bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Face Recognition Using 2D-LDA with Weighted Covariance Scatter
Authors: Lee Seok Jin , Oh Chi Min , Lee Chil Woo
Published: June 2014

In this paper, we propose a newly developed 2D-LDA method based on weighted covariance scatter for face recognition. Existing LDA uses the transform matrix that maximizes distances between classes. In LDA, we have to convert from an image to one-dimensional vector as training vector. In 2D-LDA, on the other hand, we can directly use two-dimensional image itself as training matrix, so that the classification performance can be enhanced about 20% comparing LDA, since the training matrix preserves the spatial information of two-dimensional image. However 2D-LDA uses same calculation schema for transformation matrix and therefore both LDA and 2D-LDA has the heteroscedastic problem which means that the class classification cannot obtain beneficial information of spatial distances of class clusters since LDA uses only data correlation-based covariance matrix of the training data without any reference to distances between classes. In this paper, we propose a new method to apply training matrix of 2D-LDA by using WPS-LDA idea that calculates the reciprocal of distance between classes and apply this weight to between class scatter matrix. To evaluate the performance of proposed algorithm, we use the ORL face database that includes 40 people and 10 images individually. The experimental result shows that the discriminating power of proposed 2D-LDA with weighted between class scatter has been improved up to 2% than original 2D-LDA. This method has good performance especially when the distance between two classes is very close and the dimension of projection axis is low.
Inspection of Polymer Polaroid’s Visual Defects with Stripe Light Illumination
Authors: Deng Yuan Long , Zeng Xiao Xing , Geng You Fu , Li Xue Jin
Published: June 2014

The visual defects of the polymer polaroid have a direct and serious influence on the quality of TFT-LCD panels. A variety of image detection systems have been proposed and widely used by the manufacturers of polaroid and panels in order to detect the visual defects at the earliest possible stage in the production process. Some slight visual defects, however, are barely visible in the images acquired by a camera when under a common illumination condition. In order to deal with this problem, we present a novel machine vision system in which a stripe light source is introduced to illuminate the polaroid sample, and these special defects therefore become more visible. At the base of the aforementioned image enhancement, a straightforward and fast image processing algorithm is designed and implemented. The Morphology Template Method is investigated and the shapes, the locations and the sizes of the visual defects are extracted successfully. The experimental results demonstrate this methodology’s validity to inspect the visual defects of transparent multilayer polymer films.
Study of Slice Cell Counting System
Authors: Yuan Shuai , Zhang Guo Yun , Wu Jian Hui , Guo Long Yuan
Published: June 2014

Slice cell counting system has been widely applied for medical clinical field, which studies image smoothing, threshold segmentation, morphologic processing and cell information statistics based on digital image processing technology. This paper presents system design and realization of counting technology for slice cells. Cell microscopic image is smoothed by adopting mean filtering method at first. Then HIS threshold segmentation method is used for further analysis. There are five steps in morphologic processing including hole filling, erosion, thinning, center point modification and edge extraction to search cells. Cell information statistics including number, average radius and area is carried on finally. Test result shows that the method presented has good accuracy, quick speed and strong robustness for realtime application.
Fine-Grained Access Control with Efficient Revocation in Cloud Storage
Authors: Zhong Ting , Sun You Peng , Liu Qiao
Published: June 2014

In the cloud storage system, the server is no longer trusted, which is different from the traditional storage system. Therefore, it is necessary for data owners to encrypt data before outsourcing it for sharing. Simultaneously, the enforcement of access policies and support of policies updates becomes one of the most challenging issues. Ciphertext-policy attribute-based encryption (CP-ABE) is an appropriate solution to this issue. However, it comes with a new obstacle which is the attribute and user revocation. In this paper, we propose a fine-grained access control scheme with efficient revocation based on CP-ABE approach. In the proposed scheme, we not only realize an efficient and immediate revocation, but also eliminate some burden of computational overhead. The analysis results indicate that the proposed scheme is efficient and secure for access control in cloud storage systems.
Fullbore Image Construction of Imaging Logging Based on the Improved Texture Inpainting Method
Authors: Zhang Xiang , Wang Jun Hua , Xiao Xiao Ling
Published: June 2014

The image inpainting method based on CriminiciA’s algorithm is slowly complete the image for large blank area. An improved algorithm based on the classic texture synthesis algorithm for image inpainting is proposed for imaging logging inpainting, which is used to generate the fullbore image. Two schemes, the local search method and priority calculation with TV model, are employed in the improved texture synthesis method. Some examples were given to demonstrate the effectiveness of the proposed algorithm on dealing with fullbore image construction with large blank area and raising efficiency obviously.
Taxi Bidirectional Search System Based on Smart Phone
Authors: Xie Rong , Yan Ke , Zhou Jie
Published: June 2014

For the issues of unreasonable taxi distribution, high load rate and low dispatching efficiency etc. in the current city calling taxi services, the paper presents some key technologies of implementation of taxi driver-passenger bidirectional search system based on smart phones, including map matching, hotspot analysis, taxi route planning and bidirectional search UI. The results help achieve efficiency of urban taxi service.
The EMD Analysis AE Signals of Rock Failure under Uniaxial Compression
Authors: Zhang Tian Jun , Yu Sheng Hong , Ren Jin Hu , Cui Wei
Published: June 2014

