► Photoprotection by honeybush against UVB-induced damage in a mouse model was studied. ► Honeybush extracts reduced sunburn, erythema, peeling and hardening of the skin. ► The extracts modulated ...epidermal hyperplasia, inflammation and cell proliferation. ► Mechanisms suggest honeybush protect by modulation of induced-oxidative damage.
The possible mechanism of photoprotection by polyphenolic extracts of honeybush and the two most abundant polyphenols found in honeybush, hesperidin and mangiferin were determined using a mouse model. Ethanol: acetone soluble extracts and pure honeybush compounds were applied topically to the skin of SKH-1 mice before daily exposures to ultraviolet B (UVB) (180
mJ/cm
2) for 10
days. The honeybush extracts reduced signs of sunburn, such as erythema, peeling and hardening of the skin and also significantly (
P
<
0.05) reduced edema, epidermal hyperplasia and the induction of cyclooxygenase-2 (COX-2), ornithine decarboxylase (ODC), GADD45 and OGG1/2 expression. The fermented honeybush extract significantly (
P
<
0.05) reduced lipid peroxidation and depletion of the antioxidant enzymes catalase and superoxide dismutase. Hesperidin and mangiferin were less effective. These results show that extracts of honeybush and to some extent, hesperidin and mangiferin, renders protection against UVB-induced skin damage. The mechanisms investigated suggest that honeybush extracts protected the skin via modulation of induced-oxidative damage, inflammation and cell proliferation. Other specific biological properties such as modulation of signaling pathways could also be involved.
The burden of chronic kidney disease and associated risk of kidney failure are increasing in Africa. The management of people with chronic kidney disease is fraught with numerous challenges because ...of limitations in health systems and infrastructures for care delivery. From the third iteration of the International Society of Nephrology Global Kidney Health Atlas, we describe the status of kidney care in the ISN Africa region using the World Health Organization building blocks for health systems. We identified limited government health spending, which in turn led to increased out-of-pocket costs for people with kidney disease at the point of service delivery. The health care workforce across Africa was suboptimal and further challenged by the exodus of trained health care workers out of the continent. Medical products, technologies, and services for the management of people with nondialysis chronic kidney disease and for kidney replacement therapy were scarce due to limitations in health infrastructure, which was inequitably distributed. There were few kidney registries and advocacy groups championing kidney disease management in Africa compared with the rest of the world. Strategies for ensuring improved kidney care in Africa include focusing on chronic kidney disease prevention and early detection, improving the effectiveness of the available health care workforce (e.g., multidisciplinary teams, task substitution, and telemedicine), augmenting kidney care financing, providing quality, up-to-date health information data, and improving the accessibility, affordability, and delivery of quality treatment (kidney replacement therapy or conservative kidney management) for all people living with kidney failure.
► Chemical surface modification of TiFe yields discontinuous deposits of Pd nanoparticles. ► The Pd deposition improves activation and H
2 absorption in TiFe pre-exposed to air. ► Sintered Ti
1.1Fe
...0.9O
x
is characterised by better activation than arc-melted TiFe.
Hydrogen storage performance of the TiFe-based materials suffers from difficulties with hydrogenation and sensitivity towards impurities in hydrogen gas reducing hydrogen uptake rates and decreasing the cycle stability. In present work the surface modification of the sintered Ti
1.1Fe
0.9O
x
and arc-melted TiFe was performed using autocatalytic deposition of the Pd-based catalytic layers in order to achieve improvement of the H storage characteristics. Pd deposition proved to be efficient in significant facilitation of the hydrogenation ability of the materials at moderate H
2 pressures and room temperature, even after their long exposure to air. Activation performance of the sintered Ti
1.1Fe
0.9O
x
is superior than that for the arc-melted TiFe. This effect was associated with the presence of the oxygen-containing suboxide Ti
4Fe
2O
1−
x
in the sintered sample acting as a hydrogen transfer catalyst. γ-Aminopropyltriethoxysilane pre-functionalization and subsequent Pd–P autocatalytic deposition onto the sintered Ti
1.1Fe
0.9O
x
intermetallic substrate resulted in a better hydrogenation kinetics compared to the samples prepared by the conventional Pd deposition.
