Inorganic metal halide perovskites, such as CsPbI₃ , have recently drawn extensive attention due to their excellent optical properties and high photoelectric efficiencies. However, the structural instability originating from inherent ionic defects leads to a sharp drop in the photoelectric efficiency, which significantly limits their applications in solar cells. The instability induced by ionic defects remains unresolved due to its complicated reaction process. Herein, to explore the effects of ionic defects on stability, we develop a deep learning potential for a CsPbI₃ ternary system based upon density functional theory (DFT) calculated data for large-scale molecular dynamics (MD) simulations. By exploring 2.4 million configurations, of which 7,730 structures are used for the training set, the deep learning potential shows an accuracy approaching DFT-level. Furthermore, MD simulations with a 5,000-atom system and a one nanosecond timeframe are performed to explore the effects of bulk and surface defects on the stability of CsPbI₃ . This deep learning potential based MD simulation provides solid evidence together with the derived radial distribution functions, simulated diffraction of X-rays, instability temperature, molecular trajectory, and coordination number for revealing the instability mechanism of CsPbI₃ . Among bulk defects, Cs defects have the most significant influence on the stability of CsPbI₃ with a defect tolerance concentration of 0.32 %, followed by Pb and I defects. With regards to surface defects, Cs defects have the largest impact on the stability of CsPbI₃ when the defect concentration is less than 15 %, whereas Pb defects act play a dominant role for defect concentrations exceeding 20 %. Most importantly, this machine-learning-based MD simulation strategy provides a new avenue to explore the ionic defect effects on the stability of perovskite-like materials, laying a theoretical foundation for the design of stable perovskite materials.

Keywords: CsPbI3; deep learning potential; dynamics; ionic defect; molecular; stability.

Combining classifier systems potentially improves predictive accuracy, but outcomes have proven impossible to predict. Classification most commonly improves when the classifiers are "sufficiently good" (generalized as " accuracy ") and "sufficiently different" (generalized as " diversity "), but the individual and joint quantitative influence of these factors on the final outcome remains unknown. We resolve these issues. Beginning with simulated data, we develop the DIRAC framework (DIversity of Ranks and ACcuracy), which accurately predicts outcome of both score-based fusions originating from exponentially modified Gaussian distributions and rank-based fusions, which are inherently distribution independent. DIRAC was validated using biological dual-energy X-ray absorption and magnetic resonance imaging data. The DIRAC framework is domain independent and has expected utility in far-ranging areas such as clinical biomarker development/personalized medicine, clinical trial enrollment, insurance pricing, portfolio management, and sensor optimization.

Keywords: accuracy; correlation; data fusion; decision fusion; diversity; information fusion; model fusion; ranks; scores; system fusion.

A man with recurrent syncope and remote aortic coarctation repair experienced cardiac arrest with exercise stress testing. Critical coronary stenosis was discovered. Further evaluation revealed accessory mitral valve tissue and internal mammary artery occlusion. These rare abnormalities, not previously reported together, presented challenges to treatment. (Level of Difficulty: Intermediate.).

Keywords: AMVT, accessory mitral valve tissue; CABG, coronary artery bypass grafting; IMA, internal mammary artery; LVOT, left ventricular outflow tract; cardiac arrest; coronary artery bypass grafting; echocardiogram; internal thoracic artery; mitral valve disease; transesophageal echocardiogram.

Epithelial cells lining the oviduct/fallopian tube are essential in reproduction and have been identified as the cell-of-origin in high-grade serous ovarian carcinoma (HGSOC). This protocol describes the generation of organoids from mouse oviduct epithelial cells, providing a powerful in vitro tool to study epithelial homeostasis and malignant transformation. We also outline a protocol for whole-mount immunofluorescence and 3D confocal imaging. In addition, we describe approaches of viral transduction to investigate gene function in organoid development and epithelial cell behavior. For complete details on the use and execution of this profile, please refer to Ford et al. (2021).

