bluuebunny/crossref_metadata_2025_split huggingface dataset:
Typical Zirconium Alloys Microstructures in Nuclear Components
Authors: Flores A. V. , Gomez A. G. , Juarez G. A. , Loureiro N. , Samper R. I. , Santisteban J. R. , Alvarez M. A. Vicente , Tolley A. , Condó A. , Bianchi R. D. , Banchik A. D. , Vizcaíno P. 
Published: September 2014

Abstract
The different microstructures typically found in nuclear components made of zirconium alloys are discussed in this paper. These include material in a variety of thermo-mechanical conditions, e. g., cold rolled, stress relieved, recrystallized, welded, biphasic, together with minority second phases belonging to the original material or incorporated due to in-service conditions. The anisotropic crystalline structure of zirconium is exploited in microscopical observations by means of polarizer filters that enhance the contrast between different grains, and greatly aid the identification in most microstructures. Most microstructural variations across a wide range of length-scales, such as those produced by welding processes, can be effectively resolved by traditional optical microscopy (OM). However, some finer microstructures like those found in CANDU1 (CANada Deuterium Uranium) reactor pressure tube material, or some minority second phase particles like the Zr(Fe, Cr)2 precipitates in Zircaloy-4 cannot be completely resolved by this technique. Thus, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are required in such cases. For SEM observations we show the valuable issue of the scale in specific microstructural studies, which allows quantifying microstructural parameters using image analysis. For TEM observations, we have greatly benefited from the electron diffraction diagrams, which have allowed us to investigate the crystalline structure of irradiated second phase particles, which would remain unnoticed to both, OM or SEM observations.
Assessing the Power of Electron Back Scattering Diffraction Characterization of Deformed F-138 Steel from the View Point of Crystal Diffraction
Authors: Bolmaro R. E. , Avalos M. C. , De Vincentis N. S. , Kliauga A. M. , Brokmeier H.-G. 
Published: September 2014

Abstract
Microstructural characterization by combined EBSD and X-ray diffraction analysis is shown for an FCC material deformed by rolling and further heat treatment on air. The wide variety of x-rays sources combined with EBSD allows some correlations between microstructural parameters to be withdrawn by carefully analyzing x-ray peak broadening. The combination of both techniques provides a deeper understanding of anisotropic accumulation of dislocation arrays on a deformed F 138 stainless steel. The anisotropy results in a smaller peak breadth for crystal orientations with [110] planes contained on the rolling plane, further explained as resulting from a lower storage of dislocations. After heat treatment the effect is reverted and the formerly less misoriented orientations become more uniformly oriented revealing a faster dislocation migration and annihilation and/or trapping.
Lamellar Corneal Lenticule Graft to Treat Keratolysis after Alphacor Keratoprosthesis Implantation
Authors: Hoffart Louis , Carles Gérard , Matonti Frédéric 
Published: September 2014

Purpose Clinical assessment of AlphaCor keratoprosthesis and evaluation of surgical method to treat keratolysis in case of stromal necrosis occurrence. Methods This is a noncomparative, retrospective, interventional case series. The medical records of 12 eyes of 12 patients who underwent consecutive AlphaCor keratoprosthesis implantations were reviewed. Patients with severe bilateral corneal pathology unsuitable for a conventional corneal graft, a best-corrected visual acuity (BCVA) from light perception (LP) to 20/200, with no active ocular surface inflammation, controlled intraocular pressure prior to the surgery, and an unstimulated Schirmer test of >2.5 mm at 5 minutes were included. Postoperative medications included topical dexamethasone, ciprofloxacin, and 2% cyclosporine A. Main outcome measures included BCVA and complications occurrence. Results After a mean follow-up of 25 ± 12.3 months (range 2-38 months), 8 (66.7%) AlphaCor devices were retained. Postoperative BCVA ranged from LP to 20/63 (mean gain of 2.5 ± 3.1 lines). Seven cases of stromal melt (58.3%) occurred. Three were reversed to penetrating keratoplasty and 3 had a donor corneal layer fixated over the AlphaCor with satisfactory results (mean follow-up 23 ± 1.6 months). There were no instances of endophthalmitis, retinal detachment, or glaucoma exacerbation. Conclusions AlphaCor showed a low incidence of the classic keratoprosthesis complications but a high occurrence of recipient cornea necrosis. Corneal melts were successfully managed in 3 cases by lamellar corneal lenticule graft, thereby increasing the retention of AlphaCor and maintaining BCVA.
Comparison of Primary Open-Angle Glaucoma and Exfoliation Glaucoma at Diagnosis
Authors: Tarkkanen Ahti H.A. , Kivelä Tero T. 
Published: September 2014

