The persistence of precious metals and oil during the COVID-19 pandemic: evidence from a fractional integration and cointegration approach.

In this paper, the behavior of precious metals and oil is examined using a fractionally integrated and cointegrated modeling approach. Using daily data from January 2015 to December 2020 and using both endogenous and exogenous structural breaks, we examine the behavior of the related series before and during the COVID-19 pandemic with the aim of investigating whether the degree of persistence has changed since the onset of COVID-19. We found that precious metals and oil exhibit long memory and are mean reverting regardless of the sample considered as the fractional parameter d < 0.5. However, when structural breaks are taken into consideration, an increase in persistence is found during the COVID-19 as compared to the period before it. In addition, the fractionally cointegrated vector autoregressive (FCVAR) model of Johansen and Nielsen (2010, 2012) is used to examine the existence of long-run relationship among precious metals and oil price. We find the integrated parameters at d < 0.5 for all samples except for the pre-COVID-19 sample. This highlights that the FCVAR is a better fit for the full sample and the COVID-19 and the COVID-19 pandemic period sub-samples, as the fractional parameter is d < 0.5 while the CVAR model is better fit for the pre-COVID-19 period where d> 0.5. Both cointegration techniques alongside the parameter stability tests lend support to the existence of a persistence and stable long-run relationships among the series irrespective of the sample period considered. Attendant policy recommendations for investors and policymakers are recommended.

Shifting networks and mixing metals: Changing metal trade routes to Scandinavia correlate with Neolithic and Bronze Age transformations.

Based on 550 metal analyses, this study sheds decisive light on how the Nordic Bronze Age was founded on metal imports from shifting ore sources associated with altered trade routes. On-and-off presence of copper characterised the Neolithic. At 2100-2000 BC, a continuous rise in the flow of metals to southern Scandinavia begins. First to arrive via the central German Únetician hubs was high-impurity metal from the Austrian Inn Valley and Slovakia; this was complemented by high-tin British metal, enabling early local production of tin bronzes. Increased metal use locally fuelled the leadership competitions visible in the metal-led material culture. The Únetice downfall c.1600 BC resulted for a short period in a raw materials shortage, visible in the reuse of existing stocks, but stimulated direct Nordic access to the Carpathian basin. This new access expedited innovations in metalwork with reliance on chalcopyrite from Slovakia, as well as opening new sources in the eastern Alps, along an eastern route that also conveyed Baltic amber as far as the Aegean. British metal plays a central role during this period. Finally, from c.1500 BC, when British copper imports ceased, the predominance of novel northern Italian copper coincides with the full establishment of the NBA and highlights a western route, connecting the NBA with the southern German Tumulus culture and the first transalpine amber traffic.

Dynamic Advisor-Based Ensemble (dynABE): Case study in stock trend prediction of critical metal companies.

Stock trend prediction is a challenging task due to the market's noise, and machine learning techniques have recently been successful in coping with this challenge. In this research, we create a novel framework for stock prediction, Dynamic Advisor-Based Ensemble (dynABE). dynABE explores domain-specific areas based on the companies of interest, diversifies the feature set by creating different "advisors" that each handles a different area, follows an effective model ensemble procedure for each advisor, and combines the advisors together in a second-level ensemble through an online update strategy we developed. dynABE is able to adapt to price pattern changes of the market during the active trading period robustly, without needing to retrain the entire model. We test dynABE on three cobalt-related companies, and it achieves the best-case misclassification error of 31.12% and an annualized absolute return of 359.55% with zero maximum drawdown. dynABE also consistently outperforms the baseline models of support vector machine, neural network, and random forest in all case studies.

Comparison of the Cost of Drug-Eluting Stents versus Bare Metal Stents in the Treatment of Critical Limb Ischemia in the United States.