Keywords: Cancer; Cell Biology; Cell culture; Cell isolation; Developmental biology; Microscopy; Organoids.

We recently demonstrated how lipid droplets can serve as in situ fiducials for correlating cryo-fluorescence microscopy (cryo-FM) and cryo-focused ion beam scanning electron microscopy (cryo-FIB-SEM) datasets of mammalian cells grown on grids. Here we describe a step-by-step protocol for correlative cryo-FM and cryo-FIB-SEM, starting from sample preparation of C2C12 cell line, followed by imaging with cryo-FM and cryo-FIB-SEM. Finally, we detail how to perform the 3D-correlation with sub-micron accuracy. For complete details on the use and execution of this profile, please refer to Scher et al. (2021).

Keywords: Cell Biology; Cryo-EM; Microscopy.

There is very limited experience with simulated virtual implantation of left ventricular assist devices (LVADs) to assess device fitness in pediatric patients. In this clinical vignette, we report the case of a 9-year-old male patient with dilated cardiomyopathy who underwent successful placement of an LVAD after virtual simulated implantation was performed. (Level of Difficulty: Advanced.).

Keywords: 3-dimensional imaging; CT, computed tomography; LVAD, left ventricular assist device; cardiac assist devices; computed tomography.

Here we report functional investigation of the radical S-adenosylmethionine enzyme BlsE by using cytosylglucuronamide (CGM), which is the amide analog of cytosylglucuronic acid (CGA), an intermediate involved in blasticidin S biosynthesis. We showed that, instead of decarboxylation of CGA reported previously, BlsE catalyzes C4'-dehydrogenation of CGM, and the resulting ketone is acted on by an aminotransferase BlsH to install the C4'-amino group, which uses L-Asp as the amino donor.

In vitro somatic callus culturing is used widely in plant biotechnology, but its effectiveness depends largely on the donor plant genotype. Bacteria or components of their cells are rarely used to activate morphogenesis. In this work, inoculation of explants from immature wheat (Triticum aestivum L.) embryos with a suspension of living cells of the bacterium Azospirillum brasilense Sp7 resulted in callus death after 7 days of growth, in contrast to explant treatment with a suspension of heat-killed whole cells of Sp7. The experiments used two wheat lines, LRht-B1a and LRht-B1c, which differ in morphogenic activity. Growing calluses with the lipopolysaccharide of A. brasilense Sp7 increased the yield of regenerated plants 2- to 3.5-fold in both lines. This increase was through the activation of regenerant formation from morphogenic calluses. We have demonstrated for the first time the effects of bacterial flagellin on plant tissue culture. The polar-flagellum flagellin of A. brasilense Sp7 leveled the genotypic differences in the morphogenic ability of callus tissue. Specifically, it increased the yield of morphogenic calluses in the weakly morphogenic line LRht-B1a to the yield value in the highly morphogenic line LRht-B1c but lowered the yield of regenerants in the highly morphogenic line LRht-B1c to the yield value in the weakly morphogenic line LRht-B1a. Thus, bacterial lipopolysaccharides and flagellins can be used to regulate the formation of morphogenic calluses and regenerants in plant tissue culturing in vitro.

Keywords: Azospirillum brasilense; Bacterial lipopolysaccharide; Callus culture; Flagellin; Somatic embryogenesis; Triticum aestivum L..

Purpose: In recent years, various types of indirect laryngoscopes have been developed. Nevertheless, no conclusions have been drawn about which type of indirect laryngoscope is most effective for tracheal intubation. We performed a systematic review and meta-analysis to determine whether the Airtraq® or the GlideScope® is more effective for tracheal intubation.

Methods: We extracted studies of adult prospective randomized trials comparing tracheal intubation between the Airtraq and GlideScope. An electronic database was used to extract the studies included in our meta-analysis. We extracted the following data from the identified studies: success rate, glottic visualization, and intubation time. Data from each trial were combined via a random-effects model for calculation of pooled relative risk (RR) or weighted mean difference (WMD) with a 95% confidence interval (CI). We also performed trial sequential analysis.