Purpose To compare ocular findings in eyes with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EG) at the time of diagnosis when identical diagnostic criteria for glaucoma were applied. Methods We conducted a study on records of 519 consecutive, unselected patients with chronic glaucoma filing for cost-free medication from the Finnish National Social Insurance Institute (FSII). Fourteen cases were excluded for having other types of glaucoma. The documents were provided by eye hospitals or by licensed ophthalmologists. The criteria for glaucoma were set by the Parliament of Finland and applied by FSII. A total of 329 patients had POAG and 176 had EG. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), cup-to-disc ratio of the optic nerve head (C/D), and glaucomatous changes of the visual fields (VF). Results As regards sex, the 2 groups were comparable: 66% female with POAG and 68% with EG. The EG patients were older (mean ± SD 74 ± 8.6 years) vs POAG (68 ± 11.4 years). The EG eyes had slightly lower BCVA. The POAG eyes had mean intraocular pressure (IOP) 24 ± 5.4 mm Hg. A total of 12% in this group had highest IOP of less than 18 mm Hg (low-tension glaucoma [LTG]) but there were none of EG. All EG eyes had a mean IOP 28.3 ± 9.3 mm Hg. Among EG patients, 26% had unilateral disease, with a mean IOP of 33.7 ± 8.7 mm Hg, while the opposite eyes had a mean of 19 ± 3 mm Hg. There was not much difference in the C/D ratios of POAG and EG eyes and the VF profiles were similar. Conclusions At diagnosis, patients with EG were older than those with POAG and had higher mean IOP values. Among patients with POAG, there were 12% with LTG, but none among EG. A total of 26% among EG had unilateral disease with marked IOP asymmetry. The C/D and VF profiles were similar because the patients had been seen early in the disease course. Early recognition and lifelong most effective therapy of EG are strongly advocated.
Effect of the Blue Filter Intraocular Lens on the Progression of Geographic Atrophy
Authors: Pipis Antonios , Touliou Eftychia , Pillunat Lutz E. , Augustin Albert J. 
Published: September 2014

Purpose To clinically evaluate the effect of blue light–filtering intraocular lenses (IOLs) on disease progression in patients with geographic atrophy (GA). Methods Clinical data from 66 eyes of 40 patients were investigated, 27 with a blue filter and 39 with a non–blue filter IOL. Spectral-domain optical coherence tomography technology and the advanced retinal pigment epithelium analysis software tool were used to measure lesion size and monitor its progression over 1 year. Results The mean and median baseline area of GA for the total sample was 5.55 ± 4.72 mm2 and 4.40 mm2, respectively. There was a statistically significant difference of the mean (p = 0.0002) and median (p<0.0001) GA progression in 1 year between the blue filter and non–blue filter IOL group (0.72 ± 0.39 SD mm2 mean and 0.70 mm2 median compared to 1.48 ± 0.88 SD mm2 and 1.30 mm2, respectively). Conclusions The clinical data strongly support a photoprotective role of blue light–filtering IOLs on the progression of the atrophic form of dry age-related macular degeneration after cataract surgery.
Cemented ABG-II Prosthesis: 5-Year Results
Authors: Krismer Martin , Nogler Michael , Huber Dennis , Oberaigner Wilhelm 
Published: September 2014

Purpose ABG II - cemented anatomic stems share their geometry and instrumentation with the uncemented version and provide a promising concept. This study compares a consecutive series of cemented ABG IIs to a pool of all other implants used during the same observation period at the institution of the authors. Methods This retrospective study is based on data from our regional hip arthroplasty register. The results of 141 cases with ABG II prosthesis were compared to those of 2,315 cases that were operated during the same period of time and reported in the regional arthroplasty registry. Survival was calculated using the Kaplan Meier method. Results The patients with cemented ABG II had a significantly worse preoperative WOMAC sum score and WOMAC domains, and similar ameliorated results as the control group at 1-year follow-up. The 5-year revision rate of the ABG II compares well to the 5-year revision rate of the controls in this study. Conclusions Revision rate and health related, quality of life, of cases with cemented ABG prosthesis are similar to those of a register based control group.
Preserving Arteriovenous Fistula Outcomes during Surgical Training
Authors: McGrogan Damian G. , Maxwell Alexander P. , Inston Nicholas G. , Krishnan Hari , Field Mel 
Published: September 2014

