Initial Campaign Research Articles

Survey of tungsten gross erosion from main plasma facing components in WEST during a L-mode high fluence campaign

An initial high fluence campaign was performed in WEST, in 2023, on the newly installed actively cooled tungsten divertor composed of ITER-grade monoblocks. The campaign consisted in the repetition of a 60 s long Deuterium L-mode pulse in attached divertor conditions, cumulating over 10000s of plasma exposure. A maximum deuterium fluence of approximately 5⋅1026 m−2 was reached in the outer strike point region, representative of a few high performance ITER pulses. Gross tungsten erosion inferred from visible spectroscopy shows that the most eroded plasma facing component is the inner divertor target with rates ten times larger than on the outer divertor target. The outer midplane tungsten bumpers, located a few centimeters from the plasma, show gross erosion rates two times lower than at the outer divertor. We conclude that the outer midplane bumpers have a negligible contribution to the long range tungsten migration and deposition onto the lower divertor. The cumulated gross erosion rate on the inner divertor translates in an effective gross erosion thickness of about 20μm, while it is about 2μm for the outer divertor. Strikingly, these orderings coincide with the thickness of deposits found locally on the divertor: the exposed surfaces of high field side monoblocks are covered with several tens of μm tungsten deposits, while on the lower field side, few μm thin tungsten deposits are only found on the magnetically shadowed parts of monoblocks. The strong impact of those deposits on WEST operation, namely perturbation of surface temperature measurement with infra-red thermography, and the emission of flakes causing radiative perturbation of the confined plasma, calls for anticipating similar issues in ITER. In particular, the start of research operation shall consider the definition of a divertor erosion budget in order to anticipate the formation of deleterious deposits.

Optimal Allocation of Multi-Type Vaccines in a Two-Dose Vaccination Campaign for Epidemic Control: A Case Study of COVID-19

As a typical case of the optimal planning for the provision of restricted medical resources, widespread vaccination is considered an effective and sustainable way to prevent and control large-scale novel coronavirus disease 2019 (COVID-19) outbreaks. However, an initial supply shortage of vaccines is inevitable because of the narrow production and logistical capacity. This work focuses on the multi-type vaccine resource allocation problem in a two-dose vaccination campaign under limited supply. To address this issue, we extended an age-stratified susceptible, exposed, infectious, and recovered (SEIR) epidemiological model to incorporate a two-dose vaccination campaign involving multiple vaccine types to fully characterize the various stages of infection and vaccination. Afterward, we integrated the proposed epidemiological model into a nonlinear programming (NLP) model to determine the optimal allocation strategy under supply capacity and vaccine hesitancy constraints with the goal of minimizing the cumulative number of deaths due to the pandemic over the entire planning horizon. A case study based on real-world data from the initial mass vaccination campaign against COVID-19 in the Midlands, England, was taken to validate the applicability of our model. Then, we performed a comparative study to demonstrate the performance of the proposed method and conducted an extensive sensitivity analysis on critical model parameters. Our results indicate that prioritizing the allocation of vaccines to elderly persons is an effective strategy for reducing COVID-19-related fatalities. Furthermore, we found that vaccination alone will not be sufficient for epidemic control in the short term, and appropriate non-pharmacological interventions are still important for effective viral containment during the initial vaccine rollout. The results also showed that the relative efficacy of the first dose is a vital factor affecting the optimal interval between doses. It is always best to complete the two-dose vaccination schedule as soon as possible when the relative efficacy of the first dose is low. Conversely, delaying the second dose of a vaccine as long as possible to increase the proportion of the population vaccinated with a single dose tends to be more favorable when the relative efficacy of the first dose is high. Finally, our proposed model is general and easily extendable to the study of other infectious disease outbreaks and provides important implications for public health authorities seeking to develop effective vaccine allocation strategies for tackling possible future pandemics.

