steady fluid flow with internal heat generation between two rotating cylinders was presented. The surface of the inner cylinder was kept at constant temperature while the surface of the outer cylinder was exposed to convection cooling. Analytical expressions for velocity and temperature distributions within the fluid were obtained. The effects of velocity ratio, Biot number, Brinkman number and other dimensionless parameters on the temperature distribution and local and total entropy generation rates were investigated and the results were presented graphically.
Epidemiology of Citrus tristeza virus in nursery blocks of Citrus macrophylla and evaluation of control measures
Authors: Vidal E. , Moreno A. , Bertolini E. , Martínez M. C. , Corrales A. R. , Cambra M.
Published: November 2012

The control of Citrus tristeza virus (CTV), the causal agent of tristeza disease, is essential to guarantee a productive citrus industry. The specific features of a nursery block make the control of the natural spread of viruses transmitted by vectors more difficult. Thus, the knowledge of the epidemiology of CTV in nursery blocks is basic to the design control strategies of the disease. Two experimental nursery plots of alemow (Citrus macrophylla) were planted in open field in Moncada (Valencia, Spain) (with a high CTV prevalence, 85%), and in Alcanar (Tarragona, Spain) with 700 and 843 nursery plants, respectively. The plants were analysed by tissue print-ELISA using 3DF1 and 3CA5 CTV-specific monoclonal antibodies. The CTV prevalence estimated after one year of cultivation in both plots was of 24.37% and 3.91%, respectively. At the same time, a commercial nursery plot grown under plastic-net covers established in Alcanar with 1,200 plants was also analysed as above, being the CTV prevalence estimated of 0.00%. The aphid activity present in the nursery plots was monitored. Aphis spiraecola was the most abundant aphid species visiting the plants in the nursery plots grown in the open field, whereas the aphid activity registered in the plants grown under the plastic-net covers was practically zero. The percentage of individual aphids carrying CTV PCR-amplifiable targets detected by squash real-time RT-PCR in the open-field nursery plots was 17.5% in Moncada and 1.67% in Alcanar. No significant differences in the CTV prevalence between treated and non-treated plants with horticultural mineral oils were found in the area with the high CTV-inoculum pressure.
Assessing the introduction and development of a designation of origin from the firm's perspective: The case of the Ribera del Guadiana wine PDO
Authors: García-Galán M. M. , Del Moral-Agúndez A. , Galera-Casquet C.
Published: November 2012

Designations of origin are essential brands in the agro-food market to define marketing strategies. The establishment of designations of origin in Spain has taken place during the last two decades and agro-food products have been adapted to these protection forms. However, little is known about wineries manager’s point of view during the introduction process. In this work, we have analyzed the introduction and development of a designation of origin of wine from the company point of view. To this end, we carried out a qualitative analysis of interviews conducted to winemakers of this form of protection of food products. In the period studied, the consideration of the winemakers interviewed towards their designation of origin increased to a clear commitment to this form of protection of agro-food products. The majority opinion among the winemakers about what the PDO should offer the market leant more towards the product than the brand, reaching consumers with a quality product and from there to get it associated with its brand. This process has taken place during the period studied because while some winemakers still consider the product to be more important than the brand, others have already begun the process of promoting and strengthening their brands, aware that the consumer already perceives the product's quality. It can be concluded therefore that the origin attribute is very important for brands belonging to the agro-food sector, useful to create an origin-based marketing strategy.
What makes a citrus farmer go organic? Empirical evidence from Spanish citrus farming
Authors: Beltrán-Esteve M. , Picazo-Tadeo Andrés J , Reig-Martínez E.
Published: November 2012