The wavelet packet basis is difficult to be extracted by wavelet analysis at present. To solve this problem, an experiment of Acoustic Emission under uniaxial compression is conducted by SAEU2S acoustic Emission system and Electro-hydraulic servo universal testing machine and the method of empirical mode analysis is adopted to explore the acoustic emission signal in this paper. Firstly with the method of empirical mode decomposition, the acoustic emission signal is decomposed into the forms of intrinsic mode function with several local time scale and residual components, and then these data is analyzed. After the noise-reducing IMF and residual components are refactored, the error between the final and the initial reconstruction signals is less than 10-6. The experiment indicates that the EMD method is effective in processing the local rock acoustic emission signals. The EMD method also provides an efficient way to predict deformation trend of rock damage through deformation of waveform analysis.
Research and Realization the Method of Pronunciation Conversion for Speech Synthesis of the Lhasa Dialect of Tibetan
Authors: Wu Zhi Qiang , Yu Hong Zhi , Wan Shu Hui
Published: June 2014

Pronunciation conversion is the premise to realize the speech synthesis system, besides, the conversion accuracy is directly related to the quality of synthetic speech. By studying the characteristics of Tibetan words and Lhasa pronunciation, currently method of the pronunciation conversion for Tibetan dialect in Lhasa, combination the need of speech synthesis research, designed and realized the pronunciation conversion system that can be applied in the Lhasa dialect of Tibetan speech synthesis. In tests the system is up to 95.3 percent accurate, the results of conversion are basically able to meet the needs of the Tibetan speech synthesis system.
Context-Assisted Fast Face Detection
Authors: Duan Ding Bo , Ma Jian
Published: June 2014

In this paper, we propose a novel algorithm for fast face detection in camera video. By extending the task of face detection from solely relying on visual data of camera sensor to cooperatively analyzing synchronized information of multiple sensors, we greatly reduce the time cost of face detection. Specifically, when subjects wearing motion sensors move around in the field of view (FOV) of a camera, motion status estimated from the wearable sensors helps to decide when is the good time to start face detection, and thus save large amount of work previously spent on filtering out faceless frames. To test the technical feasibility and efficiency of the proposed method, we conducted extensive experiments and compared it with state-of-the-art algorithms. Results indicate that the proposed algorithm achieves significant improvements in terms of time cost.
Transmission of Image Information in the Network Multimedia Teaching
Authors: Liu Xiao Yun , Xiong Li Ting , Shen Jian
Published: June 2014

To solve the problem of image information transmission delay in the network multimedia teaching system, the compression and multicast solutions are put forward on the basis of usual screen blocking skill of data. According to the characteristics of the multimedia teaching system, the screen changes typically little at smaller intervals. It means that only a few screen blocks, which are changing, are needed to be transferred by screen blocking skill. At the same time, the network video data transmission volume is further curtailed through compression and multicast so that the multimedia information network transmission delay is decreased. The minimal buffer size for allocation is determined to ensure the smooth transmission of video data in the multimedia teaching system.
A Novel Dead-Time Control Method for Double End Converter
Authors: Liu Shu Lin , Qi Li Li
Published: June 2014

In order to achieve symmetry of the drive signal and suppress the magnetic bias, a novel dead-time control method for the double end converter is put forward in this paper, which can generate two independent and complementary PWM waveforms by configuring EPWM (Enhanced Pulse Width Modulator) module. The magnetic bias problems of the double end converter, principle of EPWM module and adjustment process of the dead-time control method are analyzed. Two different dead-times can de realized by setting the rising edge delay and falling edge delay of the corresponding registers in Dead-band (DB) module in one cycle to meet the requirement of drive signals. Experimental research on the novel dead-time control method is done on the push-pull forward circuit and the experiment results verify the feasibility of the proposed method.
Passivity-Based Controller of Tri-State Boost Converter
Authors: Tang Qi , Wang Jiu He , Hu Jing Wei
Published: June 2014

A novel boost converter named tri-state boost converter is introduced in this paper. According to the operation principle of the tri-state boost converter, the Euler-Lagrange model is set up. Based on the passivity-based control theory and Euler-Lagrange model, a passivity-based controller of the tri-state boost converter is designed. By damping injecting, the input current and output voltage of the tri-state boost converter can reach the desired equilibrium values rapidly. The speed of the tri-state boost converter to reach the desired equilibrium values varies when the damping values changes. The controller is simple to design and makes the tri-state boost converter having better dynamic and steady performances. The passivity-based controller proposed in the paper is proved feasible by simulation results.
Appraisal of a Novel Reliability Optimisation Model Using Hypothetical Problems
Authors: Twum Stephen B. , Aspinwall Elaine
Published: June 2014