Results: We included eight trials comprising 571 patients for review. Compared with the GlideScope, Airtraq did not improve success rate, glottic visualization, or intubation time in tracheal intubation (success rate: RR, 0.98; 95% CI, 0.91 to 1.05; P = 0.58; I² = 65%; glottic visualization: RR, 1.07; 95% CI, 0.88 to 1.29; P = 0.69; I² = 64%; and intubation time: WMD, 1.4 seconds ; 95% CI, -6.2 to 9.1; P = 0.72; I² = 96%). The quality of evidence was graded as "very low." Trial sequential analysis showed that total sample size did not reach the required information size for all parameters.

Conclusion: In this meta-analysis, use of the Airtraq indirect laryngoscope did not result in improved success rate, glottic visualization, or intubation time in tracheal intubation compared with the GlideScope. Trial sequential analysis suggests that further studies are necessary to confirm these findings.

RéSUMé: OBJECTIF: Ces dernières années, différents types de laryngoscopes indirects ont été mis au point. Néanmoins, aucune conclusion n’a été tirée sur le type de laryngoscope indirect le plus efficace pour l’intubation trachéale. Nous avons réalisé une revue systématique et une méta-analyse pour déterminer quel dispositif était le plus efficace pour l’intubation trachéale, soit l’Airtraq® ou le GlideScope®. MéTHODE: Nous avons extrait les études portant sur les essais randomisés prospectifs chez l’adulte comparant l’intubation trachéale avec l’Airtraq ou le GlideScope. Une base de données électronique a été utilisée pour extraire les études incluses dans notre méta-analyse. Nous avons extrait les données suivantes des études identifiées : taux de réussite, visualisation glottique et temps d’intubation. Les données de chaque étude ont été combinées au moyen d’un modèle à effets aléatoires pour le calcul du risque relatif (RR) groupé ou de la différence moyenne pondérée (DMP) avec un intervalle de confiance (IC) de 95 %. Nous avons également réalisé une analyse séquentielle des études. RéSULTATS: Nous avons inclus huit études portant sur 571 patients pour notre revue. Par rapport au GlideScope, l’Airtraq n’a pas amélioré le taux de réussite, la visualisation glottique ou le temps d’intubation pour l’intubation trachéale (taux de réussite : RR, 0,98; IC 95 %, 0,91 à 1,05; P = 0,58; I² = 65 %; visualisation glottique : RR, 1.07; IC 95 %, 0,88 à 1,29; P = 0,69; I² = 64 %; et temps d’intubation : DMP, 1,4 seconde; IC 95 %, -6,2 à 9,1; P = 0,72; I² = 96 %). La qualité des données probantes a été classée comme « très faible ». L’analyse séquentielle des études a montré que la taille totale de l’échantillon n’atteignait pas la taille d’information requise pour tous les paramètres. CONCLUSION: Selon cette méta-analyse, l’utilisation du laryngoscope indirect Airtraq® n’entraîne pas d’amélioration du taux de réussite, de la visualisation glottique ou du temps d’intubation pour une intubation trachéale par rapport au GlideScope®. L’analyse séquentielle des études suggère que d’autres études sont nécessaires pour confirmer ces résultats.

Keywords: Airtraq; GlideScope; Meta-analysis; Tracheal intubation.

A new virulent Acinetobacter phage, BUCT629 (GenBank no. MZ712044.1), was isolated from hospital sewage. Next-generation sequencing (NGS) results demonstrated that the double-stranded linear DNA genome of phage BUCT629 is 46,325 bp in length with a G+C content of 38%. The BLASTn analysis showed that the genome sequence shared similarity with Acinetobacter phage vB_AbaM_IME285, with 65% query coverage and 98.23% identity, suggesting that phage BUCT629 is a novel phage. The phage genome contains 89 putative protein-coding genes, and no rRNA or tRNA genes were identified. The results of this study may be helpful for discovering new antibacterial agents and for understanding the evolution and genetic diversity of Acinetobacter phages.

