bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Antioxidant Pretreatment on the Survival of Embryonic Dopaminergic Neurons In Vitro and following Grafting in an Animal Model of Parkinson's Disease
Authors: Love R. M. , Branton R. L. , Karlsson J. , Brundin P. , Clarke D. J.
Published: May 2016

The effect of pretreating cell suspensions of embryonic rat ventral mesencephala (VM) with antioxidant combinations on the survival of dopaminergic (DA) neurons was studied in vitro and following transplantation into the unilateral 6-hydroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease. The in vitro experiments examined the effects of two thiol antioxidants, N-acetyl-l-cysteine (NAC) and reduced glutathione (GSH), and a member of the lazaroid family of 21-aminosteroids, U-83836E, singly and in combination, on survival of DA neurons derived from dissociated E14 rat VM tissue. For in vivo studies, cell suspensions were pretreated with combinations of NAC, GSH, and U-83836E prior to transplanting into 6-OHDA-lesioned rats to investigate whether DA neuron survival could be further improved. NAC, GSH, and U-83836E individually increased DA neuron survival in vitro and a combination of all three resulted in the greatest survival. In vivo, pretreatment with U-83836E alone resulted in a significantly greater reduction in amphetamine-induced rotation 6 weeks postgrafting compared with a control group receiving nontreated graft tissue. This functional effect correlated with a significant improvement in DA neuron survival 6 weeks postgrafting. The thiol combination pretreatment of NAC and GSH, and the triple combination of NAC, GSH, and U-83836E, however, failed to improve both functional recovery and DA neuron survival when compared with the nontreated control grafts.
Co-Stimulatory Molecules in Islet Xenotransplantation: CTLA4Ig Treatment in CD40 Ligand-Deficient Mice
Authors: Benda Birgitta , Ljunggren Hans-Gustaf , Peach Robert , Sandberg Jan-Olov , Korsgren Olle
Published: May 2016

Previous work has demonstrated that short-term systemic administration of cytotoxic T lymphocyte antigen-4 (CTLA-4) Ig blocks human pancreatic islet xenograft rejection in mice and induces long-term, donor-specific tolerance, whereas studies on pig pancreatic islet rejection in mice have failed to demonstrate a role for CTLA4Ig in preventing rejection. Treatment with anti-CD40 ligand (L) monoclonal antibodies alone is somewhat effective in prolonging the survival of islet xenografts, but ineffective when applied to skin xenografts. However, simultaneous blockade of the CD28 and CD40 co-stimulatory pathways prolongs the survival of pig skin on recipient mice. To evaluate the role of CD28 and CD40 co-stimulatory pathways in pig islet-like cell cluster (ICC) xenograft rejection in mice, CD40L-deficient mice transplanted with fetal porcine ICCs were given posttransplant treatment with human (h) CTLA4Ig or a human IgG1 chimeric mAb (hL6). Xenografts were evaluated 6 or 12 days after transplantation. Fetal porcine ICC xenografts were protected from rejection in hCTLA4Ig-treated CD40L-deficient mice, whereas xenograft rejection persisted in untreated CD40L-deficient mice. Simultaneous blockade of the CD28 and CD40 co-stimulatory pathways is mandatory to inhibit ICC xenograft rejection in the pig-to-mouse model, because the CD28 and CD40 co-stimulatory pathways seem capable of efficiently substituting for one another.
Synthesis of 2,1-benzisoxazole-3(1H)-ones by base-mediated photochemical N–O bond-forming cyclization of 2-azidobenzoic acids
Authors: Dzhons Daria Yu , Budruev Andrei V
Published: May 2016

The base-mediated photochemical cyclization of 2-azidobenzoic acids with the formation of 2,1-benzisoxazole-3(1H)-ones is reported. The optimization and scope of this cyclization reaction is discussed. It is shown that an essential step of the ring closure of 2-azidobenzoic acids is the formation and photolysis of 2-azidobenzoate anions.
SPITZER OBSERVATIONS OF EXOPLANETS DISCOVERED WITH THE KEPLER K2 MISSION
Authors: Beichman Charles , Livingston John , Werner Michael , Gorjian Varoujan , Krick Jessica , Deck Katherine , Knutson Heather , Wong Ian , Petigura Erik , Christiansen Jessie , Ciardi David , Greene Thomas P. , Schlieder Joshua E. , Line Mike , Crossfield Ian , Howard Andrew , Sinukoff Evan
Published: May 2016

We have used the Spitzer Space Telescope to observe two transiting planetary systems orbiting low-mass stars discovered in the Kepler K2 mission. The system K2-3 (EPIC 201367065) hosts three planets, while K2-26 (EPIC 202083828) hosts a single planet. Observations of all four objects in these two systems confirm and refine the orbital and physical parameters of the planets. The refined orbital information and more precise planet radii possible with Spitzer will be critical for future observations of these and other K2 targets. For K2-3b we find marginally significant evidence for a transit timing variation between the K2 and Spitzer epochs.
A HIGH-PRECISION NEAR-INFRARED SURVEY FOR RADIAL VELOCITY VARIABLE LOW-MASS STARS USING CSHELL AND A METHANE GAS CELL
Authors: Gagné Jonathan , Plavchan Peter , Gao Peter , Anglada-Escude Guillem , Furlan Elise , Davison Cassy , Tanner Angelle , Henry Todd J. , Riedel Adric R. , Brinkworth Carolyn , Latham David , Bottom Michael , White Russel , Mills Sean , Beichman Chas , Johnson John A. , Ciardi David R. , Wallace Kent , Mennesson Bertrand , von Braun Kaspar , Vasisht Gautam , Prato Lisa , Kane Stephen R. , Mamajek Eric E. , Walp Bernie , Crawford Timothy J. , Rougeot Raphaël , Geneser Claire S. , Catanzarite Joseph
Published: May 2016

