bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic Resonance Imaging–Based Topographical Differences Between Control and Recurrent Patellofemoral Instability Patients
Authors: Charles Michael D. , Haloman Sean , Chen Lina , Ward Samuel R. , Fithian Donald , Afra Robert 
Published: January 2013

Background: Plain films and computed tomography (CT)–based imaging were the first to establish measurements that evaluated patellar instability. Limited research has shown the efficacy of magnetic resonance imaging (MRI) in evaluating these established measurements. Purpose: To identify morphological differences between normal knees and those with patellofemoral instability on MRI to determine what measurements are significant and how MRI-based means differ from historical means based on radiograph and CT imaging. Study Design: Case control study; Level of evidence, 3. Methods: Eighty-one controls and 40 patients with recurrent patellar instability between 2006 and 2010 were reviewed. The control patients had a history and an examination negative for patellofemoral symptoms. Patients with patellar instability had a history of at least 2 frank patellofemoral joint dislocations (PFJDs). The MRI images were obtained on the nonweightbearing knee in full extension. Measurements of patellar tilt, trochlear morphologic characteristics, and tibial tuberosity–trochlear groove (TTTG) distance were evaluated on axial slices, and patellar height was measured on sagittal images. Trochlear shape was assessed at the proximal and distal trochlea. Results: All measurements of patellar tilt (mean ± SD) were found to be significantly different between the 2 groups. For patellar height, the Insall-Salvati ratio (control, 1.08 ± 0.02; PFJD, 1.26 ± 0.03) and Caton-Deschamps ratio (control, 1.13 ± 0.02; PFJD, 1.29 ± 0.03) proved to be significantly different. Trochlear morphologic characteristics had numerous measurements prove to be significantly different proximally and distally. These included classic measurements such as sulcus angle (control, 148.48° ± 0.94°; PFJD, 165.57° ± 2.65°) and lateral trochlear inclination (control, 21.27° ± 0.66°; PFJD, 13.31° ± 1.36°) proximally and less established measurements such as the ratio of external (lateral) trochlea to internal (medial) trochlea (control, 1.51 ± 0.05; PFJD, 2.11 ± 0.17), a measurement of facet asymmetry. Conclusion: The MRI-based patellar tilt measures proved to be an excellent group of measurements for delineating between controls and those with instability. Patella alta ratios, such as Insall-Salvati and Caton-Deschamps, demonstrated a statistically significant difference between normal and recurrent dislocators. Trochlear measurements proved significantly different at the proximal and distal trochlea. Our findings demonstrate that MRI is appropriate to help discern recognized pathologic abnormalities that characterize patellofemoral instability.
Is Magnetic Resonance Imaging Reliable in Predicting Clinical Outcome After Articular Cartilage Repair of the Knee?
Authors: de Windt Tommy S. , Welsch Goetz H. , Brittberg Mats , Vonk Lucienne A. , Marlovits Stefan , Trattnig Siegfried , Saris Daniel B.F. 
Published: January 2013

Background: While MRI can provide a detailed morphological evaluation after articular cartilage repair, its additional value in determining clinical outcome has yet to be determined. Purpose: To evaluate the correlation between MRI and clinical outcome after cartilage repair and to identify parameters that are most important in determining clinical outcome. Study Design: Systematic review and meta-analysis. Methods: A systematic search was performed in Embase, MEDLINE, and the Cochrane Collaboration. Articles were screened for relevance and appraised for quality. Guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) Statement were used. Chi-square tests were performed to find variables that could determine correlation between clinical and radiological parameters. Results: A total of 32 articles (total number of patients, 1019) were included. A majority (81%) were case series or cohort studies that used similar standardized MRI techniques. The mean Coleman score was 63 (range, 42-96). For the majority of MRI parameters, limited or no correlation was found. Nine studies (28%) found a correlation between clinical outcome and the composite magnetic resonance observation of cartilage repair tissue (MOCART) or Henderson score and 7 (22%) with defect fill. In 5 studies, a weak to moderate correlation was found between clinical outcome and the T2 index (mean Pearson coefficient r = .53). Conclusion: Strong evidence to determine whether morphological MRI is reliable in predicting clinical outcome after cartilage repair is lacking. Future research aiming specifically at clinical sensitivity of advanced morphological and biochemical MRI techniques after articular cartilage repair could be of great importance to the field.
Dynamic mechanical and thermal behavior evaluation of an epoxy/anhydride/nano-aluminum oxide composite system
Authors: Farhadinejad Zeinab , Ehsani Morteza , Moemen-Bellah Samad 
Published: January 2013

