Prospective Life-Cycle Modeling of Quantum Dot Nanoparticles for Use in Photon Upconversion Devices

Quantum dot nanoparticles (NPs) can be used in several applications, for example, photon upconversion devices that increase the electricity output of solar modules. In order to facilitate life cycle assessment (LCA) studies of such applications, this study provides ready-to-use LCA unit process data for four NPs suitable for photon upconversion applications: cadmium selenide, cadmium sulfide, lead selenide, and lead sulfide. The data is provided for two prospective scenarios: one optimistic and one pessimistic. An impact assessment is conducted in order to assess the NPs’ climate change performance, where solvent-related processes such as steam production for recycling and hazardous waste treatment are shown to be hotspots. To show the applicability of the data, a prospective assessment of a solar module with an upconversion layer is conducted to investigate whether it is preferable from a climate perspective to install more solar modules or equip existing ones with upconversion devices, leading to more electricity produced in both cases. The assessment shows that solar modules need to become 0.05–2 percentage points more efficient per gram of NPs applied, depending on the scenario, in order for the upconversion layer to be preferable

Addition to inhaled corticosteroids of long-acting beta2-agonists versus anti-leukotrienes for chronic asthma

Asthma patients who continue to experience symptoms despite being on regular inhaled corticosteroids (ICS) represent a management challenge. Long-acting beta2-agonists (LABA) or anti-leukotrienes (LTRA) are two treatment options that could be considered as add-on therapy to ICS.ObjectivesWe compared the efficacy and safety profile of adding either daily LABA or LTRA in adults and children with asthma who remain symptomatic on ICS.Search strategyWe searched the Cochrane Airways Group Specialised Register (up to and including March 2010). We consulted reference lists of all included studies and contacted authors and pharmaceutical manufacturers for other published or unpublished studies.Selection criteriaWe included randomised controlled trials (RCTs) conducted in adults or children with recurrent asthma that was treated with ICS and where a fixed dose of a long-acting beta2-agonist or leukotriene agent was added for a minimum of 28 days.Data collection and analysisTwo authors independently assessed the risk of bias of included studies and extracted data. We sought unpublished data and further details of study design, where necessary.Main resultsWe included 17 RCTs (7032 participants), of which 16 recruited adults and adolescents (6850) and one recruited children aged 6 to 17 years (182). Participants demonstrated substantial reversibility to short-acting beta-agonist at baseline. The studies were at a low risk of bias. The risk of exacerbations requiring systemic corticosteroids was lower with the combination of LABA and ICS compared with LTRA and ICS, from 11% to 9% (RR 0.83, 95% CI 0.71 to 0.97; six studies, 5571 adults). The number needed to treat (NNT) with LABA compared to LTRA to prevent one exacerbation over 48 weeks was 38 (95% CI 22 to 244). The choice of LTRA did not significantly affect the results. The effect appeared stronger in the trials using a single device to administer ICS and LABA compared to those using two devices. In the absence of data from the paediatric trial and the clinical homogeneity of studies, we could not perform subgroup analyses. The addition to ICS of LABA compared to LTRA was associated with a statistically greater improvement from baseline in several of the secondary outcomes, including lung function, functional status measures and quality of life. Serious adverse events were more common with LABA than LTRA, although the estimate was imprecise (RR 1.35, 95% CI 1.00 to 1.82), and the NNT to harm for one additional patient to suffer a serious adverse event on LABA over 48 weeks was 78 (95% CI 33 to infinity). The risk of withdrawal for any reason in adults was significantly lower with LABA and ICS compared to LTRA and ICS (RR 0.84, 95% CI 0.74 to 0.96).Authors' conclusionsIn adults with asthma that is inadequately controlled on low doses of inhaled steroids and showing significant reversibility with beta2-agonists, LABA is superior to LTRA in reducing oral steroid treated exacerbations. Differences favouring LABA in lung function, functional status and quality of life scores are generally modest. There is some evidence of increased risk of SAEs with LABA. The findings support the use of a single inhaler for the delivery of LABA and inhaled corticosteroids. We are unable to draw conclusions about which treatment is better as add-on therapy for children.PLAIN LANGUAGE SUMMARYWhat are the effects of long-acting beta2-agonists compared with anti-leukotrienes when added to inhaled steroids?People who continue to experience asthma symptoms despite regularly taking inhaled corticosteroids are a challenge for management. It is not clear whether the addition of a long-acting beta2-agonist (LABA) such as formoterol or salmeterol would provide more benefit in comparison with an oral anti-leukotriene agent (LTRA), for example zafirlukast or montelukast.Seventeen trials (16 in adults and one in children) were included in this review and were of good quality. We found that the addition of a LABA provides significantly greater protection against exacerbations requiring oral steroids when compared with a LTRA for adults. Based on the results of our analyses, approximately 38 adults (with a range of between 22 and 244) would need to be treated with a LABA rather than a LTRA for 48 weeks to prevent one experiencing an exacerbation needing a course of oral steroids. The trial on children did not contribute data on the main outcome and therefore we could not draw any conclusions for children.LABAs also led to a greater improvement in lung function, improvement in symptoms, use of rescue medication, quality of life and symptoms compared to the use of LTRAs. The magnitude of the improvements was modest. Serious adverse events were more frequent with LABA than with LTRAs although this result was imprecise. Based on our analyses, around 78 people would need to be treated for 48 weeks with a LABA rather than a LTRA for one of them to experience a serious adverse event. However, due to the lack of precision around our result, the true number could be between 33 and infinity. There are currently insufficient data to draw any conclusions about the effects of these drugs in children

A Swedish comment on ‘review: the availability of life-cycle studies in Sweden’