This paper examines further a novel series-parallel system reliability optimisation model and methodology earlier developed by the authors. The aim was to investigate how the model constructed for hypothetical series-parallel systems, reacted to slight variations to its parameters, which are the weights for the subsystem reliabilities, the feasibility factors which quantify the level of difficulty of improving a component’s reliability, and the subsystem reliability lower bounds. The optimisation algorithm based on a convex combination of the subsystem reliabilities was run using various combinations of the values of these parameters. The results show that the model was stable under the weighting scheme used and the most sensitive parameters were the feasibility factors and the subsystem reliability lower bounds.
Influence Factor Analysis of Multi-Stage Management Engineering for Multinational Micro Businesses: An Empirical Analysis Using Data Envelopment Analysis
Authors: Wang Bin , Li Jun
Published: June 2014

In recent years, to a large extent the emergence and development of micro businesses has shown the gaps of comparative advantages between large and medium sized enterprises and small enterprises. Owing to its economics of scope in production, micro businesses contribute to the development and prosperity of the overall market. For the multinational micro business, it is exposed to associated micro political risks in a foreign market in different developing stages (i.e. startup, developing, and mature periods). However, literature review indicates that little work has been done to assess and manage the political risks of multinational micro businesses, let alone provide the multi-stage analysis. To address this problem, this paper develops a multi-stage data envelopment analysis (MSDEA) model to investigate the influence of micro political risks on the efficiency of multinational micro businesses. The main influence factors of the micro political risks in the host country in different stages of startup, developing, and mature periods have been modeled by the MSDEA, to provide new perspectives on the influence mechanism of micro political risk on the multinational micro business. Then the decision makers can assess their companies’ micro political risks in different stages and hence develop target-oriented risk prevention policies. Empirical analysis has been implemented in this paper, along with discussion of potential strategies on assessment and management of the micro political risks for multinational micro businesses. The analysis results demonstrate that the factor of labor conditions was the critical one in the development of the multinational micro business in the startup stage. Good labor conditions may be more likely to avoid micro political risk. The factor of the congruence with national economic interests and goals also impacted the development of the multinational micro business in the startup stage. Hence, the findings of this work could provide valuable reference for multinational micro businesses in restraining the micro political risk.
Thermodynamic Evaluation of a 42MW Gas Turbine Power Plant
Authors: Egware Henry , Obanor Albert I. , Itoje Harrison
Published: June 2014

Energy and exergy analyses were carried out on an active 42MW open cycle gas turbine power plant. Data from the power plant record book were employed in the investigation. The First and Second Laws of Thermodynamics were applied to each component of the gas power plant at ambient air temperature range of 21 - 330C. Results obtained from the analyses show that the energy and exergy efficiencies decrease with increase in ambient air temperature entering the compressor. It was also shown that 66.98% of fuel input and 54.53% of chemical exergy are both lost to the environment as heat from the combustion chamber in the energy and exergy analysis respectively. The energy analysis quantified the efficiency of the plant arising from energy losses , while exergy analysis revealed the magnitude of losses in various components of the plant. Therefore a complete thermodynamic evaluation of gas turbine power plants requires the use of both analytical methods.
Development of Model Equations for Selecting Optimum Storage Parameters for Stored Cabbages
Authors: Sunmonu Musliu Olushola , Chukwu O. , Osunde Z.D. , Alabadan B.A.
Published: June 2014

A study was carried to develop model equations for selecting optimum storage parameters for stored cabbages in passive evaporative cooling structures.Three sets of four different types of passive evaporative cooling structures made of two different materials; clay and aluminium were designed and constructed as part of the study. One set consists of four separate cooling chambers. Two cooling chambers were made with aluminium container (cylindrical and square shapes) and the other two were made of clay container (cylindrical and square). These four containers were separately inserted inside a bigger clay pot inter-spaced with clay soil of 5 cm (to form tin-in-pot, pot-in-pot, tin-in-wall and wall-in wall) with the outside structure wrapped with jute sack. The other two sets followed the same pattern with interspacing of 7 cm and 10 cm, respectively. The set with 7 cm clearance served as the control in which the interspace soil and the jute sacks were constantly wetted at intervals of between 2 to 4 hours depending on the rate of evaporation with water at room temperature. The other two sets (5 cm and 10 cm interspaced soil) were constantly wetted with salt solution (sodium chloride) at the same interval to keep the soil in moist condition. Freshly harvested matured cabbages were used for the experiments and the temperature and relative humidity were monitored daily. The vitamin A, vitamin E, bacterial and fungal counts of this produce were determined at intervals of three days for a period of 21 days. Mathematical models (using essential regression software package) were developed to predict the vitamin A and vitamin E contents of the stored produce at various conditions considered in the study. Further analysis by optimization process revealed optimum storage conditions for the stored produce using essential regression software package. Optimum values of 8.86IU and 4.03 mg/ml in storage were obtained for vitamin A and vitamin E contents, respectively for stored cabbages at various conditions.
Preparation and Characterization of Epoxidized-30% Poly(methyl methacrylate)-grafted Natural Rubber Polymer Electrolyte
Authors: Nazir Khuzaimah , Ayub Siti Fadzilah , Aziz Ahmad Fairoz , Ali Ab Malik Marwan , Yahya Muhd Zu Azhan
Published: June 2014

