bluuebunny/crossref_metadata_2025 huggingface dataset:
Size Dependence of Evaporation Temperature by Bond Number Calculation
Authors: Wang Jia , Xiao Hao Jie , Zhang Hai Xia , Liang X.H. , Li Hui
Published: March 2015

In this study, a model based on bond number calculation in a system was developed to predict size-dependent evaporation temperature of nanoparticles. This model, free of any adjustable parameters, can be utilized to predict the thermal stability for low dimensional materials. If the atomic structure of a nanoparticle is known, the size and shape-dependent bond number can be obtained. The cubooctahedral structure was taken as the shape of nanoparticles for simplicity. According to the established model, the evaporation temperature of nanoparticles is dependent not only on their size, but also on their atomic diameter. The results indicated that the evaporation temperature decreased with the decreasing size of free-standing nanoparticle. The theoretical predictions are consistent with the evidences of the experiments or molecular dynamic simulations for Au and Ag nanoparticles.
Effects of Sm and Mn Co-Doping on Structural and Optical Properties of BiFeO3 Thin Films Prepared by Sol-Gel Technique
Authors: Zhou Wen Liang , Deng Hong Mei , He Jun , Liu Jian , Cao Hui Yi , Zhai Xue Zhen , Yang Ping Xiong , Chu Jun Hao
Published: March 2015

(Bi1-xSmx)(Fe0.95Mn0.05)O3(x=0.00, 0.03 and 0.06) thin films were deposited on the quartz substrates by sol-gel technique. The results of X-ray diffraction patterns indicated all thin films had rhombohedral perovskite structure. Moreover, the Sm and Mn co-doping at A-and B-site of BiFeO3resulted in the structural distortion. Scanning electron microscope measurements exhibited that the uniform surface morphology could be obtained by co-doping and the average grain size of the films decreased with increasing Sm content. Furthermore, the fundamental absorption edges ofxBSFMO films showed a blue shift with the increase of Sm content which can be observed in transmittance spectra. The optical band gap of the thin films forx= 0.00, 0.03 and 0.06 can be expressed by (0.84x+2.62) eV, which is due to the Burstein-Moss effect.
Investigation of the Electronic Structure of BiFeO3 Epitaxial Films by Polarized X-Ray Absorption Spectroscopy
Authors: Wang H.B. , Luo Z.L. , Dong Y.Q. , Zhao Z.L. , Yang Y.J. , Chen Z.H. , Yang M.M. , Hu S.X. , Chen L. , Gao C.
Published: March 2015

To investigate the epitaxial strain effect on local electronic structure of FeO6octahedron of BiFeO3epitaxial film, polarization-dependent FeL23-edge x-ray absorption spectroscopy studies were performed on both tetragonal (T)-like BFO/LAO and rhombohedral (R)-like BFO/STO epitaxial films. Charge transfer multiplet theory based fittings were also performed to reveal the local electronic structure difference. Due to dramatic structural difference caused by epitaxial strain between these two samples, significant electronic structure differences were observed between these two specimens. For BFO/LAO, anisotropic electronic structure appears in vertically-elongated FeO6octahedron and an additional shift of Fe ion off the central position is suggested. For BFO/STO, electronic structure is almost isotropic.
Preparation and Characterization of Mesoporous Sulfated TiO2-Graphene Oxide Composites
Authors: Lai Qi , Zhu Shi Fu , Luo Xue Ping , Fan Xing Ping
Published: March 2015

Mesoporous sulfated TiO2-graphene oxide composites were prepared by hydrothermal method. The samples were analyzed by using scanning electron microscope (SEM), X-ray diffraction (XRD), FT-IR spectroscopy (IR) and Brunauer-Emmett-Teller (BET) method. photocatalytic activities of sulfated titania-GO samples were evaluated using the photooxidation of methylene blue in aqueous solutions by ultraviolet-visible (UV-via) spectroscopy. The results indicated that oxygen-containing carbonaceous groups in the GO are incorporated into the network of C\O\Ti and coordinated to titania in bidentate model, Sulfur species in the form of sulfate are incorporated into the network of Ti\O\Ti, resulting in the strong inductive effect, large specific surface area, and mesoporous structure. All these are beneficial to improve the photocatalytic activities of the mesoporous sulfated TiO2-graphene oxide composites. The formation mechanism of sulfated mesoporous titania-graphene oxide composites was explored. Joint electronic system of reduced graphene oxide, SO42−and TiO2was also predicted.
Effects of Electroless Nickel on Hydrogen Absorption Properties of Zr-V-Fe Powders
Authors: Cui Hang , Cui Jian Dong , Xu Yao Hua , Zhou Hao , Du Jun
Published: March 2015

Nickel coated Zr-V-Fe non-evaporable getter (NEG) powders were prepared using electroless plating. The microstructure and composition of the Ni-coated Zr-V-Fe powders were analyzed by XRD, SEM and EDS. The hydrogen absorption performance of Ni-coated Zr-V-Fe powders and as-prepared powders were analyzed by dynamic method after an activation at 300°C for 2 hours. The hydrogen absorption performance of Ni-coated Zr-V-Fe powders and as-prepared powders at 100°C, 200°C, 300°C, 400°C, and 500°C were also analyzed. The results indicated that Ni existed as crystalline phase. The Ni coating played an important role as a catalyst which favored the dissociation of hydrogen on surface and Ni lowers the hydrogen diffusion energy for the Zr-V-Fe powders. The hydrogen absorption kinetics of Ni-coated Zr-V-Fe powders was improved in comparison with that of the as-prepared powders, and a relatively higher absorption rate was exhibited.
Preparation and Mechanical and Optical Properties of SF/Pyrrolidone Blend Film
Authors: Li Jiao Jiao , Zhang Shan Shan , Zhang Xin Yue , Lu Shen Zhou
Published: March 2015

