bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photo-induced changes in the Langmuir adsorption constants of metal oxide layers in self-cleaning cation sensors.
Authors: Foran Philip S. , Boxall Colin 
Published: February 2012

ABSTRACTFor the first time, we have used a metal oxide-coated quartz crystal microbalance (QCM) to measure Cs+ adsorption onto illuminated and un-illuminated mesoporous TiO2 (m-TiO2) films by microgravimetric means in-situ. In the simplest case, such experiments yield two parameters of interest: K, the Langmuir adsorption coefficient and mmax the maximum mass of adsorbate to form a complete monolayer at the m-TiO2-coated quartz crystal piezoelectric surface. Importantly, we have found that illumination of the m-TiO2 film with ultra bandgap light results in an increase in mmax i.e. illumination allows for greater adsorption of substrate to occur than in the dark. Our studies also show that under illumination, K also increases indicating a higher affinity for surface adsorption. The photoinduced change in mmax and K are thought to be due to an increase in surface bound titanol groups, thus increasing the number of available adsorption sites – and so providing evidence to support the notion of photoinduced adsorption processes in photocatalytic systems. These findings have implications for the development of a reversible adsorption based microgravimetric sensor for Cs+.
Photoluminescence and Raman scattering studies of GaN nanowires obtained by top-down and bottom-up approaches
Authors: Stoica Toma , Haab Anna , Griesche David , Mikulics Martin , Limbach Friederich , Schumann Timo , Gotschke Tobias , Sutter Eli , Calarco Raffaella , Hardtdegen Hilde , Grützmacher Detlev 
Published: February 2012

ABSTRACTWe present comparative studies of optical properties of GaN nanowires (NWs) obtained by two different self-formation techniques: Plasma-Assisted Molecular Beam Epitaxy (PAMBE) growth; and plasma etching of GaN layers deposited by Metal-Organic Vapor Phase Epitaxy (MOVPE). The effects of the coalescence process on grown NW and plasma-induced defects in etched NWs have been studied by photoluminescence (PL) and Raman scattering. In MBE grown NWs, the coalescence-associated defects are extended toward the NW top for intermediate Ga flux. Using High Resolution Electron Microscopy of reactive plasma etching (RIE) NWs, it was found that NWs obtained with an optimal combination of inductive (ICP) and capacitive (RF) plasma are free of extended structural defects. The PL efficiency is strongly increased in plasma etched NWs. However, plasma-induced point defects have to be taken into account for explaining the changes of the PL spectra. Less plasma-induced degradation is observed for high ICP/RF power ratios.
An Analytical Solution for Water Coning in Vertical Wells
Authors: Tabatabaei M.. , Ghalambor A.. , Guo B.. 
Published: February 2012

Summary
Optimizing the completion interval to minimize water coning has been long recognized as a challenge in the industry. After reviewing the mechanism of water coning, a simple analytical model is presented in this study for water-coning systems in high-conductivity reservoirs (reservoirs with low pressure gradient). This model is applicable to predict the critical rate and to determine the optimum wellbore penetration for achieving maximum water-free production rate of vertical oil wells.
The developed model predicts the critical rate on the basis of a radial/spherical/combined (RSC) 3D flow field assumption that takes into account the effect of permeability anisotropy, density difference between water and oil, and limited wellbore penetration. Moreover, optimum wellbore penetration into the oil zone has been determined by maximizing the critical rate. This analytical model reveals the optimum wellbore penetration in high-conductivity reservoirs to be almost half of the pay-zone thickness, depending on the radius of wellbore and drainage area, pay-zone thickness, and the permeability anisotropy of the reservoir.
Critical Oil Rate and Well Productivity in Cold Production From Heavy-Oil Reservoirs
Authors: Guo Boyun , Gao Deli , Ai Chi , Qu Jianfang 
Published: February 2012