Organizational Bricolage and Insurgent Group Effectiveness in Cities: The Formation and Initial Urban Campaign of the Movement of the 19th of April in Colombia (1973–1980)

Abstracts How do rebel groups form in cities? What makes urban-based insurgent organizations effective? Urban armed conflicts have become an important subject of research due to the political, economic, and demographic significance of cities. Yet, we know little about the mechanisms of insurgent group formation and effectiveness in urban contexts. Building on the case of the formation and initial urban campaign of M-19 in Colombia (1973–1980), this article argues that rebel leaders originating from multiple organizations and confronted with intramovement competition have strong motives to employ organizational bricolage to form their organization. Organizational bricolage shapes insurgent effectiveness by producing structures that are fit for achieving certain objectives but not others. M-19’s organizational bricolage combined the armed vanguard, intellectual collective, and populist party forms. This structure was effective to foster public support but ineffective to establish a robust social base and maintain urban operations under repression. The research employs the analysis of organizational repertoires and process tracing to retrace M-19’s formation and initial urban campaign. Empirical material includes an original dataset comprising M-19 founders’ biographical data, archival documents, and interviews with ex-combatants. Studying how rebel leaders employ organizational bricolage sheds light on how insurgent organizations form, behave, and transform after war.

(114) HPV-AUTOMATED VISUAL EVALUATION (PAVE) STUDY: VALIDATING A NOVEL CERVICAL SCREENING STRATEGY. PRELIMINARY RESULTS OF PHASE 1 FROM CAMBODIA

Abstract Introduction The HPV-Automated Visual Evaluation (PAVE) Study is an international, multi-centric study designed to evaluate a novel cervical screen-triage-treat strategy for resource-limited settings as part of a global strategy to reduce cervical cancer burden as part of the National Cancer Institute’s Cancer Cures Moonshot Initiative. The PAVE strategy involves: 1) screening with self-sampled HPV testing; 2) triage of HPV-positive participants with a combination of extended genotyping and visual evaluation of the cervix assisted by deep-learning-based automated visual evaluation (AVE); and 3) treatment with thermal ablation or excision (LLETZ). The PAVE study has two phases: efficacy (2023-2024) and effectiveness (planned to begin in 2024-2025). The efficacy phase aims to refine and validate the screen-triage portion of the protocol. The effectiveness phase will examine implementation of the PAVE strategy into clinical practice, cost-effectiveness, and health communication. The study will enroll a total 100,000 women in 9 different countries. Objective The Cambodia section of the study will enroll a total of 10,000 women 25 to 49 years of age. Two different cohorts are being studied: lower-risk women who are employed (and screened) at garment factories, and higher-risk women living with HIV (WLWH) who are enrolled in the Cambodian National Centre for HIV/AIDS Dermatology and STDS (NCHADS) clinics. Very few women in either cohort have ever been screened for cervical cancer. Methods After an initial educational campaign including videos and written literature, eligible women were consented and performed HPV self-sampling. HPV testing was performed with the modified AmpFire HPV isothermal testing system (Atila Biosystems, California) which provides genotyping information in following groups: 16, 18/45, 31/33/35/52/58, 39/59/68/51/56/59. All women were informed of the HPV status via SMS. All HPV positive women had digital colposcopy with 5% acetic acid using an IRIS digital colposcope (Liger, Utah) and digital images were obtained. All women hrHPV+ had ectocervical and/or endocervical biopsies with SoftBiopsy or SoftECC brush (Histologics, California). Women with CIN2+ lesions then had LEEP. Results As of October 31st, 2023, 2097 Garment workers and 530 WLWH have been enrolled. From 259 of 2097 garment workers were hrHPV+ (12.4%). 10 of the 259 (3.9%) had biopsy confirmed CIN2+ lesions. Only 9 (3.4%) of the garment workers were lost to follow up after testing positive for hrHPV. 128 of 530 WLWH were hrHPV+ (24.15%), 101 of these 128 women presented for visual evaluation of their Cervices and 21 had a CIN2+ lesions and 11 had invasive cancer. Currently, 27 of the hrHPV+ WLWH have been lost-to-follow-up, though efforts continue to reach these women. Conclusions Women in low resource settings often have great socioeconomic barriers to cervical cancer screening. Screening and treating in garment factories appears to be a very successful strategy as high numbers of women can be screened in a short period of time. Additionally, there has been very minimal loss-to-follow-up even though HPV testing was performed up to one month prior to the visual inspection of hrHPV+ women. Screening WLWH, however, is a greater challenge as they often have to travel greater distances to get screened and frequently face greater economic burdens. Strategies such as arranging and paying for all transportation and compensation for lost wages will be used in the future to limit loss-to-follow-up. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Dare Bioscience.

