Showing papers by "University of British Columbia published in 2023"

Comparative life cycle assessment of co-pyrolysing sewage sludge and wastewater-grown microalgae for biofuel production

Abstract: Using available data, we analysed the biofuel production via pyrolysis of sewage sludge (SS) and microalgae grown in wastewater, either alone or at mass ratios of 1:1, 1:2, and 2:1. The life cycle assessment (LCA), global warming potential (GWP), energy recovery, and economic feasibility were compared. GWP was 36–44% lower for the co-pyrolysis scenarios than for SS alone. For energy recovery from pyrolysis gases, a gas turbine was more effective than gas heating, compensating for up to 28% of the pyrolysis energy requirement for all five scenarios. The drying process accounted for 69−88% of the total energy consumption, indicating that the dewatering process should be improved to maximise sustainability and profitability. All scenarios were profitable; the 1:1 mixture gave the highest net profit (9% more than that of SS). To conclude, co-pyrolysis of SS and microalgae is environmentally and financially viable for biowaste management in municipal wastewater treatment plants.

The Cannabis-Dependent Relationship Between Methadone Treatment Dose and Illicit Opioid Use in a Community-Based Cohort of People Who Use Drugs

Abstract: Background: Methadone maintenance treatment (MMT) is an effective treatment for opioid use disorder. However, subtherapeutic dosing may lead to continued opioid use by failing to suppress opioid withdrawal and craving. Preclinical and pilot experimental research suggests that cannabinoids may reduce opioid withdrawal and craving. We sought to test whether the association between low methadone dose and illicit opioid use differs according to concurrent cannabis use patterns. Methods: Data for this study were derived from two community-recruited cohorts of people (≥18 years old) who use illicit drugs in Vancouver, Canada. We used generalized estimating equations to estimate the adjusted association between lower daily MMT dose (<90 mg/day) and daily illicit opioid use, testing for interaction between dose and daily cannabis use. Results: Between December 2005 and December 2018, 1389 participants reported MMT enrolment and were included in the study. We observed a significant interaction (p<0.01) between daily cannabis and lower MMT dose on concurrent daily illicit opioid use: lower MMT doses increased the odds of daily illicit opioid use by 86% (adjusted odds ratio [AOR]=1.86, 95% confidence interval [CI]=1.61–2.16) during periods of no or low-frequency cannabis use and by 30% during periods of daily cannabis use (AOR=1.30, 95% CI=1.01–1.67). Discussion: This study provides preliminary observational evidence that cannabis may mitigate some of the negative effects of subtherapeutic MMT dosing, guiding future clinical investigations into the safety and efficacy of cannabis and cannabinoids as adjunct treatment for MMT.

Comparable outcomes between immune-tolerant and active phases in noncirrhotic chronic hepatitis B: a meta-analysis

Abstract: Antiviral therapy is not indicated for patients with chronic hepatitis B (CHB) in the immune-tolerant (IT) phase. We compared the outcomes between the untreated IT phase and the treated immune-active (IA) phase in noncirrhotic HBeAg-positive CHB patients.We systematically searched 4 databases, including PubMed, Medline, Embase, and Cochrane, until August 2021. The pooled incidence rates of HCC and mortality in the IT and IA cohorts and phase change in the IT cohort were investigated. Studies that included patients with liver cirrhosis were excluded.Thirteen studies involving 11,903 patients were included. The overall median of the median follow-up period was 62.4 months. The pooled 5-year and 10-year incidence rates of HCC were statistically similar between the IT and IA cohorts (1.1%, 95% CI: 0.4%-2.8% vs. 1.1%, 95% CI: 0.5%-2.3%, and 2.7%, 95% CI: 1.0%-7.3% vs. 3.6%, 95% CI: 2.4%-5.5%, respectively, all p>0.05). The pooled 5-year odds ratio of HCC between IT and IA cohorts was 1.05 (95% CI: 0.32-3.45; p=0.941). The pooled 5-year incidence rate of mortality was statistically similar between the IT and IA cohorts (1.9%, 95% CI: 1.1%-3.4% vs. 1.0%, 95% CI: 0.3%-2.9%, p=0.285). Finally, the pooled 5-year incidence rate of phase change in the IT cohort was 36.1% (95% CI: 29.5%-43.2%).The pooled incidence rates of HCC and mortality were comparable between the untreated IT and the treated IA phases in noncirrhotic HBeAg-positive CHB patients.

