Publications by authors named "Fabian J"

The current work outlines the preparation of a TiO nanotube (NT) layer electrochemically formed on the surface of a clinically-relevant titanium alloy anodisation. This NT layer was subsequently modified alternating current electrodeposition to incorporate copper micro- and nanoparticles on top of and within the NTs. Physical characterisation of the NT layer and the copper-incorporated NTs was carried out through analysis of the surface morphology, elemental composition, crystallinity, and stability SEM, EDX, XRD, and ICP-OES, respectively.

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Heterostructures, composed of semiconducting transition-metal dichalcogenides (TMDC) and magnetic van-der-Waals materials, offer exciting prospects for the manipulation of the TMDC valley properties via proximity interaction with the magnetic material. We show that the atomic proximity of monolayer MoSe and the antiferromagnetic van-der-Waals crystal CrSBr leads to an unexpected breaking of time-reversal symmetry, with originally perpendicular spin directions in both materials. The observed effect can be traced back to a proximity-induced exchange interaction via first-principles calculations.

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Albuminuria may precede decreases in the glomerular filtration rate (GFR) and both tests are insensitive predictors of early stages of kidney disease. Our aim was to characterise the urinary proteome in black African individuals with albuminuria and well-preserved GFR from South Africa. This case-controlled study compared the urinary proteomes of 52 normoalbuminuric (urine albumin: creatinine ratio (uACR) < 3 mg/mmol) and 56 albuminuric (uACR ≥ 3 mg/mmol) adults of black African ethnicity.

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Background: In South Africa, between 1966 and 2014, there were three kidney transplant eras defined by evolving access to certain immunosuppressive therapies defined as (before availability of cyclosporine), (when cyclosporine became available), and (availability of tacrolimus and mycophenolic acid). As such, factors influencing kidney graft failure may vary across these eras. Therefore, evaluating the consistency and reproducibility of models developed to study these variations using machine learning (ML) algorithms could enhance our understanding of post-transplant graft survival dynamics across these three eras.

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Some visual neurons in the dragonfly () optic lobe respond to small, moving targets, likely underlying their fast pursuit of prey and conspecifics. In response to repetitive targets presented at short intervals, the spiking activity of these "small target motion detector" (STMD) neurons diminishes over time. Previous experiments limited this adaptation by including intertrial rest periods of varying durations.

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Interfacial ferroelectricity, prevalent in various parallel-stacked layered materials, allows switching of out-of-plane ferroelectric order by in-plane sliding of adjacent layers. Its resilience against doping potentially enables next-generation storage and logic devices. However, studies have been limited to indirect sensing or visualization of ferroelectricity.

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The Wits Transplant Unit performed its first paediatric liver transplant in 2005. Initial experiences from the unit were published in 2012 and 2014. Since then, significant progress has been made in capacity-building the unit, improving outcomes and enhancing service delivery.

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Background: Liver transplantation is the definitive management for severe acute liver failure refractory to supportive management, and end- stage chronic liver failure. Owing to a shortage of deceased liver donors, South Africa requires innovative techniques to broaden the donor pool.

Objectives: This study evaluated the outcomes of the Wits Transplant Unit ABO-incompatible liver transplant (ABOi-LT) programme.

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In 2022, the Wits Transplant Unit performed 57 liver transplants: 33/57 adult (58%) and 24/57 paediatric (42%) recipients. At the beginning of 2022, 28 candidates were on the adult waitlist. Forty-six candidates were added to the waitlist during the year.

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Background: South African transplant centres are faced with significant challenges in meeting the need for liver transplantation, owing to the low and ever-decreasing number of deceased-donor organs. To increase organ utility, deceased-donor split-liver transplant (DDSLT) and living-donor liver transplant (LDLT) programmes were initiated in the Wits Transplant Unit.

Objective: To evaluate outcomes of the LDLT and DDSLT programmes.

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Background: In the paediatric liver transplant programme in Johannesburg, South Africa (SA), tacrolimus is the calcineurin inhibitor of choice, comprising an essential component of the immunosuppression regimen. It is characterised by a narrow therapeutic index and wide interpatient variability, necessitating therapeutic drug monitoring of whole-blood concentrations. Pharmacogenetic research, although not representative of SA population groups, suggests that single-nucleotide polymorphisms within the cytochrome P450 3A5 (CYP3A5) gene contribute to the variability in tacrolimus dosing requirements.

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Background: Cytosolic phospholipase A2α (cPLA) is the key enzyme that initiates the arachidonic acid cascade through which pro-inflammatory lipid mediators can be formed. Therefore, cPLA is considered an interesting target for the development of anti-inflammatory drugs. Although several effective inhibitors of the enzyme have been developed, none of them has yet reached clinical application.