•Prototype hydrogen storage and supply system for LTPEMFC applications was developed.•Combination of MH and CGH2 tanks with common gas manifold was used.•Thermal coupling of fuel cell stack and MH ...tank was applied.•The system uses AB2-type MH; H2 equilibrium pressure ∼10bar at room temperature.•Shorter H2 charge time and stable H2 supply at a fluctuating load were observed.
This paper describes the layout and presents the results of the testing of a novel prototype “distributed hybrid” hydrogen storage and supply system that has the potential to be used for Low Temperature Proton Exchange Membrane Fuel Cell (LT-PEMFC) applications. The system consists of individual Metal Hydride (MH) and Compressed Gas (CGH2) tanks with common gas manifold, and a thermal management system where heat exchanger of the liquid heated-cooled MH tank is integrated with the cooling system of the LT-PEMFC BoP. The MH tank is filled with a medium-stability AB2-type MH material (H2 equilibrium pressure of about 10bar at room temperature). This innovative solution allows for (i) an increase in hydrogen storage capacity of the whole gas storage system and the reduction of H2 charge pressure; (ii) shorter charging times in the refuelling mode and smoother peaks of H2 consumption during its supply to the fuel cell stack; (iii) the use of standard parts with simple layout and lower costs; and (iv) adding flexibility in the layout and placement of the components of the hydrogen storage and supply system.
Situated within the context of Initial Teacher Education (ITE) in South Africa, this study introduces the notion of an interactive Teaching Practicum E- Assessment application: e-assessment ...application for the teaching practicum/Teaching Practice module to replace the current model of assessment. At present students enrolled for an Initial Teacher Education qualification have to complete a compulsory Teaching Practice module. The successful completion of the module arguably provides evidence of students' readiness for professional practice. The assessment of the teaching practicum is often riddled with anxiety on the part of the students and conflict between students and their supervisor. Two interrelated research questions guided this study: What are students' experiences of the current teaching practicum assessment? and What were students' responses to the ICT-based assessment proposal? Data were collected from a sample of Teaching Practice students (N = 40) and a focus group discussion conducted with eight (8) students. Technological pedagogical content knowledge (TPCK) and critical connectivity theory provided the study with analytical and conceptual lenses. Findings are discussed in response to the research questions posed in preparation of the software development stage of the project.
Commercial pre-weaning diets are formulated to be highly digestible and nutrient-dense and contain low levels of dietary fibre. In contrast, pigs in a natural setting are manipulating fibre-rich ...plant material from a young age. Moreover, dietary fibre affects gastrointestinal tract (GIT) development and health in older pigs. We hypothesised that supplemental diets that contain vegetal fibres are accelerating GIT development in suckling piglets in terms of size and functionality. From d 2 of life, sow-suckled piglets had access to a low fibre diet (CON), a diet with a fermentable long-chain arabinoxylan (lc-AXOS), a diet with a largely non-fermentable purified cellulose (CELL), or a diet containing both fibres. During the initial 2 weeks, the control diet was a high-density milk replacer, followed by a dry and highly digestible creep meal. Upon weaning at 25 d, 15 piglets from each treatment group, identified as eaters and originating from six or seven litters, were sacrificed for post-mortem examination of GIT morphology, small intestinal permeability and metabolic profile of the digesta. The microbiota composition of the mid-colon was evaluated in a sub-set of ten piglets.
No major statistical interactions between the fibre sources were observed. Piglets consumed the fibre-containing milk supplements and creep diets well. Stomach size and small intestinal permeability was not affected. Large intestinal fill was increased with lc-AXOS only, while relative large intestinal weight was increased with both fibre sources (
< 0.050). Also, CELL decreased ileal pH and tended to increase ileal DM content compared to CON (
< 0.050). Moreover, the concentration of volatile fatty acids was increased in the caecum (
< 0.100) and mid-colon (
< 0.050) by addition of CELL. lc-AXOS only stimulated caecal propionate (
< 0.050). The microbiota composition showed a high individual variation and limited dietary impact. Nonetheless, CELL induced minor shifts in specific genera, with notable reductions of
-
.