To improve the properties of silk fibroin film, the silk fibroin/pyrrolidone blend films were prepared by mixing silk fibroin and pyrrolidone solution at different ratios. The structure and mechanical properties of blend films were characterized. X-ray diffraction was used to investigate structure of the SF/PYR films, and the results indicated that the blend films were composed of the β-sheet form. Tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that tensile strength and elongation at break of blend films were high enough for application. Furthermore, the films’ flexibility was significantly improved. The optical clarity of blend film was tested by Microplate system. It can be seen from the results that optical clarity is not stable, but in some particular ratios we also can get high light transmittance blend films. At last, biocompatibility of blend films (the rate of the blend film is 30%) was accessed with L929 cell. The results showed that all types of blend films were able to support cell adhesion and proliferation. In addition, the cellular morphology of the cells cultured on blend films was better than that on silk fibroin films. In view of the mechanical properties and optical clarity, combined with their ability to support L929 proliferation suggests that this blend films will offer new options in many different biomedical applications.
Synthesis and Self-Assembly of Well-Defined pH-Responsive Block Glycopolymers
Authors: Yu Qing Yun , Lin Lu Bin , Xing Xue Yu , Dong Hai Liang , Jiang Xiao Ze , Zhu Mei Fang
Published: March 2015

Two pH-responsive block glycopolymers, poly (ethylene glycol)-b-Poly (2- (diethylamino) ethyl methacrylate-co-2-gluconamidoethyl methacrylate) (PEG113-b-P(DEA55-co-GAMA12)) and poly (ethylene glycol)-b-poly (2-(diethylamino) ethyl methacrylate)-b-poly (2-gluconamido ethyl methacrylate) (PEG113-b-PDEA55-b-PGAMA15), were synthesized via atom transfer radical polymerization (ATRP) by directly or successively polymerization of GAMA and DEA monomers using a PEG-based macroinitiator, respectively, without protecting group chemistry. Those block glycopolymers were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC), and their self-assembly behaviors were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta-potential. The results show both synthetic block glycopolymers were dissolved molecularly in aqueous solution at acidic pH (such as pH 3), thus it can reversibly convert to be two-layer micelles comprising DEA and GAMA cores, PEG coronas with size of around 50 nm, or micelles comprising DEA cores, GAMA and PEG outer coronas with bigger size of 70 nm for PEG113-b- P(DEA55-co-GAMA12) and PEG113-b-PDEA55-b-PGAMA15), respectively, at basic condition. Both glycopolymers have the micellization process at middle pH (pH 6-8), but possess different isoelectric points (pIs) (at pH 8.0 and 7.8) for their pH responsive block of PEG113-b-P(DEA55-co-GAMA12) and PEG113-b-PDEA55-b-PGAMA15 with DEA-co-GAMA random structure or DEA chain only, respectively. This study not only reveals the self-assembly of pH responsive block glycopolymers with different architectures by fixing similar degree polymerization (DP) of their blocks, but also provides a tool to investigate pH induced dynamic covalent interaction between glycopolymers and phenylboronic acid derivatives or a light for designing novel drug delivery carriers.
Preparation of an Ultra-Thin, Highly Filled, Neutron-Shielding Material
Authors: Hou Xin Peng , Li Shu Feng , Chen Yan , Xu Di , Tang Wei
Published: March 2015

We develop an ultra-thin, highly filled, neutron-shielding material. This material exhibits a desirable neutron-shielding performance, and also has certain advantageous mechanical properties and uses. We study the physical properties of shielding materials with different polyolefins as base materials, and investigate the neutron-shielding performance of boron-containing and lithium-containing shielding materials. We furthermore report on the effect of additive amounts of functional additives on shielding properties and physical-chemical properties. We additionally study the effect of radiation crosslinking technology on shielding material properties. We show that, using ethylene-octene copolymer (POE) modified low-density polyethylene (PE-LD), the additive amounts of boron carbide (B4C) and nano-montmorillonite (OMMT) are 60–70% and 4%, respectively. The optimal radiation dose is 160 kGy, and the shielding materials exhibit good neutron-shielding performance and mechanical strength.
Rheological and Thermomechanical Properties of Meso and Non-Porous Silica Filled Epoxy Composites
Authors: Li Gang , Zhu Peng Li , Zhao Tao , Sun Rong , Lu Daniel
Published: March 2015

In the present study, epoxy based composite filled with meso and non-porous silica microspheres with similar size were prepared respectively and their rheological and thermo-mechanical properties were studied systematically. The results showed that the mesoporous silica/epoxy composites showed much higher viscosity, storage modulus and glass transition temperature (Tg) while lower coefficient of thermal expansion (CTE) than did epoxy composites with nonporous silica particles, which could be attributed to the stronger interface interaction between the mesoporous silica filler with larger specific surface area (BET) and the epoxy matrix.
Study of Black Center in Silicon Wafer for Solar Cell
Authors: Qiao Liu , Wang Yan Jun , Zhang Xue Nan , Liu Zheng , Liu Jia , Wang Zun Yi , Shen Hao Ping
Published: March 2015