The ubiquitin-proteasome system plays an important role in protein degradation. The process of ubiquitination requires ubiquitin activating enzyme E1, ubiquitin-conjugating enzyme E2, and ubiquitin ligase E3 to complete the coordination. Our previous studies have shown that HUWE1 (HECT, UBA and WWE domain containing 1), as an E3 ubiquitin ligase, can degrade epidermal growth factor receptor (EGFR) to inhibit renal tubulointerstitial fibrosis. However, E2 ubiquitin-conjugating enzymes binding to HUWE1 are still unclear. The aim of the present study was to identify E2 ubiquitin-conjugating enzymes of HUWE1. Real-time PCR was used to identify E2 ubiquitin-conjugating enzyme that may interact with HUWE1. The expression of E2 ubiquitin-conjugating enzyme was detected in kidney of unilateral ureteral obstruction (UUO) mice and HK-2 cells treated with transforming growth factor-β (TGF-β). The results showed that the expressions of E2 ubiquitin-conjugating enzyme UBE2Q2 were significantly down-regulated at both RNA and protein levels in UUO kidneys. The expression of UBE2Q2 was also down-regulated in HK-2 cells stimulated with TGF-β, which was consistent with the change in the expression of HUWE1. These findings indicated that UBE2Q2 expression was synergistic with HUWE1 in the injured kidney. Co-immunoprecipitation (Co-IP) experiments showed that HUWE1 interacted with UBE2Q2 in HK-2 cells. The co-localization of UBE2Q2 and HUWE1 was confirmed by cell immunofluorescence staining. After knocking down UBE2Q2 by siRNA, ubiquitin binding to HUWE1 and EGFR was decreased. In sum, our results demonstrated that UBE2Q2, ubiquitin-conjugating enzyme, works with HUWE1 to mediate ubiquitination and degradation of target protein in kidney.

Cutaneous T-cell lymphoma (CTCL) is a life-debilitating malignancy of lymphocytes homing to the skin. Although CTCL is thought to arise from a combination of genetic, epigenetic, and environmental factors, specific triggers are unclear. The skin is colonized by a unique microbiota and is heavily influenced by its interactions. We hypothesized that adaptive immune responses to skin commensals lead to clonal T-cell proliferation and transformation in the appropriate genetic background. We therefore collected lesional and nonlesional skin microbiota from patients with CTCL to study T cell interactions using skin T cell explants and peripheral, skin-homing CD4⁺ T cells. By various methods, we identified Bacillus safensis in CTCL lesions, a rare human commensal in healthy skin, and showed that it can induce malignant T cell activation and cytokine secretion. Taken together, our data suggest microbial triggers in the skin microbiota of patients with CTCL as potential instigators of tumorigenesis.

Keywords: ASV, amplicon sequence variant; CLA, cutaneous lymphocyte‒associated antigen; CTCL, cutaneous T-cell lymphoma; MF, mycosis fungoides; STAT3, signal transducer and activator of transcription 3; rRNA, ribosomal RNA.

Extensive investigation of the passivating agents has been performed to suppress the perovskite defects. However, very few attentions have been paid to rationally design the passivating agents for the balance of the carrier confinement and transfer in quasi-2D perovskites, which is essential to achieve high-performance perovskite LEDs (PeLEDs). In this work, tributylphosphine oxide (TBPO) with moderate carbon chain length is demonstrated as a decent passivator for the quasi-2D perovskites by strengthening the carrier confinement for massive radiative recombination within the perovskites, and more importantly providing efficient carrier transfer in the quasi-2D perovskites. Benefiting from these interesting optoelectronic properties of TBPO-incorporated perovskites, we achieve high-efficient blue PeLEDs with an external quantum efficiency up to 11.5% and operational stability as long as 41.1 min without any shift of the electroluminescence spectra. Consequently, this work contributes an effective approach to promote the carrier confinement and transfer for high-performance and stable blue PeLEDs.