SummaryCold heavy-oil production with sand (CHOPS) has been widely used for recovering heavy oil from unconsolidated sandstones (UCSs). Although this technology is considered to be mature in some oil fields in Canada, there are some technical issues that need to be addressed when this technology is transferred to fields in other parts of the world. These issues are primarily related to the variations in local geological and reservoir conditions. One of the concerns is whether the designed well production rate is high enough to self-clean the wellbore against sand accumulation. During planning of CHOPS completions, it is imperative to know if the designed fluid-production rate will be adequate to carry sand to surface, especially when horizontal wells are employed, where a significant amount of sand can accumulate in the horizontal wellbore that can kill the well. However, it is not clear what constitutes the "adequate" fluid-production rate. A theoretical investigation of sand transport in heavy oil was conducted in this study. A critical fluid-production rate was defined to quantitatively describe the "adequate" production rate required to carry sand to surface in vertical, inclined, and horizontal wells. Also developed in this study is a CHOPS-well deliverability model based on self-stimulation of reservoir and oil/water/gas/solid four-phase flow in the production string. Combined use of the critical-production-rate model and the well-deliverability model allows for optimal selection of pumps that will ensure the smooth production of fluids in CHOPS operations. This paper provides petroleum engineers with essential knowledge and information for planning CHOPS well completions.
Effect of Composite Insertion Technique on Cuspal Deflection Using an In Vitro Simulation Model
Authors: Jafarpour S , El-Badrawy W , Jazi HS , McComb D 
Published: February 2012

SUMMARY

Objective
The objective of this study was to investigate, by simulation, the effect of conventional composite resin insertion techniques on cuspal deflection using bonded typodont artificial teeth. The deflection produced by a new low-shrinkage composite was also determined.

Materials and Methods
Sixty standardized MOD preparations on ivorine maxillary premolars were prepared: group A at 4 mm depth and group B at 6 mm depth. Each group was further subdivided according to composite insertion technique (n=6), as follows: 1) bulk insertion, 2) horizontal increments, 3) tangential increments, and 4) a modified tangential technique. Preparations were microetched, acid-cleaned, and bonded with adhesive resin to provide micromechanical attachment before restoration with a conventional composite (Spectrum TPH3, Dentsply). Two additional subgroups at 4 mm and 6 mm depth (n=6) were restored in bulk using low-shrinkage composite (Filtek LS, 3M/ESPE). All groups received the same total photo-polymerization time. Cuspal deflection was measured during the restorative procedure using two Linear Variable Differential Transformers attached to a data acquisition system.

Results
The average cuspal deflections for group A were 1) 40.17 ± 1.18 μm, 2) 25.80 ± 4.98 μm, 3) 28.27 ± 5.12 μm, and 4) 27.33 ± 2.42 μm. The deflections in group B were 1) 38.82 ± 3.64 μm, 2) 50.39 ± 9.17 μm, 3) 55.62 ± 8.16 μm, and 4) 49.61 ± 8.01 μm. Cuspal flexure for the low-shrinkage composite was 11.14 ± 1.67 μm (group A: 4 mm depth) and 16.53 ± 2.79 μm (group B: 6 mm depth).

Conclusions
All insertion techniques using conventional composite caused cuspal deformation. In general, deeper preparations showed increased cuspal deflection—except in the case of bulk insertion, which was likely affected by decreased depth of cure. Cuspal movement using low-shrinkage composite was significantly reduced.
Clinical Evaluation of a Low-shrinkage Composite in Posterior Restorations: One-Year Results
Authors: Baracco B , Perdigão J , Cabrera E , Giráldez I , Ceballos L 
Published: February 2012

SUMMARY

Objectives
The aim of this study was to compare the one-year clinical performance of three restorative systems, which included a novel low-shrinkage composite and two bonding strategies.

Materials and Methods
Twenty-five patients received three Class I (occlusal) or Class II restorations performed with one of three restorative systems: Filtek Silorane Restorative System (FS); Adper Scotchbond 1 XT, a two-step etch-and-rinse adhesive, with Filtek Z250 (XT); and Adper Scotchbond SE, a two-step self-etch adhesive, with Filtek Z250 (SE). All materials were applied following the manufacturer's instructions. Two independent observers evaluated the restorations at baseline, after six months, and after one year, according to the United States Public Health System modified criteria. The Kruskal-Wallis test and the Mann-Whitney U-test were computed to compare the behavior of the restorative systems; Friedman and Wilcoxon tests were used to analyze the intrasystem data (α=0.05).