Purpose Arteriovenous fistulae (AVFs) are the preferred option for vascular access, as they are associated with lower mortality in hemodialysis patients than in those patients with arteriovenous grafts (AVGs) or central venous catheters (CVCs). We sought to assess whether vascular access outcomes for surgical trainees are comparable to fully trained surgeons. Methods A prospectively collected database of patients was created and information recorded regarding patient demographics, past medical history, preoperative investigations, grade of operating surgeon, type of AVF formed, primary AVF function, cumulative AVF survival and functional patency. Results One hundred and sixty-two patients were identified as having had vascular access procedures during the 6 month study period and 143 were included in the final analysis. Secondary AVF patency was established in 123 (86%) of these AVFs and 89 (62.2%) were used for dialysis. There was no significant difference in survival of AVFs according to training status of surgeon (log rank x2 0.506 p=0.477) or type of AVF (log rank x2 0.341 p=0.559). Patency rates of successful AVFs at 1 and 2 years were 60.9% and 47.9%, respectively. Conclusion We have demonstrated in this prospective study that there are no significant differences in outcomes of primary AVFs formed by fully trained surgeons versus surgical trainees. Creation of a primary AVF represents an excellent training platform for intermediate stage surgeons across general and vascular surgical specialties.
A Prospective, Randomized Comparison of three different types of Valved and Non-Valved Peripherally inserted Central Catheters
Authors: Pittiruti Mauro , Emoli Alessandro , Porta Patrizia , Marche Bruno , DeAngelis Rosa , Scoppettuolo Giancarlo 
Published: September 2014

Purpose Few randomized studies have investigated the impact of valved and non-valved power-injectable peripherally inserted central catheters (PICCs) in terms of incidence of occlusion, infection, malfunction and venous thrombosis. Methods We have prospectively compared three types of third-generation polyurethane PICCs. One hundred and eighty adult patients candidate to chemotherapy were randomized into three groups: power-injectable PICCs with Solo-2 proximal valve (Bard); power-injectable PICCs with PASV (Pressure Activated Safety Valve) proximal valve (Navilyst); and non-valved power-injectable PICCs (Medcomp). All PICCs were single lumen 4Fr, inserted according to a well-defined protocol - maximal barrier precautions, ultrasound guidance, intracavitary electrocardiography (IC-ECG), and so on - and managed according to the recommendations of the most recent guidelines (antisepsis with 2% chlorhexidine, transparent dressing, sutureless device, strict ‘scrub the hub’ policy, neutral displacement needle-free connectors and so on). All catheters were flushed with 10 ml saline before and after each infusion, or with 20 ml saline after blood sampling or infusion of blood products. No heparin was used. Results We detected no complications at insertion; no PICC-related bloodstream infections; no dislocations; five cases of transient occlusion and two cases of persistent withdrawal occlusion, evenly distributed among the groups; one episode of complete irreversible obstruction (group A); four episodes of asymptomatic peripheral venous thrombosis; one episode of symptomatic, severe central vein thrombosis (group B). In 31% of PICCs in group A (19/61) and in 65% of group B (39/60), difficulties with gravity infusion were reported; three PICCs of group A were complicated by rupture of the intravascular tract during pump infusion. Five PICCs were removed because of complications, four in group A (one obstruction; three ruptures) and one in group B (central venous thrombosis). Conclusion We found no clinical advantages of valved vs. non-valved PICCs.
The Intracavitary ECG Method for Positioning the Tip of Central Venous access Devices in Pediatric Patients: Results of an Italian Multicenter Study
Authors: Rossetti Francesca , Pittiruti Mauro , Lamperti Massimo , Graziano Ugo , Celentano Davide , Capozzoli Giuseppe 
Published: September 2014