Thin highly cross-linked polyethylene liners combined with large femoral heads in primary total hip arthroplasty show excellent survival and low wear rates at a mean follow-up of 12.8 years

Abstract: Several short- and mid-term studies have shown minimal liner wear of highly cross-linked polyethylene (HXLPE) in total hip arthroplasty (THA), but the safety of using thinner HXLPE liners to maximize femoral head size remains uncertain. The objective of this study was to analyze clinical survival and radiological wear rates of patients with HXLPE liners, a 36 mm femoral head, and a small acetabular component with a minimum of ten years' follow-up.We retrospectively identified 55 patients who underwent primary THA performed at a single centre, using HXLPE liners with 36 mm cobalt-chrome heads in acetabular components with an outer diameter of 52 mm or smaller. Patient demographic details, implant details, death, and all-cause revisions were recorded. Cox regression and Kaplan-Meier survival was used to determine all-cause and liner-specific revision. Of these 55 patients, 22 had a minimum radiological follow-up of seven years and were assessed radiologically for linear and volumetric wear.Overall survival rate for all-cause revision was 94.5% (95% confidence interval (CI) 81.7% to 97.2%) at a mean follow-up of 12.8 years (10.9 to 18.7). Three patients were revised, none for liner wear, fracture, or dissociation. A total of 22 patients were included in the radiological analysis (mean follow-up 9.9 years (7.5 to 13.7)). Mean linear liner wear was 0.085 mm (95% CI -0.086 to 0.257) and the volumetric wear rate was 11.097 mm3/year (95% CI -6.5 to 28.7).Using HXLPE liners with 36 mm heads in 52 mm acetabular components or smaller is safe, with excellent survival and low rates of linear and volumetric wear at medium-term follow-up. Patients did not require revision surgery for liner complications such as fracture, dissociation, or wear. Our results suggest that the advantages of using larger heads outweigh the potential risks of using thin HXLPE liners.Cite this article: Bone Joint J 2023;105-B(1):29-34.

Gender Identity Change Efforts Are Associated with Depression, Panic Disorder, and Suicide Attempts in South Korean Transgender Adults

Abstract: Gender identity change efforts (GICEs), sometimes referred to as "conversion therapy," are considered pseudoscientific and unethical practices that are not supported by the existing scientific literature. However, a substantial portion of transgender people face such practices during their lives. We assessed lifetime exposure to GICEs and its associations with mental health indicators among transgender adults in South Korea.We analyzed a nationwide cross-sectional survey of 566 Korean transgender adults conducted in October 2020. Lifetime exposure to GICEs was classified as follows: "never had GICE-related experiences," "received a referral, but did not undergo GICEs," and "undergone GICEs." We assessed mental health indicators, including past-week depressive symptoms; medical diagnosis or treatment of depression and panic disorder; and past 12-month suicidal ideation, suicide attempts, and self-harm.Of the total participants, 12.2% had "received a referral, but did not undergo GICEs," and 11.5% had "undergone GICEs." Compared with those who had "never had GICE-related experiences," participants who had "undergone GICEs" showed significantly higher prevalence of depression (adjusted prevalence ratio [aPR]=1.34, 95% confidence interval [CI]=1.11-1.61), panic disorder (aPR=2.52, 95% CI=1.75-3.64), and suicide attempts (aPR=1.73, 95% CI=1.10-2.72). However, we did not find significant associations between having "received a referral, but did not undergo GICEs" and mental health indicators.Given our findings suggest that lifetime exposure to GICEs may harm transgender adults' mental health, legal restrictions should be imposed to ban GICEs in South Korea.