Organic farming is increasing its share of total world food output and receiving grow-ing support from policymakers concerned with agricultural sustainability issues. This paper studies the characteristics of citrus farmers in the Spanish region of Valencia that affect their probability of becoming organic farmers. A fair understanding of these characteristics may help policymakers improve the design of agricultural policies aimed at supporting organic citrus practices. As regards the methodology, a probit model is estimated with information from a sample of conventional and organic citrus farmers obtained from a survey designed for a larger research project aimed at analysing Valencian citrus farming. Our main finding is that university education and agricultural professional training both increase the probability of becoming an organic farmer. Conversely, older farmers, farmers selling their production to foreign markets and those with larger farms and/or managing family farms are less likely to adopt organic citrus farming. The main policy implication is that, in order to support organic citrus production, more attention needs to be paid to improving farmers’ technical training and education.
Impacts of climate change on water footprint of spring wheat production: the case of an irrigation district in China
Authors: Sun S. K. , Wu P. T. , Wang Y. B. , Zhao X. N.
Published: November 2012

The potential impacts of climate change are expected to reshape the patterns of demand and supply of water for agriculture, therefore the assessment of the impacts of climate change on agricultural water consumption will be essential. The water footprint provides a new approach to the assessment of agricultural water consumption under climate change. This paper provides an analysis of the impacts of climate changes on the water footprint of spring wheat in Hetao Irrigation District, China during 1980-2009. Results indicate that: 1) crop evapotranspiration and irrigation water requirements of spring wheat presented a downtrend owing to the climate factors variation in the study period; 2) under the combined influence of increasing crop yield and decreasing crop evapotranspiration, the water footprint decreased during the study period, exhibiting a trend of 0.025 m3 kg-1 yr-1; 3) the total contribution rate of the climatic factors for the decline of water footprint of spring wheat during the study period was only 10.45%. These results suggest that the water footprint of a crop, to a large extent, is determined by agricultural management rather than by the regional agro-climate and its variation. Nevertheless, we should pay attention to the adaptation of effective strategies for minimizing the agricultural production risk caused by climate change.
Effect of fatty acids source on growth performance, carcass characteristics, plasma urea nitrogen concentration, and fatty acid profile in meat of pigs fed standard- or low-protein diets
Authors: Martínez-Aispuro M. , Figueroa-Velasco J. L. , Zamora-Zamora V. , Sánchez-Torres M. T. , Ortega-Cerrilla M. E. , Cordero-Mora J. L. , Ruiz-Flores A. , González-Muñoz S. S.
Published: November 2012

Thirty six Landrace × Yorkshire barrows with 18.6 kg of initial body weight were used to evaluate three sources of fatty acids: crude soybean oil, conjugated linoleic acid (CLA), and soybean soapstock in standard crude protein (CP) and low-protein diets for starter (21 d; 205, 160 g kg-1 CP), growing (28 d; 160, 145 g kg-1 CP), and finishing (29 d; 140, 125 g kg-1 CP) phases. Growth performance, carcass characteristics, plasma urea nitrogen concentration and fatty acid profile in meat were evaluated. The reduction of CP diminished average daily gain, feed:gain ratio, longissimus muscle area and plasma urea nitrogen concentration in nursery pigs; reduced longissimus muscle area and plasma urea nitrogen concentration in growing pigs; increased average daily feed intake, and reduced lean meat percentage and plasma urea nitrogen content in finishing pigs. It also increased c9, t11 and c11, t9 CLA isomers and total lipids and lowered eicosapentaenoic and docosahexaenoic acids concentrations in semimembranosus muscle; linolenic acid decreased with low-protein diets in longissimus and semimembranosus muscles; the oil type affected the concentration of c9, t11 and c11, t9 CLA isomers and total saturated fatty acids in semimembranosus muscle; CLA increased individually and total saturated fatty acids, reduced linoleic and docosapentaenoic acids, and increased total lipids in longissimus muscle. These results indicate that decreasing CP changes the profile of fatty acids. The soybean soapstock can replace crude soybean oil in pig diets; while conjugated linoleic acid does not improve response of pigs fed standard- or low-protein diets.