We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2–M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25–150 Myr) moving groups, the young field star ε Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8–15 m s−1with a long-term stability of 15–50 m s−1 over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25–50 m s−1 at ≈2.3125 μm, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3σ–5σ. Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of ≲5 m s−1 in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.
ISM EXCITATION AND METALLICITY OF STAR-FORMING GALAXIES AT Z ≃ 3.3 FROM NEAR-IR SPECTROSCOPY
Authors: Onodera M. , Carollo C. M. , Lilly S. , Renzini A. , Arimoto N. , Capak P. , Daddi E. , Scoville N. , Tacchella S. , Tatehora S. , Zamorani G.
Published: May 2016

We study the relationship between stellar mass, star formation rate (SFR), ionization state, and gas-phase metallicity for a sample of 41 normal star-forming galaxies at 3 ≲ z ≲ 3.7. The gas-phase oxygen abundance, ionization parameter, and electron density of ionized gas are derived from rest-frame optical strong emission lines measured on near-infrared spectra obtained with Keck/Multi-Object Spectrograph for Infra-Red Exploration. We remove the effect of these strong emission lines in the broadband fluxes to compute stellar masses via spectral energy distribution fitting, while the SFR is derived from the dust-corrected ultraviolet luminosity. The ionization parameter is weakly correlated with the specific SFR, but otherwise the ionization parameter and electron density do not correlate with other global galaxy properties such as stellar mass, SFR, and metallicity. The mass–metallicity relation (MZR) at z ≃ 3.3 shows lower metallicity by ≃0.7 dex than that at z = 0 at the same stellar mass. Our sample shows an offset by ≃0.3 dex from the locally defined mass–metallicity–SFR relation, indicating that simply extrapolating such a relation to higher redshift may predict an incorrect evolution of MZR. Furthermore, within the uncertainties we find no SFR–metallicity correlation, suggesting a less important role of SFR in controlling the metallicity at high redshift. We finally investigate the redshift evolution of the MZR by using the model by Lilly et al., finding that the observed evolution from z = 0 to z ≃ 3.3 can be accounted for by the model assuming a weak redshift evolution of the star formation efficiency.
ACTIVE REGION FILAMENTS MIGHT HARBOR WEAK MAGNETIC FIELDS
Authors: Díaz Baso C. J. , Martínez González M. J. , Asensio Ramos A.
Published: May 2016

Recent spectropolarimetric observations of active region filaments have revealed polarization profiles with signatures typical of the strong field Zeeman regime. The conspicuous absence in those observations of scattering polarization and Hanle effect signatures was then pointed out by some authors. This was interpreted as either a signature of mixed “turbulent” field components or as a result of optical thickness. In this article, we present a natural scenario to explain these Zeeman-only spectropolarimetric observations of active region (AR) filaments. We propose a two-component model, one on top of the other. Both components have horizontal fields, with the azimuth difference between them being close to 90°. The component that lies lower in the atmosphere is permeated by a strong field of the order of 600 G, while the upper component has much weaker fields, of the order of 10 G. The ensuing scattering polarization signatures of the individual components have opposite signs, so its combination along the line of sight reduces—and even can cancel out—the Hanle signatures, giving rise to an apparent Zeeman-only profile. This model is also applicable to other chromospheric structures seen in absorption above ARs.
A TRANDISCIPLINARIDADE DA CIÊNCIA DE ALEXANDER VON HUMBOLDT (1769-1859): INTERSECÇÕES JUNTO AOS DEBATES CONTEMPORÂNEOS SOBRE O CONHECIMENTO
Authors: Verges João Vitor Gobis , Bauab Fabrício Pedroso
Published: May 2016

A partir das bases da epistemologia em Geografia, busca-se com este artigo vincular as construções científicas de Alexander von Humboldt (1769-1859) aos debates contemporâneos sobre o conhecimento transdisciplinar. Neste sentido, propõe-se entender que as formulações humboldtianas, conectando espírito humano e empiria, fundamentam-se enquanto bases profícuas e como exemplo concreto de uma ciência superadora da fragmentação disciplinar. Para isso, a partir da revisão bibliográfica, expõe-se a construção da diferenciação da realidade em qualidades primárias e secundárias nos interstícios do advento da Modernidade, as caracterizações gerais do Romantismo alemão e a ciência humboldtiana como síntese entre empirismo e espírito humano, corroborando com as “novas” perspectivas transdisciplinares.
AGRICULTURA FAMILIAR NO MUNICÍPIO DE CURVELÂNDIA/MT: ANÁLISE DA PRODUÇÃO VINCULADA AO PROGRAMA DE AQUISIÇÃO DE ALIMENTOS (PAA)
Authors: De Queiroz Rafaella Ferreira Neres , Neves Sandra Mara Alves da Silva , Seabra Junior Santino , Machado Tamires Da Silva
Published: May 2016