In this study, a freestanding thin film composed of lithium triflate (LiTf) salt (30-40 wt.%) and epoxidized-30% poly (methyl methacrylate)-grafted natural rubber (EMG30) (50, 54.6, 62.3 mol %) were prepared by a solvent cast technique. The EMG30 were found to increase the ionic conductivity of EMG30-LiTf by one order of magnitude compared to MG30-LiTf. The highest ionic conductivity achieved was 5.584 x10-3 Scm-1 at room temperature when 40 wt.% of LiTf salts were introduced into 62.3 mol % EMG30. The ionic conduction mechanisms in EMG30-LiTf electrolytes obey Arrhenius rule in which the ion transport in these materials is thermally assisted.
Synthesis, Characterization and Magnetic Properties of Defective Nitrogen-Doped Multiwall Carbon Nanotubes Encapsulating Ferromagnetic Nanoparticles
Authors: García-Betancourt María Luisa , Vega-Cantu Yadira , Vega-Díaz Sofía M. , Morelos-Gómez Aaron , Perea-López Nestor , Cruz-Silva Rodolfo , Gutiérrez Humberto , Terrones Humberto , Terrones Mauricio , Muñoz-Sandoval Emilio
Published: June 2014

Nitrogen-doped multi-walled carbon nanotubes (CNxMWNTs) with multiple morphological defects were produced using a modified chemical vapor deposition (CVD) method. In a typical CNxMWNTs synthesis by CVD, an acetone trap is used to catch organic by-products from pyrolysis. In the present work, an aqueous solution of NaCl (26.82 wt%) was used in the trap, instead of acetone. Carbon nanotubes with sharp tips and lumps were found in the products. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy showed the formation of nanoparticles of different shapes inside the nanotubes. The electronic and magnetic properties were studied using a physical properties measurement Evercool system (PPMS). With this simple change in the CVD-trap, it is possible to control the morphology of carbon nanotubes and metallic nanoparticles. Differences in gas flow are proposed as a possible mechanism to produce these changes in both nanoparticles and CNxMWNTs.
Electrochromic Properties of Nanoporous α and β Nickel Hydroxide Thin Films Obtained by Chemical Bath Deposition
Authors: Vidales-Hurtado Mónica Araceli , Mendoza-Galván Arturo
Published: June 2014

Nickel hydroxide nanoporous electrochromic thin films were obtained by chemical bath deposition method using nickel nitrate in two different formulations. In one case, ammonium hydroxide controlled the precipitation of the β-Ni (OH)2 phase through the formation of coordination compounds. In the second case, the decomposition of urea yielded the α-Ni (OH)2 phase. After thermal annealing in air in between 250 and 300 °C, the electrochromic behavior of the films was examined by cyclic voltammetry and single wavelength transmittance. The optical contrast and structural transformations between colored and bleached states of the samples were studied by ex-situ optical transmittance, X-ray diffraction, as well as Raman and infrared reflectance spectroscopies. The α-Ni (OH)2 films showed higher optical contrast and reversibility, properties associated with their porous morphology which is revealed by scanning electron microscopy studies.
Effect of Pd Addition on the Nanostructure and Properties of Pd/TiO2 Catalysts for the Photocatalytic Degradation of 4-Chlorophenol
Authors: García-Zaleta D.S. , Montes De Oca-Valero J.A. , Torres-Huerta A.M. , Domínguez-Crespo M.A. , Dorantes-Rosales H.J. , López-González Rosendo , García-Murillo A.
Published: June 2014

In this work, the effect of Pd addition on nanostructured TiO2 powders is studied. The materials were obtained by the sol-gel method and characterized by XRD, Rietveld refinement, TEM, Raman and UV-vis spectroscopies. The crystal structure and the nature of the different TiO2 phases were modified by varying the palladium/TiO2 ratio: 0.01, 0.03, and 0.05. The XRD results revealed the presence of different combinations of TiO2 (B), anatase, rutile and PdO phases as well as their coexistence in the different samples. The Rietveld analysis showed that the composition of the phases is rather affected by the amount of Pd added to the TiO2 structure. The Raman spectroscopy confirmed the characteristic bands of the TiO2 phases in the samples and their variation depending on the Pd/TiO2 ratio. The TEM results indicated that the as-prepared samples displayed crystal sizes of nanometric order (˂ 80nm). The observed reduction of the band gap was also correlated with the combination of phases due to the palladium addition. All the Pd/TiO2 samples showed a significant improvement in the elimination of 4-chlorophenol during the application of water treatment technology.
Synthesis and Characterization of SnS Nanoparticles through a Non-Aqueous Chemical Route for Depositing Photovoltaic Absorber Layers
Authors: Pal Mou , Martinez Ayala A. , Mathews N.R. , Mathew Xavier
Published: June 2014

