bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enamel Mineral Content Changes After Bleaching With High and Low Hydrogen Peroxide Concentrations: Colorimetric Spectrophotometry and Total Reflection X-ray Fluorescence Analyses
Authors: Pinto AVD , Bridi EC , Amaral FLB , França FMG , Turssi CP , Pérez CA , Martinez EF , Flório FM , Basting RT 
Published: May 2017

SUMMARY
The purpose of this study was to evaluate the calcium (Ca) and phosphorous (P) content in enamel bleached with high and low concentrations of hydrogen peroxide (HP) using Total Reflection X-Ray Fluorescence (TXRF) and colorimetric spectrophotometry (SPEC). Forty-eight sound human third molars were used. Their roots were embedded in polystyrene resin and immersed for seven days in an artificial saliva solution. Then they were distributed into six groups to receive the bleaching treatments. The agents of high HP concentration (for in-office use) evaluated were Whiteness HP Maxx/FGM (35% HP), Whiteness HP Blue/FGM (35% HP, 2% calcium gluconate), Pola Office+/SDI (37.5% HP, 5% potassium nitrate), and Opalescence Boost/Ultradent (38% HP, 1.1% ion fluoride, 3% potassium nitrate); these agents were applied to enamel in three sessions. The agents of low HP concentration (for home use) evaluated were Pola Day/SDI (9.5% HP) and White Class 10%/FGM (10% HP, potassium nitrate, calcium, fluoride), and these agents were applied for 14 days. Enamel microbiopsies were evaluated by TXRF and SPEC analysis before the bleaching treatment (baseline), during the treatment, and 14 days after the end of the treatment. For TXRF, the Kruskal-Wallis test showed that Ca and P were not influenced by agent (p&gt;0.05). For SPEC, Pola Office+, Opalescence Boost, Pola Day, and White Class 10% caused a decrease of Ca over time; there was a significant decrease of P over time to Pola Office+ and White Class 10%. The Spearman test showed no correlation between the Ca (p=0.987; r2=−0.020) and P (p=0.728, r2=0.038) obtained by SPEC and TXRF. For TXRF and SPEC, changes in Ca and P during bleaching occurred independently of the HP concentration used.
The Survival of Class V Composite Restorations and Analysis of Marginal Discoloration
Authors: Kim J-H , Cho J , Lee Y , Cho B-H 
Published: May 2017

SUMMARY
The aims of this retrospective clinical study were to analyze the longevity of class V composite restorations and compare the results obtained from clinical and laboratory evaluation of marginal discoloration. A total of 186 restorations were evaluated with modified US Public Health Service criteria. Longevity and associated variables were analyzed with the Kaplan-Meier method and a Cox proportional hazard model. Restorations with marginal discoloration were additionally evaluated using digital photographs and epoxy resin replicas under a stereomicroscope. The mean survival time was 15.0 years, with five- and 10-year survival rates of 95.5% and 83.1%, respectively. Z250 had a higher risk of failure (hazard ratio=7.01, 95% confidence interval=2.07-23.72) than Z100. In addition, the presence of occlusal wear facets and bleeding on probing were associated with an increased risk of failure of the restorations. However, the use of an adhesive system (Scotchbond Multi-Purpose or Clearfil SE Bond) did not affect the longevity of the restorations. The results of laboratory evaluation were significantly different from clinical evaluation (p&lt;0.001, McNemar test). Among 55 restorations rated as Bravo in the clinical evaluation, 24 restorations (43.6%) were determined to have penetrating discoloration on laboratory evaluation. When evaluating aged composite restorations, surface refurbishment and the use of a microscope are recommended, which will be helpful in determining the need for timely repair or replacement.
La ecuación de Gauss y el indicador Oraqi para simulación de la calidad del aire durante la emisión de gases de combustión de un caldero
Authors: Terry Calderón Víctor , Adrianzen Matienzo Elba , Bengoa Gaby , Flores María Teresa 
Published: May 2017