O município de Curvelândia/MT, situado na região sudoeste mato-grossense de planejamento, tem como base econômica a pecuária extensiva e a agricultura. Objetivou-se analisar a produção da agricultura familiar vinculada ao Programa de Aquisição de Alimentos (PAA) do município Curvelândia, na perspectiva de contribuir com informações para a diversificação da produção e a melhoria da competitividade da atividade na região. A pesquisa realizada teve enfoque qualitativo e foi dirigida aos agricultores familiares que acessam o PAA. A metodologia consistiu nas seguintes etapas: pesquisas, bibliográfica e documental; trabalho de campo, para a realização de entrevistas e georreferenciamento das propriedades; elaboração de mapas, tabulação e análises dos dados. Os resultados indicaram que a mão-de-obra utilizada na produção é totalmente familiar e as propriedades são de pequeno porte, fundamentadas no tripé propriedade, trabalho e família, bases da agricultura familiar; a produção esta alicerçada nas espécies hortícolas: quiabo, alface, rúcula, mandioca, cebolinha, pepino e abóbora; a maioria dos agricultores familiares está satisfeito com o PAA, que tem contribuído no sentido de trazer seguridade à comercialização dos produtos cultivados, contribuindo para o desenvolvimento e fortalecimento da agricultura familiar regional; os gargalos identificados na produção são: falta de assistência técnica, baixa tecnologia empregada no manejo, como rotação de culturas, adubação, irrigação e controle de pragas e doenças; falta de organização do sistema produtivo e dificuldade de acesso a financiamentos. Conclui-se que agricultura familiar, mesmo que não supra a demanda local, apresenta grande potencial produtivo e tem amplo mercado para incorporação de sua produção. Relativo ao PAA os agricultores que o acessam estão satisfeitos com o Programa e tem como anseio que este seja convertido em uma política pública que beneficie o setor.
FOTOPEDOLOGIA E SISTEMAS DE INFORMAÇÃO GEOGRÁFICA INTEGRADOS NA CARACTERIZAÇÃO E MAPEAMENTO DE SOLOS
Authors: Corrêa Edvania Aparecida , Moraes Isabel Cristina , Pereira Luiz Henrique , Pinto Sérgio Dos Anjos Ferreira
Published: May 2016

O mapa de solos como produto cartográfico de síntese pode ser utilizado como ferramenta norteadora aplicada a estudos sobre a capacidade produtiva de solos, adequabilidade do uso agrícola e planejamento territorial. Neste contexto, quando da utilização de determinadas ferramentas, como a fotointerpretação pedológica e a utilização de técnicas de geoprocessamento, são obtidos mapeamentos coerentes e com erros padronizados, elevando desta maneira a precisão das ações referentes ao planejamento territorial. Neste viés, o presente artigo apresenta a aplicação de técnicas de fotopedologia e geoprocessamento na elaboração do mapeamento digital de solos, visando a cartografação da variabilidade espacial de unidades pedológicas, bem como à verificação da confiabilidade das unidades mapeadas por meio da validação em campo e obtenção de coeficientes de concordância. Na validação do mapeamento, realizada por meio da correlação geral dos dados presentes no esboço fotopedológico com os dados de campo, foi possível obter a exatidão global do mapeamento de 0,72% e índice Kappa geral de 0,61, sendo este último classificado como um dado de confiabilidade substancial. Tendo em vista tais dados, a aplicação da fotopedologia aliada aos aspectos morfométricos e a relação solo versus relevo apresentaram resultados satisfatórios quando da correlação com a verdade terrestre, demonstrando assim um elevado poder preditivo do método. As informações obtidas a partir da fotointerpretação pedológica, bem como as informações geomorfométricas, obtidas a partir de produtos cartográficos e técnicas de geoprocessamento, aliadas aos conceitos pertinentes aos processos geomorfológicos ocorrentes nas vertentes e os seus reflexos na paisagem e na formação dos solos foram eficazes na caracterização e mapeamento digital dos solos. Complementar à fotointerpretação, o uso de material pedológico preexistente e do Modelo Digital de Elevação do Terreno mostrou-se como ferramenta consistente, de maior agilidade em relação ao levantamento de solos tradicionais e menos onerosa quanto aos recursos humanos utilizados.
Diversity and Evolution of Disease Resistance Genes in Barley (Hordeum vulgare L.)
Authors: Andersen Ethan J. , Ali Shaukat , Reese R. Neil , Yen Yang , Neupane Surendra , Nepal Madhav P.
Published: May 2016

Plant disease resistance genes (R-genes) play a critical role in the defense response to pathogens. Barley is one of the most important cereal crops, having a genome recently made available, for which the diversity and evolution of R-genes are not well understood. The main objectives of this research were to conduct a genome-wide identification of barley Coiled-coil, Nucleotide-binding site, Leucine-rich repeat (CNL) genes and elucidate their evolutionary history. We employed a Hidden Markov Model using 52 Arabidopsis thaliana CNL reference sequences and analyzed for phylogenetic relationships, structural variation, and gene clustering. We identified 175 barley CNL genes nested into three clades, showing (a) evidence of an expansion of the CNL-C clade, primarily due to tandem duplications; (b) very few members of clade CNL-A and CNL-B; and (c) a complete absence of clade CNL-D. Our results also showed that several of the previously identified mildew locus A ( MLA) genes may be allelic variants of two barley CNL genes, MLOC_66581 and MLOC_10425, which respond to powdery mildew. Approximately 23% of the barley CNL genes formed 15 gene clusters located in the extra-pericentromeric regions on six of the seven chromosomes; more than half of the clustered genes were located on chromosomes 1H and 7H. Higher average numbers of exons and multiple splice variants in barley relative to those in Arabidopsis and rice may have contributed to a diversification of the CNL-C members. These results will help us understand the evolution of R-genes with potential implications for developing durable resistance in barley cultivars.
Active Learning in Medical Education: Application to the Training of Surgeons
Authors: Luc Jessica G.Y. , Antonoff Mara B.
Published: May 2016