Keywords: 2-Dimentional; Blue perovskite LEDs; Carrier confinement and transfer; Defect passivation.

Objective: This study aimed to investigate journal club prevalence, implementation, and perceived effectiveness among psychiatry residency program directors in order to highlight best practices.

Methods: The authors distributed a 44-item thoughtfully designed and peer-reviewed questionnaire electronically via Qualtrics to 235 accredited U.S. psychiatry residency program directors identified using the American Medical Association database.

Results: Eighty-nine programs (38%) responded. Of these, 83 (93%) had a journal club. Journal clubs were mandatory in 80 programs (96%), met biweekly or monthly in 62 programs (75%), and lasted 46-60 min in 66 programs (80%). Twenty-three programs (28%) offered a list of articles to choose from, and 22 programs (27%) provided a critical appraisal tool. Only 7 programs (8%) measured learner outcomes from journal clubs. Respondents believed that promoting lifelong learning and practicing evidence-based psychiatry were the most relevant educational goals of journal club (2.57 and 2.51 on a Likert scale of 0 to 3). Journal club's effectiveness in achieving those goals was believed to be lower (2.16 and 2.09).

Conclusions: Journal clubs are common in U.S. psychiatry residency programs and tend to follow a traditional format. In order to boost journal club's effectiveness in achieving the desired educational goals, more programs might elect to infuse elements known to augment learning.

Keywords: Critical appraisal; Evidence-based psychiatry; Graduate medical education; Journal club.

Extracellular vesicles (EVs) are lipid bilayer-enclosed structures containing diverse bioactive cargoes that play a major role in intercellular communication in both physiological and pathological conditions. Currently, the field of EV-based therapy has been rapidly growing, and two main therapeutic uses of EVs can be surmised: (i) exploiting stem cell-derived EVs as therapeutic agents; and (ii) employing EVs as natural therapeutic vectors for drug delivery. This review will discuss the recent advances in EV-based therapy in the treatment of renal disease.

Foot rot disease caused by Phytophthora capsici is a serious threat to black pepper cultivation in India and globally. High diversity exists among the Phytophthora isolates of black pepper and hence detailed investigations of their morphology and phylogenetic taxonomy were carried out in the present study. In order to resolve the diversity, 182 isolates of Phytophthora, collected from different black pepper-growing tracts of South India during 1998-2013 and maintained in the National Repository of Phytophthora at ICAR-Indian Institute of Spices Research, Kozhikode, were subjected to morphological, molecular and phylogenetic characterization. Morphologically all the isolates were long pedicellate with umbellate/simple sympodial sporangiophores and papillate sporangia with l/b ranging from 1.63 to 2.55 µm. Maximum temperature for the growth was ~ 34 °C. Chlamydospores were observed in "tropicalis" group, whereas they were absent in "capsici" group. Initial molecular studies using internal transcribed spacer (ITS) marker gene showed two clear cut lineages-"capsici-like" and "tropicalis-like" groups among them. Representative isolates from each group were subjected to host differential test, multilocus sequence typing (MLST) and phylogeny studies. MLST analysis of seven nuclear genes (60S ribosomal protein L10, beta-tubulin, elongation factor 1 alpha, enolase, heat shock protein 90, 28S ribosomal DNA and TigA gene fusion protein) clearly delineated black pepper Phytophthora isolates into two distinct species-P. capsici and P. tropicalis. On comparing with type strains from ATCC, it was found that the type strains of P. capsici and P. tropicalis differed from black pepper isolates in their infectivity on black pepper. The high degree of genetic polymorphism observed in black pepper Phytophthora isolates is an indication of the selection pressure they are subjected to in the complex habitat which ultimately may lead to speciation. So based on the extensive analysis, it is unambiguously proved that the foot rot disease of black pepper in India is predominantly caused by two species of Phytophthora, viz. P. capsici and P. tropicalis. Presence of multiple species of Phytophthora in the black pepper agro-ecosystem warrants a revisit to the control strategy being adopted for managing this serious disease. The silent molecular evolution taking place in such an ecological niche needs to be critically studied for the sustainable management of foot rot disease.

