Soybean production potential in Africa

Soybean (Glycine max [L.] Merr.) could possibly become a major crop in Africa due to its many uses as a food, feed, and in industry. Also, its ability to undertake symbiotic nitrogen fixation is a great advantage over cereal crops. This study simulated yield potential across west and east Africa. A number of areas were excluded from soybean production because of inadequate early season rains to allow timely sowing of the crop. Among the remaining areas, average yields greater than 200 g m−2 were commonly simulated. Two drought traits were examined as plant modifications to increase yields. These results identified those areas and plant traits in Africa where soybean has the potential to be an important, viable crop

Adsorption at cell surface and cellular uptake of silica nanoparticles with different surface chemical functionalizations: impact on cytotoxicity

International audienceSilica nanoparticles are particularly interesting for medical applications because of the high inertness and chemical stability of silica material. However, at the nanoscale their innocuousness must be carefully verified before clinical use. The aim of this study was to investigate the in vitro biological toxicity of silica nanoparticles depending on their surface chemical functionalization. To that purpose, three kinds of 50 nm fluorescent silica-based nanoparticles were synthesized: 1) sterically stabilized silica nanoparticles coated with neutral polyethylene glycol (PEG) molecules, 2) positively charged silica nanoparticles coated with amine groups and 3) negatively charged silica nanoparticles coated with carboxylic acid groups. RAW 264.7 murine macrophages were incubated for 20 hours with each kind of nanoparticles. Their cellular uptake and adsorption at the cell membrane were assessed by a fluorimetric assay and cellular responses were evaluated in terms of cytotoxicity, pro-inflammatory factor production and oxidative stress. Results showed that the highly positive charged nanoparticle, were the most adsorbed at cell surface and triggered more cytotoxicity than other nanoparticles types. To conclude, this study clearly demonstrated that silica nanoparticles surface functionalization represents a key parameter in their cellular uptake and biological toxicity

Treatment of lung cancer using nanoparticle drug delivery systems

Context: One of the leading causes of cancer-associated deaths in most men and women in the Western world is lung cancer. There are various types of treatments depending on the type and the stage of the cancer. A recent type of therapy is targeted gene therapy which aims to target genes that cause lung cancer. However, this therapy has some drawbacks including lack of proper vectors for delivery. These drawbacks can potentially be overcome by using various types of nanoparticles.Objective: To review current literature on the treatment of lung cancer with nanoparticles.Methods: Researchers have attempted to treat lung cancer with a variety of types of nanoparticle matrices including lipid, polylactide-co-glycolide, albumin, poly (-pentadecalactone-co-butylene-co-succinate), cerium oxide, gold, ultra-small superparamagnetic iron oxide nanoparticles, super paramagnetic iron oxide, lipid–polycation–DNA, N-[1-(2,3-dioleoyloxyl)propyl]-NNN-trimethylammoniummethylsulfate, silica-overcoated magnetic cores, and polyethyleneglycol phosphatidylethanolamine. There are various ways in which nanoparticles enhance drug delivery, and these include encapsulation against immune response, tissue penetration, target selectivity and specificity, delivery monitoring, promoting apoptosis, and blocking pathways for cancer initiation and progression.Conclusion: In the past decade, a lot has been said about targeting of NPs for lung and other cancers, but little has been actually successfully delivered to date. Nevertheless, nanoparticles can act as good vectors for delivering drug to the target neoplastic lesions within the lung, increase cellular uptake, increase tissue penetration and help in tracking the drug. In the future, combination therapies may play a key role in the treatment of lung cancer using the existing therapies

Sertoli Cells Loaded with Doxorubicin in Lipid Micelles Reduced Tumor Burden and Dox-Induced Toxicity

The toxic side effects of doxorubicin (Dox) limit its long-term use as a lung cancer chemotherapeutic. Additionally, drug delivery to the deep lung is challenging. To address these challenges, isolated rat Sertoli cells (SCs) were preloaded with Dox conjugated to lipid micelle nanoparticles (SC-DLMNs) and delivered to mouse lungs. These immunocompetent cells, when injected intravenously, travel to the lung, deliver the payload, and get cleared by the system quickly without causing any adverse reaction. We observed that SC-DLMNs effectively treated Lewis lung carcinoma 1-induced lung tumors in mice and the drug efficacy was comparable to SC-Dox treatment. Mice treated with SC-DLMNs also showed significantly less toxicity compared to those treated with SC-Dox. The encapsulation of Dox in lipid micelle nanoparticles reduced the toxicity of Dox and the SC-based delivery method ensured drug delivery to the deep lung without evoking any immune response. Taken together, these results provide a novel SC-based nanoparticle drug delivery method for improved therapeutic outcome of cardiotoxic antilung cancer drugs

Strong Geometrical Effects in Submillimeter Selective Area Growth and Light Extraction of GaN Light Emitting Diodes on Sapphire

Advanced semiconductor devices often utilize structural and geometrical effects to tailor their characteristics and improve their performance. We report here detailed understanding of such geometrical effects in the epitaxial selective area growth of GaN on sapphire substrates and utilize them to enhance light extraction from GaN light emitting diodes. Systematic size and spacing effects were performed side-by-side on a single 2” sapphire substrate to minimize experimental sampling errors for a set of 144 pattern arrays with circular mask opening windows in SiO(2). We show that the mask opening diameter leads to as much as 4 times increase in the thickness of the grown layers for 20 μm spacings and that spacing effects can lead to as much as 3 times increase in thickness for a 350 μm dot diameter. We observed that the facet evolution in comparison with extracted Ga adatom diffusion lengths directly influences the vertical and lateral overgrowth rates and can be controlled with pattern geometry. Such control over the facet development led to 2.5 times stronger electroluminescence characteristics from well-faceted GaN/InGaN multiple quantum well LEDs compared to non-faceted structures