Para el presente trabajo se consideró los siguientes datos de una planta pesquera, cuyas emisiones gaseosas proceden de un caldero Cleaver Broke: ( CO): 0,045kg/s; (SO2) : 0,010 kg/s y (NOx) : 0,006 kg /s, consignándose la altura de la chimenea (H ):15 m, la velocidad del viento ( u): 1,62 m/s, la temperatura de los gases de chimenea (To) : 623 ºK, la temperatura del medio en 291 ºK, y para efectos del cálculo, se consideró a la atmósfera en forma estable. Las emisiones de material particulado MP10 y de hidrocarburos alifáticos CnH2n+2 se calcularon mediante lo indicadores de la tabla 1. Con todos estos datos se procedió a realizar la simulación de la dispersión de estas emisiones, a fin de determinar valores de inmisión. Se utilizó la ecuación de Gauss y sus parámetros respectivos, dando como resultado que la mayor concentración de estos gases contaminantes se localiza a 0,60 km del punto fijo de emisión.Con ese resultado se procedió a aplicar la ecuación de ORAQI, determinándose que los valores de inmisión encontrados a esa distancia no afectan la calidad del aire, pues el indicador de calidad del aire (I.C.A), da como valor 96,7%, con lo cual la actividad del caldero y sus emisiones no dañan en forma traumática al entorno. Como podrá apreciarse este método permite predecir la calidad del aire conociendo las emisiones de un caldero. Por lo cual, se convierte en una herramienta importante para los Estudios de Impacto Ambiental (EIA).Palabras claves: Gauss, ORAQI, emisiones gaseosas, simulación
Influencia climatológica en el comportamiento de taxones de moluscos fluviales y terrestres, Villa Clara-Cuba
Authors: Fimia Duarte Rigoberto , Argota Pérez George , Osés Rodríguez Ricardo , Cepero Rodríguez Omelio , González González Ramón 
Published: May 2017

El objetivo de esta investigación fue determinar posibles impactos de variables climatológicas sobre la reproducción y supervivencia de taxones de moluscos fluviales y terrestres en la provincia Villa Clara, Cuba. Para ello el estudio se realizó en los trece municipios de la provincia entre los años 2012 y 2013. Fueron recogidos los datos de registros en archivos pertenecientes al Centro Provincial de Vigilancia y Lucha Antiventorial provincial referidos a diferentes taxones de moluscos fluviales y terrestres. En cuanto a las variables climatológicas se analizaron: humedad relativa media, humedad relativa mínima, humedad relativa máxima, precipitación, temperatura máxima, temperatura mínima y temperatura media, las cuales se midieron en el Centro Meteorológico Provincial. Se observó que las variables climáticas de mayor influencia sobre el desarrollo y reproducción fueron la humedad relativa media y temperatura media respectivamente. Los taxones fluviales y terrestres con mayor representatividad fueron la Tarebia granifera, Praticorella griseola y Pomacea poeyana, mientras que los municipios con mayor presencia fueron Placetas, Santa Clara, Encrucijada y Camajuaní respectivamente. Se concluyó que es necesario incrementar medidas de control para las especies de moluscos fluviales y terrestres identificadas, dada su epidemiología en la transmisión de enfermedades zoonóticas.Palabras clave: variables climatológicas, reproducción, supervivencia, taxones, moluscos fluviales y terrestres, Villa Clara, Cuba
Demanda social y mercado ocupacional de carreras profesionales, Facultad de Medicina “Hipólito Unanue” Universidad Nacional Federico Villarreal
Authors: Viaña Pérez José María , Bello Vidal Catalina , Añaños Castilla Dante , Seminario Rivas Ruth 
Published: May 2017

La función profesional, producto de la formación universitaria, se caracteriza por un saber y un hacer específicos que permite su inserción en el mercado ocupacional. La actividad profesional nace, se desarrolla, perfecciona o desaparece en el devenir histórico, condición que se encuentra vinculada a la demanda social. El objetivo fue determinar cómo se relaciona la demanda social y el mercado ocupacional de las carreras profesionales de medicina y enfermería. El estudio fue descriptivo, con una muestra de 203 sujetos entre estudiantes, egresados de la Facultad de Medicina “Hipólito Unanue” y funcionarios de establecimientos de salud. Se aplicaron dos instrumentos con una confiabilidad Alfa de Cronbach 77% y 78% respectivamente. La edad promedio de los estudiantes fue 24±2.6, egresados 34±8.3 y funcionarios 54±8 años. Un 80% de egresados reconoce que tuvo una formación según las necesidades del país, y 96% admite que el internado fue muy importante en su formación. El 90% afirmó que su profesión es más rentable en el extranjero que en el Perú y no hubo diferencias entre ambos grupos (p>0.05). Los funcionarios reconocen destreza profesional en nuestros egresados. En la carrera de medicina se evidencia una gran demanda de vacantes, pero limitada oferta institucional; solo ingresaron en los últimos siete años entre el 5% al 9% de postulantes, en comparación con otras carreras de la salud, lo que evidencia diferencias estadísticamente significativas (p<o,oo1). Se concluye que la demanda social para los egresados de las carreras profesionales de medicina y enfermería desde la percepción de funcionarios y egresados es muy alta, dentro y fuera del país por tratarse de personal altamente capacitado.Palabras clave: demanda social, mercado ocupacional, estudiante, egresado, funcionario
Riesgo de caries dental en pacientes de tres a seis años que acuden a la clínica de la de la Universidad Nacional Federico Villarreal
Authors: Peltroche Nimia O. , Gabrielli Enrique , Vásquez Miriam , Castro Antonieta 
Published: May 2017