Purpose The Italian Group for Venous Access Devices (GAVeCeLT) has carried out a multicenter study investigating the safety and accuracy of intracavitary electrocardiography (IC-ECG) in pediatric patients. Methods We enrolled 309 patients (age 1 month-18 years) candidate to different central venous access devices ( VAD) - 56 peripherally inserted central catheters (PICC), 178 short term centrally inserted central catheters (CICC), 65 long term VADs, 10 VADs for dialysis - in five Italian Hospitals. Three age groups were considered: A (<4 years, n = 157), B (4-11 years, n = 119), and C (12-18 years, n = 31). IC-ECG was applicable in 307 cases. The increase of the P wave on IC-ECG was detected in all cases but two. The tip of the catheter was positioned at the cavo-atrial junction (CAJ) (i.e., at the maximal height of the P wave on IC-ECG) and the position was checked during the procedure by fluoroscopy or chest x-ray, considering the CAJ at 1-2 cm (group A), 1.5-3 cm (group B), or 2-4 cm (group C) below the carina. Results There were no complications related to IC-ECG. The overall match between IC-ECG and x-ray was 95.8% (96.2% in group A, 95% in group B, and 96.8% in group C). In 95 cases, the IC-ECG was performed with a dedicated ECG monitor, specifically designed for IC-ECG (Nautilus, Romedex): in this group, the match between IC-ECG and x-ray was 98.8%. Conclusions We conclude that the IC-ECG method is safe and accurate in the pediatric patients. The applicability of the method is 99.4% and its feasibility is 99.4%. The accuracy is 95.8% and even higher (98.8%) when using a dedicated ECG monitor.
Association between Multiple IV attempts and Perceived Pain levels in the Emergency Department
Authors: Fields J. Matthew , Piela Nicole E. , Ku Bon S. 
Published: September 2014

Purpose Intravenous (IV) access is the most commonly performed procedure in the emergency department (ED). Patients with difficult venous access require multiple needlesticks (MNS) for successful IV cannulation and may experience increased pain with many attempts. Objective To determine the association between number of IV attempts and overall pain experienced by the patient from IV placement. Methods Cross-sectional observational study on consecutive patients undergoing IV placement with a 20-gauge IV in the upper extremity in an urban academic hospital. Exclusion criteria included refusal to participate or fully complete all survey questions. The total number of IV attempts and patient pain scores marked on a standardized visual analog scale was recorded. Mean pain scores of two groups, single needlestick (SNS) and MNS, were compared using Student's t-test. Results A total of 760 patients were approached, of whom 31 were excluded, leaving 729 patients in the analysis; 556 with SNS (76%) and 173 with MNS (24%). The mean pain score (95% CI) was 51 mm (46–55 mm) for the MNS group and 25 mm (23–28 mm) for the SNS group, p<0.001. Compared to patients who underwent one IV attempt, patients with two and three attempts had an average 19 mm and 33 mm increase in pain scores, respectively, with the highest average pain associated with five attempts. A total of 58% of MNS patients rated IV placement as the most painful experience while in the ED. Conclusions Patients experience increased pain in association with multiple IV attempts.
Novel Modular Anastomotic Valve Device for Hemodialysis Vascular Access: Preliminary Computational Hemodynamic Assessment
Authors: McNally Andrew , Akingba A. George , Robinson Eric A. , Sucosky Philippe 
Published: September 2014

Purpose Arteriovenous graft patency is limited by terminal occlusion caused by intimal hyperplasia (IH). Motivated by evidence that flow disturbances promote IH progression, a modular anastomotic valve device (MAVD) was designed to isolate the graft from the circulation between dialysis periods (closed position) and enable vascular access during dialysis (open position). The objective of this study was to perform a preliminary computational assessment of the device ability to normalize venous flow between dialysis periods and potentially limit IH development and thrombogenesis. Methods Computational fluid dynamics simulations were performed to compare flow and wall shear stress (WSS) in a native vein and MAVD prototypes featuring anastomotic angles of 90° and 30°. Low WSS (LWSS) regions prone to IH development were characterized in terms of temporal shear magnitude (TSM), oscillatory shear index (OSI), and relative residence time (RRT). Thrombogenic potential was assessed by investigating the loading history of fluid particles traveling through the device. Results The closed MAVD exhibited the same flow characteristics as the native vein (0.3% difference in pressure drop, 3.5% difference in surface-averaged WSS). The open MAVD generated five LWSS regions (TSM <0.5 Pa) exhibiting different degrees of flow reversal (surface-averaged OSI: 0.03–0.36) and stagnation (max RRT: 2.50–37.16). Reduction in anastomotic angle resulted in the suppression of three LWSS regions and overall reductions in flow reversal (surface-averaged OSI <0.21) and stagnation (max RRT <18.05). Conclusions This study suggests the ability of the MAVD to normalize venous flow between dialysis periods while generating the typical hemodynamics of end-to-side vein-graft anastomoses during dialysis.
Mechanical Properties of Seldinger Guidewires
Authors: Schummer Wolfram , Trommer Sabine , Kleemann Frieder , Schummer Claudia 
Published: September 2014