The center of czochralski (CZ) wafer for solar cell often has black center, due to the existence of high impurities content, many defects such as dislocations. This has serious effect on solar cells’ conversion efficiency. To solve this problem, we developed a new kind of material-czochralski and floating zone (CFZ) silicon. But there is still black center in the CFZ-Si wafer with conventional process. In order to solve this problem successfully a new technology-alternant forward and reverse rotation was introduced. By testing the crystal defects, metal and oxygen impurities content, it has been found that the black center is related to oxygen distribution in the wafer. However since the content was very low and not enough to affect the solar cells’ conversion efficiency, which has been testified in solar cell. Therefore CFZ technology offers a new kind of silicon material, which can avoid the black center problem in CZ silicon wafer.
Design Inspirations Derived from Botanical Plants: Insights from Jewellery Design
Authors: Pathirana Hiranthi
Published: March 2015

Learning to see and understand Nature comes only after a careful and enthusiastic search for her minute and apparently insignificant productions. Studies thus made when translated in terms of design principles, concepts and mathematics suggest endless ideas and unfolding of natural laws.This paper looks at the principles of Nature’s creations that can be used in the design of jewellery. It discusses about certain principles observed, recorded and put into studio experiments in design of neck chains inspired from parts of plants such as flowers and leaves. The plants were chosen from the neighborhood. Certain design principles were taken from Nature, carefully analyzed and applied in the design of neck chains. In the process, certain commonly known ‘flower forms’ were studied, in their plan forms, sections, and details to understand the principles of design. In the conclusion the observations on the characteristics of flowers and leaves were made into constructive design experiences that were carried through the design process into a unique set of neck ornaments.DOI: http://dx.doi.org/10.4038/besl.v11i2.7609Built-environment: Sri Lanka Vol.11(2) 2015: 39-48
Ambient light intensity and direction determine relative attractiveness of yellow traps toRhagoletis indifferens(Diptera: Tephritidae)
Authors: Yee W.L.
Published: March 2015

Understanding factors that influence attraction of tephritid fruit flies (Diptera: Tephritidae) to objects can lead to development of more sensitive traps for fly detection. Here, the objective was to determine if differences in attractiveness between two sticky yellow rectangle traps to western cherry fruit fly,Rhagoletis indifferensCurran, depend on ambient light intensity and direction. The translucent plastic Yellow Sticky Strip (YSS) was compared with the less translucent yellow cardboard Alpha Scents (AS). Flies were released inside a box or cage opposite a trap or traps illuminated from outside at different intensities to generate variable light passage. Regardless of type, the trap with greatest light passage was most attractive. When the same light intensity was shone on both traps, the YSS, which allowed greater light passage, was more attractive than the AS. When the light was inside a cage and shone onto the two traps in the same direction as approaching flies, the AS reflected more light and was more attractive. A field experiment generally supported light passage effects seen in the laboratory. Results suggest trap placement with respect to sunlight intensity and direction affects light passage and the attractiveness of yellow traps toR. indifferens.
IL-18 Acts in Synergy with IL-7 To Promote Ex Vivo Expansion of T Lymphoid Progenitor Cells
Authors: Gandhapudi Siva K. , Tan Chibing , Marino Julie H. , Taylor Ashlee A. , Pack Christopher C. , Gaikwad Joel , Van De Wiele C. Justin , Wren Jonathan D. , Teague T. Kent
Published: March 2015

Although IL-18 has not previously been shown to promote T lymphopoiesis, results obtained via a novel data mining algorithm (global microarray meta-analysis) led us to explore a predicted role for this cytokine in T cell development. IL-18 is a member of the IL-1 cytokine family that has been extensively characterized as a mediator of inflammatory immune responses. To assess a potential role for IL-18 in T cell development, we sort-purified mouse bone marrow–derived common lymphoid progenitor cells, early thymic progenitors (ETPs), and double-negative 2 thymocytes and cultured these populations on OP9–Delta-like 4 stromal layers in the presence or absence of IL-18 and/or IL-7. After 1 wk of culture, IL-18 promoted proliferation and accelerated differentiation of ETPs to the double-negative 3 stage, similar in efficiency to IL-7. IL-18 showed synergy with IL-7 and enhanced proliferation of both the thymus-derived progenitor cells and the bone marrow–derived common lymphoid progenitor cells. The synergistic effect on the ETP population was further characterized and found to correlate with increased surface expression of c-Kit and IL-7 receptors on the IL-18–treated cells. In summary, we successfully validated the global microarray meta-analysis prediction that IL-18 affects T lymphopoiesis and demonstrated that IL-18 can positively impact bone marrow lymphopoiesis and T cell development, presumably via interaction with the c-Kit and IL-7 signaling axis.
Minimal Sequence Requirements for Oligodeoxyribonucleotides Activating Human TLR9
Authors: Pohar Jelka , Kužnik Krajnik Alenka , Jerala Roman , Benčina Mojca
Published: March 2015

Synthetic oligodeoxyribonucleotides (ODNs) containing CpG (unmethylated deoxycytidylyl-deoxyguanosine dinucleotide) motifs activate endosomal TLR9. The nucleotide sequence, length, and dimerization properties of ODNs modulate their activation of TLR9. We performed a systematic investigation of the sequence motifs of B-class and C-class phosphodiester ODNs to identify the sequence properties that govern TLR9 activation. ODNs shorter than 21 nt and with the adenosine adjacent to the cytidine-guanosine (CG) dinucleotide motif led to a significant loss of the propensity to activate TLR9. The distance between the stimulatory CpG motifs within the ODN fine-tunes the activation of B cells. The minimal ODNs that activate human TLR9 comprise 2 CG dinucleotides separated by 6–10 nt, where the first CpG motif is preceded by the 5′-thymidine and the elongated poly-thymidine tail at the 3′ end of the ODN. The minimal sequence provides insight into the molecular mechanism of TLR9 ligand recognition. On the basis of sequence requirements, we conclude that two binding sites with different affinities for CG are formed in the human TLR9 dimer, with a very stringent binding site interacting with the 5′ CpG motif.
Geology of the Rocky Mountain Foothills, Alberta (between latitudes 53°15' and 54°15')
Authors: Irish E J W
Published: March 2015

