Efficient Catalytic Production Of Biodiesel Using Nano-sized Sugar Beet Agro-industrial Waste

This paper addresses the use of agro-industrial residue as a promising heterogeneous catalyst for the efficient production of biodiesel. That is, CaO-rich Sugarbeet agro-industrial waste (smashed down to nano-size) shows superb catalytic activity for biodiesel production via transesterification process employing sunflower oil and methanol. Physicochemical properties of the proposed catalyst are probed by TGA–DTG, XRF, XRD, FT-IR, SEM, BET, and CO2-TPD techniques. Biodiesel conversion (%) of Ca. 93% is achieved under the optimal conditions (catalyst loading of 1 wt%, methanol/oil molar ratio of 4.5:1, refluxed at 75 °C for 60 min). The relatively short reaction time indicates the enhanced kinetics of the process using the proposed agro-industrial residue which imparts its economic feasibility. Also, the proposed CaO-rich residue can be reused twice while retaining its catalytic activity. The thus-produced biodiesel fuel compiles the ASTM D6751 and EN-14214 specifications

Parental awareness regarding pediatric antibiotic use in Madinah, Saudi Arabia

Purpose: To determine the level of awareness of antibiotic use in children in Madinah, Saudi Arabia, and to identify factors associated with parental decisions regarding it. Methods: Using a multiple-choice-question-based questionnaire survey, 1256 forms were distributed to visitors of major shopping malls in Madinah City to obtain socio-demographic and antibiotics knowledgebased data from October 2017 to January 2018. Differences in scores between and within groups on knowledge of parents about antibiotics were determined. Results: Most participants (67 %) had good basic knowledge of antibiotics: 69 and 40 % of respondents were aware of their side effects and antibacterial resistance, respectively. Participants in high age groups (> 46 years old) have a significantly higher mean knowledge score (55.4 ± 20.1, p < 0.05) than those in younger groups. Educational status increased the mean knowledge score by approximately 60 %, with the most educated group having a mean score of 61.2 ± 16.4 (p < 0.05). Conclusion: These results reveal the importance of awareness campaigns on antibiotic use and the role of healthcare professionals in the education of patients and parents on correct use of antibiotics, as well as the significance of antibacterial resistance. Keywords: Antibiotics misuse, Pediatrics, Patient education, Antibacterial resistanc

Visualizing the attack of RNase enzymes on dendriplexes and naked RNA using atomic force microscopy.

Cationic polymers such as poly(amidoamine), PAMAM, dendrimers have been used to electrostatically complex siRNA molecules forming dendriplexes for enhancing the cytoplasmic delivery of the encapsulated cargo. However, excess PAMAM dendrimers is typically used to protect the loaded siRNA against enzymatic attack, which results in systemic toxicity that hinders the in vivo use of these particles. In this paper, we evaluate the ability of G4 (flexible) and G5 (rigid) dendrimers to complex model siRNA molecules at low +/- ratio of 2/1 upon incubation for 20 minutes and 24 hours. We examine the ability of the formed G4 and G5 dendriplexes to shield the loaded siRNA molecules and protect them from degradation by RNase V1 enzymes using atomic force microscopy (AFM). Results show that G4 and G5 dendrimers form similar hexagonal complexes upon incubation with siRNA molecules for 20 minutes with average full width of 43±19.3 nm and 62±8.3 at half the maximum height, respectively. AFM images show that these G4 and G5 dendriplexes were attacked by RNase V1 enzyme leading to degradation of the exposed RNA molecules that increased with the increase in incubation time. In comparison, incubating G4 and G5 dendrimers with siRNA for 24 hours led to the formation of large particles with average full width of 263±60 nm and 48.3±2.5 nm at half the maximum height, respectively. Both G4 and G5 dendriplexes had a dense central core that proved to shield the loaded RNA molecules from enzymatic attack for up to 60 minutes. These results show the feasibility of formulating G4 and G5 dendriplexes at a low N/P (+/-) ratio that can resist degradation by RNase enzymes, which reduces the risk of inducing non-specific toxicity when used in vivo

AFM image of free siRNAs before and after attack by RNase enzyme.

<p>(A) AFM image of free anti-GAPDH siRNA dissolved in 1 mM PBS containing 2 mM MgCl₂ after adding to the surface of freshly cleaved mica, which shows rod-, sphere-, and bead-like arrangements. (B) AFM image taken 1.5 minutes after adding RNase V1 enzyme, which shows rapid fragmentation of adsorbed siRNA molecules. (C) Time-lapse images showing a single siRNA molecule denoted by the white arrow (<i>t</i> = 0 min), the attack of RNase V1 enzyme on free siRNA molecule (<i>t</i> = 1.5 min), and complete siRNA degradation (<i>t</i> = 3 min). The scale bar in images A and B is 100 nm and the Z scale is 9 nm. The scale bar in image C is 35 nm and Z scale is 7 nm.</p

AFM image of G4 dendriplexes prepared for 20 minutes attacked by RNase enzyme.

<p>(A) AFM image of hexagonal G4 dendriplexes prepared by mixing of G4 dendrimers with 0.7 µg of anti-GAPDH siRNA at N/P ratio of 2/1 for 20 minutes at room temperature before loading onto the surface of freshly cleaved mica. AFM images of G4 dendriplexes after incubation with RNase V1 enzyme for 1–28 minutes (B–F) shows separation of the adsorbed dendriplexes and degradation of the complexed siRNA molecules (dark spots) that increased with the increase in incubation time. Two dendriplexes (defined wit dotted circles) remained intact throughout the incubation time with RNase V1 enzyme suggesting the formation of individual compact particles. Scale bar in these images is 200 nm and the Z scale is 15 nm.</p

AFM image of G4 dendriplexes prepared for 24 hours attacked by RNase enzyme.

<p>AFM image of G4 dendriplexes prepared for 24 hours attacked by RNase enzyme.</p

Electrophoretic mobility of free siRNA, free G4 and G5 dendrimers, and the particles.

<p>Image of the 1% w/v agarose gel stained with ethidium bromide showing the electrophoretic mobility of free siRNA, free G4 and G5 dendrimers, and the particles prepared by mixing G4 and G5 dendrimers with 0.7 µg of anti-GAPDH siRNA at an N/P (+/−) ratio of 2/1 for 20 minutes or 24 hours.</p

AFM image of G5 dendriplexes prepared for 24 hours attacked by RNase enzyme.

<p>(A) AFM image of G5 dendriplexes prepared by mixing of G5 dendrimers with 0.7 µg of anti-GAPDH siRNA at N/P ratio of 2/1 for 24 hours at room temperature before loading onto the surface of freshly cleaved mica. G5 dendriplexes remain intact upon incubating with RNase V1 enzyme for 30 (B) and 60 minutes (C). Scale bar in these AFM images is 140 nm and the Z scale is 5 nm.</p

AFM image of G5 dendriplexes prepared for 20 minutes attacked by RNase enzyme.

<p>(A) AFM image of hexagonal G5 dendriplexes prepared by mixing of G5 dendrimers with 0.7 µg of anti-GAPDH siRNA at N/P ratio of 2/1 for 20 minutes at room temperature before loading onto the surface of freshly cleaved mica. AFM images of G5 dendriplexes after incubation with RNase V1 enzyme for 1–60 minutes (B–F) shows separation of the adsorbed dendriplexes and degradation of the complexed siRNA molecules (dark spots) that increased with the increase in incubation time. Scale bar in these images is 200 nm and the Z scale is 17 nm.</p