Our article defines active learning in the context of surgical education and reviews the growing body of research on new approaches to teaching. We then discuss future perspectives and the challenges faced by the trainee and surgeon in applying active learning to surgical training. As modern surgical education faces numerous challenges, we hope our article will help surgical educators in the evaluation of curriculum development, methods of instruction, and assessment.
H-index and How to Improve it?
Authors: Izet Masic
Published: May 2016

The h-index is an index that attempts to measure both the productivity and citation impact of the published work of a scientist or scholar. The index is based on the set of the scientist's most cited papers and the number of citations that they have received in other publications and on the distribution of citations received by a given researcher's publications. The h-index is important for individual users as well as scientific research institutions, universities and main journal editors. There are a lot of methods to improve your h-score. It takes a lot of work and to promote papers and journals, but it is all part of developing as a researcher, working together with your community and improving communication methods.

How to cite this article

Masic I. H-index and How to Improve it? Donald School J Ultrasound Obstet Gynecol 2016;10(1):83-89.
Comparative Evaluation of Microroughness created on Titanium Alloy for use in Dental Implants subjected to Two Different Acid Etching Techniques: An in vitro Study
Authors: Madaan Vishwas , Padhye Ashvini M , Mapara Manjeet
Published: May 2016

Aim

The aim of this study was to comparatively evaluate the microroughness created on titanium alloy for use in dental implants subjected to two different acid etching techniques.

Materials and Methods

Commercially available grade 5 pure titanium plates were machine prepared into 26 plates measuring 3 × 1 cm × 5 mm for acid etching with hydrofluoric acid (HF) and dual acid etching technique using sulfuric acid (H2SO4) followed by hydrochloric acid (HCl). Twenty-five plates were divided into four groups based on the duration and sequence of acid etching. Upon completion of the acid etching procedure, the titanium plates were assessed for their surface characteristics by a surface profilometer. The average roughness parameters values Ra, Rq, Rz obtained for each titanium plate were compared against each other and with unetched titanium plate.

Results

The average roughness value Ra obtained was 0.480 μm for untreated surface and 3.65 μm maximum for the titanium plate etched for 72 hours in H2SO4and 48 hours in HCl, which is about seven times the value of surface roughness on the unetched plates. The roughness values obtained after acid etching with HF for any duration were nonsignificant compared with the unetched plates.

Conclusion

The dual acid etching technique seems to be a simple method to develop a titanium implant surface, though evaluation of the biological response to this surface is necessary.

Clinical significance

The present study showed that by optimizing the parameters of acid etching, a rough titanium surface can be obtained similar to the various implant surfaces available commercially.

How to cite this article

Madaan VU, Mapara M, Padhye AM. Comparative Evaluation of Microroughness created on Titanium Alloy for use in Dental Implants subjected to Two Different Acid Etching Techniques: An in vitro Study. J Contemp Dent 2016;6(1):1-8.
Alveolar Bone Dimensions of Mandibular Posterior Teeth using Cone Beam Computed Tomography: A Pilot Study
Authors: Kunte Varun Rajeev , Bhoosreddy Ajay Ramesh , Bhoosreddy Seema Ajay , Pandharbale Atul Ashok , Shinde Manila Rajaram , Ahire Bhushan Sukhdeo
Published: May 2016

Aim

The aim of this study was to analyze bone dimensions of the dentate posterior mandible using cone beam computed tomography (CBCT).

Objectives

The objectives of this study were

• To measure thickness of buccal and lingual bone walls in mandibular posterior teeth using CBCT.

• To measure alveolar bone width in mandibular posterior teeth using CBCT.

Materials and Methods

Ten CBCT scans were included in the study (n = 65 teeth). Thicknesses of buccal and lingual walls were measured at measurement point 1 (MP1) and measurement point 2 (MP2). Alveolar width was assessed at most coronal detected alveolar bone (BW1) and at superior border of mandibular canal (BW2). Vertical distance between BW1 and BW2 was measured (H). Data were tabulated and results were statistically analyzed using unpaired t test.

Results

The study showed that there was an increase in bone wall thickness from 1st premolar to 2nd molar for buccal and lingual alveolar plates. Lingual bone walls were thicker than buccal bone walls at MP1 and MP2 for all teeth. Bone width for premolars was considerably less than bone width of molars.

Conclusion

Careful preoperative analysis using CBCT is important to assess need of bone augmentation procedures. As the bone thickness and width in the molar region is more adequate, prognosis of implants placed in molar region may be better.

Clinical significance

Analysis of bone dimensions is of utmost importance for successful outcome of bone augmentation procedures in implant treatment.