This report describes the geology of a vast area of the northern part of the Rocky Mountain Foothills, Alberta. The stratigraphic succession ranges from Cambrian? to Paleocene. The author has described in some detail the relationships and lithological content of
all the formations (comprising some 25,000 feet of strata) and has attempted to clarify the nomenclature of Cretaceous stratigraphy by using the Athabasca River as an arbitrary cut-off for the northern nomenclature. Compressive stresses have deformed the region from the southwest; thrust faulting is
perhaps the dominant and initial type of deformation. Folding may post-date the initial thrusts but continued on the faults and persisted after thrusting ceased. Most of the thrusts are west dipping but there are some east-dipping faults. The formation of drag anticlines and the mechanism of
steeply-dipping and folded back-limb thrusts is analysed in some detail. Coal is perhaps the most important economic material and is treated according to locality and age. The report includes a discussion of the oil and gas potentialities of the region. Appendices contain detailed measured sections
of most formations of the larger exposed coal seams, and of the logs of wells drilled for oil. Fossils are listed according to their age, enclosing formations and geographic location.
The education of prospective ministers as an invitation to life: Moving from moral failure to moral excellence through a process of moral formation
Authors: Kretzschmar Louise
Published: March 2015

This article discusses the importance of the moral formation of students who are in training for the Christian ministry. Moral formation is defined and its importance is discussed with reference to the scholarly debate, both in South Africa and elsewhere. The complex nature of moral formation, the individuality of students and the multiplicity of contexts in which formation takes place are noted. A model that has God’s grace and human volition at its core and discusses the goals, obstacles and means of moral formation, is presented. It extends beyond a ‘head, hearts and hands’ approach and discusses the crucial areas of thinking, being, relating and doing. It seeks to avoid the extremes of both indoctrination and laissez-faire non-involvement with ministerial students.Die opvoeding van voornemende predikante as ‘n uitnodiging tot die lewe: Beweging vanaf morele bankrotskap tot morele uitmuntendheid deur middel van ‘n proses van morele vorming. Hierdie artikel bespreek die belangrikheid van morele vorming van studente in Christelike bedieningsopleiding. Morele vorming word gedefinieer en die belangrikheid daarvan word bespreek met verwysing na die wetenskaplike debat in Suid-Afrika en elders. Die komplekse aard van morele vorming, die individualiteit van studente en die veelheid van kontekste waarin vorming plaasvind, word genoteer. ‘n Model wat God se genade en menslike wilsinspanning as kern het en wat die doelwitte, struikelblokke en middele tot morele vorming beskryf, word voorgelê. Dit strek veel verder as ‘n ‘kop-, hart- en hande’-benadering en bespreek die kritieke areas van denke, wese, verhoudings en handel. Dit streef daarna om die uiterstes van indoktrinasie sowel as laissez-faire onbetrokkenheid teenoor teologiese studente te vermy.
Rotavirus Seasonal Distribution and Prevalence Before and After the Introduction of Rotavirus Vaccine in a Peri-Urban Community of Lima, Peru
Authors: Chang Millie R. , Velapatiño Grace , Campos Miguel , Chea-Woo Elsa , Baiocchi Nelly , Cleary Thomas G. , Ochoa Theresa J.
Published: March 2015

We evaluated the monthly distribution of rotavirus diarrhea in a cohort of children 12–24 months of age followed as part of a diarrhea clinical trial in a peri-urban community of Lima. We observed a peak of rotavirus diarrhea in the winter months and a decrease in rotavirus prevalence after the introduction of the rotavirus vaccine in Peru.
Clinical and Epidemiological Characteristics of Scrub Typhus and Murine Typhus among Hospitalized Patients with Acute Undifferentiated Fever in Northern Vietnam
Authors: Hamaguchi Sugihiro , Cuong Ngo Chi , Tra Doan Thu , Doan Yen Hai , Shimizu Kenta , Tuan Nguyen Quang , Yoshida Lay-Myint , Mai Le Quynh , Duc-Anh Dang , Ando Shuji , Arikawa Jiro , Parry Christopher M. , Ariyoshi Koya , Thuy Pham Thanh
Published: March 2015