SnS nanocrystals of sub-10 nm in size were synthesized by a room temperature, non-aqueous chemical route in the presence of different amounts of triethanolamine (TEA) used as a complexing agent. The crystallinity, size, morphology, chemical composition and optical properties of the as-prepared SnS nanoparticles were investigated by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Energy-dispersive X-ray spectroscopy (EDS), micro Raman and optical absorption spectroscopy. The XRD analysis and HRTEM investigation of SnS nanoparticles confirmed the presence of crystalline orthorhombic SnS phase. Upon increasing the amount of TEA, the crystallite size of the samples decreased gradually showing evidence of quantum confinement. EDS analysis showed that SnS nanoparticles (NPs) grown in absence of TEA were highly stoichiometric whereas in TEA capped samples, the atomic concentration of S is slightly higher than that of Sn. As-synthesized SnS nanocrystals displayed strong absorption in the visible and near-infrared spectral regions followed by a blue shift of their absorption edge on increasing the TEA concentration. These nanoparticles were used to prepare SnS paste which was deposited on conducting glass substrates to obtain thin films for photovoltaic applications. The crystallinity, morphology, chemical composition and optical properties of annealed SnS films were investigated.
Four Implants Connected Bar with an All Ceramic Milled Superstructure Solution Assesment in Mandibular Edantation
Authors: Bara Nicolae Adrian , Chisalita Daniela , Lazar Andreea , Sinescu Cosmin , Negrutiu Meda Lavinia , Rominu Mihai
Published: June 2014

Implant supported prostheses have led to drastic improvements in edentulous patients ‘standard of living and quality of life compared with treatment with conventional dentures. However the solution with four implants connected with a bar and a prosthetic superstructure seems to gain more trust.
Hydrolytic Degradation of Dental Composites
Authors: Sarosi Codruta , Antoniac Aurora , Prejmerean Cristina , Pastrav Ovidiu Cristian , Patroi Dan , Popescu George , Moldovan Marioara
Published: June 2014

This study evaluated the hydrolytic degradation of two experimental (C1, C2) and two commercial composite (Tetric EvoCeram and Premise) prepared to be used in dental restorations. Two experimental composites and two commercial composites were undergoing hydrolytic degradation in three different medium: distilled water, artificial saliva and alcoholic solution (50/50). The samples were investigated immediately after polymerisation with halogen lamp Optilux 501 and after 33 days of immersion in all three medium, using Fourier transforms infrared analysis (FTIR). FT-IR spectra of samples from the same composite immersed in distilled water, artificial saliva and alcoholic solution, revealed mostly reducing the intensity of the characteristic peaks of Si-O-Si bond less Tetric composite immersed in artificial saliva, which peak intensity remains unchanged.
Morphologic Characterization of Ceramic-Ceramic Dental Systems Failure
Authors: Miculescu Florin , Ciocan Lucian Toma , Meghea Daniela , Miculescu Marian
Published: June 2014

Sintered ceramics and ceramic glasses are frequently used as biomaterials for dental restorations, usually for inlays, onlays, veneers, crowns or bridges. In this study we analyzed several types of ceramic-ceramic type prosthetic restorations in order to assess the types of defects that can lead to their failure. The research aim is to morphologically identify by scanning electron microscopy the main types of defects that lead to failure over time of ceramic-ceramic prostheses type. The type of failure registered were fracture of plating material (feldspatic porcelain) and fracture of entire structure (zirconia and feldspatic porcelain).
Biomaterials in the Arthroscopic Anterior Cruciate Ligament Reconstruction
Authors: Popescu Gheorghe Ion , Patru Cristina , Tecu Camelia , Bajenescu Titi , Soare Gabriela
Published: June 2014

We conducted this clinical study in order to compare the quality of graft fixation with a bioabsorbable screw, as compared to a metal screw, in the anterior cruciate ligament reconstruction. A number of 124 patients were submitted to the surgical intervention and 113 out of them were kept under medical survey up to 1 year after the surgery. This included: anamnesis, physical examination, IKDC evaluation and the knee arthrometric measurements. After 1 year, there was no significant difference between the two groups, from the IKDC evaluation point of view. The final IKDC evaluation was normal or almost normal in 92% out of the patients in the group with absorbable screws and in 90% out of the patients making part of the control group. The incidence of post surgery complications was similar in both of the groups. The study shows that the absorbable screw is an efficient alternative to the fixation with a metal screw in the anterior cruciate ligament reconstruction.
Cement Filling of Contained Defects from Bone Tumor Resections
Authors: Prejbeanu Radu , Patrascu Jenel , Poenaru Dan , Vermesan Dinu , Popa Iulian , Hărăgus Horia
Published: June 2014

The management of bone defects of the extremities has important particularities. Patients prefer limited procedures when facing with complex reconstructions and each filling option has benefits and disadvantages. We aimed to present our short and long term results with small contained bone defects after tumoral resections filled with different types of cement. Over a period of five years we identified ten cases that were operated in our service and met the inclusion criteria: contained bony defects following intralesional or marginal tumoral resections of the lower limb (weight bearing extremity skeleton) with a minimum of one year of follow-up. The most important finding of our study is that polymethylmethacrylate cement filling of contained bony defects after tumoral resections is the only one that allowed for immediate postoperative weight bearing. In addition, the bone cement interface proved stable as far as two years after the surgery. The cases described can contribute to a greater understanding when searching for solutions targeted on filling contained bone defects after intralesional resections. Polymethylmethacrylate cement proves to be a validated, versatile and safe procedure but future perspectives already show good outcomes with new osteoinductive components.
Biocompatible Porous Scaffolds from Derivatized PVA Composites
Authors: Petreus Tudor , Cotrutz Carmen Elena , Sirbu Paul Dan , Tudoran Lucian Barbu , Olinici Doinita , Badescu Laurentiu , Petreus Oana , Stoica Bogdan Alexandru
Published: June 2014