Background Almost all central venous catheters are placed using the Seldinger technique. Despite the introduction of ISO 11070 in 1998, we continue to see mechanical wire failures and their associated complications. Methods Seven different wire types were tested regarding their tensile strength and eight different types for their flexing performance. For each wire type six wires were assessed. Tensile strength was examined using the test method described in ISO 11070, but the test did not end at 10 N. For flexing performance testing a new apparatus, closely mimicking clinical requirements, was designed. Wires were scanned digitally after testing for measurement and analysis. Results All wire types tested, except one, consistently met ISO 11070 requirements for 10 N tensile strength. The maximum tension the wires were able to withstand ranged from 15.06 N to 257.76 N. None of the wires kinked. The monofil wires had no evidence of bending. Two core and coil wires displayed minor bending (angle 1.5°). All other wires displayed bending angles between 22.5° and 43.0°. The degree of bending was also dependent on the angle between the dilator and wire. Conclusion The mechanical properties of different types of guidewires show considerable differences, not detected with current ISO 11070 based testing. Uncovering those may allow set up of clinical trials to examine whether regular use of wires with high-end mechanical properties could reduce CVC insertion-related complication rates.
External Jugular Vein Approach for TIVAD Implantation: First Choice or Only an Alternative? A Review of the Literature
Authors: Iorio Olga , Cavallaro Giuseppe 
Published: September 2014

Purpose Totally implantable venous access devices (TIVADs) can be implanted by percutaneous approach (to the subclavian or internal jugular vein) or by surgical approach, through cephalic vein or external jugular vein (EJV). The authors present a review of the literature about EJV approach for TIVAD implantation. Methods A review of articles indexed in MEDLINE (PubMed) and Cochrane Central Register on “EJV access,” “EJV cut-down,” and “TIVADs” was performed, even matching the terms. We gathered articles from papers quoting patient number, specialist involved, number of devices implanted, site and technique of implantation and complications. Results A total of 1,308 TIVAD implantations through EJV have been reported, with a success rate ranging from 73.7% to 100% and a complication rate up to 13%. Only in 4 on 10 series reported (with more than 15 procedures) the EJV approach was the first choice, while in the other 6 series this approach was the alternative after failure of other approaches. Conclusions Despite the lack of consistent series and prospective studies comparing EJV with other approaches, data present in the literature may support the evidence that EJV approach for TIVAD implantation is safe and effective, and may be considered as the first approach in selected patients.
Transjugular Tunnelled Dialysis Catheter Tip Placement into the Inferior Vena Cava Upper Segment after Length Overestimation
Authors: Renaud Claude J. , Seow Ying Ying , Teh Hui Siong 
Published: September 2014

Purpose The right atrium is preferred over the superior vena cava (SVC) for tunnelled dialysis catheter (TDC) tip placement as it offers the best compromise between optimal catheter performance and complications. However, clinical practice guidelines are not all unanimous on this as a universal recommendation. Right atrial tip placement may also fail due to variations in body surface area, venous anatomy or TDC designs and lengths. Moreover, the presence of recurrent long intra-cardiac fibrin sheath or cardiac rhythm management device leads serves as contraindications. Extra-cardiac tip placement in the azygous, hepatic veins and lower segment of the inferior vena cava (IVC) is an alternative but is invariably associated with poor blood flow and shortened patency. Methods We report the concept of extra-cardiac tip placement into the larger calibre hepatic segment IVC via a transjugular approach in two diabetic haemodialysis patients with overestimated TDC length out of 380 insertions. Results Blood flow was maintained above 250 ml/min for 5-6 months and no tip migration ensued. Conclusions The IVC upper segment is a reliable site for extra-cardiac tip placement in select cases but its safety and efficacy need to be further studied in larger clinical trials.