Healthy environments for athleTes (HEAT): environmental conditions along a 90km ultra-marathon event, South Africa.

This paper provides an overview of the HEAT (Healthy Environments for AthleTes) project, which aims to understand the impact of environmental conditions on athlete health and performance during major sporting events such as long-distance running, cycling, and triathlons. In collaboration with the SAFER (Strategies to reduce Adverse medical events For the ExerciseR) initiative, the HEAT project carried out a field campaign at the 2022 Comrades Marathon in the KwaZulu-Natal province of South Africa. The measurement campaign deployed seven weather stations, seven PM2.5 monitors and one spore trap along the 90km route to capture spatially representative measurements of complex micro-climates, allergenic aerospora, and particulate matter exposure. The results indicate that runners were exposed to moderate risk heat stress conditions. Novel findings from this initial campaign shows elevated and potentially harmful PM2.5 levels at spectator areas, possibly coinciding with small fire events around the race day festivities. Our findings show values PM2.5 levels over the WHO 24-h guidelines at all stations, while 2000µg/m3 at two stations. However, the lack of an acute exposure standard means direct health impacts cannot be quantified in the context of a sport event. The HEAT project highlights important aspects of race day monitoring; regional scale climatology has an impact on the race day conditions, the microclimatic conditions (pollution and meteorology) are not necessarily captured by proximity instruments and direct environmental measurements are required to accurately capture conditions along the route.

New municipalism and feminist leadership after the Indignados: The political aesthetics of truth in Ada Colau for Mayor (Faus 2016)

In this article, I reflect on the intersection between feminism and documentary art as truth-telling by focusing on Alcaldessa ( Ada Colau for Mayor), the most relevant documentary of the long-term collaboration between the film-maker Pau Faus and Ada Colau, the first female mayor of Barcelona (2015–2023). My argument is critical of a reductionist interpretation which portrays Alcaldessa as a personalist postfeminist documentary overly fixated on ‘biography rather than policy’. In contrast, I posit that Faus’ documentary, delving into Colau’s initial electoral campaign (2014–2015), offers valuable insights into pivotal aspects of an underexamined political vision that merges the principles of new municipalism with a focus on the ‘common people’ ( gent comú) and feminism. Furthermore, the documentary sheds light on unreconciled dilemmas inherent in the lived new politics and feminist leadership, issues that often remain concealed within the ideological trappings of political manifestos and programmes.

Reflectance characterization of Starlink-like satellite with HELIOS brightness testing facility

The HELIOS (High Efficiency Light Intensity Observation System) project addresses the issue of excessive brightness from LEO satellite constellations. The system aims to develop a reflectance model of a satellite prior to launch, enabling the validation of compliance with astronomer guidelines, which suggest a minimum magnitude of 7. This ensures that the constellation is not visible to the naked eye and does not excessively interfere with astronomical observations. Additionally, the reflectance model obtained can be used for attitude determination by comparing the light curves with those obtained from observations. This application extends to Space Traffic Management, debris reentry prediction, and active debris removal. The system utilizes a light source consisting of 14 high-power LEDs with different wavelengths that replicate the solar spectrum. The light is positioned on an arc and can slide along a rail, allowing sampling at various angles. The arc itself can rotate on its axis, enabling the placement of the light source at any point on the hemisphere. At the center of the hemisphere, a scaled 3D printed model of the satellite under study is placed, with surface finishes resembling the actual satellite. Creating models with varying levels of detail permits to assess their impact on the reflectance model. Finally, the robotic arm Arm4NDO (Arm For Near Distance Observations) permits the movement of a high-efficiency quantum camera mounted at its end across the entire hemisphere’s surface for data acquisition. The camera records a video, stopping at points of interest for capturing frames. To strike a balance between continuous data acquisition and reasonable testing times, both the light source and capture points are positioned every 15° in elevation and azimuth. The initial test campaign aimed to determine optimal camera settings (exposure, aperture, and ISO) to achieve good model visibility and a dark background. Preliminary tests focused on Starlink’s chassis and the most significant observation configurations. Frames of interest were extracted from the videos, and their luminous flux (sum of pixel intensity values) was derived. With the obtained data, curves normalized relative to the maximum were plotted, allowing for a comparison of flux variations among different configurations.