A descriptive study on rickettsiosis was conducted at the largest referral hospital in Hanoi, Vietnam, to identify epidemiological and clinical characteristics of specific rickettsiosis. Between March 2001 and February 2003, we enrolled 579 patients with acute undifferentiated fever (AUF), excluding patients with malaria, dengue fever, and typhoid fever, and serologically tested for Orientia tsutsugamushi and Rickettsia typhi. Of the patients, 237 (40.9%) and 193 (33.3%) had scrub and murine typhus, respectively, and 149 (25.7%) had neither of them (non–scrub and murine typhus [non-ST/MT]). The proportion of murine typhus was highest among patients living in Hanoi whereas that of scrub typhus was highest in national or regional border areas. The presence of an eschar, dyspnea, hypotension, and lymphadenopathy was significantly associated with a diagnosis of scrub typhus (OR = 46.56, 10.90, 9.01, and 7.92, respectively). Patients with murine typhus were less likely to have these findings but more likely to have myalgia, rash, and relative bradycardia (OR = 1.60, 1.56, and 1.45, respectively). Scrub typhus and murine typhus were shown to be common causes of AUF in northern Vietnam although the occurrence of spotted fever group rickettsiae was not determined. Clinical and epidemiological information may help local clinicians make clinical diagnosis of specific rickettsioses in a resource-limited setting.
Availability of Emergency Drugs and Equipment in General and Specialist Dental Settings in Babol, Iran
Authors: Hamzeh Mahtab , Mehdizadeh Mohammad , Nosrati Kamran
Published: March 2015

Aim

Medical emergencies can frequently happen in dental settings and it is critical to outfit the clinic by emergency drugs and equipment. The aim of this study was to evaluate the emergency drugs and equipment in general and specialist dental settings in Babol, Iran.

Materials and methods

A questionnaire containing closed ended questions about the available emergency drugs and equipment was used in this descriptive-analytical study. Data were subjected to descriptive analysis using SPSS 18.0 to identify the most frequent drugs and equipment. Chi-square and t-test were used to evaluate the correlation between the variables. p < 0.05 was considered statistically significant.

Results

One hundred and twelve dentists answered the questionnaire. The most available drug and equipment were epinephrine (67%) and single use syringe (81.3%) respectively. Significant correlation was found between degree of education and availability of first group of emergency drugs and between sex and possession of second group of emergency equipment (p < 0.05).

Conclusion

Degree of availability of emergency drugs and equipment was moderate to low and training about emergencies should be included in the didactic topics of universities and workshops.

Clinical significance

Information about emergency drug and equipment would help to manage the unwanted emergency situations.

How to cite this article

Mehdizadeh M, Nosrati K, Hamzeh M. Availability of Emergency Drugs and Equipment in General and Specialist Dental Settings in Babol, Iran. J Contemp Dent Pract 2014;15(6):677-680.
Influence of Metalloproteinases on Dentin Hybridization of One-bottle or Self-etch Dental Bonding Systems
Authors: Pinheiro Sérgio Luiz , Pereira Diana Roberta , Milito Flávia De , Villalpando Karina Teixeira
Published: March 2015

Aim

To assess the influence of dentin substrate and chlorhexidine on the marginal seal of composite resin restorations.

Materials and methods

The sample comprised 20 third molars. Four cavities were drilled in the dentin surface, followed by sealing and restoration of sound dentin (n = 10) or carious dentin (n = 10). In the control group, cavities were immediately restored as follows: G1: one-bottle bonding agent (OB) + composite resin (CR); G2: chlorhexidine 2.0% (CLX) + OB + CR; G3: self-etch bonding agent (SE) + CR; G4: CLX + SE + CR. In the experimental group (carious dentin), carious lesions were induced with S. mutans and cavities were restored as in the control group. Five specimens from each group (sound and carious) were stored in brain–heart infusion (BHI) medium for 6 months. All specimens were submerged in methylene blue 0.5% to test for microleakage. The Kruskal-Wallis and Student- Newman-Keuls tests were used to assess results.

Results

On immediate assessment, there were no significant between-group differences in the sound dentin group, whereas in carious dentin, there was less leakage when OB and CLX were used. At 6 months, there was less leakage in the sound dentin group when OB and CLX were used; there were no between-group differences in carious dentin. Comparison of immediate and 6-month assessments showed a significant increase in leakage at 6 months when sound dentin was treated with SE and CLX and when carious dentin was treated with OB and CLX.

Conclusion

To ensure better dentin hybridization and preservation of the organic constituents of the dentin matrix, the properties of chlorhexidine digluconate and the components of the resin matrix must be taken into account.

Clinical significance

Metalloproteinases influence degradation of the hybrid layer in composite resin restorations, regardless of whether the bonding system used is one-bottle or self-etching.

How to cite this article

Pinheiro SL, Pereira DR, Milito FD, Villalpando KT. Influence of Metalloproteinases on Dentin Hybridization of One-bottle or Self-etch Dental Bonding Systems. J Contemp Dent Pract 2014;15(6):705-711.
An Unusual Case of Ameloblastoma observed in the Left Anterior Mandible
Authors: Gunhan Omer , Canger Emin Murat , Çelenk Peruze , Bulut Emel
Published: March 2015

Aim

To report a small intaalveolar ameloblastoma which resembled cystic lesion, and to emphasize the value of Computed tomography (CT) in radiographic examination.

Background

Ameloblastoma is a slow-growing, locally invasive odontogenic neoplasm that accounts for approximately 10% of all tumors detected in the jaws. Radiographically, those tumors are usually well-defined. Computerized tomography is highly recommended to confirm the diagnosis.

Case description

A 48-year-old female attended with a chief complaint of painless swelling in the left anterior of mandible, 1 month duration. In intraoral examination, non-fluctuant, immobile, approximately 1 × 1 cm in dimension, painless, swelling which had a bone-like hardness and located in the mandibular canine region was detected. Panoramic radiography revealed a well circumscribed unilocular radiolucent lesion located in the inter-radicular area of left mandibular lateral and canine teeth. In CT examination it was realized that the lesion was multilocular. Histopathological examination of the biopsy specimen was reported as ameloblastoma.

Clinical significance

It is extremely difficult to find such an ameloblastoma in small dimension in alvolar bone.