TRIM24 controls induction of latent HIV-1 by stimulating transcriptional elongation

Abstract: Binding of USF1/2 and TFII-I (RBF-2) at conserved sites flanking the HIV-1 LTR enhancer is essential for reactivation from latency in T cells, with TFII-I knockdown rendering the provirus insensitive to T cell signaling. We identified an interaction of TFII-I with the tripartite motif protein TRIM24, and these factors were found to be constitutively associated with the HIV-1 LTR. Similar to the effect of TFII-I depletion, loss of TRIM24 impaired reactivation of HIV-1 in response to T cell signaling. TRIM24 deficiency did not affect recruitment of RNA Pol II to the LTR promoter, but inhibited transcriptional elongation, an effect that was associated with decreased RNA Pol II CTD S2 phosphorylation and impaired recruitment of CDK9. A considerable number of genomic loci are co-occupied by TRIM24/TFII-I, and we found that TRIM24 deletion caused altered T cell immune response, an effect that is facilitated by TFII-I. These results demonstrate a role of TRIM24 for regulation of transcriptional elongation from the HIV-1 promoter, through its interaction with TFII-I, and by recruitment of P-TEFb. Furthermore, these factors co-regulate a significant proportion of genes involved in T cell immune response, consistent with tight coupling of HIV-1 transcriptional activation and T cell signaling.

The Near-Critical Two-Point Function and the Torus Plateau for Weakly Self-avoiding Walk in High Dimensions

Abstract: We use the lace expansion to study the long-distance decay of the two-point function of weakly self-avoiding walk on the integer lattice $$\mathbb {Z}^d$$ in dimensions $$d>4$$ , in the vicinity of the critical point, and prove an upper bound $$|x|^{-(d-2)}\exp [-c|x|/\xi ]$$ , where the correlation length $$\xi $$ has a square root divergence at the critical point. As an application, we prove that the two-point function for weakly self-avoiding walk on a discrete torus in dimensions $$d{>}4$$ has a “plateau.” We also discuss the significance and consequences of the plateau for the analysis of critical behaviour on the torus.

A solvable model of flat space holography

Abstract: A bstract We propose an explicit realization of flat space holography in two dimensions where both sides of the duality are independently defined and the boundary theory is completely solvable. In the bulk, we define a novel 𝒩 = 1 flat space supergravity theory and exactly compute the full topological expansion of its Euclidean partition function with an arbitrary number of boundaries. On the boundary, we consider a double scaled Hermitian random matrix model with Gaussian potential and use the loop equations to show it independently reproduces the bulk partition function to all orders in the topological expansion. The non-perturbative completion of the supergravity theory provided by the solvable Gaussian matrix model allows for the exact, and in many cases analytic, computation of observables in flat space quantum gravity.

Assessing the role of Piscine orthoreovirus in disease and the associated risk for wild Pacific salmon

Abstract: This paper is a response to Polinski, M. P. et al. Innate antiviral defense demonstrates high energetic efficiency in a bony fish. BMC Biology 19, 138 (2021). https://doi.org/10.1186/s12915-021-01069-2.

Land‐Atmosphere Coupling Constrains Increases to Potential Evaporation in a Warming Climate: Implications at Local and Global Scales

Abstract: The magnitude and extent of runoff reduction, drought intensification, and dryland expansion under climate change are unclear and contentious. A primary reason is disagreement between global circulation models and current potential evaporation (PE) models for the upper limit of evaporation under warming climatic conditions. An emerging body of research suggests that current PE models including Penman-Monteith and Priestley-Taylor may overestimate future evaporation for non-water-stressed conditions. However, they are still widely used for climatic impact analysis although the underlying physical mechanisms for PE projections remain unclear. Here, we show that current PE models diverge from observed non-water-stressed evaporation across site (>1,500 flux tower site years), watershed (>10,000 watershed-years), and global (25 climate models) scales. By not incorporating land-atmosphere coupling processes, current models overestimate non-water-stressed evaporation and its driving factors for warmer and drier conditions. To resolve this, we introduce a land-atmosphere coupled PE model by extending the Surface Flux Equilibrium theory. The proposed PE model accurately reproduces non-water-stressed evaporation across spatiotemporal scales. We find that terrestrial PE will increase at a similar rate to ocean evaporation but much slower than rates suggested by current PE models. This finding suggests that land-atmosphere coupling moderates continental drying trends. Budyko-based runoff projections incorporating our PE model are well aligned with those from coupled climate simulations, implying that land-atmosphere coupling is key to improving predictions of climatic impacts on water resources. Our approach provides a simple and robust way to incorporate coupled land-atmosphere processes into water management tools.