Keywords: Black pepper; Foot rot disease; Genetic diversity; Hybrid analysis; MLST; Phytophthora capsici; Phytophthora tropicalis; Piper nigrum.

Background: Left ventricular ejection fraction (LVEF) can provide hemodynamic information and may influence the response to spironolactone and other heart failure (HF) therapies.

Aims: To study the patient characteristics and circulating protein associations with LVEF, and whether LVEF influenced the response to spironolactone.

Methods: HOMAGE enrolled patients aged >60 years at high risk of developing HF with a LVEF ≥45%. 527 patients were randomized to either spironolactone or standard-of-care for ≈9 months. 276 circulating proteins were measured using Olink® technology.

Results: 364 patients had available LVEF determined by the Simpson's bi-plane method. The respective LVEF tertiles were: Tertile1:<60% (N = 122), Tertile2:60%-65% (N = 121), and Tertile3:>65% (N = 121). Patients with a LVEF>65% had smaller LV chamber size and volumes, and lower natriuretic peptide levels. Compared to patients with a LVEF<60%, those with LVEF>65% had higher levels of circulating c-c motif chemokine ligand-23 and interleukin-8, and lower levels of tissue plasminogen activator, BNP, S100 calcium binding protein A12, and collagen type I alpha 1 chain (COL1A1). Spironolactone significantly reduced the circulating levels of BNP and COL1A1 without significant treatment-by-LVEF heterogeneity: BNP change β = -0.36 Log₂ and COL1A1 change β = -0.16 Log₂ (P < 0.0001 for both; interactionP>0.1 for both). Spironolactone increased LVEF from baseline to month 9 by 1.1%, P = 0.007.

Conclusion: Patients with higher LVEF had higher circulating levels of chemokines and inflammatory markers and lower levels of stretch, injury, and fibrosis markers. Spironolactone reduced the circulating levels of natriuretic peptides and type 1 collagen, and increased LVEF. This article is protected by copyright. All rights reserved.

Keywords: ejection fraction; fibrosis; inflammation; spironolactone.

Purpose: In the absence of arthropathy, symptomatic massive irreparable rotator cuff tears contribute to a therapeutic challenge for orthopedic surgeons. The concept of superior capsular reconstruction (SCR) was introduced as an option for these challenging cases. The purposes of this study were to evaluate the clinical outcome scores when using a decellularized porcine xenograft and to evaluate the graft healing and incorporation.

Methods: A multicentric retrospective study of consecutive SCR's performed between 2016 and 2019 by four surgeons in four centers. Preoperative and postoperative Constant score, Subjective shoulder value (SSV) and Visual analog scale for pain (VAS) were recorded. Graft healing was evaluated by ultrasound or magnetic resonance imaging (MRI).

Results: A total of 28 shoulders were retrospectively analyzed with an average follow-up of 24 ± 9 months. One infection and four revisions (14%) to reversed shoulder arthroplasty (RSA) were reported at the final follow-up. The absolute Constant score showed a moderate, but significant improvement from 40 ± 12 to 57 ± 20 (P = 0.001). A significant improvement in pain scores was observed (P < 0.001). For patients undergoing SCR as a primary surgery, an average postoperative Constant score of 62 ± 16 was observed. This was in contrast to 43 ± 22 for patients who underwent SCR after failed rotator cuff repair. Although a strong trend in absolute differences was observed in regard to the Constant score, they did not reach statistical significance. For all other recorded outcome scores, a significant difference was reported between these groups. Graft healing was observed in (7/22) 30% of the patients. In the case of graft incorporation, an absolute constant score of 70 ± 9 was observed compared to 48 ± 21 in the graft failure group (P = 0.003). All cases with graft healing were considered to have a successful clinical outcome. This compared to only (7/15) 47% in the case of graft failure.