Adding dietary fibres to the supplemental diet of suckling piglets altered large intestinal morphology but not small intestinal permeability. Moreover, dietary fibre showed effects on fermentation and modest changes of microbial populations in the hindgut, with more prominent effects from the low-fermentable cellulose.
There is increased use of neoadjuvant fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) in the management of localized pancreatic ductal adenocarcinoma (PDAC), yet there are few ...validated biomarkers of treatment response.
Consecutive patients (n = 196) with resectable, borderline resectable or locally advanced PDAC (2012-2019) receiving FOLFIRINOX as initial treatment and with targeted sequencing of a pretreatment biopsy were identified in a prospective institutional database. Genomic alterations were determined in the 4 driver mutations (KRAS, TP53, CDKN2A, SMAD4), and associations between genomic alterations and clinical outcomes were assessed.
Alterations in KRAS (n = 172, 87.8%) and TP53 (n = 131, 66.8%) were common; alterations in CDKN2A (n = 49, 25.0%) and SMAD4 (n = 36, 18.4%) were less frequently observed. A total of 105 patients (53.6%) were able to undergo resection, of whom 8 (7.6%) had a complete/near-complete pathologic response. There were no somatic alterations associated with major pathologic response. Alterations in SMAD4 were associated with a lower rate of surgical resection (27.8% vs 59.4%, p < 0.001); this was additionally observed in a multivariable regression model accounting for resectability status (OR 0.35, 95% confidence interval CI 0.15-0.85). Thirty-three patients (16.8%) developed metastatic disease while on neoadjuvant therapy. SMAD4 alterations were associated with a significant risk of metastatic progression on therapy when controlling for resectability status (OR 3.31, 95% CI 1.44-7.60).
SMAD4 alterations are associated with more frequent development of metastasis during neoadjuvant FOLFIRINOX and lower probability of reaching surgical resection. Evaluation of alternative chemotherapy regimens in patients with SMAD4 alterations will be important to distinguish whether this represents a prognostic or predictive biomarker.
Background. The Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations are two commonly used formulae to estimate glomerular filtration ...rate (GFR) in adults. The CKD-EPI equation is recommended in current international and local guidelines for the diagnosis and management of chronic kidney disease (CKD), unless an alternative equation has been shown to have superior accuracy. Validation and comparison of the equations in local populations are therefore required. Previous studies have reported on the accuracy of these prediction equations in black South Africans and those of Indian ancestry. Objectives. To evaluate the MDRD and CKD-EPI equations in South African (SA) adults of mixed ancestry. Methods. In all participants, GFR was measured (mGFR) from plasma clearance of 99mTc-diethylenetetraaminepenta-acetic acid (99mTc- DTPA), using a standardised technique. Serum creatinine assays were isotope dilution mass spectrometry traceable. GFR was estimated (eGFR) using the MDRD and CKD-EPI equations, with and without the black ethnicity factor. The agreement, bias, precision and accuracy of each equation was determined. Results. Eighty adults were included (30 male, median age 39 years, median GFR 59 mL/min/1.73 m2). Sixty-eight had a diagnosis of CKD, 10 were potential kidney donors, and 2 were healthy volunteers. Both equations, without the black ethnicity factor, had good agreement with measured GFR. The equations tended to overestimate GFR, with bias of 1.6 and 7.9 mL/min/1.73 m2 for the MDRD and CKD-EPI equations, respectively. The interquartile ranges of the differences were 15.9 and 20.2 mL/min/1.73 m2, and as a measure of accuracy, the percentages of estimates that fell within 30% of the mGFR (P30) were 80% and 72.5% (p=0.18). For identification of individuals with a GFR <60 mL/min/1.73 m2, the sensitivity of MDRD eGFR was 97.3% and that of CKD-EPI eGFR was 97.1%. Conclusions. The MDRD and CKD-EPI equations have shown satisfactory and comparable performance in this SA mixed-ancestry adult population, with the MDRD equation marginally less biased than the CKD-EPI.
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