This paper presents sugar and organic acid content and composition, the principal determinants of flavour, of strawberries of the cultivars Festival and Ventana at four consecutive developmental ...stages. The metabolite profiles of these two cultivars were very similar. Glucose was the predominant sugar at approximately twice the concentration of fructose and sucrose. Total acid concentrations were five times lower than total sugar concentrations in ripe berries, with citrate comprising roughly two thirds of the total acid content. The maximum extractable catalytic activities of key enzymes in the relevant metabolic pathways were also quantified during berry development, in an attempt to elucidate possible correlations. Sucrose synthase activity was very low or undetected, while neutral invertase activity was relatively high, suggesting that sucrose synthase does not make a significant contribution to sink strength in these cultivars. Three enzymes, invertase, pyrophosphate-dependent phosphofructokinase (PFP) and fructose-1,6-bisphosphatase (FBPase), showed distinct activity patterns during development and may affect sugar and acid accumulation and sugar composition of strawberries.
There is a global concern that rising atmospheric CO2 concentrations may impact the medicinal or nutritional properties of medicinal plants. Portulacaria afra is a South African medicinal plant that ...is used by traditional healers to treat various skin conditions. The aim of this study was to determine whether elevated CO2 concentrations would affect the medicinal properties of the leaves of P. afra. This was achieved by comparing the phytochemical presence, antioxidant and antimicrobial activity of the leaves of P. afra which were exposed to ambient (420 ppm) and elevated (600 ppm) CO2 concentrations of plants grown in greenhouse conditions. The results revealed that leaf samples that were exposed to elevated CO2 concentrations exhibited a significant increase in flavonoid presence, compared to the control group. The antioxidant activity of the leaves of P. afra (DPPH activity) remained mostly unchanged in the samples that were exposed to elevated CO2 concentrations. The antimicrobial activity efficacy against Cutibacterium acnes increased with increasing global atmospheric CO2 concentration. These findings suggest that P. afra is a resilient medicinal plant and that its leaves may continue to provide relief against certain ailments, despite rising atmospheric CO2 concentrations.
Rapid cold-hardening (RCH) is a unique form of phenotypic plasticity which confers survival advantages at low temperature. The fitness costs of RCH are generally poorly elucidated and are important ...to understanding the evolution of plastic physiology. This study examined whether RCH responses, induced by ecologically relevant diel temperature fluctuations, carry metabolic, survival, or fecundity costs. We predicted that potential costs in RCH would be manifested as differences in metabolic rate, fecundity, or survival in flies which have hardened versus those which have not, or flies that have experienced more RCH events would show greater costs than those which have experienced fewer events. One group of flies cooled to 10° C for 2 h for 11 consecutive days experienced daily RCH (Hardened), whereas the other group exposed to 15° C for the same 2-h period each day formed a Control group. Hardened flies had higher survival at -5° C for 2 h than control flies (69 ± 9% vs. 44 ± 19%, P = 0.04). Hardened flies showed no metabolic or fecundity costs, but had reduced average survival (P = 0.0403). Thus, a major cost to repeated low temperature exposures in Ceratitis capitata is through direct mortality caused by chilling injury, although this appears not to be a direct cost of RCH.
Significant advances in the management of cardiovascular disease have been made possible by the development of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors—“statins.” Initial ...studies explored the impact of statin therapy on coronary artery disease (CAD) progression and regression. Although the angiographic changes were small, associated clinical responses appeared significant. Subsequent large prospective placebo-controlled clinical trials with statins demonstrated benefit in the secondary and primary prevention of CAD in subjects with elevated cholesterol levels. More recently, the efficacy of statins has been extended to the primary prevention of CAD in subjects with average cholesterol levels. Recent studies also suggest that statins have benefits beyond the coronary vascular bed and are capable of reducing ischemic stroke risk by approximately one-third in patients with evidence of vascular disease. In addition to lowering low-density lipoprotein (LDL) cholesterol, statin therapy appears to exhibit pleiotropic effects on many components of atherosclerosis including plaque thrombogenicity, cellular migration, endothelial function and thrombotic tendency. Growing clinical and experimental evidence indicates that the beneficial actions of statins occur rapidly and yield potentially clinically important anti- ischemic effects as early as one month after commencement of therapy. Future investigations are warranted to determine threshold LDL values in primary prevention studies, and to elucidate effects of statins other than LDL lowering. Finally, given the rapid and protean effects of statins on determinants of platelet reactivity, coagulation, and endothelial function, further research may establish a role for statin therapy in acute coronary syndromes.