The <scp>WZA</scp> : A window‐based method for characterizing genotype–environment associations

Abstract: Genotype–environment association (GEA) studies have the potential to identify the genetic basis of local adaptation in natural populations. Specifically, GEA approaches look for a correlation between allele frequencies and putatively selective features of the environment. Genetic markers with extreme evidence of correlation with the environment are presumed to be tagging the location of alleles that contribute to local adaptation. In this study, we propose a new method for GEA studies called the Weighted-Z Analysis (WZA) that combines information from closely linked sites into analysis windows in a way that was inspired by methods for calculating FST. Performing GEA methods in analysis windows has the advantage that it takes advantage of the increased linkage disequilibrium expected surrounding sites subject to local adaptation. We analyse simulations modelling local adaptation to heterogeneous environments to compare the WZA with existing methods. In the majority of cases we tested, the WZA either outperformed single-SNP (single nucleotide polymorphism)-based approaches or performed similarly. In particular, the WZA outperformed individual SNP approaches when a small number of individuals or demes were sampled. Particularly troubling, we found that some GEA methods exhibit very high false positive rates. We applied the WZA to previously published data from lodgepole pine and identified candidate loci that were identified in the original study alongside numerous loci that were not found in the original study.

Improved cognitive-motor processing speed and decreased functional connectivity after high intensity aerobic exercise in individuals with chronic stroke

Abstract: Abstract After stroke, impaired motor performance is linked to an increased demand for cognitive resources. Aerobic exercise improves cognitive function in healthy populations and may be effective in altering cognitive function post-stroke. We sought to determine if high intensity aerobic exercise paired with motor training in individuals with chronic stroke alters cognitive-motor function and functional connectivity between the dorsolateral prefrontal cortex (DLPFC), a key region for cognitive-motor processes, and the sensorimotor network. Twenty-five participants with chronic stroke were randomly assigned to exercise (n = 14; 66 ± 11 years; 4 females), or control (n = 11; 68 ± 8 years; 2 females) groups. Both groups performed five-days of paretic upper limb motor training after either high intensity aerobic exercise (3 intervals of 3 minutes each, total exercise duration of 23-minutes) or watching a documentary (control). Resting-state fMRI, and TMT-A and B were recorded pre- and post-intervention. Both groups showed implicit motor sequence learning ( p < .001), but there was no added benefit of exercise ( p = .738). Regardless of group, the changes in task score ( p = .025), and dwell time ( p = .043) were correlated with a decrease in DLPFC-sensorimotor network functional connectivity ( p = .024), which is thought to reflect a reduction in the cognitive demand and increased automaticity. The exercise group experienced greater overall cognitive-motor improvements measured with the trail making test part A (TMT-A: task score: p = .012; dwell time: p = .024; movement time: p = .567). Aerobic exercise may improve cognitive-motor processing speed post-stroke. Significance statement After stroke, impaired motor performance is linked to an increased demand for cognitive resources. In our work we show that high intensity aerobic exercise paired with an implicit motor learning task improves cognitive-motor processing speed and reduces resting-state functional connectivity between the dorsolateral prefrontal cortex and the sensorimotor network in individuals living with chronic stroke. These data likely reflect a reduction in cognitive resource dependence during a cognitive-motor task after stroke and a shift towards cognitive-motor automaticity.