BACKGROUND: Despite significant technical advancement in the last decade, the durability of endovascular management of critical limb ischemia (CLI) remains highly debatable. Drug-eluting stents (DESs) are being popularized for the management of CLI after its precedent success in coronary intervention. Initial reports on the durability of DES are promising. However, little is known on the additional cost of this relatively newer technology. The aim of this study is to compare the cost of the traditional bare metal stents (BMSs) to the newly introduced DES in a large cohort of CLI patients. METHODS: Using the Premier database (2009-2015), we identified all patients with CLI undergoing DES and BMS. A multivariable generalized linear model was implemented to examine in-hospital cost adjusting for patients' characteristics, comorbidities, and regional characteristics. RESULTS: A total of 20,702 patients with CLI underwent peripheral artery revascularization using BMS (18,924 [91.41%]) or DES (1,778 [8.6%]). Majority of patients were males (53%) and whites (71%). Patients undergoing BMS were slightly younger (median age [interquartile range]: 70 [62-79] versus 71 [63-80]) and were more likely to be smokers (46% vs. 39%) and have a history of cerebrovascular disease (10% vs. 8%) and chronic pulmonary disease (24.5% vs. 20.9%) as compared with those undergoing DES (all P < 0.05). On the other hand, DES patients had a high prevalence of diabetes (4% vs. 3%) and renal disease (25% vs. 22%) (both P < 0.05). There was also a significant increase in the proportion of patients undergoing DES and a corresponding decrease in BMS (P < 0.001) over the study period. Median total in-hospitalization cost (BMS: $13,342 [8,574 to 21,166], DES: $13,243 [8,560-20,232], P = 0.76) was similar for both approaches. After adjusting for potential confounders, DES was associated with $407 higher cost than BMS (adjusted mean difference [95% confidence interval]: 407 [17 to 798], P = 0.04). In addition, the cost was $672 higher in teaching hospitals, $1,153 higher in Rural areas, and increased in all regions compared with the Midwest (adjusted mean difference [95% confidence interval]-South: $293 [31 to 555], Northeast: $2,006 [1,517 to 2,495], West: $3,312 [2,930 to 3,695], all P < 0.05). CONCLUSIONS: In this large cohort of CLI patients, after controlling for potential confounders, we demonstrated that the cost of endovascular revascularization is significantly higher in patients undergoing DES than those undergoing BMS. Regional disparities in cost were also observed. Further studies looking at the long-term durability and costs of DES versus BMS are needed.

Randomized pilot study to compare metal needles versus plastic cannulae in the development of complications in hemodialysis access.

BACKGROUND: Hemodialysis requires needle insertions every treatment. Needle injury (mechanical or hemodynamic) may cause complications (aneurysms/stenosis) that compromise dialysis delivery requiring interventions. Metal needles have a sharp slanted "V"-shaped cutting tip; plastic cannulae have a dull round tip and four side holes. Preliminary observations demonstrated a difference in intradialytic blood flow images and mean Doppler velocities at cannulation sites between the two devices. Complications from mechanical and hemodynamic trauma requiring interventions were compared in each group. MATERIALS AND METHODS: In all, 33 patients (13 females and 17 new accesses) were randomized to metal group (n = 17) and plastic group (n = 16). Mechanical trauma was minimized by having five nurses performing ultrasound-guided cannulations. Complications were identified by the clinician and addressed by the interventionalists, both blinded to study participation. Patients were followed for up to 12 months. RESULTS: Baseline characteristics were not significant. Procedures to treat complications along cannulation segments increased from 0.41 to 1.29 per patient (metal group) and decreased from 1.25 to 0.69 per patient (plastic group; p = 0.004). The relative risks of having an intervention (relative risk = 1.5, 95% confidence interval = 0.88-2.67) and having an infiltration during hemodialysis (relative risk = 2.26, 95% confidence interval = 1.03-4.97) were higher for metal needles. Time to first intervention trended in favor of plastic cannula (p = 0.069). Cost of supplies for these interventions was approximately CAD$20,000 lower for the plastic group. CONCLUSION: Decreased burden of illness related to cannulation (less infiltrations during hemodialysis) and Qb were associated with plastic cannulae. Decreased procedure costs were suggested during the study period in the plastic group.