How to cite this article

Kunte VR, Bhoosreddy AR, Bhoosreddy SA, Pandharbale AA, Shinde MR, Ahire BS. Alveolar Bone Dimensions of Mandibular Posterior Teeth using Cone Beam Computed Tomography: A Pilot Study. J Contemp Dent 2016;6(1):9-14.
A Comparative Study of Reliability and Accuracy of Manual and Digital Lateral Cephalometric Tracing
Authors: Mhatre Amol , Ravindranath VK , Karandikar Girish , Shah Alok Rajendra
Published: May 2016

Objective

The aim of this study was to assess the reliability and accuracy of several types of lateral cephalometric attributes commonly used: Angular measurements, linear measurements, and ratio when using digital cephalometric software (Nemoceph) with manual tracing method.

Materials and Methods

Sample size consisted of 26 lateral cephalometric radiographs. All cephalograms were subjected to both manual and digital cephalometric analysis by the same examiner. Digital analyses were performed on Nemotec digital imaging software. Cephalograms were assessed for a total of 17 cephalometric attributes. The results were assessed using Student's t-test.

Results

Six out of 17 measurements, i.e., sella, nasion, B point, ANB, incisor mandibular plane angle, mandibular plane angle, L1-NB, and Jarabak ratio, showed statistically significant difference between the manual and digital methods.

Conclusion

Digital measurements obtained with Nemotec digital imaging software were found to be comparable to the manual method for most of the variables used in clinical practice.

How to cite this article

Shah AR, Karandikar G, Ravindranath VK, Sonawane M, Mhatre A. A Comparative Study of Reliability and Accuracy of Manual and Digital Lateral Cephalometric Tracing. J Contemp D ent 2016;6(1):15-18.
Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures
Authors: Mhatre Amol , Ravindranath VK , Doshi Sachin , Karandikar Girish , Vivek PS
Published: May 2016

Aim

The aim of thisin vitrostudy was to investigate the efficiency of the new generation of elastomeric ligatures with innovative designs (SlideTMand AlastiKTMEasy-to-Tie) in reducing frictional resistance (FR) during sliding mechanics as compared with conventional ligatures.

Materials and Methods

Sixty ligature samples divided into four groups were used for the study. Group A: QuiK-StiK™ (3M Unitek, Monrovia, CA, USA), Group B: AlastiK™ Easy-to-Tie (3M Unitek, Monrovia, CA, USA), Group C: Slide™ (Leone, Firenze, Italy), and Group D: SS ligatures 0.010” (Libral Traders, New Delhi, India). Universal Testing Machine, Instron was used for measuring FR at the bracket-wire interface.

Results

There was statistically significant difference in FR among all the four groups of ligatures tested (p < 0.001). Slide ligatures produced the least amount of FR followed by SS ligatures, Easy-to-Tie, and QuiK-StiK in the increasing order of the FR values registered.

Conclusion

SlideTMligatures may represent a valid alternative to passive self-ligating brackets when minimal amount of friction is desired. Angulation introduced into the elastomeric ligatures reduces the friction in comparison to conventional elastomeric ligatures.

How to cite this article

Vivek PS, Ravindranath VK, Karandikar G, Doshi S, Mhatre A, Sonawane M. Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures. J Contemp Dent 2016;6(1):19-23.
Oral Submucous Fibrosis
Authors: Galinde Jyotsna , Wagh Ashvin Panditrao
Published: May 2016

The pedicled buccal pad of fat has been widely used for the reconstruction of defect; application of this flap in the treatment of patient suffering from oral submucous fibrosis (OSMF) is reported here. The patient underwent incision of fibrotic bands and coverage of this buccal defect with buccal pad of fat. The surgical technique is described and the results suggest that this is a logical, reliable, and convenient technique for OSMF.

How to cite this article

Wagh AP, Galinde J. Oral Submucous Fibrosis. J Contemp Dent 2016;6(1):67-69.
Correction of Skeletal Sagittal Dysplasia using Twin Block Traction Technique
Authors: Ravindranath VK , Doshi Sachin , Daga Prateek Navratan
Published: May 2016

The primary concern of the patient as well as their parent seeking orthodontic treatment is the sagittal relationship of the dentition and jaws. Twin block is the most common functional appliance used successfully in correction of growing patient with skeletal class II malocclusion. However, the method of using extraoral traction in combination with twin block appliance (twin block traction technique) is to reinforce the functional component for correction of a class II sagittal relationship. A 12-year-old male patient reported to the Department of Orthodontics with a chief complaint of forwardly placed upper front teeth. With the help of clinical examination, cephalometrics, and diagnostic records, the diagnosis of the patient was confirmed as skeletal class II maxillomandibular relationship with prognathic maxilla and retrognathic mandible with a vertical growth pattern. The patient was treated with twin block appliance along with headgear. The appliance design and postfunctional results are demonstrated in the following case report. Although twin block with high-pull headgear is known to produce favorable results in mixed dentition, the same was observed in permanent dentition during growth phase. Combination of twin block appliance with high pull headgear gave the desired results.

How to cite this article

Daga PN, Karandikar GR, Ravindranath VK, Doshi S. Correction of Skeletal Sagittal Dysplasia using Twin Block Traction Technique. J Contemp Dent 2016;6(1): 75-79.
Rejuvenating Smile with All-ceramic Crowns
Authors: Gandhi Kushal N , Shah Naisargi P
Published: May 2016

Smile enhancement for a patient instills self-confidence by rendering an attractive smile. All-ceramic restorations have the potential to replicate the natural esthetics close to natural dentition, i.e., lacking in metal ceramic restorations. A young female patient unhappy with her smile was rehabilitated with all-ceramic restorations; thereby, the beauty of an individual within the functional and physiological functions could be restored. The final outcome with regard to esthetics and function was found to be good.