CO2 Mineralization and Critical Battery Metals Recovery from Olivine and Nickel Laterites

Abstract: The global clean energy transitionClean energy transition requires CO2 emissionCO2 emission reduction with a concurrent increase in the global supply of critical battery metals. A process has been developed at the lab scale. The hydrometallurgical process achieves CO2 mineralizationCO2 mineralization and selective battery metal recovery from olivine and lateritesOlivine and laterites. The natural minerals are processed at a modest temperature with a carbon dioxide pressure in a sodium bicarbonate solution containing soluble ligands enabling nickel and cobaltCobalt extraction. Iron and magnesium react with CO2 gas to form stable mineral carbonates for carbon dioxide sequestration. The leached nickel and cobaltCobalt are recovered by sulfide precipitation as high-value sulfides. The corresponding barren solution is recycled with no decrease in performance. The process consumes carbon dioxide and a source of sulfide. No additional acid or base is consumed in this novel process. Therefore, this work can potentially make significant contributions to the enhanced production of critical battery metals with enhanced CO2 storage and to the clean energy transitionClean energy transition.

A closed‐form multigrid smoothing factor for an additive Vanka‐type smoother applied to the Poisson equation

Abstract: We consider an additive Vanka-type smoother for the Poisson equation discretized by the standard finite difference centered scheme. Using local Fourier analysis, we derive analytical formulas for the optimal smoothing factors for vertex-wise and element-wise Vanka smoothers. In one dimension the element-wise Vanka smoother is equivalent to the scaled mass operator obtained from the linear finite element method and in two dimensions the element-wise Vanka smoother is equivalent to the scaled mass operator discretized by bilinear finite element method plus a scaled identity operator. Based on these findings, the mass matrix obtained from finite element method can be used as a smoother for the Poisson equation, and the resulting mass-based relaxation scheme yields small smoothing factors in one, two, and three dimensions, while avoiding the need to compute an inverse of a matrix. Our analysis may help better understand the smoothing properties of additive Vanka approaches and develop fast solvers for numerical solutions of other partial differential equations.

The rights way forward: reconciling the right to food with biodiversity conservation

Abstract: Abstract The current paradigm of biodiversity conservation, with its continued focus on the notion of pristine nature, has resulted in the separation of humans and nature at the expense of both biological and cultural–linguistic diversity. The continued annexation of land for the cause of conservation has resulted in the curtailment of both rights and access to local and diverse food sources for many rural communities. Indigenous Peoples and local communities are fundamental to conserving biodiversity through sustainable use of nature despite repeated attempts to dispossess them from their lands, cultures and knowledge. It has been this traditional and land-based knowledge that has contributed to the conservation of biodiversity whilst also supporting healthy, diverse and nutritious diets. If we are to achieve a more just and sustainable future, we need to continue to centre conservation initiatives around rights, access and equity whilst respecting a plurality of perspectives, worldviews and knowledge systems. Here we review alternative approaches that help reconcile the right to food with biodiversity conservation, such as biocultural rights, rights-based approaches and integrated land management schemes, with the aim of identifying optimal ways forward for conservation that break away from the dichotomous view that pits people against nature and instead embrace the importance of this symbiotic relationship.

Microstates of a 2d Black Hole in string theory

Abstract: A bstract We analyse models of Matrix Quantum Mechanics in the double scaling limit that contain non-singlet states. The finite temperature partition function of such systems contains non-trivial winding modes (vortices) and is expressed in terms of a group theoretic sum over representations. We then focus in the case when the first winding mode is dominant (model of Kazakov-Kostov-Kutasov). In the limit of large representations (continuous Young diagrams), and depending on the values of the parameters of the model such as the compactification radius and the string coupling, the dual geometric background corresponds to that of a long string (winding mode) condensate or a 2 d (non-supersymmetric) Black Hole. In the matrix model we can tune these parameters and explore various phases and regimes. Our construction allows us to identify the origin of the microstates of these backgrounds, arising from non trivial representations, and paves the way for computing various observables on them.