Results
All restorations were evaluated at one year. FS and XT performed statistically similarly at one year, but marginal staining for SE was statistically worse. Intrasystem comparisons between baseline and one year also showed deterioration of marginal staining for SE, while a deterioration of the marginal adaptation was recorded for both SE and FS. XT was the only system for which there was no statistical change of the parameters measured in this study.

Conclusions
Both restorative systems using self-etch adhesives showed a tendency to degradation of marginal adaptation after one year of clinical use, compared to baseline values. Although the clinical performance of FS was deemed acceptable after one year, this study did not find any advantage of the silorane-based composite over the methacrylate-based composite. The low-shrinkage associated with FS may not be a determinant factor for clinical success.
Selective Enamel Etching: Effect on Marginal Adaptation of Self-Etch LED-Cured Bond Systems in Aged Class I Composite Restorations
Authors: Souza-Junior EJ , Prieto LT , Araújo CTP , Paulillo LAMS 
Published: February 2012

SUMMARY
The aim of this study was to evaluate the influence of previous enamel etch and light emitting diode (LED) curing on gap formation of self-etch adhesive systems in Class I composite restorations after thermomechanical aging (TMA). Thus, on 192 human molars, a box-shaped Class I cavity was prepared maintaining enamel margins. Self-etch adhesives (Clearfil SE and Clearfil S3) were used to restore the preparation with a microhybrid composite. Before application of the adhesives, half of the teeth were enamel etched for 15 seconds with 37% phosphoric acid; the other half were not etched. For the photoactivation of the adhesives and composite, three light-curing units (LCUs) were used: one polywave (Ultra-Lume LED 5, UL) and two single-peak (FlashLite 1401, FL and Radii-cal, RD) LEDs. After this, epoxy resin replicas of the occlusal surface were made, and the specimens were submitted to TMA. New replicas were made from the aged specimens for marginal adaptation analysis by scanning electron microscopy. Data were submitted to Kruskal-Wallis and Wilcoxon tests (α=0.05). Before TMA, when enamel was etched before the application of S3, no gap formation was observed; however, there were gaps at the interface for the other tested conditions, with a statistical difference (p≤0.05). After TMA, the selective enamel etching previous to the S3 application, regardless of the LCU, promoted higher marginal adaptation compared to the other tested groups (p≤0.05). Prior to TMA, higher marginal integrity was observed, in comparison with specimens after TMA (p≤0.05). With regard to Clearfil SE and Clearfil Tri-S cured with FL, no differences of gap formation were found between before and after aging (5.3 ± 3.8 and 7.4 ± 7.5, respectively), especially when the Clearfil Tri-S was used in the conventional protocol. When cured with RD or UL and not etched, Clearfil Tri-S presented the higher gap formation. In conclusion, additional enamel etching promoted better marginal integrity for Clearfil Tri-S, showing it to be an efficient technique for Class I composite restorations. The two-step self-etch adhesive was not influenced by selective enamel etching or by the LED-curing unit.
In Vitro and In Vivo Evaluations of Three Computer-Aided Shade Matching Instruments
Authors: Yuan K , Sun X , Wang F , Wang H , Chen J 
Published: February 2012

SUMMARYThis study evaluated the accuracy and reliability of three computer-aided shade matching instruments (Shadepilot, VITA Easyshade, and ShadeEye NCC) using both in vitro and in vivo models. The in vitro model included the measurement of five VITA Classical shade guides. The in vivo model utilized three instruments to measure the central region of the labial surface of maxillary right central incisors of 85 people. The accuracy and reliability of the three instruments in these two evaluating models were calculated. Significant differences were observed in the accuracy of instruments both in vitro and in vivo. No significant differences were found in the reliability of instruments between and within the in vitro and the in vivo groups. VITA Easyshade was significantly different in accuracy between in vitro and in vivo models, while no significant difference was found for the other two instruments. Shadepilot was the only instrument tested in the present study that showed high accuracy and reliability both in vitro and in vivo. Significant differences were observed in the L*a*b* values of the 85 natural teeth measured using three instruments in the in vivo assessment. The pair-agreement rates of shade matching among the three instruments ranged from 37.7% to 48.2%, and the incidence of identical shade results shared by all three instruments was 25.9%. As different L*a*b* values and shade matching results were reported for the same tooth, a combination of the evaluated shade matching instruments and visual shade confirmation is recommended for clinical use.
Influence of Volumetric Shrinkage and Curing Light Intensity on Proximal Contact Tightness of Class II Resin Composite Restorations: In Vitro Study
Authors: El-Shamy H , Saber MH , Dörfer CE , El-Badrawy W , Loomans BAC 
Published: February 2012

SUMMARYBackgroundProximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and technique of placement. However, the effect of volumetric shrinkage of resin and intensity of curing light has yet to be determined. Thus, the aim of this study was to identify the influence of these factors on the proximal contact tightness when restoring class II cavity preparations in vitro.MethodsSixty artificial molars were restored with either a low-shrinkage (Filtek Silorane, 3M ESPE) or a conventional (Z100, 3M ESPE) composite and polymerized with low-intensity (Smartlite IQ2, Dentsply) or high-intensity light curing units (DemiTM, Kerr). Proximal contact tightness was measured using the Tooth Pressure Meter. Data were statistically analyzed using one-way analysis of variance and Tukey post hoc test.ResultsUse of low-shrinkage composite (Filtek Silorane) resulted in significantly tighter proximal contacts compared to the use of conventional composite (Z100) when cured with the same polymerization unit (p&lt;0.001). Moreover, the low-intensity curing unit (IQ2) resulted in significantly tighter contacts than the high-intensity unit when material is constant (p&lt;0.001).ConclusionsLow-shrinkage resin composite and low curing light intensity is associated with tighter proximal contact values.
Equiconnected spaces and Baire classification of separately continuous functions and their analogs
Authors: Karlova Olena , Maslyuchenko Volodymyr , Mykhaylyuk Volodymyr 
Published: February 2012

Abstract
We investigate the Baire classification of mappings f: X × Y → Z, where X belongs to a wide class of spaces which includes all metrizable spaces, Y is a topological space, Z is an equiconnected space, which are continuous in the first variable. We show that for a dense set in X these mappings are functions of a Baire class α in the second variable.
Proprotein convertase subtilisin/kexin type 9: A new target molecule for gene therapy
Authors: Banaszewska Anna , Piechota Michal , Plewa Robert 
Published: February 2012

AbstractProprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a novel target for controlling plasma levels of low-density lipoprotein cholesterol (LDL-C) and decreasing the risk of cardiovascular diseases. At present it is clear that the major classes of commonly prescribed lipid-lowering medications increase serum PCSK9 levels and fail to protect a significant percentage of patients from cardiovascular events. Therefore development of new LDL-C lowering medications that either do not increase circulating PCSK9 levels or work through inhibition of PCSK9 expression and protease activity is a highly desirable approach to overcome hypercholesterolemia. Since there are several agents which are being evaluated in human preclinical and clinical trials, this review summarizes current therapeutic strategies targeting PCSK9, including specific antibodies, antisense oligonucleotides, small interfering RNAs (siRNAs) and other small-molecule inhibitors.
Palaeoecology, facies and stratigraphy of shallow marine macrofauna from the Upper Oligocene (Palaeogene) of the southern Pre-North Sea Basin of Astrup (NW Germany)
Authors: Diedrich Cajus 
Published: February 2012

AbstractThe 22 meter thick marine carbonate Upper Oligocene series of Astrup (NW Germany) is correlated with the Chattian type section of Doberg. It indicates a more constrained palaeogeographical and biostratigraphical position ranging from the biozones of Chlamys (C.) decussata (upper Chattian A) to Chlamys (C.) semistriatus (lower Chattian C). The macrofauna can be subdivided into three main benthic communities: A. the „coarse gravel spondylid beach fauna“ of the shore zone with „pebble beach facies“ dominated by sessile brachiopods, large balanids, spondylids, oysters or small regular echinoids. Borings are common in pebbles; B. the „glauconite fine gravel brachiopod-bryozoan littoral fauna“ of the shallow subtidal zone where a terebratulid/lithothamnid dominated fauna/flora is present. The rhodophyceans were most possibly anker stones and substrates for cirripeds and serpulids; C. the „glauconite carbonate sand phytal fauna“ of the shallow subtidal zone with a rich benthic mollusc dominated fauna. Indirect evidence for seagrass and macroalgae occurs on the attachment negatives of balanids and oysters, and also on Cibicides foraminifera or bryozoans like Cellepora. The facies types along the Wiehengebirge Island and Teutoburger Wald Peninsula coasts of the southern Pre-North Sea Basin differ with respect to their benthic communities to that of the siliciclastic Leipziger and the Rhenish Bay facies.
Intraocular Femtosecond Laser Use in Traumatic Cataracts Following Penetrating and Blunt Trauma
Authors: Nagy Zoltán Zsolt , Kránitz Kinga , Takacs Agnes , Filkorn Tamás , Gergely Róbert , Knorz Michael C. 
Published: February 2012

