Short-term recovery of macroinvertebrate communities following a flash flood in an urban river: a case study of the Palmiet River in Durban, South Africa

Extreme floods have become frequent in the urban Palmiet River due to exacerbating climate change. Therefore,  the current study aimed to explore a short-term recovery of macroinvertebrate communities following a flash flood in the Palmiet River, KwaZulu-Natal, South Africa. Different biotopes, i.e. stones, gravel sand and mud, and vegetation were sampled after the March-April heavy rain in 2018. Ephemeroptera, Odonatan, and Hemipteran have shown similar trends across weeks at all sites. Plecoptera and Coleoptera started recovering at week four However, the total abundance and taxa richness had significantly recovered during the fourth week at site 2 and 3, and fifth week at site 1. Communities have shown no significant difference for each site from weeks six to eight (ANOVA, p> 0.5), which implies that climax on macroinvertebrate communities was reached at week six. Hydrologic regime change has not influenced water quality parameters across all weeks (ANOVA, p > 0.5) and this was also reflected on the average score per taxon (ASPT), which has shown no significant difference (ANOVA, p > 0.5) across weeks at all sites. These findings provide a baseline for future studies on flood effect on urban streams and supplement the understanding of the effects of sudden hydrologic regime changes on macroinvertebrate communities

Graphene Oxide-Coated Gold Nanorods: Synthesis and Applications

The application of gold nanorods (AuNRs) and graphene oxide (GO) has been widely studied due to their unique properties. Although each material has its own challenges, their combination produces an exceptional material for many applications such as sensor, therapeutics, and many others. This review covers the progress made so far in the synthesis and application of GO-coated AuNRs (GO–AuNRs). Initially, it highlights different methods of synthesizing AuNRs and GO followed by two approaches (ex situ and in situ approaches) of coating AuNRs with GO. In addition, the properties of GO–AuNRs composite such as biocompatibility, photothermal profiling, and their various applications, which include photothermal therapy, theranostic, sensor, and other applications of GO–AuNRs are also discussed. The review concludes with challenges associated with GO–AuNRs and future perspectives

The cancer-promoting potential of fumonisin B1 in rat liver using diethylnitrosamine as a cancer initiator

ArticleThe cancer-promoting potential of fumonisin B1 (FB1) was investigated by feeding different dietary levels (10, 50, 100, 250, 500 mg FB1/kg) to diethynitrosamine (DEN)-initiated rats for 21 days. Dietary levels containing 50 mg FB1/kg and higher, markedly increased the number and size of the placental form of glutathione-S-transferase-positive (GSTP+) foci in the liver of the rats. The cancer-promoting activity of FB1 was associated with an inhibitory effect on partial hepatectomy (PH)-induced regenerative hepatocyte proliferation, as the incorporation of 3H-labelled thymidine was significantly (P < 0.05) reduced by those FB1-containing diets that exhibited cancer promotion. In vitro studies on the mitogenic activity of epidermal growth factor (EGF) in primary rat hepatocytes further supported the in vivo data in that FB1, similar to other cancer promoters such as phenobarbital and 2-acetylaminofluorene (2-AAF), alters growth stimulatory responses in primary hepatocytes. No significant (P > 0.05) changes in the sphinganine/sphingosine (Sa/So) ratio were observed in the liver of the rats fed the lowest FB1-containing diet (50 mg FB1/kg diet) that effected cancer promotion. The present study indicated that FB1 exhibited cancer-promoting activity in the absence of adverse hepatotoxic effects and at dietary levels that failed to effect cancer initiation

Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer)

Hepatotoxicity and -carcinogenicity of the fumonisins in rats. A review regarding mechanistic implications for establishing risk in humans

ArticleCancer induction by the non-genotoxic mycotoxin, fumonisin B1, has been investigated by studying the mechanisms involved during cancer initiation and promotion in rat liver. Cancer initiation is effected through a toxic-proliferative response while the inhibitory effect on hepatocyte cell proliferation appears to be a key aspect determining cancer promotion. Dose-response effects of the fumonisins on the induction of early neoplastic lesions in both long- and short-term animal experiments have been established. The biphasic response of FB1 on hepatocyte proliferation will be discussed in relation to the known mechanisms of cancer induction by the genotoxic hepatocarcinogens. Recent investigations regarding the effect of the fumonisins on lipid biosynthesis and its inhibitory effect on hepatocyte growth stimulatory responses in vitro will be highlighted. Integration of our current knowledge regarding the carcinogenic potential of the fumonisins in setting a realistic and applicable risk assessment model for this non-genotoxic carcinogen will finally be addressed

The Therapeutic Effect of Second Near-Infrared Absorbing Gold Nanorods on Metastatic Lymph Nodes via Lymphatic Delivery System

Photothermal therapy has been established recently as a non-invasive treatment protocol for cancer metastatic lymph nodes. Although this treatment approach shows efficient tumour ablation towards lymph node metastasis, the monitoring and reporting of treatment progress using the lymphatic delivery channel still need to be explored. Herein, we investigated the anti-tumour effect of pegylated gold nanorods with a high aspect ratio (PAuNRs) delivered via the lymphatic route in a mouse model. In this study, breast carcinoma (FM3A-Luc) cells were inoculated in the subiliac lymph node (SiLN) to induce metastasis in the proper axillary lymph node (PALN). The treatment was initiated by injecting the PAuNRs into the accessory axillary lymph node (AALN) after tumour metastasis was confirmed in the PALN followed by external NIR laser irradiation under a temperature-controlled cooling system. The anti-tumour impact of the treatment was evaluated using an in vivo bioluminescence imaging system (IVIS). The results showed a time-dependent reduction in tumour activity with significant treatment response. Tumour growth was inhibited in all mice treated with PAuNRs under laser irradiation; results were statistically significant (** p &lt; 0.01) even after treatment was concluded on day 3. We believe that this non-invasive technique would provide more information on the dynamics of tumour therapy using the lymphatically administered route in preclinical studies