Factors influencing cervical cancer re-screening in a semi-rural health district of Cameroon: a cohort study

BackgroundScreening participation at recommended intervals is a crucial component of cervical cancer prevention effectiveness. However, little is known regarding the rate of re-screening in a Sub-Saharan context. This study aimed to estimate the re-screening rate of women in a semi-rural after an initial HPV-based screening and identify factors that influence adherence.MethodsThis cohort study at the Annex Regional Hospital of Dschang enrolled women screened for cervical cancer over 5 years ago and due for re-screening. Women who initially tested HPV-positive (n = 132) and a random sample of HPV-negative women (n = 220) participated in a telephone survey between October 2021 and March 2022 to assess re-screening participation and reasons. Sociodemographic factors were collected, and associations with rescreening were evaluated.ResultsA total of 352 participants aged under 50 years (mean age 37.4 years) were contacted, and 203 (58.0%) completed the survey. The proportion of women who complied with the screening recommendation was 34.0% (95% CI 27.5% − 40.5%), The weighted re-screening proportion was 28.4%. Age, marital status, education level, type of employment, and place of residence were not associated with the rate of re-screening. Main reported barriers to re-screening were lack of information (39.0%), forgetfulness (39.0%), and impression of being in good health (30.0%). Women who remembered the recommended screening interval were 2 to 3 times more likely to undergo re-screening (aOR (adjusted odds ratio) = 2.3 [1.2–4.4], p = 0.013). Human papilloma virus- positive status at the initial screening was also associated with the re-screening((aOR) (95% CI): 3.4 (1.8–6.5).ConclusionFollowing an initial Human Papilloma Virus-based screening campaign in the West Region of Cameroon, one third of women adhered to re-screening within the recommended timeframe. Existing screening strategies would benefit from developing better information approaches to reinforce the importance of repeated cervical cancer screening.

Performance Evaluation of the Pressurized Synhelion Absorbing Gas Receiver

The pressurized design of the Synhelion absorbing gas receiver concept has been presented. Despite its intrinsic increased design complexity, foreseen advantages such as receiver downscaling and more compact piping and insulation systems were the drivers for the initial development of the 250 kWth receiver design operating at high pressure (10 bar absolute). The latter was driven by the results of specific computational fluid dynamics (CFD) simulations aimed at evaluating the receiver thermo-fluid dynamics behaviour along with the relative performance. This paper shows the results of the two initial CFD simulations campaigns aimed at evaluating the effect, on the receiver performance, of the integration of absorbing inserts (i.e., a series of concentric disks specifically arranged into the cavity to capture the incoming concentrated solar radiation) and the position and shape of the inlet section of the heat transfer fluid. The simulations results allowed not only to evaluate the receiver performance, in terms of thermal efficiency, but also to observe some criticalities related to the motion of the HTF through the receiver.

An unlikely coalition to defend the nation and banish “gender ideology” from Brazilian schools

In 2011, Jair Bolsonaro initiated a fight against the federal program proposal School without Homophobia (2009), which aimed to educate children, school staff, and parents on the respect to sexual diversity and prevention of violence against LGBTQIA + students. Bolsonaro’s Gay Kit unleashed an anti-gender campaign in Brazil. The fight against "gender ideology" that follows Jair Bolsonaro initial campaign indicates a turn in the articulation and the discourse of conservative and right-wing actors. This anti-gender campaign brough together groups that historically have been divided along class, race and gender lines, such as radical Catholic, middle- and upper-class white conservative Brazilians, and Neo-Pentecostals. In this paper, I analyze the power of the anti-gender campaign unleashed since the 2010s to find a common enemy, a common language and a common interest among conservative sectors of Brazilian society. I argue that gender works as the main symbolic glue that helps right-wing actors to forge a common identity in opposition to a new common Other, namely leftists. The main factor bridging them together is the preservation of the masculinist national identity that denies any form of structural inequality and critical thinking.

Chemical tools for the Gid4 subunit of the human E3 ligase C-terminal to LisH (CTLH) degradation complex.