The article entitled ‘Review: the availability of life-cycle studies in Sweden’ by Croft and colleagues (January 2019, volume 24, issue 1, pages 6–11) has puzzled many researchers in Sweden. The stated purpose of the article is to review the availability of water and carbon footprinting studies and life-cycle assessment (LCA) studies in Sweden. Despite its title and purpose suggesting otherwise, the article appears to be about the accessibility of life-cycle case studies from Sweden in South Africa. It is problematic that the article claims to be a review in the title and text, but is presented by the journal as a commentary. We believe that the article’s method is unclear and that its title and results are misleading. The authors of the article found only 12 academic papers, 10 academic theses, 8 company reports, and 1 presentation. This result significantly underestimates the actual production and availability of Swedish LCA case studies

The limitations of in vitro experimentation in understanding biofilms and chronic infection

We have become increasingly aware that during infection, pathogenic bacteria often grow in multi- cellular biofilms which are often highly resistant to antibacterial strategies. In order to understand how biofilms form and contribute to infection, in vitro biofilm systems such as microtitre plate as- says and flow cells, have been heavily used by many research groups around the world. Whilst these methods have greatly increased our understanding of the biology of biofilms, it is becoming increasingly apparent that many of our in vitro methods do not accurately represent in vivo conditions. Here we present a systematic review of the most widely used in vitro biofilm systems, and we discuss why they are not always representative of the in vivo biofilms found in chronic infections. We present examples of methods that will help us to bridge the gap between in vitro and in vivo biofilm work, so that our bench-side data can ultimately be used to improve bedside treatment

AD51B in Familial Breast Cancer

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

Prospective environmental risk screening of seven advanced materials based on production volumes and aquatic ecotoxicity

The number and volume of advanced materials being manufactured is increasing. In order to mitigate future impacts from such materials, assessment methods that can provide early indications of potential environmental risk are required. This paper presents a further development and testing of an environmental risk screening method based on two proxy measures: aquatic ecotoxicity and global annual production volumes. In addition to considering current production volumes, this further developed method considers potential future production volumes, thereby enabling prospective environmental risk screening. The proxy measures are applied to seven advanced materials: graphene, graphene oxide, nanocellulose, nanodiamond, quantum dots, nano-sized molybdenum disulfide, and MXenes. Only MXenes show high aquatic ecotoxicity, though the number of test results is still very limited. While current production volumes are relatively modest for most materials, several of the materials (graphene, graphene oxide, nanocellulose, nano-sized molybdenum disulfide, and MXenes) have the potential to become high-volume materials in the future. For MXenes, with both high aquatic ecotoxicity and high potential future production volumes, more detailed environmental risk assessments should be considered. For the other materials with high potential future production volumes, the recommendation is to continuously monitor their aquatic ecotoxicity data. Based on the application of the proxy measures combined with future scenarios for production volumes, we recommend this environmental risk screening method be used in the early development of advanced materials to prioritize which advanced materials should be subject to more detailed environmental assessments

Using industrial default values for prospective modeling of new materials production – the case of photon upconversion materials for solar modules

Several approaches to upscaling of materials production processes in the context of prospective life cycle assessment (LCA) have been proposed. Often, such approaches are bottom-up, departing from laboratory-scale descriptions of production processes and from that creating a model of future large-scale production. While such approaches make use of the material-specific knowledge available at the time of the assessment, they often neglect emergent aspects that may be present at factory level. An alternative, more top-down approach is to use industrial default values, i.e. average or typical values of inputs and outputs reflecting materials production today. Since production facilities normally do not change drastically over at least 10 years, such values might be relevant in prospective LCAs, at least given modest time horizons. Such default values can also be modified based on assumptions about future changes, such as increased energy recovery or novel solvent recovery processes. We applied previously derived industrial default values for fine chemical production when modeling the production of two materials with potential use in photon upconversion applications: lead sulfide (PbS) and lead selenide (PbSe) nanoparticles. Photon upconversion means that two low-energy photons are converted into one higher-energy photon utilizable by a solar module. While we used some material-specific values, such as synthesis-specific yields, most auxiliary input and output values (e.g. solvents, inert gas, heat, electricity and emissions) instead represent factory-scale values for current fine chemical production. Considering the availability of both best- and worst-case default values, it was possible to derive ranges for the likely future environmental impacts of the two materials. We conclude that the approach is feasible, but the availability of more up-to-date industrial default values would make it even more relevant in prospective LCAs

Psychological Sense of Community in Australia and the Challenges of Change

Social change is a phenomenon experienced in all societies, whether from gradual passages and time and interaction with other groups, or through the more immediate impacts such as war, invasion, or physical catastrophe. How societies manage change indicates much about their abilities to survive and the type of social cohesion that will be evidenced. In this article, the authors investigate the use of common symbols and shared history as ways of either maintaining social identity and moving with change, or using them in negative ways to resist change. The case study of immigration to Australia is used to demonstrate that members of the community are able to identify a series of salient identity markers—whether they wish to accept all of them or not—as the types of knowledge that all members share. Many of the markers reflect decades of passed history, but are seen as foundational to Australia today. Although they are core to identity, they are the types of symbols that are grasped as a lifestyle under threat by those who are newcomers. Often the markers are there as more unconscious constructions, to be evoked at times of high emotion to indicate what must be “saved” for current ideas to survive. The authors discuss the meanings of these markers as ways in which the identity of members of the community has been established. But these are seen as reminders, or glorifications, of the past, and how such markers are able to be captured and (mis)used by narrow populist and extremist interest groups. The challenge of managing change is how to build forward, maintaining those markers of real social value, and incorporating the new ones that are brought by newcomers, and those that are developed together. © 2002 Wiley Periodicals, Inc