Locating Buzz and Liveness: The Role of Geoblocking and Co-presence in Virtual Film Festivals

Abstract: Abstract The sudden and near-complete move of festivals into the online space in 2020 complicated our understanding of the “there” and “then” involved in film festival participation. Experiencing festivals in lockdown (often from domestic spaces), “taking part” in these virtual events had the potential to dramatically expand the points of access. Although this approach was taken early with the YouTube-based We Are One global film festival, for the vast majority of single-festival-run online events access was limited to specific geographic areas through geoblocking technology. This chapter examines the function of geofenced access in virtual and hybrid virtual/real-world film festivals. It poses the question: what are the benefits for festivals in enforcing territoriality and place-boundedness in the de-territorialized world of online media? Looking to the importance of embodied co-presence and networked publics in existing understandings of liveness, buzz, and value creation at festivals, we interrogate the role of “place” in defining festival prestige and influence. We ask, if the mechanisms of value creation linked to the physical spectacle and viral spread of buzz at festivals are disrupted, will the film festival experience still be seen as valuable? And what might that mean for the future of festivals and their study?

How the volatile organic compounds emitted by corpse plant change through flowering

Abstract: Abstract The corpse plant ( Amorphophallus titanum ) is so named because it produces a pungent, foul odor when flowering. Little is known about how the emitted volatiles change throughout the two-day flowering period. In this study, the comprehensive monitoring of the presence and change in volatile molecules during the female and the male flowering phases of A. titanum was conducted, and the plant temperature was monitored. A total of 422 volatile features were detected over the entire sampling period, of which 118 features were statistically significantly different between the pre-flowering and both flowering phases, and an additional 304 features were found present throughout the flowering period. A total of 45 molecules could be assigned putative names. The volatile profile of A. titanum changes over the two-day flowering period, with the S-containing molecules and aldehydes dominant in the female flowering phase, and the alcohols and hydrocarbons dominant in the male flowering phase. The two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) enabled us to identify 32 new molecules produced by A. titanum . Each of these molecules alone, and in combination, likely contribute to the different odors emitted during the flowering phase of A. titanum .

Using behavioral interventions to reduce single-use produce bags

Abstract: Plastic pollution is a major conservation challenge. Current policies have primarily focused on plastic bags but neglected produce bags which are a pervasive source of packaging in grocery stores. To reduce produce bag use, we designed and tested 12 behavioral interventions in a simulated online shopping task. Each intervention reduced produce bag use by 9.2% to 48.7% against the control condition. Among the 12, the most effective interventions included using an indirect incentive or punishment (via donations to an environmental organization), reminding people of the positive consequence of not using produce bags, using normative messaging, drawing attention to the no produce bag option, and reminding or visualizing the negative consequence of using produce bags. These interventions were more effective for liberal participants than conservatives or independents. These findings provide new evidence for effective behavioral interventions and heterogenous effects in encouraging people to reduce produce bag use to curb plastic pollution.

An update on corticosteroid treatment for IgA nephropathy

Abstract: The use of corticosteroids to treat IgA nephropathy (IgAN) has been limited by many controversies related to uncertain benefit and safety concerns. Recent trials have tried to address these limitations.After being paused because of an excess of adverse events in the full-dose steroid arm, the TESTING trial compared a reduced dose of methylprednisolone to placebo in patients with IgAN after optimization of supportive therapy. Steroid treatment was associated with a significant reduction in the risk of a 40% decline in estimated glomerular filtration rate (eGFR), kidney failure and kidney death as well as a sustained decrease in proteinuria compared with placebo. Serious adverse events were more frequent with the full dose regimen but less common in the reduced dose regimen. A phase III trial evaluating a new formulation of targeted-release budesonide showed a significant reduction in short-term proteinuria and has resulted in accelerated FDA approval for use in the United States. In a subgroup analysis of DAPA-CKD trial, sodium-glucose transport protein 2 inhibitors reduced the risk of kidney function decline in patients who have completed or are not eligible for immunosuppression.Both reduced-dose corticosteroids and targeted-release budesonide are new therapeutic options that can be used in patients with high-risk disease. More novel-targeted therapies with a better safety profile are currently under investigations.