El objetivo del presente estudio fue determinar el riesgo de caries dental que presentan los pacientes de tres a seis años que acudieron a la clínica de la Universidad Nacional Federico Villarreal en el año 2011. La muestra fue de 50 niños de ambos sexos que cumplieron con los criterios de inclusión y exclusión, a quienes se les realizó una encuesta y una evaluación del índice de higiene oral para determinar la presencia y nivel de riesgo de caries dental. Los resultados obtenidos fueron que en los factores de riesgo de caries dental estudiados en la presente investigación están presentes indistintamente la edad y el sexo. El factor de riesgo más prevalente es el cepillado dental con 21 casos, seguido del factor visita al odontólogo con 19 casos. El riesgo de caries dental más prevalente es el “Riesgo Bajo” con un 40.8%, seguido de 37.6% con un “Riesgo Mediano” y 21.8% presentan “Riesgo Alto”. Al relacionar los valores se determinó que no hay diferencias significativas de los factores de riesgo de caries dental en relación al sexo, encontrándose diferencias altamente significativas entre los niveles de caries dental y la presencia de los factores de riesgo.Palabras claves: caries dental, riesgo, factores de riesgo
Circulating Hormone Levels in Hatchlings of Green Turtle, Chelonia mydas, from Ras Al-Hadd Reserve, Oman
Authors: AlKindi A. Y. A. 
Published: May 2017

Post-hatching levels of plasma estradiol (E2), Progesterone (Pro), testosterone (T), Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH) and thyroxine (T4) were monitored in hatchlings of Green Turtle, Chelonia mydas immediately after emergence. Eggs were collected at random from 5 nests. The eggs were placed in incubators 16 hr after oviposition set at 26-27oC for male producing hatchlings and at 30-31oC for female producing hatchlings. Blood was collected after sacrifice. Chemiluminescence immunoassay was used for determination of plasma hormone levels, using Beckman Coulter Access-2-immunoassay and reagents (Beckman Coulter, Inc.). Sex was determined from histological examination of gonads. In males, plasma T levels were positively correlated with temperature (rho = 0.67, P<0.001). However, plasma E2 levels were negatively correlated but not strongly with temperature (rho = -0.396, P<0.05) and there was a weak correlation between plasma LH levels and temperatures (rho = 0.38, P<0.05). Also in the males, there was no correlation between temperature and either plasma Pro or T4 levels. In females, there was no correlation between temperature and any of the hormones. In addition, there was no significant difference in plasma concentrations of T, Pro, LH or T4 between sexes. However, plasma E2 concentrationwas significantly higher in males (P<0.05). FSH was undetectable in plasma from both sexes. The significance of these findings will be discussed.
Evaluation of Seminal Fluid Parameters, Reproductive Hormones and Testicular Biopsy for non-obstructive Azoospermic Patients with Sertoli cell only Syndrome
Authors: Qhraman Naso S. , Fakhrildin Muhammad-Baqir M-R. , Bra Dhaher H. 
Published: May 2017

The aims of this study were (i) to determine the seminal fluid parameters, levels of serum reproductive hormones, testicular size and diameter of seminiferous tubules depending on multiple testicular biopsies from non-obstructive azoospermic (NOA) patients, and (ii) to assess the effect of smoking on concentrations of serum reproductive hormones. Thirty four NOA patients were involved in the present study. The selection of patients was based on an average of 2 pelleting seminal analysis, reproductive hormones profile and diagnostic testicular biopsy. A detailed questionnaire was used to obtain a thorough history from the patients. The results of this study showed that the mean age of NOA patients with Sertoli cell only syndrome (SCOS) was 33.875 years, and 47.05 % of NOA patients have had 2-4 years duration of infertility. Macroscopic examination of seminal fluid appeared to have normal values as reported by WHO. Non-significant (P>0.05) difference was observed for testicular size and diameter of seminiferous tubules between right and left testis. High and abnormal concentrations of serum FSH were registered for NOA patients with SCOS. However, non-significant (P>0.05) differences were reported for concentrations of serum reproductive hormones between smokers and non smokers. In conclusion, testicular biopsy is the useful and predictable diagnostic tool for NOA patients with SCOS. Further studies are needed to explain the etiology, management and prognosis of NOA patients with SCOS.
Limits of the Efficiency of Imaging with Obstructing Apertures
Authors: Mohammed A.T. 
Published: May 2017