How to cite this article

Canger EM, Çelenk P, Bulut E, Günhan Ö. An Unusual Case of Ameloblastoma observed in the Left Anterior Mandible. J Contemp Dent Pract 2014;15(6):775-778.
The Complex Radicular Groove: Interdisciplinary Management with Mineral Trioxide Aggregate and Bone Substitute
Authors: Thakur Sophia , Narmatha VJ , Shetty Sheetal , Bali Praveen Kumar
Published: March 2015

This article is a case report of the successful interdisciplinary management of a maxillary lateral incisor with a deep palatogingival groove. The tooth presented with severe periodontal destruction owing to the deep extension of the groove up to the root apex. The groove was meticulously diagnosed and treated by endodontic and subsequent periodontal surgery leading to complete resolution of the pathological process.

How to cite this article

Narmatha VJ, Thakur S, Shetty S, Bali PK. The Complex Radicular Groove: Interdisciplinary Management with Mineral Trioxide Aggregate and Bone Substitute. J Contemp Dent Pract 2014;15(6):792-796.
Gaseous products and secondary organic aerosol formation during long term oxidation of isoprene and methacrolein
Authors: Brégonzio-Rozier L. , Siekmann F. , Giorio C. , Pangui E. , Morales S. B. , Temime-Roussel B. , Gratien A. , Michoud V. , Ravier S. , Cazaunau M. , Tapparo A. , Monod A. , Doussin J.-F.
Published: March 2015

Abstract. First- and higher order-generation products formed from the oxidation of isoprene and methacrolein with OH radicals in the presence of NOx have been studied in a simulation chamber. Significant oxidation rates have been maintained for up to 7 h, allowing the study of highly oxidized products. Gas-phase product distribution and yields were obtained, and show good agreement with previous studies. Secondary organic aerosol (SOA) formation has also been investigated. SOA mass yields from previous studies show large discrepancies. The mass yields obtained here were consistent with the lowest values found in the literature, and more specifically in agreement with studies carried out with natural light or artificial lamps with emission similar to the solar spectrum. Differences in light source are therefore proposed to explain partially the discrepancies observed between different studies in the literature for both isoprene- and methacrolein-SOA mass yields. There is a high degree of similarity between the SOA mass spectra from isoprene and methacrolein photooxidation, thus strengthening the importance of the role of methacrolein in SOA formation from isoprene photooxidation under our experimental conditions (i.e., presence of NOx and long term oxidation). According to our results, SOA mass yields from both isoprene and methacrolein in the atmosphere could be lower than suggested by most of the current chamber studies.
Exploring the severe winter haze in Beijing: the impact of synoptic weather, regional transport and heterogeneous reactions
Authors: Zheng G. J. , Duan F. K. , Su H. , Ma Y. L. , Cheng Y. , Zheng B. , Zhang Q. , Huang T. , Kimoto T. , Chang D. , Pöschl U. , Cheng Y. F. , He K. B.
Published: March 2015

Abstract. Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012–2013, causing major environmental and health problems. To better understand these extreme events, we performed a model-assisted analysis of the hourly observation data of PM2.5 and its major chemical compositions. The synthetic analysis shows that (1) the severe winter haze was driven by stable synoptic meteorological conditions over northeastern China, and not by an abrupt increase in anthropogenic emissions. (2) Secondary species, including organics, sulfate, nitrate, and ammonium, were the major constituents of PM2.5 during this period. (3) Due to the dimming effect of high loading of aerosol particles, gaseous oxidant concentrations decreased significantly, suggesting a reduced production of secondary aerosols through gas-phase reactions. Surprisingly, the observational data reveals an enhanced production rate of secondary aerosols, suggesting an important contribution from other formation pathways, most likely heterogeneous reactions. These reactions appeared to be more efficient in producing secondary inorganics aerosols than organic aerosols resulting in a strongly elevated fraction of inorganics during heavily polluted periods. (4) Moreover, we found that high aerosol concentration was a regional phenomenon. The accumulation process of aerosol particles occurred successively from cities southeast of Beijing. The apparent sharp increase in PM2.5 concentration of up to several hundred μg m−3 per hour recorded in Beijing represented rapid recovery from an interruption to the continuous pollution accumulation over the region, rather than purely local chemical production. This suggests that regional transport of pollutants played an important role during these severe pollution events.
Two years of near real-time chemical composition of submicron aerosols in the region of Paris using an Aerosol Chemical Speciation Monitor (ACSM) and a multi-wavelength Aethalometer
Authors: Petit J.-E. , Favez O. , Sciare J. , Crenn V. , Sarda-Estève R. , Bonnaire N. , Močnik G. , Dupont J.-C. , Haeffelin M. , Leoz-Garziandia E.
Published: March 2015