How to cite this article

Gandhi KN, Ram SM, Shah NP. Rejuvenating Smile with All-ceramic Crowns. J Contemp Dent 2016;6(1):80-84.
Masking Conventional Metallic Cast Post for Enhancing Esthetics
Authors: Nadgere Jyoti B , Shah Naisargi P , Gaikwad Amit Mahadeo
Published: May 2016

Loss of tooth structure occurs due to caries, endodontic treatment, or fracture caused by trauma; restoring these teeth is difficult task for a clinician. Post and core is an option for teeth when excessive tooth structure is lost and teeth need to be restored with crown and bridge procedure. They can be prefabricated post with composite built up or a one-piece custom-made post. The custom-made cast metal post and core have disadvantage due to their color that imparts grayish hue to overlying ceramic restorations. Masking the metal core can enhance the esthetic of all ceramic restorations that are placed over the cast post and core. A case report is being presented where the metallic core was masked with ceramic built up on labial surface of metal core.

How to cite this article

Shah NP, Gaikwad AM, Ram SM, Nadgere JB. Masking Conventional Metallic Cast Post for Enhancing Esthetics. J Contemp Dent 2016;6(1):85-89.
Rehabilitation of a Patient with Immediate Complete Denture
Authors: Shah Naisargi P , Nadgere Jyoti B , Masram Suyog Kisanrao
Published: May 2016

Patient's desire to have a replacement with complete dentures before losing all their natural teeth, this is important for the psychology of the patient. Patients with gross mobility of the teeth needing replacement with complete denture without going through a period of edentulousness has become mandatory for a prosthodontist to treat. An immediate denture is a treatment of choice for such patients. A case report is being presented for a patient with flared, prominent, mobile anterior teeth treated with a successful immediate denture.

How to cite this article

Nadgere JB, Masram SK, Ram SM, Shah NP. Rehabilitation of a Patient with Immediate Complete Denture. J Contemp Dent 2016;6(1):90-95.
Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe
Authors: Ulevicius Vidmantas , Byčenkienė Steigvilė , Bozzetti Carlo , Vlachou Athanasia , Plauškaitė Kristina , Mordas Genrik , Dudoitis Vadimas , Abbaszade Gülcin , Remeikis Vidmantas , Garbaras Andrius , Masalaite Agne , Blees Jan , Fröhlich Roman , Dällenbach Kaspar R. , Canonaco Francesco , Slowik Jay G. , Dommen Josef , Zimmermann Ralf , Schnelle-Kreis Jürgen , Salazar Gary A. , Agrios Konstantinos , Szidat Sönke , El Haddad Imad , Prévôt André S. H.
Published: May 2016

Abstract. In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m−3 and black carbon (BC) up to 17 µg m−3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OCnf) was the dominant fraction of PM1, with the primary (POCnf) and secondary (SOCnf) fractions contributing 26–44 % and 13–23 % to the total carbon (TC), respectively. 5–8 % of the TC had a primary fossil origin (POCf), whereas the contribution of fossil secondary organic carbon (SOCf) was 4–13 %. Non-fossil EC (ECnf) and fossil EC (ECf) ranged from 13–24 and 7–13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.
Laboratory-generated mixtures of mineral dust particles with biological substances: characterization of the particle mixing state and immersion freezing behavior
Authors: Augustin-Bauditz Stefanie , Wex Heike , Denjean Cyrielle , Hartmann Susan , Schneider Johannes , Schmidt Susann , Ebert Martin , Stratmann Frank
Published: May 2016

Abstract. Biological particles such as bacteria, fungal spores or pollen are known to be efficient ice nucleating particles. Their ability to nucleate ice is due to ice nucleation active macromolecules (INMs). It has been suggested that these INMs maintain their nucleating ability even when they are separated from their original carriers. This opens the possibility of an accumulation of such INMs in soils, resulting in an internal mixture of mineral dust and INMs. If particles from such soils which contain biological INMs are then dispersed into the atmosphere due to wind erosion or agricultural processes, they could induce ice nucleation at temperatures typical for biological substances, i.e., above −20 up to almost 0 °C, while they might be characterized as mineral dust particles due to a possibly low content of biological material. We conducted a study within the research unit INUIT (Ice Nucleation research UnIT), where we investigated the ice nucleation behavior of mineral dust particles internally mixed with INM. Specifically, we mixed a pure mineral dust sample (illite-NX) with ice active biological material (birch pollen washing water) and quantified the immersion freezing behavior of the resulting particles utilizing the Leipzig Aerosol Cloud Interaction Simulator (LACIS). A very important topic concerning the investigations presented here as well as for atmospheric application is the characterization of the mixing state of aerosol particles. In the present study we used different methods like single-particle aerosol mass spectrometry, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), and a Volatility–Hygroscopicity Tandem Differential Mobility Analyser (VH-TDMA) to investigate the mixing state of our generated aerosol. Not all applied methods performed similarly well in detecting small amounts of biological material on the mineral dust particles. Measuring the hygroscopicity/volatility of the mixed particles with the VH-TDMA was the most sensitive method. We found that internally mixed particles, containing ice active biological material, follow the ice nucleation behavior observed for the pure biological particles. We verified this by modeling the freezing behavior of the mixed particles with the Soccerball model (SBM). It can be concluded that a single INM located on a mineral dust particle determines the freezing behavior of that particle with the result that freezing occurs at temperatures at which pure mineral dust particles are not yet ice active.
Single-particle characterization of biomass burning organic aerosol (BBOA): evidence for non-uniform mixing of high molecular weight organics and potassium
Authors: Lee Alex K. Y. , Willis Megan D. , Healy Robert M. , Wang Jon M. , Jeong Cheol-Heon , Wenger John C. , Evans Greg J. , Abbatt Jonathan P. D.
Published: May 2016