The conventional properties of composites may be improved by incorporating the nanoparticles in polymer matrix to achieve high-performance polymer nanocomposites. In this respect, a commercial formulation of an epoxy electrical insulator was prepared by the chemical reaction of bisphenol A-based epoxy resin with an anhydride hardener and mixed with microsilica as filler. The effect of different contents of nano-aluminum oxide on dynamic mechanical and thermal properties of the cast epoxy composite was evaluated. The obtained result revealed that the effect of uniform dispersion of nanoparticles on storage modulus was as important as the filler content. In other words, increasing nanoparticle contents up to 10 wt% could not necessarily improve the properties of the nanocomposite while a uniform dispersion of nanofiller of just 1 wt% in a sample provided an efficient nanocomposite in which the values of storage modulus, dissipation factor and thermal stability were optimized. Furthermore, the combination of stiffness and high damping may be achieved in well-dispersed nanocomposites where strong interfacial interaction dominates between particle surface and polymer chain segments. This kind of sample possesses the highest thermal stability as well.
A new organosilicon adhesive based on polysiloxane and polysilazane
Authors: Liu Wei , Luo Yongming , Xu Caihong 
Published: January 2013

A new organosilicon adhesive was prepared by combining a vinyl-containing polysilazane (PSN) and a multifunctional polysiloxane (PSO). The adhesive was characterized by Fourier transform infrared spectroscopy. The effect of the PSN content on thermal properties of the adhesive was investigated by differential scanning calorimetry and thermal gravimetric analysis. On the basis of lap shear strength (LSS) test, the effects of the PSN content and the curing conditions on adhesive properties were evaluated. The sample with 20% of PSN cured at 170°C/4 h and then 330°C/4 h showed an LSS as high as 15.32 MPa at room temperature and 1.93 MPa at 400°C. The LSS decreased with the increase in testing temperature.
Effect of barium-containing glass filler reinforcement on shear bond strength of poly(ether ether ketone) to resin cement
Authors: Yan Pengtao , Xu Da , Wang Yongpeng , Wang Bing , Li Na , Zhang Haibo , Jiang Zhenhua 
Published: January 2013

The purpose of this study was to evaluate how barium-containing glass filler (BGF) reinforcement and pretreatment methods affect shear bond strength (SBS) of poly(ether ether ketone) (PEEK) to resin cement. PEEK composites with various amounts of BGF (10, 20, 30 and 40 wt%) were prepared as PEEK-BGF10, PEEK-BGF20, PEEK-BGF30 and PEEK-BGF40. Afterward, PEEK and PEEK-BGF40 specimens were treated with hydrofluoric acid, sulfuric acid (H2SO4), silica coating and polishing, respectively. Acrylic hollow cylinders were luted with Dentex dual-curing resin cement to the specimens. Finally, SBS measurements were conducted with a universal testing machine. The introduction of BGFs greatly enhanced SBS of PEEK to resin cement. After simply polishing with 150 grit silicon carbide papers (G150), PEEK-BGF40 exhibited the SBS value up to 19.73 ± 4.30 MPa, similar to the PEEK treated with H2SO4 etching. Scanning electron microscopy and x-ray photoelectron spectroscopy were used to investigate the surface morphological and chemical changes in PEEK and PEEK-BGF composites before and after surface treatment. The results indicate that the introduction of BGF particles plays a key role in improving the adhesion between PEEK and resin cement. This study provides a new method to enhance the adhesion to PEEK without breaking its surface structure, which encourage further research in PEEK composite application in dentistry.
Subtalar Distraction Osteogenesis for Posttraumatic Arthritis Following Intra-Articular Calcaneal Fractures
Authors: Fan Wei-Li , Sun Hong-Zhen , Wu Si-Yu , Wang Ai-Min 
Published: January 2013