Abstract. Aerosol mass spectrometer (AMS) measurements have been successfully used towards a better understanding of non-refractory submicron (PM1) aerosol chemical properties based on short-term campaigns. The recently developed Aerosol Chemical Speciation Monitor (ACSM) has been designed to deliver quite similar artifact-free chemical information but for low cost, and to perform robust monitoring over long-term periods. When deployed in parallel with real-time black carbon (BC) measurements, the combined data set allows for a quasi-comprehensive description of the whole PM1 fraction in near real time. Here we present 2-year long ACSM and BC data sets, between mid-2011 and mid-2013, obtained at the French atmospheric SIRTA supersite that is representative of background PM levels of the region of Paris. This large data set shows intense and time-limited (a few hours) pollution events observed during wintertime in the region of Paris, pointing to local carbonaceous emissions (mainly combustion sources). A non-parametric wind regression analysis was performed on this 2-year data set for the major PM1 constituents (organic matter, nitrate, sulfate and source apportioned BC) and ammonia in order to better refine their geographical origins and assess local/regional/advected contributions whose information is mandatory for efficient mitigation strategies. While ammonium sulfate typically shows a clear advected pattern, ammonium nitrate partially displays a similar feature, but, less expectedly, it also exhibits a significant contribution of regional and local emissions. The contribution of regional background organic aerosols (OA) is significant in spring and summer, while a more pronounced local origin is evidenced during wintertime, whose pattern is also observed for BC originating from domestic wood burning. Using time-resolved ACSM and BC information, seasonally differentiated weekly diurnal profiles of these constituents were investigated and helped to identify the main parameters controlling their temporal variations (sources, meteorological parameters). Finally, a careful investigation of all the major pollution episodes observed over the region of Paris between 2011 and 2013 was performed and classified in terms of chemical composition and the BC-to-sulfate ratio used here as a proxy of the local/regional/advected contribution of PM. In conclusion, these first 2-year quality-controlled measurements of ACSM clearly demonstrate their great potential to monitor on a long-term basis aerosol sources and their geographical origin and provide strategic information in near real time during pollution episodes. They also support the capacity of the ACSM to be proposed as a robust and credible alternative to filter-based sampling techniques for long-term monitoring strategies.
VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China
Authors: Huang C. , Wang H. L. , Li L. , Wang Q. , Lu Q. , de Gouw J. A. , Zhou M. , Jing S. A. , Lu J. , Chen C. H.
Published: March 2015

Abstract. VOC species from vehicle exhaust and gas evaporation were investigated by chassis dynamometer and on-road measurements of 9 gasoline vehicles, 7 diesel vehicles, 5 motorcycles, and 4 gas evaporation samples. The SOA mass yields of gasoline, diesel, motorcycle exhausts, and gas evaporation were calculated based on the mixing ratio of individual VOC species. The SOA mass yields of gasoline and motorcycle exhaust were similar to the results of the published smog chamber study with the exception of that of diesel exhaust was 20% lower than experimental data (Gordon et al., 2013, 2014a, b). This suggests the requirement for further research on SVOC or LVOC emissions. A vehicular emission inventory was compiled based on a local survey of vehicle mileage traveled and real-world measurements of vehicle emission factors. The inventory-based vehicular initial emission ratio of OA to CO was 15.6 μg m−3 ppmv−1. The OA production rate reached 22.3 and 42.7 μg m−3 ppmv−1 under high-NOx and low-NOx conditions, respectively. To determine the vehicular contribution to OA pollution, the inventory-based OA formation ratios for vehicles were calculated with a photochemical-age-based parameterization method and compared with the observation-based OA formation ratios in the urban atmosphere of Shanghai. The results indicated that VOC emissions from vehicle exhaust and gas evaporation only explained 15 and 22% of the total organic aerosols observed in summer and winter, respectively. SOA production only accounted for 25 and 18% of the total vehicular OA formation in summer and winter. VOC emissions from gasoline vehicles contribute 21–38% of vehicular OA formation after 6–24 h of photochemical aging. The results suggest that vehicle emissions are an important contributor to OA pollution in the urban atmosphere of Shanghai. However, a large number of OA mass in the atmosphere still cannot be explained in this study. SOA formation contributions from other sources (e.g. coal burning, biomass burning, cooking, dust, etc.) as well as IVOCs and SVOCs from the combustion sources need to be considered in future studies.
OMI tropospheric NO2 profiles from cloud slicing: constraints on surface emissions, convective transport and lightning NOx
Authors: Belmonte Rivas M. , Veefkind P. , Eskes H. , Levelt P.
Published: March 2015

Abstract. We derive a global climatology of tropospheric NO2 profiles from OMI cloudy observations for the year 2006 using the cloud slicing method on six pressure levels centered about 280, 380, 500, 620, 720 and 820 hPa. A comparison between OMI and the TM4 model tropospheric NO2 profiles reveals striking overall similarities, which confer great confidence to the cloud-slicing approach, along with localized discrepancies that seem to probe into particular model processes. Anomalies detected at the lowest levels can be traced to deficiencies in the model surface emission inventory, at mid tropospheric levels to convective transport and horizontal advective diffusion, and at the upper tropospheric levels to model lightning NOx production and the placement of deeply transported NO2 plumes such as from the Asian summer monsoon. The vertical information contained in the OMI cloud-sliced NO2 profiles provides a global observational constraint that can be used to evaluate chemistry transport models (CTMs) and guide the development of key parameterization schemes.
Organic photolysis reactions in tropospheric aerosols: effect on secondary organic aerosol formation and lifetime
Authors: Hodzic A. , Madronich S. , Kasibhatla P. S. , Tyndall G. , Aumont B. , Jimenez J. L. , Lee-Taylor J. , Orlando J.
Published: March 2015