Introduction: Many polymer supports for cell seeding formulations based on chitosan are usually prepared by chemical cross-linking with glutaraldehyde, urea formaldehyde, epichlorohydrine, even if the chemical cross-linking agents possibly induce toxicity and other undesirable effects.
Experimental: Derivatized poly (vinyl alcohol) was blended and foamed with chitosan to produce porous scaffolds with improved elastic and mechanical properties and also acceptable water solubility. Derivatized PVA (in example phosphorylated PVA) (P-PVA) also exhibited improved hydrophilicity, anionic properties and molecular electrostatic repulsion, and retained the bulk morphological features, compatible property, and solution stability.
Results: Porous scaffolds formed by derivatized PVA crosslinked with chitosan proved a good cytocompatibility for human fibroblasts. Viability and apoptosis assays were performed indicating that this porous scaffold allow cell multiplication and scarce apoptotic induction.
Conclusion: Tested porous scaffolds may represent an interesting support for three dimensional cell cultures destined to simulate tumor or normal tissue microenvironment.
Comparative Study of Design and PCL-Substituting Systems of Total Knee Prosthesis
Authors: Adam Razvan , Orban Carmen , Orban Horia
Published: June 2014

Knee arthroplasty represents a laborious surgical procedure, involving a high degree of difficulty, concerning the bony tissue as well as soft tissues. Nevertheless, knee arthroplasty represents a procedure frequently used in orthopaedic clinics around the world, and its incidence it keeps growing [1].
Efficacy of a Biphasic Ceramic Bone Substitute in Management of Complex Tibial Plateau Fractures — Clinical and Radiologic Medium-Term Results
Authors: Sirbu Paul Dan , Berea Grigore , Petreus Tudor , Sova Rares , Tudor Razvan , Plaiasu Constantin , Botez Paul
Published: June 2014

The purpose of this retrospective study is to evaluate the efficacy of a biphasic synthetic ceramic bone substitute (Eurocer) combined with plate fixation in treating collapse tibial plateau fractures. 32 patients were included in the study. The surgical protocol consisted of: elevation of the articular depression through a limited cortical window using a curved bone compactor and image intensification, filling the defect with Eurocer granules and fixation with plates. Clinical and radiologic follow-up after 36 to 48 months revealed uneventful primary bone healing, excellent osseous integration of Eurocer and a mean Neer score of 87, 5 points. We conclude that Eurocer400® combined with plate fixation in managing collapsed tibial plateau fracture is a promising alternative in this difficult lesion regarding a fast healing, a good quality osseointegration, preventing secondary collapse and improving medium term results.
Formation of Alumina Layer on Ti Alloy for Artificial Hip Joint
Authors: Khanna Rohit , Matsushita Tomiharu , Kokubo Tadashi , Takadama Hiroaki
Published: June 2014

The purpose of this research is to form a layer of alumina on Ti-6Al-4V alloy for hip joint by deposition of Al layer on the Ti alloy and its subsequent oxidation. In this work, a thick layer of Al was deposited onto the Ti alloy by cold spraying. The reaction layer of Al3Ti was formed by heat treatment of cold sprayed Al at 640°C in air/Ar atmosphere to ensure a good adhesion between cold sprayed Al layer and the Ti alloy. A thick Al3Ti layer formed by heat treatment of Al layer at 640°C for 12 h in air, was subjected to heat treatment at 850°C for 96 h in air to form a-alumina and Al2Ti. Thus, alumina scales can be formed on the top surface of the Ti alloy and can be densified by increasing the time duration of heat treatment.
Injectable Bioactive Glass/Polysaccharide Polymers Nanocomposites for Bone Substitution
Authors: Sohrabi Mehri , Hesaraki Saeed , Kazemzadeh Asghar
Published: June 2014

nanobioactive glasses are biocompatible and osteoconductive materials which can be mixed with solution of biocompatible polymers to make nanobiocomposite paste for hard and even soft tissue treatment. In this study, bioactive glass based on CaO-SiO2-P2O5 system was produced via sol-gel technique and mixed with a solution phase. The solution phase was a 1:1 mixture of 3% hyaluronic acid solution and 3% sodium alginate solution in v/v. Rheological behaviors of the paste in rotation and oscillation modes were measured. For surface reactivity measurements, the paste was immersed in simulated body fluid (SBF) for different intervals and then characterized by SEM. The paste exhibited a superior injectability even from syringes with too narrow tips. It was a thixotropic fluid with shear thinning behavior. The results of surface reactivity revealed precipitation of apatite phase on the paste surfaces meanwhile an appropriate structural stability was observed against disintegration (anti-washout behavior). It seems that this biocomposite paste is an appropriate alternative for injectable bone substitute materials.
The Effect of α-Tricalcium Phosphate Powder Preparation Methods on Cement Properties
Authors: Irbe Zilgma , Berzina-Cimdina Liga
Published: June 2014