Background: The most common treatment for old calcaneal fractures accompanied by subtalar joint injury is the use of subtalar in situ arthrodesis and subtalar distraction bone-block arthrodesis or osteotomy. This article describes the introduction of a novel surgical treatment, gradual subtalar distraction with external fixation and restoration of the calcaneal height, and presents an assessment of its efficacy. Methods: The protruding lateral calcaneus and the articular surfaces and subchondral bone of the posterior facet of the subtalar joint were surgically removed. An external fixator, attached with 2 pins in the subcutaneous tibia and 2 pins in the posterolateral calcaneus, was used to fix the subtalar joint for 7 to 10 days followed by gradual subtalar distraction at 1 mm/d. The lengthening procedure was stopped when the calcaneal height was restored according to radiography. The external fixator was removed after bone fusion. Seven cases of old calcaneal fractures accompanied by severe subtalar joint injury (8 feet) were treated using this method. Average follow-up was 14.3 months (range, 7-36 months). Results: In all 7 cases (1 case of both feet), the postoperative wound healed primarily. The calcaneal heights of all 8 feet were partially restored. Subtalar joint bone fusion was completed within 4 to 6 months after the operation. The average preoperative American Orthopedic Foot & Ankle Society (AOFAS) hindfoot score was 25.3, and the average postoperative AOFAS score was 76.3. Conclusion: Subtalar distraction osteogenesis with external fixation was a novel and effective method for the treatment of old calcaneal fractures accompanied by severe subtalar joint injury in this small group of patients. Level of Evidence: Level IV, retrospective case series.
Urinal or conduit? Institutional information flow between the UK intelligence services and the news media
Authors: Lashmar Paul 
Published: January 2013

Since the 1990s, the Secret Intelligence Service (MI6) and the Security Service (MI5) have developed formal links with most major UK news organisations in an effort to improve the agencies’ media presentation. This article discusses the impact and inherent problems of these relationships, including whether the news media can have official, formal but non-attributable links with these agencies without compromising their role as the fourth estate. Utilising epistemologies for crime reporting and news sources, this article proposes an initial framework to analyse these institutional relationships. It also takes as a case study the controversy over whether MI5 deliberately played down their prior knowledge of 7/7 suicide bomber Mohammed Sidique Khan. The author was one of the journalists briefed by MI5 on Khan and has here taken the Khan controversy as a case study to investigate the Security Service’s information flow and whether the agency misled, and indeed intended to mislead, the media and the public.
Chemical durability of vitrified wasteforms: effects of pH and solution composition
Authors: Utton C. A. , Swanton S. W. , Schofield J. , Hand R. J. , Clacher A. , Hyatt N. C. 
Published: January 2013

AbstractVitrification is used for the immobilization and conditioning of high-level waste (HLW) arising from the reprocessing of spent nuclear fuel in the UK. Vitrification is also under consideration for the immobilization of certain intermediate-level wastes (ILW), where there may be advantages of volume reduction and removal of uncertainties in long-term waste behaviour, compared to encapsulation in a cement grout. This paper gives an overview of recent work into the chemical durability of UK vitrified wasteforms to inform the technical specification for the disposal facilities for these waste products and the treatment of their long-term behaviour in post-closure performance assessment. This has included: (1) measurements of the initial glass dissolution rates of a simulated HLW Magnox waste glass in a range of groundwater types representative of potential UK host geologies and in simulated high pH near-field porewaters relevant to potential disposal concepts, using Product Consistency Test type-B (PCT-B) at 40°C; and (2) durability testing of three simulant ILW glasses in a saturated calcium hydroxide buffered solution to simulate conditions in cement-based disposal vaults, using PCT-B tests at 50°C.The experimentally defined initial rate of HLW Magnox waste glass dissolution in a range of simulated groundwater compositions appears to be similar regardless of the ionic strength and major element composition of the solution. The release of caesium from HLW Magnox waste glass appears to be sensitive to solution composition. Caesium is selectively retained in the glass compared to other soluble components in the two low ionic strength solutions, but is released at similar rates to other soluble components in the three groundwaters and Ca(OH)2 solution. Whether this change in caesium retention is an ionic strength effect or is related to changes in the nature of the surface alteration layer formed on the glass, has yet to be established. For HLW Magnox waste glass, dissolution is accelerated at high pH in NaOH solution, however, the presence of calcium acts to mitigate the effects of high pH, at least initially. In Ca(OH)2 solution, calcium is found to react with all the glasses studied leading to the formation of calcium-containing alteration products. The initial dissolution behaviour in Ca(OH)2 solution varies with glass composition and in particular appears to be sensitive to the boron content.
Reaction of bentonite in low-alkali cement leachates: an overview of the Cyprus Natural Analogue Project (CNAP)
Authors: Alexander W. R. , Milodowski A. E. , Pitty A. F. , Hardie S. M. L. , Kemp S. J. , Korkeakoski P. , Rigas M. , Rushton J. C. , Sellin P. , Tweed C. J. 
Published: January 2013