Abstract. Biomass burning organic aerosol (BBOA) can be emitted from natural forest fires and human activities such as agricultural burning and domestic energy generation. BBOA is strongly associated with atmospheric brown carbon (BrC) that absorbs near-ultraviolet and visible light, resulting in significant impacts on regional visibility degradation and radiative forcing. The mixing state of BBOA can play a critical role in the prediction of aerosol optical properties. In this work, single-particle measurements from a Soot-Particle Aerosol Mass Spectrometer coupled with a light scattering module (LS-SP-AMS) were performed to examine the mixing state of BBOA, refractory black carbon (rBC), and potassium (K, a tracer for biomass burning aerosol) in an air mass influenced by wildfire emissions transported from northern Québec to Toronto, representing aged biomass burning plumes. Cluster analysis of single-particle measurements identified five BBOA-related particle types. rBC accounted for 3–14 wt % of these particle types on average. Only one particle type exhibited a strong ion signal for K+, with mass spectra characterized by low molecular weight organic species. The remaining four particle types were classified based on the apparent molecular weight of the BBOA constituents. Two particle types were associated with low potassium content and significant amounts of high molecular weight (HMW) organic compounds. Our observations indicate non-uniform mixing of particles within a biomass burning plume in terms of molecular weight and illustrate that HMW BBOA can be a key contributor to low-volatility BrC observed in BBOA particles. The average mass absorption efficiency of low-volatility BBOA is about 0.8–1.1 m2 g−1 based on a theoretical closure calculation. Our estimates indicate that low-volatility BBOA contributes ∼ 33–44 % of thermo-processed particle absorption at 405 nm; and almost all of the BBOA absorption was associated with low-volatility organics.
Photochemical degradation of isoprene-derived 4,1-nitrooxy enal
Authors: Xiong Fulizi , Borca Carlos H. , Slipchenko Lyudmila V. , Shepson Paul B.
Published: May 2016

Abstract. In isoprene-impacted environments, carbonyl nitrates are produced from NO3-initiated isoprene oxidation, which constitutes a potentially important NOx reservoir. To better understand the fate of isoprene carbonyl nitrates, we synthesized a model compound, trans-2-methyl-4-nitrooxy-2-buten-1-al (4,1-isoprene carbonyl nitrate, or 4,1-isoprene nitrooxy enal), and investigated its photochemical degradation process. The measured OH and O3 oxidation rate constants (298 K) for this nitrooxy enal are 4.1(±0.7)  ×  10−11 cm3 molecules−1 s−1 and 4.4(±0.3)  ×  10−18 cm3 molecules−1 s−1, respectively. Its UV absorption spectrum was determined, and the result is consistent with TDDFT calculations. Based on its UV absorption cross section and photolysis frequency in a reaction chamber, we estimate that the ambient photolysis frequency for this compound is 3.1(±0.8)  ×  10−4 s−1 for a solar zenith angle of 45°. The fast photolysis rate and high reactivity toward OH lead to a lifetime of less than 1 h for the isoprene nitrooxy enal, with photolysis being a dominant daytime sink. The nitrate products derived from the OH oxidation and the photolysis of the nitrooxy enal were identified with an iodide-based chemical ionization mass spectrometer. For the OH oxidation reaction, we quantified the yields of two nitrate products, methyl vinyl ketone nitrate and ethanal nitrate, which together contributed to 36(±5) % of the first-generation products.
Dynamics of N2 fixation and fate of diazotroph-derived nitrogen in a low-nutrient, low-chlorophyll ecosystem: results from the VAHINE mesocosm experiment (New Caledonia)
Authors: Bonnet Sophie , Berthelot Hugo , Turk-Kubo Kendra , Fawcett Sarah , Rahav Eyal , L'Helguen Stéphane , Berman-Frank Ilana
Published: May 2016