Comparison of Metal and Plastic Disposable Laryngoscope Blade with Reusable Macintosh Blade in Difficult and Inhalation Injury Airway Scenario: A Manikin Study.

BACKGROUND: Single-use plastic blades (SUPB) and single-use metal blades (SUMB) for direct laryngoscopy and tracheal intubation have not yet been compared with reusable metal blades (RUMB) in difficult airway scenarios. OBJECTIVE: The purpose of our manikin study was to compare the effectiveness of these different laryngoscope blades in a difficult airway scenario, as well as in a difficult airway scenario with simulated severe inhalation injury. METHODS: Thirty anesthetists performed tracheal intubation (TI) with each of the three laryngoscope blades in the two scenario manikins. RESULTS: In the inhalation injury scenario, SUPB were associated with prolonged intubation times when compared with the metal blades. In the inhalation injury scenario, both metal laryngoscope blades provided a quicker, easier, and safer TI. In the difficult airway scenario, intubation times were significantly prolonged in the SUPB group in comparison to the RUMB group, but there were no significant differences between the SUPB and the SUMB. In this scenario, the RUMB demonstrated the shortest intubation times and seems to be the most effective device. CONCLUSIONS: Generally, results are in line with previous studies showing significant disadvantages of SUPB in both manikin scenarios. Therefore, metal blades might be beneficial, especially in the airway management of patients with inhalation injury.

Impact of stent diameter and length on in-stent restenosis after DES vs BMS implantation in patients needing large coronary stents-A clinical and health-economic evaluation.

AIMS: The British National Institute of Clinical Excellence (NICE) guidelines recommend to use drug-eluting stents (DES) instead of bare-metal stents (BMS) only in lesions >15 mm in length or in vessels <3 mm in diameter. We analyzed the impact of stent length and stent diameter on in-stent restenosis (ISR) in the BASKET-PROVE study population and evaluated the cost-effectiveness of DES compared to BMS. METHODS/RESULTS: The BASKET-PROVE trial compared DES vs BMS in large coronary arteries (≥3 mm). We calculated incremental cost-effectiveness ratios (ICERs) and cost-effectiveness acceptability curves with regard to quality-adjusted life years (QALYs) gained and target lesion revascularizations (TLRs) avoided. A total of 2278 patients were included in the analysis. A total of 74 ISR in 63 patients were observed. In-stent restenosis was significantly more frequent in segments treated with a BMS compared to segments treated with a DES (5.4% vs 0.76%; P<.001). The benefit of a DES compared to a BMS regarding ISR was consistent among the subgroups of stent length >15 mm and ≤15 mm, respectively. With the use of DES in short lesions, there was only a minimal gain of 0.005 in QALYs. At a threshold of 10 000 CHF per TLR avoided, DES had a high probability of being cost-effective. CONCLUSION: In the BASKET-PROVE study population, the strongest predictor of ISR is the use of a BMS, even in patients in need of stents ≥3.0 mm and ≤15 mm lesion length and DES were cost-effective. This should prompt the NICE to reevaluate its recommendation to use DES instead of BMS only in vessels <3.0 mm and lesions >15 mm length.

Comparison of patency and cost-effectiveness of self-expandable metal and plastic stents used for malignant biliary strictures: a Polish single-center study.