AbstractThe Cyprus Natural Analogue Project was carried out due to the requirement to support ongoing laboratory and modelling efforts on the potential reaction of the bentonite buffer with cementitious leachates in the repository engineered barrier system. Although it is known that the higher pH (12.5–13) leachates from ordinary Portland cement will degrade bentonite, it is unclear if this will also be the case for the lower pH (10–11) leachates typical of low alkali cements. Ongoing laboratory and underground rock laboratory programmes, which are currently investigating this, face the obstacle of slow kinetics and the production of short-lived metastable phases, meaning obtaining unambiguous results may take decades. It was therefore decided to implement a focussed natural analogue study on bentonite/low alkali cement leachate reactions to provide indications of the probable long-term reaction products and reaction pathways to provide feedback on the existing short-term investigations noted above and to ascertain if any critical path research and development needs to be instigated now. The results of the analyses presented here, in this short overview of the project, suggest that there has been very limited alkaline groundwater reaction with the bentonite. This is generally supported by both the geomorphological evidence and the natural decay series data which imply groundwater/rock interaction in the last 105 a.
Modelling evolution in the near field of a cementitious repository
Authors: Hoch A. R. , Baston G. M. N. , Glasser F. P. , Hunter F. M. I. , Smith V. 
Published: January 2013

AbstractIn the United Kingdom, disposal of radioactive waste may involve packages of grouted waste being placed in a geological disposal facility (GDF) and surrounded by a cementitious backfill. This paper describes modelling that has been carried out to develop an understanding of the possible spatial and temporal evolution within the GDF.A single waste package is assumed to be filled with an encapsulation grout, placed in an underground vault and surrounded by a cementitious backfill. Groundwater from the host rock flows into the vault and through the backfill. A simplified model system examines the interactions between groundwater, cementitious backfill and grout.In most cases the model predicts a reduction in the backfill porosity due to precipitation and dissolution reactions, particularly at the upstream edge of the vault. The degree to which this occurs depends on the groundwater composition. The model also predicts precipitation and dissolution reactions would occur in the grouts close to their interface with the backfill, reducing the local porosity significantly which may isolate the grouts from the backfill, so that the pH within the grouts would be unchanged over an extended period.
Europium interaction with a vault backfill at high pH
Authors: Telchadder R. , Smith K. , Bryan N. D. 
Published: January 2013