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  • Recent studies have questioned whether newer HIV treatments like dolutegravir (DTG) and tenofovir alafenamide (TAF) lead to higher blood pressure levels.
  • The ADVANCE clinical trial in South Africa analyzed changes in systolic blood pressure (SBP) over 96 weeks among participants, revealing significant differences in SBP changes among various treatment regimens.
  • The results indicated that approximately 18.2%, 15.4%, and 13.3% of participants developed treatment-emergent hypertension with no significant connection between kidney function changes and BP outcomes; however, body mass index changes were linked to increased SBP.
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  • This study is the largest genome-wide association study (GWAS) focusing on urinary albumin-to-creatinine ratio (UACR) in Sub-Saharan African (SSA) populations, involving nearly 18,000 participants.
  • Researchers identified two significant genetic loci associated with UACR, one in residents of SSA and another in non-resident individuals of African ancestry.
  • The findings highlight the limited transferability of polygenic scores across different populations, underscoring the importance of diverse genetic studies to understand kidney disease susceptibility in underrepresented groups.
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In Josephson diodes the asymmetry between positive and negative current branch of the current-phase relation leads to a polarity-dependent critical current and Josephson inductance. The supercurrent nonreciprocity can be described as a consequence of the anomalous Josephson effect -a φ-shift of the current-phase relation- in multichannel ballistic junctions with strong spin-orbit interaction. In this work, we simultaneously investigate φ-shift and supercurrent diode efficiency on the same Josephson junction by means of a superconducting quantum interferometer.

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The impact of proximity-induced spin-orbit and exchange coupling on the correlated phase diagram of rhombohedral trilayer graphene (RTG) is investigated theoretically. By employing ab initio-fitted effective models of RTG encapsulated by transition metal dichalcogenides (spin-orbit proximity effect) and ferromagnetic Cr_{2}Ge_{2}Te_{6} (exchange proximity effect), we incorporate the Coulomb interactions within the random-phase approximation to explore potential correlated phases at different displacement fields and doping. We find a rich spectrum of spin-valley resolved Stoner and intervalley coherence instabilities induced by the spin-orbit proximity effects, such as the emergence of a spin-valley-coherent phase due to the presence of valley-Zeeman coupling.

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Purpose Of Review: In this report, we summarize why the availability of cystatin C is important across a variety of clinical scenarios, the recent literature on when, why and in whom cystatin C testing should be considered, and how nephrologists can take practical steps to incorporate cystatin C testing into their practice.

Recent Findings: Large intra-individual discrepancies between estimated glomerular filtration rate by creatinine (eGFRcr) and estimated glomerular filtration rate by creatinine eGFRcys (known as eGFRdiff) are observed in at least 1 in 4 people. These differences are seen more commonly among more vulnerable individuals: older adults, females, non-White individuals and those living with multiple medical conditions.

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Background: Hypertension is an important public health priority with a high prevalence in Africa. It is also an independent risk factor for kidney outcomes. We aimed to identify potential proteins and pathways involved in hypertension-associated albuminuria by assessing urinary proteomic profiles in black South African participants with combined hypertension and albuminuria compared to those who have neither condition.

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This study evaluated performance of the European Kidney Function Consortium (EKFC) equation in a US cohort, comparing population-specific (EKFCPS) with race-free (EKFCRF) Q values (median normal creatinine). Both EKFCPS and EKFCRF equations showed less bias than the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation. The percentage of estimated glomerular filtration rate (GFR) within 30% of measured GFR was similar for CKD-EPI 2021 (79.

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Article Synopsis
  • * Researchers identified two significant genetic loci associated with urinary albumin-to-creatinine ratio (UACR) — one on chromosome 6 and another on chromosome 11 — while confirming links to previously known regions associated with UACR.
  • * The findings highlight the genetic diversity in SSA populations and the limitations of polygenic scores from European ancestry studies, underscoring the need for more genetic research in diverse groups to better understand chronic kidney disease risk factors.
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High-dose methotrexate is part of the polychemotherapy protocols for the treatment of Acute lymphoblastic leukaemia (ALL) with therapeutic drug monitoring (TDM) to adjust leucovorin rescue. An immunoassay is commonly used to analyse serum samples collected via venous blood sampling. However, immunoassays cannot distinguish between the parent drug and its metabolites.

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  • Interlayer excitons in van der Waals heterostructures are important for innovations like excitonic devices and quantum emitters, yet past studies mainly focused on low-energy transitions near the band edges.
  • This research identifies both neutral and charged exciton species in bilayer WSe that emit in the ultraviolet, with impressive stability and narrow linewidths, even though they are above the band edge.
  • These high-lying interlayer trions show significant binding energies and are influenced by electric fields, acting as effective sensors for interlayer electric field strengths and allowing exploration of new moiré physics.
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