INTRODUCTION: Most patients with malignant biliary obstruction are suited only for palliation by endoscopic drainage with plastic stents (PS) or self-expandable metal stents (SEMS). OBJECTIVE: To compare the clinical outcome and costs of biliary stenting with SEMS and PS in patients with malignant biliary strictures. PATIENTS AND METHODS: A total of 114 patients with malignant jaundice who underwent 376 endoscopic retrograde biliary drainage (ERBD) were studied. RESULTS: ERBD with the placement of PS was performed in 80 patients, with one-step SEMS in 20 patients and two-step SEMS in 14 patients. Significantly fewer ERBD interventions were performed in patients with one-step SEMS than PS or the two-step SEMS technique (2.0±1.12 vs. 3.1±1.7 or 5.7±2.1, respectively, P<0.0001). The median hospitalization duration per procedure was similar for the three groups of patients. The patients' survival time was the longest in the two-step SEMS group in comparison with the one-step SEMS and PS groups (596±270 vs. 276±141 or 208±219 days, P<0.001). Overall median time to recurrent biliary obstruction was 89.3±159 days for PS and 120.6±101 days for SEMS (P=0.01). The total cost of hospitalization with ERBD was higher for two-step SEMS than for one-step SEMS or PS (1448±312, 1152±135 and 977±156&OV0556;, P<0.0001). However, the estimated annual cost of medical care for one-step SEMS was higher than that for the two-step SEMS or PS groups (4618, 4079, and 3995&OV0556;, respectively). CONCLUSION: Biliary decompression by SEMS is associated with longer patency and reduced number of auxiliary procedures; however, repeated PS insertions still remain the most cost-effective strategy.

Economics of All-Polyethylene Versus Metal-Backed Tibial Prosthesis Designs.

With the large number of total knee arthroplasties being performed and expectations that these numbers will be on the rise over the coming decades, efforts to provide cost-efficient care are of greater interest. The preferred design of knee arthroplasty implants has changed over time, with the original all-polyethylene tibial (APT) design being replaced by metal-backed tibial (MBT) components, as well as more recent considerations of newer APT designs. Modern APT components have been shown to have similar or superior outcomes than MBT components. Despite their limitations, APT components can be used to reduce the economic burden to the provider, medical institution, and health care system as a whole. There is a paucity of evidence-based literature directly comparing the cost associated with APT and MBT components. The purpose of this report is to review the literature to assess the available data regarding direct and indirect costs of both designs so that orthopedic surgeons can account for economic differences in everyday practice. [Orthopedics. 2016; 39(3):S61-S66.].

Cost-effectiveness and clinical efficacy of biliary stents in patients undergoing neoadjuvant therapy for pancreatic adenocarcinoma in a randomized controlled trial.

BACKGROUND AND AIMS: The optimal type of stent for the palliation of malignant biliary obstruction in patients with pancreatic adenocarcinoma undergoing neoadjuvant chemoradiotherapy with curative intent is unknown. We performed a prospective trial comparing 3 types of biliary stents-fully covered self-expandable metal (fcSEMS), uncovered self-expandable metal (uSEMS), and plastic-to determine which best optimized cost-effectiveness and important clinical outcomes. METHODS: In this prospective randomized trial, consecutive patients with malignant biliary obstruction from newly diagnosed pancreatic adenocarcinoma who were to start neoadjuvant chemoradiotherapy were randomized to receive fcSEMSs, uSEMSs, or plastic stents during the index ERCP. The primary outcomes were time to stent occlusion, attempted surgical resection, or death after the initiation of neoadjuvant therapy, and the secondary outcomes were total patient costs associated with the stent, including the index ERCP cost, downstream hospitalization cost due to stent occlusion, and the cost associated with procedural adverse event. RESULTS: Fifty-four patients were randomized and reached the primary end point: 16 in the fcSEMS group, 17 in the uSEMS group, and 21 in the plastic stent group. No baseline demographic or tumor characteristic differences were noted among the groups. The fcSEMSs had a longer time to stent occlusion compared with uSEMSs and plastic stents (220 vs 74 and 76 days, P < .01), although the groups had equivalent rates of stent occlusion, attempted surgical resection, and death. Although SEMS placement cost more during the index ERCP (uSEMS = $24,874 and fcSEMS = $22,729 vs plastic = $18,701; P < .01), they resulted in higher procedural AE costs per patient (uSEMS = $5522 and fcSEMS = $12,701 vs plastic = $0; P < .01). Conversely, plastic stents resulted in an $11,458 hospitalization cost per patient due to stent occlusion compared with $2301 for uSEMSs and $0 for fcSEMSs (P < .01). CONCLUSIONS: In a prospective trial comparing fcSEMSs, uSEMSs, and plastic stents for malignant biliary obstruction in patients undergoing neoadjuvant therapy with curative intent for pancreatic adenocarcinoma, no stent type was superior in optimizing cost-effectiveness, although fcSEMSs resulted in fewer days of neoadjuvant treatment delay and a longer time to stent occlusion. (Clincial trial registration number: NCT01038713.).