The properties of calcium phosphate cements are influenced both by presence of setting aids in cement paste and also by surface properties and particle size distribution of solid phase. In this study the influence of α-tricalcium phosphate powder preparation methods on properties of cement are examined: milling, thermal treatment at temperatures up to 600°C and treatment with deionized water. The properties of cements based on prepared powders evaluated are: setting time, injectability and cohesion. The compressive strength of selected cement samples was determined. Thermal treatment improves injectability, but significantly prolongs setting time and reduces cohesiveness. Treatment of powder particles with deionized water increases setting time, but also significantly reduces injectability. It was not possible to significantly increase powder liquid ratio (from 1.75 to 2.00), if thermally treated powders were used. It was found that reduction of particle size, under certain conditions, can increase the injectability of cements. Powder preparation methods do not significantly affect the compression strength of cement, but fast setting upon the contact water based fluids is necessary to obtain cohesive cements.
2D Versus 3D Aesthetic Preview in Prosthodontic Rehabilitation for Elderly Patients
Authors: Pantea Mihaela , Oancea Luminita , Petre Alexandru Eugen , Gagiu Catalin
Published: June 2014

The study aims at obtaining an aesthetic preview in complex prosthetic restorations for elderly patients. Ten elderly patients were selected for this study; an extra-and intra-oral set of photographs is performed for each patient and edited with available software. Additionally, a series of standardized photos of the head is made using a new method to collect and process them with special software packages. Processed 2D digital photographs and tridimensional personalized models are obtained and a comparison between the two categories of data is made. Compared to the bi-dimensional planning, the 3D aesthetic preview offers better possibilities and it proves to be a useful instrument in aesthetic diagnosis and treatment, in increasing the patients acceptance of the final results. Tridimensional computerized personalized model allows building up a valuable preview in prosthetic reconstruction for elderly patients.
Immune Memory–Boosting Dose of Rapamycin Impairs Macrophage Vesicle Acidification and Curtails Glycolysis in Effector CD8 Cells, Impairing Defense against Acute Infections
Authors: Goldberg Emily L. , Smithey Megan J. , Lutes Lydia K. , Uhrlaub Jennifer L. , Nikolich-Žugich Janko
Published: June 2014

Direct mammalian target of rapamycin (Rapa) complex 1 inhibition by short-term low-dose Rapa treatment has recently been shown to improve CD8 T cell immunological memory. Whereas these studies focused on memory development, the impact of low-dose Rapa on the primary immune response, particularly as it relates to functional effector immunity, is far less clear. In this study, we investigated the impact of acute Rapa treatment on immune effector cell function during the primary immune response to several acute infections. We found that functional CD8 T cell and macrophage responses to both viral and intracellular bacterial pathogens were depressed in mice in vivo and in humans to phorbol ester and calcium ionophore stimulation in vitro in the face of low-dose Rapa treatment. Mechanistically, the CD8 defect was linked to impaired glycolytic switch in stimulated naive cells and the reduced formation of short-lived effector cells. Therefore, more than one cell type required for a protective effector immune response is impaired by Rapa in both mice and humans, at the dose shown to improve immune memory and extend lifespan. This urges caution with regard to the relative therapeutic costs and benefits of Rapa treatment as means to improve immune memory.
Cytokine-Regulated Neutrophil Recruitment Is Required for Brain but Not Spinal Cord Inflammation during Experimental Autoimmune Encephalomyelitis
Authors: Simmons Sarah B. , Liggitt Denny , Goverman Joan M.
Published: June 2014

Multiple sclerosis (MS) is an autoimmune disease in which inflammatory lesions lead to tissue injury in the brain and/or spinal cord. The specific sites of tissue injury are strong determinants of clinical outcome in MS, but the pathways that determine whether damage occurs in the brain or spinal cord are not understood. Previous studies in mouse models of MS demonstrated that IFN-γ and IL-17 regulate lesion localization within the brain; however, the mechanisms by which these cytokines mediate their effects have not been identified. In the present study, we show that IL-17 promoted, but IFN-γ inhibited, ELR+ chemokine–mediated neutrophil recruitment to the brain, and that neutrophil infiltration was required for parenchymal tissue damage in the brain. In contrast, IFN-γ promoted ELR+ chemokine expression and neutrophil recruitment to the spinal cord. Surprisingly, tissue injury in the spinal cord did not exhibit the same dependence on neutrophil recruitment that was observed for the brain. Our results demonstrate that the brain and spinal cord exhibit distinct sensitivities to cellular mediators of tissue damage, and that IL-17 and IFN-γ differentially regulate recruitment of these mediators to each microenvironment. These findings suggest an approach toward tailoring therapies for patients with distinct patterns of neuroinflammation.
Themis2 Is Not Required for B Cell Development, Activation, and Antibody Responses
Authors: Hartweger Harald , Schweighoffer Edina , Davidson Sophia , Peirce Matthew J. , Wack Andreas , Tybulewicz Victor L. J.
Published: June 2014