Evaluation Options for Wildlife Management and Strengthening of Causal Inference

Abstract: Abstract Wildlife management aims to halt and then reverse the decline of threatened species, to sustainably harvest populations, and to control undesirable impacts of some species. We describe a unifying framework of three feasible options for evaluation of wildlife management, including conservation, and discuss their relative strengths of statistical and causal inference. The first option is trends in abundance, which can provide strong evidence a change has occurred (statistical inference) but does not identify the causes. The second option assesses population outcomes relative to management efforts, which provides strong evidence of cause and effect (causal inference) but not the trend. The third option combines the first and second options and therefore provides both statistical and causal inferences in an adaptive framework. We propose that wildlife management needs to explicitly use causal criteria and inference to complement adaptive management. We recommend incorporating these options into management plans.

Wrestling with “the new” state capitalism

Abstract: This paper introduces an Exchange section dedicated to the question of the new state capitalism. It is suggested that the new state capitalism, both as an ascendant concept and as marker of socioinstitutional facts on the ground, signals a significant geohistorical moment, perhaps not a new “era” as such, but a notable inflection point. This warrants critical attention, even if first-generation treatments of the phenomenon itself may have been somewhat wanting. Contributions follow from Ilias Alami, Jennifer Bair, Isabella Weber, Marion Werner, and Heather Whiteside, each of whom provide a critical take on (debates around) the new state capitalism from their own theoretical perspective and vantage point.

Thermally Activated Delayed Fluorescence and Room‐Temperature Phosphorescence in Sulfidoazatriangulene‐Based Materials and their S‐oxides

Abstract: Structural constraint is an emerging strategy for improving the photoluminescence quantum yield, molar absorptivity, and color purity of luminescent materials. In this report, emitters displaying thermally activated delayed fluorescence (TADF) are achieved for the first time using the planarized donor sulfidotetramethyazatriangulene (SMAT). Compared to non-planarized phenothiazine (PTZ) donors, the enhanced rigidity of SMAT contributes to improved color purity and photoluminescence quantum yield, with up to 90% quantum yield observed for donor–acceptor compounds in toluene solution. Planarized SMAT-based emitters also offer up to tenfold enhancement in two-photon absorption cross-section compared to analogous PTZ-based materials. Oxidation of sulfur-containing donors to sulfoxide and sulfone derivatives is demonstrated as a simple and generalizable means of tuning the electron-donating ability of sulfur-containing moieties. SMAT-TRZ and SOMAT-TRZ both exhibit TADF, with green and blue emission, respectively, while SO2MAT-TRZ displays blue room temperature phosphorescence. Overall, this work demonstrates that SMAT and its S-oxides can be used to design high-performance luminescent materials with emergent properties such as TADF or room-temperature phosphorescence.

Experiencing homelessness and progression through the HIV cascade of care among people who use drugs

Abstract: To investigate the longitudinal association between periods of homelessness and progression through the HIV cascade of care among people who use drugs (PWUD) with universal access to no-cost HIV treatment and care.Prospective cohort study.Data were analysed from the ACCESS study, including systematic HIV clinical monitoring and a confidential linkage to comprehensive antiretroviral therapy (ART) dispensation records. We used cumulative link mixed-effects models to estimate the longitudinal relationship between periods of homelessness and progression though the HIV cascade of care.Between 2005 and 2019, 947 people living with HIV were enrolled in the ACCESS study and 304 (32.1%) reported being homeless at baseline. Homelessness was negatively associated with overall progression through the HIV cascade of care [adjusted partial proportional odds ratio (APPO) = 0.56, 95% confidence interval (CI): 0.49-0.63]. Homelessness was significantly associated with lower odds of progressing to each subsequent stage of the HIV care cascade, with the exception of initial linkage to care.Homelessness was associated with a 44% decrease in the odds of overall progression through the HIV cascade of care, and a 41-54% decrease in the odds of receiving ART, being adherent to ART and achieving viral load suppression. These findings support calls for the integration of services to address intersecting challenges of HIV, substance use and homelessness among marginalized populations such as PWUD.