Finite element modelling approaches for well-ordered porous metallic materials for orthopaedic applications: cost effectiveness and geometrical considerations.

The mechanical properties of well-ordered porous materials are related to their geometrical parameters at the mesoscale. Finite element (FE) analysis is a powerful tool to design well-ordered porous materials by analysing the mechanical behaviour. However, FE models are often computationally expensive. This article aims to develop a cost-effective FE model to simulate well-ordered porous metallic materials for orthopaedic applications. Solid and beam FE modelling approaches are compared, using finite size and infinite media models considering cubic unit cell geometry. The model is then applied to compare two unit cell geometries: cubic and diamond. Models having finite size provide similar results than the infinite media model approach for large sample sizes. In addition, these finite size models also capture the influence of the boundary conditions on the mechanical response for small sample sizes. The beam FE modelling approach showed little computational cost and similar results to the solid FE modelling approach. Diamond unit cell geometry appeared to be more suitable for orthopaedic applications than the cubic unit cell geometry.

The effect of metal density in thoracic adolescent idiopathic scoliosis.

PURPOSE: Determine impact of metal density on curve correction and costs in thoracic adolescent idiopathic scoliosis (AIS). Ascertain if increased metal density is required for larger or stiffer curves. METHODS: Multicentre retrospective case series of patients with Lenke 1-2 AIS treated with single-stage posterior only surgery using a standardized surgical technique; constructs using >80 % screws with variable metal density. All cases had >2-year follow up. Outcomes measures included coronal and sagittal radiographic outcomes, metal density (number of instrumented pedicles vs total available), fusion length and cost. RESULTS: 106 cases included 94 female. 78 Lenke 1. Mean age 14 years (9-26). Mean main thoracic (MT) Cobb angle 63° corrected to 22° (66 %). No significant correlations were present between metal density and: (a) coronal curve correction rates of the MT (r = 0.13, p = 0.19); (b) lumbar curve frontal correction (r = -0.15, p = 0.12); (c) correction index in MT curve (r = -0.10, p = 0.32); and (d) correction index in lumbar curve (r = 0.11, p = 0.28). Metal density was not correlated with change in thoracic kyphosis (r = 0.22, p = 0.04) or lumbosacral lordosis (r = 0.27, p = 0.01). Longer fusions were associated with greater loss of thoracic kyphosis (r = -0.31, p = 0.003). Groups differing by preoperative curve size and stiffness had comparable corrections with similar metal density. The pedicle screw cost represented 21-29 % of overall cost of inpatient treatment depending on metal density. CONCLUSIONS: Metal density affects cost but not the coronal and sagittal correction of thoracic AIS. Neither larger nor stiffer curves necessitate high metal density.

Annual cost of stable coronary artery disease in France: A modeling study.

BACKGROUND: Few studies have analyzed the cost of treatment of chronic angina pectoris, especially in European countries. AIM: To determine, using a modeling approach, the cost of care in 2012 for 1year of treatment of patients with stable angina, according to four therapeutic options: optimal medical therapy (OMT); percutaneous coronary intervention with bare-metal stent (PCI-BMS); PCI with drug-eluting stent (PCI-DES); and coronary artery bypass graft (CABG). METHODS: Six different clinical scenarios that could occur over 1year were defined: clinical success; recurrence of symptoms without hospitalization; myocardial infarction (MI); subsequent revascularization; death from non-cardiac cause; and cardiac death. The probability of a patient being in one of the six clinical scenarios, according to the therapeutic options used, was determined from a literature search. A direct medical cost for each of the therapeutic options was calculated from the perspective of French statutory health insurance. RESULTS: The annual costs per patient for each strategy, according to their efficacy results, were, in our models, €1567 with OMT, €5908 with PCI-BMS, €6623 with PCI-DES and €16,612 with CABG. These costs were significantly different (P<0.05). A part of these costs was related to management of complications (recurrence of symptoms, MI and death) during the year (between 3% and 38% depending on the therapeutic options studied); this part of the expenditure was lowest with the CABG therapeutic option. CONCLUSION: OMT appears to be the least costly option, and, if reasonable from a clinical point of view, might achieve appreciable savings in health expenditure.