Abstract. N2 fixation rates were measured daily in large (∼ 50 m3) mesocosms deployed in the tropical southwest Pacific coastal ocean (New Caledonia) to investigate the temporal variability in N2 fixation rates in relation with environmental parameters and study the fate of diazotroph-derived nitrogen (DDN) in a low-nutrient, low-chlorophyll ecosystem. The mesocosms were fertilized with  ∼ 0.8 µM dissolved inorganic phosphorus (DIP) to stimulate diazotrophy. Bulk N2 fixation rates were replicable between the three mesocosms, averaged 18.5 ± 1.1 nmol N L−1 d−1 over the 23 days, and increased by a factor of 2 during the second half of the experiment (days 15 to 23) to reach 27.3 ± 1.0 nmol N L−1 d−1. These later rates measured after the DIP fertilization are higher than the upper range reported for the global ocean. During the 23 days of the experiment, N2 fixation rates were positively correlated with seawater temperature, primary production, bacterial production, standing stocks of particulate organic carbon (POC), nitrogen (PON) and phosphorus (POP), and alkaline phosphatase activity, and negatively correlated with DIP concentrations, DIP turnover time, nitrate, and dissolved organic nitrogen and phosphorus concentrations. The fate of DDN was investigated during a bloom of the unicellular diazotroph UCYN-C that occurred during the second half of the experiment. Quantification of diazotrophs in the sediment traps indicates that ∼ 10 % of UCYN-C from the water column was exported daily to the traps, representing as much as 22.4 ± 5.5 % of the total POC exported at the height of the UCYN-C bloom. This export was mainly due to the aggregation of small (5.7 ± 0.8 µm) UCYN-C cells into large (100–500 µm) aggregates. During the same time period, a DDN transfer experiment based on high-resolution nanometer-scale secondary ion mass spectrometry (nanoSIMS) coupled with 15N2 isotopic labeling revealed that 16 ± 6 % of the DDN was released to the dissolved pool and 21 ± 4 % was transferred to non-diazotrophic plankton, mainly picoplankton (18 ± 4 %) followed by diatoms (3 ± 2 %). This is consistent with the observed dramatic increase in picoplankton and diatom abundances, primary production, bacterial production, and standing stocks of POC, PON, and POP in the mesocosms during the second half of the experiment. These results offer insights into the fate of DDN during a bloom of UCYN-C in low-nutrient, low-chlorophyll ecosystems.
What drives the spatial variability of primary productivity and matter fluxes in the North-West African upwelling system? A modelling approach and box analysis
Authors: Auger Pierre-Amaël , Gorgues Thomas , Machu Eric , Aumont Olivier , Brehmer Patrice
Published: May 2016

Abstract. A comparative box analysis based on a multi-decadal physical-biogeochemical hindcast simulation (1980–2009) was conducted to characterize the drivers of the spatial distribution of phytoplankton biomass and production in the North-West (NW) African upwelling system. Alongshore geostrophic flow related to large scale circulation patterns associated with the influence of coastal topography are suggested to modulate the coastal divergence, and then the response of nutrient upwelling to wind forcings. In our simulation, this translates into a coastal upwelling of nitrate being significant in all regions but the Cape Blanc (CB) area. However, upwelling is found to be the dominant supplier of nitrate only in the northern Saharan Bank (NSB) and the Senegalo-Mauritanian (SM) regions. Elsewhere, nitrate supply is dominated by meridional advection, especially off Cape Blanc. Phytoplankton displays a similar behaviour with a supply by lateral advection which equals the net coastal phytoplankton growth in all coastal regions except the Senegalo-Mauritanian area. Noticeably, in the Cape Blanc area, the net coastal phytoplankton growth is mostly sustained by high levels of regenerated production exceeding new production by more than two fold which is in agreement with the locally weak input of nitrate by coastal upwelling. Further offshore, the distribution of nutrients and phytoplankton is explained by the coastal circulation. Indeed, in the northern part of our domain (i.e. Saharan Bank), the coastal circulation is mainly alongshore resulting in low offshore lateral advection of nutrients and phytoplankton. On the contrary, lateral advection transport coastal nutrients and phytoplankton towards offshore areas in the latitudinal band off the Senegalo-Mauritanian region. Moreover, this latter offshore region benefits from transient southern intrusions of nutrient-rich waters from the Guinean upwelling.
Effects of melting ice sheets and orbital forcing on the early Holocene warming in the extratropical Northern Hemisphere
Authors: Zhang Yurui , Renssen Hans , Seppä Heikki
Published: May 2016

Abstract. The early Holocene is marked by the final transition from the last deglaciation to the relatively warm Holocene. Proxy-based temperature reconstructions suggest a Northern Hemisphere warming, but also indicate important regional differences. Model studies have analyzed the influence of diminishing ice sheets and other forcings on the climate system during the Holocene. The climate response to forcings before 9 kyr BP (referred to hereafter as kyr), however, remains not fully comprehended. We therefore studied, by employing the LOVECLIM climate model, how orbital and ice-sheet forcings contributed to climate change and to these regional differences during the earliest part of the Holocene (11.5–7 kyr). Our equilibrium experiment for 11.5 kyr suggests lower annual mean temperatures at the onset of the Holocene than in the preindustrial era with the exception of Alaska. The magnitude of this cool anomaly varied regionally, and these spatial patterns are broadly consistent with proxy-based reconstructions. Temperatures throughout the whole year in northern Canada and northwestern Europe for 11.5 kyr were 2–5 °C lower than those of the preindustrial era as the climate was strongly influenced by the cooling effect of the ice sheets, which was caused by enhanced surface albedo and ice-sheet orography. In contrast, temperatures in Alaska for all seasons for the same period were 0.5–3 °C higher than the control run, which were caused by a combination of orbital forcing and stronger southerly winds that advected warm air from the south in response to prevailing high air pressure over the Laurentide Ice Sheet (LIS). The transient experiments indicate a highly inhomogeneous early Holocene temperature warming over different regions. The climate in Alaska was constantly cooling over the whole Holocene, whereas there was an overall fast early Holocene warming in northern Canada by more than 1 °C kyr−1 as a consequence of progressive LIS decay. Comparisons of simulated temperatures with proxy records illustrate uncertainties related to the reconstruction of ice-sheet melting, and such a kind of comparison has the potential to constrain the uncertainties in ice-sheet reconstruction. Overall, our results demonstrate the variability of the climate during the early Holocene, both in terms of spatial patterns and temporal evolution.