Pharmacology is an increasingly important area of study for oral hygienists, as it provides the scientific basis for safe and effective oral healthcare. However, a lack of fundamental understanding ...of the discipline among clinical graduates can present significant challenges. Oral hygienists require pharmacological training to meet the requirements of their scope of practice. Pharmacology knowledge assists with the diagnosis and treatment of oral conditions and forms the foundation for further clinical competency development. The knowledge and perceptions of pharmacology for pharmacy, nursing and medical students have been well documented; however, little information is present for Bachelor of Oral Hygiene (BOH) students. This paper sets out to evaluate BOH students' and recent graduates' knowledge and perceptions of pharmacology at a single higher institution in Pretoria to identify possible gaps and weaknesses.
A cross-sectional study design was used to collect data using an online questionnaire. The English-language questionnaire consisted of the self-reported perceptions and knowledge and actual knowledge of pharmacology of undergraduate BOH students and recent graduates. The questionnaire consisted of multiple choice questions, true or false questions and Likert scale questions. Ethics was obtained from the institution's Research Ethics Committee (REC 350/2021).
Overall, the participants perceived the pharmacology module positively and understood its importance. Concerns were raised about insufficient time for studying and that assessments were more aligned to gaining factual knowledge than the development of problem-solving skills. Students rated their knowledge between 57.24% and 69.44%, with BOH III students and graduates having a statistically significant greater self-rated knowledge of antivirals, antifungals and common agents used to treat oral conditions in comparison with BOH I and BOH II students. Overall, BOH students and graduates' actual knowledge was between 45.24% and 66.84%. Although not statistically significant, the total self-rated knowledge of BOH III students and recent graduates tended to be higher than their actual knowledge. Knowledge deficits were evident with some pharmacological concepts across the various BOH groups, such as pharmacokinetics, pain, drugs altering dental treatment I: central nervous system drugs, drugs altering dental treatment II: respiratory and endocrine drugs, drugs altering dental treatment III: cardiovascular drugs, drug-drug interactions and common agents used to treat oral conditions.
Self-rated knowledge deficiencies were noted by students and recent graduates for certain pharmacological concepts and were supported by the measurement of their actual knowledge. Further investigation into knowledge deficiencies is needed to guide curriculum review to further strengthen oral hygienists' pharmacological competencies and ensure alignment to their scope of practice.
Heavy metals are natural elements characterized by their relatively large atomic mass as well as high density. It can be introduced into the ecosystem by the mining of heavy metals from deep within ...the earth's crust, thereby exposing the metals into air and water systems. Cigarette smoke is another source of heavy metal exposure and has been shown to have carcinogenic, toxic and genotoxic properties. Cadmium, lead, and chromium are the most abundant metals found in cigarette smoke. In response to tobacco smoke exposure, endothelial cells release inflammatory and pro-atherogenic cytokines that are linked to endothelial dysfunction. Endothelial dysfunction is directly related to the production of reactive oxygen species, leading to endothelial cell loss through necrosis and/or apoptosis. The current study aimed to investigate the effect of cadmium, lead, and chromium, alone and as part of metal mixtures, on endothelial cells. The EA.hy926 endothelial cell line was exposed to different concentrations of each of these metals and their combinations and analyzed using flow cytometric analyses with Annexin V. A clear trend was seen with the Pb + Cr as well as the triple combination group with the significant increase of early apoptotic cells. Scanning electron microscopy was used to study possible ultrastructural effects. Morphological changes observed with scanning electron microscopy included cell membrane damage and membrane blebbing at certain metal concentrations. In conclusion, the exposure of endothelial cells to cadmium, lead, and chromium, caused a disruption in cellular processes and morphology, possibly diminishing the protective ability of endothelial cells.
Mutations in the gene encoding the homeobox transcription factor NKX2-5 were found to cause nonsyndromic, human congenital heart disease. A dominant disease locus associated with cardiac ...malformations and atrioventricular conduction abnormalities was mapped to chromosome 5q35, where NKX2-5, a Drosophila tinman homolog, is located. Three different NKX2-5 mutations were identified. Two are predicted to impair binding of NKX2-5 to target DNA, resulting in haploinsufficiency, and a third potentially augments target-DNA binding. These data indicate that NKX2-5 is important for regulation of septation during cardiac morphogenesis and for maturation and maintenance of atrioventricular node function throughout life.
The ongoing development in manufacturing technology facilitates flexibility in production and faces challenges of product handling. Flexibility was required in the form of adaptable grippers for ...robotic arms in pick-and-place procedures for reconfigurable assembly systems. A conceptual system was designed and tested according to the surface geometric conformity of grasped objects. The system proposed was a biologically inspired Fin Ray Effect® gripper. Grasping occurs due to the deformation of the rib structure of the appendage. The appendages were simulated for conformity by means of a finite element analysis, and performance was analysed by means of a physical sample mass test and a force test.
PDF