We have developed a novel chemical handle (PFI-E3H1) and a chemical probe (PFI-7) as ligands for the Gid4 subunit of the human E3 ligase CTLH degradation complex. Through an efficient initial hit-ID campaign, structure-based drug design (SBDD) and leveraging the sizeable Pfizer compound library, we identified a 500 nM ligand for this E3 ligase through file screening alone. Further exploration identified a vector that is tolerant to addition of a linker for future chimeric molecule design. The chemotype was subsequently optimized to sub-100 nM Gid4 binding affinity for a chemical probe. These novel tools, alongside the suitable negative control also identified, should enable the interrogation of this complex human E3 ligase macromolecular assembly.

EXPANDING CDC’S STILL GOING STRONG CAMPAIGN TO INCLUDE TRIBAL POPULATIONS AND PROMOTE SOCIAL CONNECTEDNESS

Abstract The Centers for Disease Control and Prevention (CDC) launched the Still Going Strong (SGS) campaign in 2021 to promote ways older adults (65+) can age without injury. The goal was to encourage older adult participation in lifelong activities while taking steps to prevent injuries. Based on initial campaign evaluation, CDC plans to expand SGS to include social connectedness content and reflect greater diversity. To inform this expansion, CDC conducted spring 2023 focus groups with Tribal elders (n=8) and differently-abled older adults (n=9) and presented different concepts depicting older adults engaging in activities with others. Tribal elders were affiliated with five tribes: Navajo, Ojibwa, Citizen Potawatomi, Lumbee Indian, and Wailaki. Half were female (n=4), and majority were 63–70 years of age (n=5). This group tested two new radio concepts: (1) Walking and Talking and (2) Sharing Lessons. Themes across Tribal participants included the importance of connecting with loved ones, sharing culture and spirituality through service, and connecting with younger generations. The differently abled focus group was majority female (n=6), white, (n=5), 70–75 years of age (n=5) and reported using a mobility aid (n=6). This group tested two new video concepts: (1) Best Friends and (2) Health in Numbers. Participants identified social connection and being with others as important for their overall health. Using these data, we will create and refine campaign materials targeting both populations, which will be disseminated and further evaluated. By creating culturally relevant and respectful health promotion messages, we can better engage disproportionately affected persons and reduce injuries.

Decline in prevalence of tuberculosis following an intensive case finding campaign and the COVID-19 pandemic in an urban Ugandan community

BackgroundSystematic screening is a potential tool for reducing the prevalence of tuberculosis (TB) and counteracting COVID-19-related disruptions in care. Repeated community-wide screening can also measure changes in the prevalence of...

Data-driven model for predicting indoor air quality and thermal comfort levels in naturally ventilated educational buildings using easily accessible data for schools

Modeling indoor air quality and thermal conditions in educational buildings is significant for protecting students' health, well-being, and productivity. The predictive models in existing studies were mainly built and applied in controlled environments with HVAC systems. These models did not involve occupant-related factors, had limited scope in a single building or space, and required indoor environmental monitoring data for the model input. This limits the applicability and generalization ability of the model in a large number of schools relying on natural ventilation, where indoor air quality and thermal conditions are significantly affected by occupants’ activities and ventilation practices. Hence, this paper proposes a methodology to develop a data-driven model for predicting the level of indoor air quality and thermal comfort in naturally ventilated educational buildings, and identifies the key influential factors. The model was developed using the class-weighted random forest algorithm with data collected from a large measurement campaign. The developed model demonstrated good accuracy, generalization ability, and robustness. The analysis concluded that occupancy, windows and doors operation, and outdoor environmental parameters are key factors must be involved, whereas building characteristics have no practical contribution to the prediction. The model inputs are easily accessible data for schools. Once the model is developed with data collected from an initial measurement campaign in representative educational buildings, it can be used in all local schools without requiring monitoring sensor networks, thereby rendering a “cost-effective” way of assessing indoor air quality and thermal comfort to help relevant stakeholders improve building management practices in schools.