PURPOSE:
To investigate the use of femtosecond laser cataract surgery in traumatic cataracts of different origin.

METHODS:
The first case developed acute traumatic cataract due to penetrating injury of the cornea and the anterior lens capsule; the second developed traumatic cataract 11 years after a penetrating corneal injury; and the third developed a “white” cataract 12 months after blunt ocular trauma. In all cases, 4.5-mm capsulorrhexis and corneal incisions were performed using a femtosecond laser system (Alcon LenSx Inc), and nucleus liquefaction with the laser was performed additionally in the second case.

RESULTS:
In all patients, a capsulorrhexis could be created with the femtosecond laser. Preexisting radial tears were present in the first case, but the remaining anterior capsule could be cut with the laser. The second and third cases showed an intact 4.5-mm capsulorrhexis. Corneal incisions were stable in all cases, and nucleus liquefaction was possible in the second case (grade 1–2 nuclear density).

CONCLUSIONS:
Results indicate that a femtosecond laser can be used successfully in certain instances of traumatic cataract after penetrating eye injury, even if an anterior capsule laceration is present, and also after blunt trauma resulting in “white” cataracts.
A Descriptive Study of Cooperating Teachers’ Perceptions Regarding Student Teacher Preparation
Authors: MacLeod Rebecca B. , Walter Jennifer S. 
Published: February 2012

Abstract
The purpose of this study was to investigate the perceptions of cooperating teachers regarding the level of preparedness of specific student teachers at the beginning of the student-teaching experience. Fifty-three secondary ensemble teachers (orchestra, band, and choir) completed a survey rating how prepared their most recent student teacher was in the areas of personal skills, teaching skills, and musical skills and provided feedback regarding the skill that needed the most attention from the university to improve music teacher preparation. Cooperating teachers rated student teachers similarly in all three categories. Differences were found between orchestra, band, and choir teachers relative to the skill that was selected in each category as needing the most attention. Orchestra and band teachers selected effective rehearsal pace, knowledge of subject matter, and secondary instrument skills as needing additional focus from university programs, while choral teachers selected piano skills and teaching and learning strategies as important areas to develop. Additional trends were noted between orchestra, band, and choral teachers and implications for music teacher education were discussed.
Reconstruction of a Total Soft Palatal Defect Using a Folded Radial Forearm Free Flap and Palmaris Longus Tendon Sling
Authors: Lee Myung Chul , Lee Dong Won , Rah Dong Kyun , Lee Won Jai 
Published: February 2012

Background The soft palate functions as a valve and helps generate the oral pressure required for normal speech resonance. Speech problems and nasal regurgitation can result from a soft palatal defect. Reduction of the size of the velopharyngeal orifice is required to compensate for the lack of mobility in a reconstructed soft palate. We suggest a large volume folded free flap for reduction of the caliber and a palmaris longus tendon sling for suspension of the reconstructed palate.
Methods Six patients had total soft palate resection for tonsillar cancer and reconstruction with a large volume folded radial forearm free flap combined with a palmaris longus sling. A single surgeon and speech therapist examined the patients with three standardized speech assessment tools: nasometer test, consonant articulation test, and speech acuity test performed for speech evaluation.
Results Mean nasalance score was 76.20% for sentences with nasal sounds and 43.60% for sentences with oral sounds. Hypernasality was seen for oral sound sentences. The mean score of the picture consonant articulation test was 84% (range, 63% to 100%). The mean score of the speech acuity test was 5.84 (range, 5 to 6). These mean ratings represent a satisfactory level of speech function.
Conclusions The large volume folded free flap with a palmaris longus tendon sling for total soft palate reconstruction resulted in satisfactory prognosis for speech despite moderate hypernasality.