Landfill mining: Case study of a successful metals recovery project.

Worldwide, the generation of municipal solid waste (MSW) is increasing and landfills continue to be the dominant method for managing solid waste. Because of inadequate diversion of reusable and recoverable materials, MSW landfills continue to receive significant quantities of recyclable materials, especially metals. The economic value of landfilled metals is significant, fostering interest worldwide in recovering the landfilled metals through mining. However, economically viable landfill mining for metals has been elusive due to multiple barriers including technological challenges and high costs of processing waste. The objective of this article is to present a case study of an economically successful landfill mining operation specifically to recover metals. The mining operation was at an ashfill, which serves a MSW waste-to-energy facility. Landfill mining operations began in November 2011. Between December 2011 and March 2015, 34,352 Mt of ferrous and non-ferrous metals were recovered and shipped for recycling, which consisted of metals >125 mm (5.2%), 50-125 mm (85.9%), <50mm (3.4%), zorba (4.6%), and mixed products (0.8%). The conservative estimated value of the recovered metal was $7.42 million. Mining also increased the landfill's airspace by 10,194 m(3) extending the life of the ashfill with an estimated economic value of $267,000. The estimated per-Mt cost for the extraction of metal was $158. This case study demonstrates that ashfills can be profitably mined for metals without financial support from government. Although there are comparatively few ashfills, the results and experience obtained from this case study can help foster further research into the potential recovery of metals from raw, landfilled MSW.

An inexpensive replacement for dry ice in the laboratory.

A reusable inexpensive replacement for dry ice in laboratory use is presented. Commercially available small pellets of stone or metal can be stored in a -80 °C freezer and used for quickly freezing small samples with a freezing rate that is actually somewhat faster than with dry ice itself. Following use, the material is returned to the freezer to re-chill until the next usage.

Endoscopic ultrasound-guided placement of plastic vs. biflanged metal stents for therapy of walled-off necrosis: a retrospective single-center series.

BACKGROUND AND STUDY AIMS: Recently, a novel fully covered and biflanged metal stent (BFMS)dedicated to the drainage of walled-off necrosis(WON) was developed. The aim of this study was to retrospectively evaluate the safety, efficacy, and cost performance of drainage of WON using the novel BFMS compared with a traditional plastic stent. PATIENTS AND METHODS: A total of 70 patients with symptomatic WON were treated under endoscopic ultrasound (EUS) guidance. Initial drainage was conducted using the single gateway technique with placement of one or more plastic stents or a single BFMS.If drainage was unsuccessful,direct endoscopic necrosectomy (DEN)was performed. RESULTS: There were no statistically significant differences in rates of technical success, clinical success,and adverse events between plastics stents and BFMS, despite the size of WON in the BFMS group being significantly larger than that in the plastic stent group (105.6 vs. 77.1 mm; P=0.003).The mean procedure times for the first EUS-guided drainage and for re-intervention were significantly shorter in the BFMS group than in the plastic stent group (28.8±7.1 vs. 42.6±14.2, respectively,for drainage, P<0.001; and 34.9±8.5 vs.41.8±7.6, respectively, for re-intervention, P<0.001). There was no statistically significant difference in the total cost between plastic stent and BFMS use in the treatment of WON ($5352vs. $6274; P=0.25). CONCLUSIONS: Plastic stents and BFMS were safe and effective for the treatment of WON. In particular,BFMS placement appeared to be preferable for initial EUS-guided drainage and additional reintervention(e.g. DEN) as it reduced the procedure time. Prospective randomized controlled trials are warranted.