Promotion of a neurosurgical academic journal on social media: a 1-year experience

BackgroundSocial media (SoMe) use, in all of its forms, has seen massively increased throughout the past two decades, including academic publishing. Many journals have established a SoMe presence, yet the influence of promotion of scientific publications on their visibility and impact remains poorly studied. The European Journal of Neurosurgery «Acta Neurochirurgica» has established its SoMe presence in form of a Twitter account that regularly promotes its publications. We aim to analyze the impact of this initial SoMe campaign on various alternative metrics (altmetrics).MethodsA retrospective analysis of all articles published in the journal Acta Neurochirurgica between May 1st, 2018, and April 30th, 2020, was performed. These articles were divided into a historical control group — containing the articles published between May 1st, 2018, and April 30th, 2019, when the SoMe campaign was not yet established — and into an intervention group. Several altmetrics were analyzed, along with website visits and PDF downloads per month.ResultsIn total, 784 articles published during the study period, 128 (16.3%) were promoted via Twitter. During the promotion period, 29.7% of published articles were promoted. Overall, the published articles reached a mean of 31.3 ± 50.5 website visits and 17.5 ± 31.25 PDF downloads per month. Comparing the two study periods, no statistically significant differences in website visits (26.91 ± 32.87 vs. 34.90 ± 61.08, p = 0.189) and PDF downloads (17.52 ± 31.25 vs. 15.33 ± 16.07, p = 0.276) were detected. However, overall compared to non-promoted articles, promoted articles were visited (48.9 ± 95.0 vs. 29.0 ± 37.0, p = 0.005) and downloaded significantly more (25.7 ± 66.7 vs. 16.6 ± 18.0, p = 0.045) when compared to those who were not promoted during the promotion period.ConclusionsWe report a 1-year initial experience with promotion of a general neurosurgical journal on Twitter. Our data suggest a clear benefit of promotion on article site visits and article downloads, although no single responsible element could be determined in terms of altmetrics. The impact of SoMe promotion on other metrics, including traditional bibliometrics such as citations and journal impact factor, remains to be determined.

THE CHRONOLOGY OF WESTERN ZHOU

AbstractBy systematically analyzing the relative relationship between complete bronze inscription dates, this study deduces the lunar phases described by the specialized terms jishengba 既生霸, jiwang 既望, and jisiba 既死霸, finding that the term chuji 初吉 is unrelated to the lunar phase. The study then reconstructs a complete chronology of Western Zhou that is highly consistent with archaeological and textual evidence. The results support the traditional notion that the Zhou calendar year began in the month containing the winter solstice, and show that the Western Zhou calendar month began with the first invisibility of the waning lunar crescent while the calendar day began at sunrise. The overall evidence indicates that King Wu 武王 led an initial campaign against the Shang in 1046 b.c.e. and defeated Zhòu 紂 in 1044 b.c.e., lending credence to the narrative of the military display at Mengjin (觀兵孟津). The derived chronology reveals a previously unknown seven-year gap between King You's 幽王 final year and King Ping's 平王 first year, thus explaining the discrepancies between Shi ji 史記 and the archaeological evidence. This study demonstrates that the Modern Text (jinben 今本) Bamboo Annals 竹書紀年 is unsuitable for use in chronological studies, and suggests that the dates of Western Zhou were already obscure in Eastern Zhou. These results provide testable hypotheses and raise new questions that can guide further research into Western Zhou archaeology, history, society, and culture.

Shifts in Social Determinants of Vitamin A Supplementation Among Children Under Five in Kenya, 2003–2014

In Africa and Asia, 190million preschoolers are vitamin A deficient. This study examined the social determinants of intake of vitamin A supplementation (VAS) among children aged 6-59 months during three different time periods in Kenya to identify those most vulnerable to vitamin A deficiency and highlight the varied targeting and outreach efforts; before the onset of a national restructuring and targeted distribution of VAS in children below 5 years through a twice-yearly door-to-door campaign called Child Health Weeks, during the implementation period, and several years later. The cross-sectional, national Demographic and Health Surveys were administered in Kenya in 2003, 2008-09, and 2014. Bivariate and multivariable logistic regression analyses were used to assess variables associated with VAS among children (n = 28,239). An overall two-fold increase in VAS was recorded between 2003 (31.8%) and 2014 (67.5%). In 2008-09, children aged 6-11 months were the most likely to receive VAS. In 2003 and 2014, geographical regions and settings, birth order of the child, educational level of the mother, religion, wealth index, number of antenatal visits, and access to a radio were identified as being significantly associated with VAS, in at least one of the years. These determinants were not significant in 2008-09 during the initial Child Health Weeks promotion campaign. The determinants of VAS varied during the three study periods, particularly in 2008-09 when the Child Health Weeks was first implemented. As efforts to increase VAS continue, addressing child-specific determinants will be essential to reduce health disparities.