AbstractBatch experiments have been used to assess the sorption properties of a potential cementitious repository backfill, NRVB (Nirex reference vault backfill), using Eu3+as a model trivalent radionuclide and ethylenediaminetetraacetic acid (EDTA) as a competing ligand. The NRVB is an effective scavenger of Eu from solution, with most sorbed within minutes onto the crushed material and less than 1.5% remaining in solution after one day (Rdvalues in the range 0.3–2.4 × 104l kg−1). Ultrafiltration showed that nearly all of this remaining Eu (>94%) is attached to NRVB derived colloids or particulates that are mainly retained by a 100 kDa ultrafilter. High concentrations of EDTA (>0.01 M) reduced the extent of sorption at apparent equilibrium. The addition of EDTA to a pre-equilibrated system of Eu3+and NRVB resulted in a temporary suspension of some Eu, but this very quickly returned to the solid phase. There is some irreversibility in these systems, with EDTA able to prevent removal of Eu(III) from solution, but unable to bring it back into solution under the same conditions.
Uranium uptake onto Magnox sludge minerals studied using EXAFS
Authors: van Veelen A. , Copping R. , Law G. T. W. , Smith A. J. , Bargar J. R. , Rogers J. , Shuh D. K. , Wogelius R. A. 
Published: January 2013

AbstractAround the world large quantities of sludge wastes derived from nuclear energy production are currently kept in storage facilities. In the UK, the British government has marked sludge removal as a top priority as these facilities are nearing the end of their operational lifetimes. Therefore chemical understanding of uranium uptake in Mg-rich sludge is critical for successful remediation strategies. Previous studies have explored uranium uptake by the calcium carbonate minerals, calcite and aragonite, under conditions applicable to both natural and anthropogenically perturbed systems. However, studies of the uptake by Mg-rich minerals such as brucite [Mg(OH)2], nesquehonite [MgCO3·3H2O] and hydromagnesite [Mg5(CO3)4(OH)2·4H2O], have not been previously conducted. Such experiments will improve our understanding of the mobility of uranium and other actinides in natural lithologies as well as provide key information applicable to nuclear waste repository strategies involving Mg-rich phases. Experiments with mineral powders were used to determine the partition coefficients (Kd) and coordination of UO22+ during adsorption and co-precipitation with brucite, nesquehonite and hydromagnesite. The Kd values for the selected Mg-rich minerals were comparable or greater than those published for calcium carbonates. Extended X-ray absorption fine structure analysis results showed that the structure of the uranyl-triscarbonato [UO2(CO3)3] species was maintained after surface attachment and that uptake of uranyl ions took place mainly via mineral surface reactions.
Observations of heterogeneous pore pressure distributions in clay-rich materials
Authors: Cuss R. J. , Harrington J. F. , Graham C. C. , Sathar S. , Milodowski A. E. 
Published: January 2013

AbstractThe concept of effective stress is one of the basic tenets of rock mechanics where the stress acting on a rock can be viewed as the total stress minus the pore water pressure. In many materials, including clay-rich rocks, this relationship has been seen to be imperfect and a coefficient (χ) is added to account for the mechanical properties of the clay matrix. Recent experimental results during the flow testing (both gas and water) of several rocks (Callovo-Oxfordian claystone, Opalinus Clay, Boom Clay) and geomaterials (bentonite, kaolinite) has given evidence for stable high pressure differentials. The design of the experiments allows multiple measurements of pore pressure, which commonly shows a complex distribution for several different experimental geometries. The observed stable high pressure differentials and heterogeneous pore pressure distribution makes the describing of stress states in terms of effective stress complex. Highly localized pore pressures can be sustained by argillaceous materials and concepts of evenly distributed pore pressures throughout the sample (i.e. conventional effective stress) do not fit many clay-rich rocks if the complexities observed on the micro-scale are not incorporated, especially when considering the case of gas flow.
An overview of gas research in support of the UK geological disposal programme
Authors: Williams S. J. 
Published: January 2013

AbstractGases will be generated in waste packages during their transport to a geological disposal facility (GDF), this generation will continue during GDF operations and after GDF closure. The range of gases produced will include flammable, radioactive and chemotoxic species. These must be managed to ensure safety during transport and operations, and the post-closure consequences need to be understood. The two primary post-closure gas issues for a GDF are the need for the system pressure to remain below a value at which irreversible damage to the engineered barrier system and host geology could occur, and the need to ensure that any flux of gas (in particular gaseous radionuclides) to the biosphere does not result in unacceptable risk. This paper provides an overview of the research of the Nuclear Decommissioning Authority, Radioactive Waste Management Directorate into gas generation and its migration from a GDF.