Palliative radiotherapy in addition to self-expanding metal stent for improving dysphagia and survival in advanced oesophageal cancer (ROCS: Radiotherapy after Oesophageal Cancer Stenting): study protocol for a randomized controlled trial.

BACKGROUND: The single most distressing symptom for patients with advanced esophageal cancer is dysphagia. Amongst the more effective treatments for relief of dysphagia is insertion of a self-expanding metal stent (SEMS). It is possible that the addition of a palliative dose of external beam radiotherapy may prolong the relief of dysphagia and provide additional survival benefit. The ROCS trial will assess the effect of adding palliative radiotherapy after esophageal stent insertion. METHODS/DESIGN: The study is a randomized multicenter phase III trial, with an internal pilot phase, comparing stent alone versus stent plus palliative radiotherapy in patients with incurable esophageal cancer. Eligible participants are those with advanced esophageal cancer who are in need of stent insertion for primary management of dysphagia. Radiotherapy will be administered as 20 Gray (Gy) in five fractions over one week or 30 Gy in 10 fractions over two weeks, within four weeks of stent insertion. The internal pilot will assess rates and methods of recruitment; pre-agreed criteria will determine progression to the main trial. In total, 496 patients will be randomized in a 1:1 ratio with follow up until death. The primary outcome is time to progression of patient-reported dysphagia. Secondary outcomes include survival, toxicity, health resource utilization, and quality of life. An embedded qualitative study will explore the feasibility of patient recruitment by examining patients' motivations for involvement and their experiences of consent and recruitment, including reasons for not consenting. It will also explore patients' experiences of each trial arm. DISCUSSION: The ROCS study will be a challenging trial studying palliation in patients with a poor prognosis. The internal pilot design will optimize methods for recruitment and data collection to ensure that the main trial is completed on time. As a pragmatic trial, study strengths include collection of all follow-up data in the usual place of care, and a focus on patient-reported, rather than disease-orientated, outcomes. Exploration of patient experience and health economic analyses will be integral to the assessment of benefit for patients and the NHS. TRIAL REGISTRATION: The trial was registered with Current Controlled Trials (registration number: ISRCTN12376468) on 10 July 2012.

Recovering valuable metals from recycled photovoltaic modules.

Recovering valuable metals such as Si, Ag, Cu, and Al has become a pressing issue as end-of-life photovoltaic modules need to be recycled in the near future to meet legislative requirements in most countries. Of major interest is the recovery and recycling of high-purity silicon (> 99.9%) for the production of wafers and semiconductors. The value of Si in crystalline-type photovoltaic modules is estimated to be -$95/kW at the 2012 metal price. At the current installed capacity of 30 GW/yr, the metal value in the PV modules represents valuable resources that should be recovered in the future. The recycling of end-of-life photovoltaic modules would supply > 88,000 and 207,000 tpa Si by 2040 and 2050, respectively. This represents more than 50% of the required Si for module fabrication. Experimental testwork on crystalline Si modules could recover a > 99.98%-grade Si product by HNO3/NaOH leaching to remove Al, Ag, and Ti and other metal ions from the doped Si. A further pyrometallurgical smelting at 1520 degrees C using CaO-CaF2-SiO2 slag mixture to scavenge the residual metals after acid leaching could finally produce > 99.998%-grade Si. A process based on HNO3/NaOH leaching and subsequent smelting is proposed for recycling Si from rejected or recycled photovoltaic modules. Implications: The photovoltaic industry is considering options of recycling PV modules to recover metals such as Si, Ag, Cu, Al, and others used in the manufacturing of the PV cells. This is to retain its "green" image and to comply with current legislations in several countries. An evaluation of potential resources made available from PV wastes and the technologies used for processing these materials is therefore of significant importance to the industry. Of interest are the costs of processing and the potential revenues gained from recycling, which should determine the viability of economic recycling of PV modules in the future.