Conclusions: In these series, SCR with a dermal xenograft successfully alleviated pain, but provided only a moderate improvement in functional outcome. In the case of graft healing, satisfactory clinical outcomes and patient satisfaction were observed. The present study indicates the benefit of performing SCR as a primary surgery, yet warns against using SCR as a salvage option for failed rotator cuff repair. In this group, the use of dermal xenografts is limited by the low healing rates and high complication rate.

Level of evidence: IV. Retrospective case series, treatment study.

Keywords: Complications; Failed rotator cuff repair; Graft healing; Results; Reverse shoulder arthroplasty; SCR; Shoulder.

Background: This is the first systematic review and meta-analysis assessing cardiovascular disease incidence and risk factors among refugees and asylum seekers.

Methods and results: PubMed, PsycINFO, CINAHL, and Embase databases were searched for studies in English from January 1, 1977, to March 8, 2020. Inclusion criteria were (1) observation of refugee history in participants; (2) diagnosis of CVD (coronary artery disease, heart failure, stroke, or CVD mortality) and risk factors (hypertension, diabetes, tobacco use, hyperlipidemia, obesity, psychosocial factors); (3) assessment of effect size and spread, (4) adjustment for sex; and (5) comparison with non-refugee migrants or natives. Data were extracted and evaluated by multiple reviewers for study quality. Of the 1158 screened articles, Participants from 7 studies (0.6%) involving 116.989 refugees living in Denmark, Sweden, and the United States were included in the systematic review, of which three studies synthesized the quantitative analyses. A fixed-effects model was created to pool the effect sizes of included studies. The pooled incidence of CVD in refugees was 1.71 (95% CI: 1.03, 2.83) compared with non-refugee counterparts. Pyschosocial factors were associated with increased risk of CVD in refugees but evidence on CVD risk factors varied by nativity and duration since resettlement.

Conclusions: Refugee experience is an independent risk factor for CVD. Robust research on CVD in displaced populations is needed to improve the quality of evidence, clinical and preventive care, and address health equity in this marginalized population globally.

Keywords: CVD; Displaced; Migrants; Refugees; Risk factors; Stroke.

This work presents the first comprehensive investigation of natural organic matter (NOM) fraction removal using ceramic membranes in South Africa. The rate of removal of bulk NOM (measured as UV₂₅₄ and DOC % removal), the biodegradable dissolved organic carbon (BDOC) fraction, polarity-based fractions, and fluorescent dissolved organic carbon (FDOM) fractions was investigated from water abstracted from drinking water treatment plants (WTPs) in South Africa. Further, mechanisms of ceramic membrane fouling by waters of South Africa were studied. Ceramic membranes removed more than 80% DOC from samples from coastal WTPs, whereas for inland plants, the removal was between 60% and 75% of DOC. FDOM was removed to at least 80% regardless of the site of the plant. The BDOC removal by the ceramic membranes was above 85%. The hydrophobic fraction was the most amenable to removal by ceramic membranes regardless of the site of sample abstraction (above 60% for all sites). The freshness index (β:α) correlated strongly to UV₂₅₄ removal (R² = 0.96), thus UV₂₅₄ removal can serve as a proxy for the susceptibility to removal of such class of NOM by ceramic membranes. This investigation demonstrated that ceramic membranes could be a valuable technology if integrated into the existing WTPs. PRACTITIONER POINTS: The removal of bulk parameters by ceramic membrane was greater than unit conventional processes used in all the sampled water treatment plants. The hydrophobic polarity-based fraction of NOM was the most amenable to removal by ceramic membranes regardless of the site of the WTP. Polarity-based fractions, aromaticity, and initial DOC had a combined influence on the removal of organic matter by ceramic membranes as explained by principal component three.

Keywords: biodegradable dissolved organic carbon; ceramic membranes; fouling mechanism; natural organic matter; spectroscopic indices.