108 Workplace Exposure to Ultrafine Particles, Dust, and Chemicals During Plastic Production with Recycled Plastics

Abstract The plastics industry is a major contributor to the world economy, and in 2019 alone, there were some 480 million metric tons of plastic produced worldwide. Although a great deal of attention has been given to measuring and understanding the extent of plastic in the environment and its associated human exposure, much less is known about the human exposure to plastics during its production. The aim of this study is to characterize in detail the particulate matter (PM) emitted from various processes involved in the manufacturing and recycling of plastics. Here we report our findings from an initial campaign carried out at a Danish plastics factory. Online instruments were used to determine the particle number and mass concentrations for particles in the range of 10nm to 10µm, over the course of five hours, at both near- and far-field positions with respect to activities associated with the processing of plastics, including extruding, thermoforming, mixing, crushing, and rolling. For fine particles (<300nm), the average total particle number concentrations associated with these activities were 3.3x104, 4.0x103, 2.8x104, 3.5x104, and 6.9x104 #/cm3, respectively. Respirable dust concentrations were 13, 7, 9, 7 (calculated), and 12 µg/m3, respectively, and total dust concentrations were similar or slightly higher. These data suggest that the principal contributions to human exposure in the facility are fine and ultrafine particles. In addition to the real-time data and mass concentrations, samples are also analyzed for elemental composition and plastics. This research was supported by FFIKA, a grant from the Danish government.

Three years of wastewater surveillance for new psychoactive substances from 16 countries

The proliferation of new psychoactive substances (NPS) over recent years has made their surveillance complex. The analysis of raw municipal influent wastewater can allow a broader insight into community consumption patterns of NPS. This study examines data from an international wastewater surveillance program that collected and analysed influent wastewater samples from up to 47 sites in 16 countries between 2019 and 2022. Influent wastewater samples were collected over the New Year period and analysed using validated liquid chromatography – mass spectrometry methods. Over the three years, a total of 18 NPS were found in at least one site. Synthetic cathinones were the most found class followed by phenethylamines and designer benzodiazepines. Furthermore, two ketamine analogues, one plant based NPS (mitragynine) and methiopropamine were also quantified across the three years. This work demonstrates that NPS are used across different continents and countries with the use of some more evident in particular regions. For example, mitragynine has highest mass loads in sites in the United States, while eutylone and 3-methylmethcathinone increased considerably in New Zealand and in several European countries, respectively. Moreover, 2F-deschloroketamine, an analogue of ketamine, has emerged more recently and could be quantified in several sites, including one in China, where it is considered as one of the drugs of most concern. Finally, some NPS were detected in specific regions during the initial sampling campaigns and spread to additional sites by the third campaign. Hence, wastewater surveillance can provide an insight into temporal and spatial trends of NPS use.

High-Throughput Experimentation, Theoretical Modeling, and Human Intuition: Lessons Learned in Metal-Organic-Framework-Supported Catalyst Design.

We have screened an array of 23 metals deposited onto the metal-organic framework (MOF) NU-1000 for propyne dimerization to hexadienes. By a first-of-its-kind study utilizing data-driven algorithms and high-throughput experimentation (HTE) in MOF catalysis, yields on Cu-deposited NU-1000 were improved from 0.4 to 24.4%. Characterization of the best-performing catalysts reveal conversion to hexadiene to be due to the formation of large Cu nanoparticles, which is further supported by reaction mechanisms calculated with density functional theory (DFT). Our results demonstrate both the strengths and weaknesses of the HTE approach. As a strength, HTE excels at being able to find interesting and novel catalytic activity; any a priori theoretical approach would be hard-pressed to find success, as high-performing catalysts required highly specific operating conditions difficult to model theoretically, and initial simple single-atom models of the active site did not prove representative of the nanoparticle catalysts responsible for conversion to hexadiene. As a weakness, our results show how the HTE approach must be designed and monitored carefully to find success; in our initial campaign, only minor catalytic performances (up to 4.2% yield) were achieved, which were only improved following a complete overhaul of our HTE approach and questioning our initial assumptions.