Themis1 is a protein implicated in transducing signals from the TCR. Mice deficient in Themis1 show a strong impairment in T cell selection in the thymus and defective T cell activation. The related Themis2 protein is expressed in B cells where it associates with signaling proteins Grb2 and Vav1, and is tyrosine phosphorylated after BCR stimulation. Thus, it has been proposed that Themis2 may transduce BCR signals, and hence play important roles in B cell development and activation. In this article, we show that Themis2 is expressed in all developing subsets of B cells, in mature follicular and marginal zone B cells, and in activated B cells, including germinal center B cells and plasma cells. In contrast, B lineage cells express no other Themis-family genes. Activation of B cells leads to reduced Themis2 expression, although it remains the only Themis-family protein expressed. To analyze the physiological function of Themis2, we generated a Themis2-deficient mouse strain. Surprisingly, we found that Themis2 is not required for B cell development, for activation, or for Ab responses either to model Ags or to influenza viral infection.
Global emission projections for the transportation sector using dynamic technology modeling
Authors: Yan F. , Winijkul E. , Streets D. G. , Lu Z. , Bond T. C. , Zhang Y.
Published: June 2014

Abstract. In this study, global emissions of gases and particles from the transportation sector are projected from the year 2010 to 2050. The Speciated Pollutant Emission Wizard (SPEW)-Trend model, a dynamic model that links the emitter population to its emission characteristics, is used to project emissions from on-road vehicles and non-road engines. Unlike previous models of global emission estimates, SPEW-Trend incorporates considerable detail on the technology stock and builds explicit relationships between socioeconomic drivers and technological changes, such that the vehicle fleet and the vehicle technology shares change dynamically in response to economic development. Emissions from shipping, aviation, and rail are estimated based on other studies so that the final results encompass the entire transportation sector. The emission projections are driven by four commonly-used IPCC (Intergovernmental Panel on Climate Change) scenarios (A1B, A2, B1, and B2). With global fossil-fuel use (oil and coal) in the transportation sector in the range of 128–171 EJ across the four scenarios, global emissions are projected to be 101–138 Tg of carbon monoxide (CO), 44–54 Tg of nitrogen oxides (NOx), 14–18 Tg of non-methane total hydrocarbons (THC), and 3.6–4.4 Tg of particulate matter (PM) in the year 2030. At the global level, a common feature of the emission scenarios is a projected decline in emissions during the first one or two decades (2010–2030), because the effects of stringent emission standards offset the growth in fuel use. Emissions increase slightly in some scenarios after 2030, because of the fast growth of on-road vehicles with lax or no emission standards in Africa and increasing emissions from non-road gasoline engines and shipping. On-road vehicles and non-road engines contribute the most to global CO and THC emissions, while on-road vehicles and shipping contribute the most to NOx and PM emissions. At the regional level, Latin America and East Asia are the two largest contributors to global CO and THC emissions in the year 2010; this dominance shifts to Africa and South Asia in the future. By the year 2050, for CO and THC emissions, non-road engines contribute the greatest fraction in Asia and the former USSR, while on-road vehicles make the largest contribution in Latin America, Africa, and the Middle East; for NOx and PM emissions, shipping controls the trend in most regions. These forecasts include a formal treatment of the factors that drive technology choices in the global vehicle sector and therefore represent a robust and plausible projection of what future emissions may be. These results have important implications for emissions of gases and aerosols that influence air quality, human health, and climate change.
What controls the recent changes in African mineral dust aerosol across the Atlantic?
Authors: Ridley D. A. , Heald C. L. , Prospero J. M.
Published: June 2014

Abstract. Dust from Africa strongly perturbs the radiative balance over the Atlantic, with emissions that are highly variable from year to year. We show that the aerosol optical depth (AOD) of dust over the mid-Atlantic observed by the AVHRR satellite has decreased by approximately 10% per decade from 1982 to 2008. This downward trend persists through both winter and summer close to source and is also observed in dust surface concentration measurements downwind in Barbados during summer. The GEOS-Chem model, driven with MERRA re-analysis meteorology and using a new dust source activation scheme, reproduces the observed trend and is used to quantify the factors contributing to this trend and the observed variability from 1982 to 2008. We find that changes in dustiness over the east mid-Atlantic are almost entirely mediated by a reduction in surface winds over dust source regions in Africa and are not directly linked with changes in land use or vegetation cover. The global mean all-sky direct radiative effect (DRE) of African dust is −0.18 Wm−2 at top of atmosphere, accounting for 46% of the global dust total, with a regional DRE of −7.4 ± 1.5 Wm−2 at the surface of the mid-Atlantic, varying by over 6.0 Wm−2 from year to year, with a trend of +1.3 Wm−2 per decade. These large interannual changes and the downward trend highlight the importance of climate feedbacks on natural aerosol abundance. Our analysis of the CMIP5 models suggests that the decreases in the indirect anthropogenic aerosol forcing over the North Atlantic in recent decades may be responsible for the observed climate response in African dust, indicating a potential amplification of anthropogenic aerosol radiative impacts in the Atlantic via natural mineral dust aerosol.
Margaret Murray’s Meat Curry
Authors: Thornton Amara
Published: June 2014

In 1937 in Jerash, Transjordan, Margaret Murray gave Gerald Lankester Harding recipes for meat curry and dahl. This article briefly traces each archaeologist’s personal and professional trajectory as they moved between Britain and various imperial outposts, and situates the recipes within the complex contexts of their histories. The recipes, staples of Anglo-Indian cuisine, take on new meaning as symbols of the hybridity of archaeological identity in the late 19th and early 20th centuries.