Two-dimensional numerical solutions are carried out to asses the quality of obstructing apertures in terms of the diffraction limited resolution. This include the quality of the point spread function (psf), the modulation transfer function (MTF), and an image of double lines. These are average intensity of the psf (AI), maximum intensity of the psf,(MI), full width at half maximum of the psf (FW) average frequency components of MTF (AFC), and average side loops of an image of a double lines. The results indicate that the separation of the two lines becomes recognizable using central obstruction of radius equal to or greater than approximately 0.6 times the radius of the primary aperture.
PCR Based Detection of Genetically Modified Soy in Processed Foods Commercially Available in Saudi Arabia
Authors: Alaraidh Ibrahim Abdullah 
Published: May 2017

In this research, PCR (polymerase chain reaction) technique was applied to detect the presence of GMO sold in the Saudi Arabian market. This method was applied to detect genetically modified soy (GM-soy) in particular the roundup ready soy (RRS). To confirm the presence of soy, samples were first tested for the existence of the soy specific lectin gene. A total of eighty samples were tested out of which two samples tested positive as GM-soy. Not surprisingly, the findings showed the existence of GM-soy in food products in Saudi. This supports the necessity of developing precise quantitative and qualitative ways for routine analyses and detection of GMO products in the Saudi Arabian market. With the discovery of GM products in the Saudi Arabian market it would be of no surprise that other Middle Eastern nations also knowingly or unknowingly import GM crops.
Anisotropy in RFe2 Intermetallics: An NMR Study
Authors: Carboni C 
Published: May 2017

The anisotropy of the Ho3+, Tb3+ and Tm3+ rare-earth ions in RFe2 compounds is investigated using the field dependence of the NMR spectra of 169Tm, 159Tb and 165Ho in polycrystalline TmFe2, TbFe2, HoFe2 and related pseudo-binary compounds. The very large hyperfine interaction in these ions dominates the NMR spectrum; the NMR frequencies in the 2 to 7 GHz range provide therefore a measure of the localized moment and its orientation in the crystal field. We compare the NMR measurements to single ion computations that include magnetostriction. KEYWORDS:
Study of Ground water Groundwater Potentiality and Sea Water Intrusion Along along the Coastal Plain, Wadi Thuwal, KSA- A Case Study Based on DC Resistivity
Authors: Al-Garni Mansour A. , Hassanein Hamdy I.E. 
Published: May 2017

The present study mainly aims to outline zones that have groundwater potentiality with good quality and those which are affected by sea water intrusion. The electrical resistivity data were acquired over an area of about 170 km2 of a coastal plain, Wadi Thuwal, which is bounded by the Red Sea in the west and the volcanic hills in the east. In such an area, resistivity measurements, using n-layering model, reveal generally reveal a wide range of resistivity values which do not reflect the reality. Hence, the statistical analysis has to be involved to overcome this problem and to make the final interpretation reliable. In our case, the n-layer models were modified to another statistical geoelectric models (SLM), consisting of a number of layers equivalent to the stratigraphic layering beneath each VES site. The modified models were used to outline the depth to the bed rock, groundwater accumulation zones and water table as well as to define the effect of sea water intrusion through the study area. Check alignment above
Filtering and M-ary Detection of Markov Modulated Mean Reverting Model
Authors: Aggoun Lakhdar , Al-Lawati Mohamed , Malcolm W.P. 
Published: May 2017

In an earlier paper we developed a stochastic model incorporating a double-Markov modulated mean-reversion model. The model is based on an explicit discretisation of the corresponding continuous time dynamics. Here we discuss parameter estimation via the technique of M-ary detection.
Surface Morphology of Cus Thin Films Observed by Atomic Force Microscopy
Authors: Kassim Anuar , Min Ho Soon , Siang Lim Kian , Nagalingam Saravanan 
Published: May 2017