Abstract. This study presents the first modeling estimates of the potential effect of gas- and particle-phase organic photolysis reactions on the formation and lifetime of secondary organic aerosols (SOA). Typically only photolysis of smaller organic molecules (e.g. formaldehyde) for which explicit data exist is included in chemistry-climate models. Here, we specifically examine the photolysis of larger molecules that actively partition between the gas and particle phases. The chemical mechanism generator GECKO-A is used to explicitly model SOA formation from α-pinene, toluene, and C12 and C16 n-alkane reactions with OH at low- and high-NOx. Simulations are conducted for typical mid-latitude conditions and a solar zenith angle of 45° (permanent daylight). The results show that after four days of chemical aging under those conditions (equivalent to eight days in the summer mid-latitudes), gas-phase photolysis leads to a moderate decrease in SOA yields i.e ~15% (low-NOx) to ~45% (high-NOx) for α-pinene, ~15% for toluene, ~25% for C12-alkane, and ~10% for C16-alkane. The small effect on low volatility n-alkanes such as C16-alkane is due to the rapid partitioning of early-generation products to the particle phase where they are assumed to be protected from gas-phase photolysis. Minor changes are found in the volatility distribution of organic products and in oxygen to carbon ratios. The decrease in SOA mass seems increasingly more important after a day of chemical processing, suggesting that most laboratory experiments are likely too short to quantify the effect of gas-phase photolysis on SOA yields. Our results also suggest that many molecules containing chromophores are preferentially partitioned into the particle phase before they can be photolyzed in the gas-phase. Given the growing experimental evidence that these molecules can undergo in-particle photolysis, we performed sensitivity simulations using an estimated SOA photolysis rate of JSOA=4 x 10-4JNO2. Modeling results indicate that this photolytic loss rate would decrease SOA mass by 40–60% for most species after ten days of equivalent atmospheric aging at mid-latitudes in the summer. It should be noted that in our simulations we do not consider in-particle or aqueous-phase reactions which could modify the chemical composition of the particle, and thus the amount of photolabile species. The atmospheric implications of our results are significant for both the SOA global distribution and lifetime. GEOS-Chem global model results suggest that particle-phase photolytic reactions could be an important loss process for SOA in the atmosphere, removing aerosols from the troposphere on timescales (less than 7 days) that are comparable to wet deposition.
Some insights into the condensing vapors driving new particle growth to CCN sizes on the basis of hygroscopicity measurements
Authors: Wu Z. J. , Poulain L. , Birmili W. , Größ J. , Niedermeier N. , Wang Z. B. , Herrmann H. , Wiedensohler A.
Published: March 2015

Abstract. New particle formation (NPF) and growth is an important source of cloud condensation nuclei (CCN). In this study, we investigated the potential chemical species driving new particle growth to the CCN sizes on the basis of particle hygroscopicity measurements carried out at the research station Melpitz, Germany. The predicted CCN number concentrations using κ-Köhler theory were analyzed to assess the contribution of NPF to possible CCN. Three consecutive NPF events occurred during summertime were chosen as examples to perform the study. Hygroscopicity measurements showed that the (NH4)2SO4-equivalent water-soluble fraction respectively accounts for 20 and 16% of 50 and 75 nm particles during the NPF events. Numerical analysis showed the ratios of H2SO4 condensational growth to the observed particle growth were 20 and 13% for 50 and 75 nm newly formed particles, respectively. Both hygroscopicity measurements and numerical analysis confirmed that organic compounds were major contributors driving particle growth to CCN sizes. The critical diameters at different supersaturations estimated using AMS data and κ-Köhler theory increased significantly during the later course of NPF events. This indicated that the enhanced organic mass fraction caused a reduction in CCN efficiency of newly formed particles. Our results implied that the CCN production associated with atmospheric nucleation may be overestimated if assuming that newly formed particles can serve as CCN in case they grow to a fixed particle size, which was used in some previous studies, especially for organic-rich environments. In our study, the enhancement in CCN number concentration associated with individual NPF events have been 63, 66, 69% for supersaturation 0.1, 0.4, and 0.6%, respectively.
A numerical study of convection in rainbands of Typhoon Morakot (2009) with extreme rainfall: roles of pressure perturbations with low-level wind maxima
Authors: Wang C.-C. , Kuo H.-C. , Johnson R. H. , Lee C.-Y. , Huang S.-Y. , Chen Y.-H.
Published: March 2015

Abstract. This paper investigates the formation and evolution of deep convection inside the east–west oriented rainbands associated with a low-level jet (LLJ) in Typhoon Morakot (2009). With typhoon center to the northwest of Taiwan, the westerly LLJ was resulted from the interaction of typhoon circulation with the southwest monsoon flow, which supplied the water vapor for the extreme rainfall (of ~1000 mm) over southwestern Taiwan. The Cloud-Resolving Storm Simulator with 1 km grid spacing was used to simulate the event, and it successfully reproduced the slow-moving rainbands, the embedded cells, and the dynamics of merger and back-building (BB) on 8 August as observed. Our model results suggest that the intense convection interacted strongly with the westerly LLJ that provided reversed vertical wind shear below and above the jet core. Inside mature cells, significant dynamical pressure perturbations (pd') are induced with positive (negative) pd' at the western (eastern) flank of the updraft near the surface and a reversed pattern aloft (>2 km). This configuration produced an upward directed pressure gradient force (PGF) to the rear side and favors new development to the west, which further leads to cell merger as the mature cells slowdown in eastward propagation. The strong updrafts also acted to elevate the jet and enhance the local vertical wind shear at the rear flank. Additional analysis reveals that the upward PGF there is resulted mainly by the shearing effect but also by the extension of upward acceleration at low levels. In the horizontal, the upstream-directed PGF induced by the rear-side positive pd' near the surface is much smaller, but can provide additional convergence for BB development upstream. Finally, the cold-pool mechanism for BB appears to be not important in the Morakot case, as the conditions for strong evaporation in downdrafts do not exist.