CuS thin films were deposited onto microscope glass substrates using the chemical bath deposition method in the presence of tartaric acid as a complexing agent. The objective of this paper was to study the influence of the deposition time on the morphology of thin films. The surface morphology of the thin films was investigated using atomic force microscopy. The thin films deposited for the shortest time were found to be uniform, without cracks and with a dense surface morphology covering the entire substrate surface area. However, the films prepared for 60 min and above indicated incomplete coverage of the material over the substrate surface. The surface roughness and film thickness values that were observed depended mainly on the deposition time.
Fabrication and surface characterization of poly(4-aminodiphenylamine) film modified electrode and its application for lead and cadmium determination
Authors: Al-Hinaai Mohammed M. , Al-Harthi Salim H. , Khudaish Emad A. 
Published: May 2017

Poly(4-aminodiphenylamine), Padpa, film was synthesized electrochemically on a glassy carbon electrode by potentiodynamic repetitive cycling of 4‑aminodiphenylamine (4adpa) in 1.0 M HCl. The mechanistic steps involved the oxidation of the protonated monomer to diimine species which underwent dimerization process to form the mono-charged radical intermediate which was considered as the initiation step for the progress of polymerization. The electrochemical properties and surface morphology of the film modified electrode were characterized using electrochemical and various surface scanning techniques. The XPS data demonstrated the existence of (=N-) bonding responsible for polymer formation, while the AFM image revealed a uniform and symmetrical fiber structure with low energy dissipation. The modified electrode was primarily applied as an environmental sensor for the simultaneous and selective determination of Cd2+ and Pb2+ ions in water samples. The detection limit for Cd2+ and Pb2+ ions was found 25 and 14 mg L-1, respectively.
Dioxygen Binding by Cobalt(II) Complexes of 8,8'-bis(aminomethyl)-2,2'-biquinoline
Authors: Khan Muhammad S. , Al-Rasbi Nawal K. , C.Constable Edwin 
Published: May 2017

A new series of Co(II) complexes of the type CoLX2 , where Lis a tetra-dentate ligand 8,8'-bis(aminomethyl)-2,2'-biquinoline and X= SCN–, BF4–, I– or NO3– , have been synthesized and characterized. The complexes have magnetic moments in the range typical of a low-spin d7 Co(II) center. The interaction of these Co(II) complexes with dioxygen was studied by E.S.R. spectroscopy. A dicobalt(III) peroxo-bridged complex was formed in DMF solution, associated with the formation of an E.S.R.-silent solution compatible with the formation of low-spin d6 Co(III) species. Similar behavior was also observed for the interaction of these Co(II) complexes with dioxygen in the presence of ancillary ligands such as pyridine and 2-methylimidazole. The dioxygen complexes proved successful as oxygen carrier oxidation catalysts for tripehnylphosphine and 2,6-bis(t-butyl)phenol.
The Influence of Diets Containing Phenols and Condensed Tannins on Protein Picture, Clinical Profile and Rumen Characteristics in Omani Sheep
Authors: Mahgoub Osman , T.Kadim Isam , Babiker Hamza A. , Al-Kindi Mohammed N. 
Published: May 2017

A study was carried out to investigate the effects of feeding low quality non-conventional feeds (NCF) containing phenols and condensed tannins on health and performance characteristics in Omani sheep. Twelve Omani sheep were fed one of two base roughages, urea-treated palm frond (UTPF) or Rhodesgrass hay, (RGH) plus a commercial concentrate for 63 days. Haematological, serum biochemical and urine analyses were used to assess sheep health. Serum protein fractions were measured using electrophoresis. Urea-treated palm frond contained higher levels of polyphenols and condensed tannins and fiber than Rhodesgrass hay or concentrate feed. Animals fed UTPF had lower feed intake (P<0.05) and lower body gain (P<0.001) than those fed RGH. Rumen liquor of UTPF-fed animals had higher pH, ammonia-nitrogen and butyric fatty acid but lower acetic fatty acid (P<0.05). Animals fed UTPF had higher neutrophil (P<0.05) but lower lymphocyte (P<0.05) and monocyte (P<0.001) counts by the end of the trial than those fed RGH. There were no effects of diet on serum albumin or globulin fraction levels or albumin:globulin ratio. There were no major effects on urine analysis but there was a trend by control animals to have higher protein and specific gravity than treated ones. This study indicated that feeding low quality non-conventional feeds containing polyphenols or tannins would reduce body gain and may produce some effects on clinical parameters. Although tannins are known to influence protein digestion and absorption in ruminants, it did not significantly affect the serum protein picture in sheep.