A novel two-phase bioprocess for the production of Arthrospira (Spirulina) maxima LJGR1 at pilot plant scale during different seasons and for phycocyanin induction under controlled conditions.

A two-phase outdoor cultivation bioprocess for Arthrospira maxima LJGR1 combined with phycocyanin induction in concentrated cultures under controlled conditions was evaluated using a modified low-cost Zarrouk medium. Growth was monitored during 4 cycles in 2018 and 4 cycles in 2019. Biomass was harvested and concentrated using membrane technology at the end of each cycle for further phycocyanin induction using blue LED light (controlled conditions, 24 h). The highest biomass productivity was observed during spring and summer cycles (13.63-18.97 gDWm-2 d-1); during mid-fall and mid-end fall, a decrease was observed (9.93-7.76 gDWm-2 d-1). Under favorable growth conditions, phycocyanin induction was successful. However, during cycles with unfavorable growth condition, phycocyanin induction was not observed. Reactive-grade phycocyanin (3.72 ± 0.14) was recovered and purified using microfiltration and ultrafiltration technologies.

Biotransformation of water lettuce (Pistia stratiotes) to biohydrogen by Rhodopseudomonas palustris.

AIMS: Aim of the paper was to assess the feasibility of producing hydrogen as a biofuel by photofermentation of fermented water lettuce (Pistia stratiotes L.) waste biomass, after a nitrogen-stripping treatment. METHODS AND RESULTS: A natural (42OL) and an engineered strain (CGA676, with low-ammonium sensitivity) of Rhodopseudomonas palustris were used for producing hydrogen. The stripping procedure was highly effective for ammonium removal, with an acceptable selectivity (91% of ammonium was removed; only 14% of total organic acids were lost). Both strains were able to produce hydrogen only in the nitrogen-stripped substrate. The natural strain R. palustris 42OL showed a higher Biochemical Hydrogen Potential (1224 ml l-1 vs 720 ml l-1 ; 50·0 mol m-3 vs 29·4 mol m-3 ), but at a lower rate (5·6 ml l-1  h-1 vs 7·3 ml l-1  h-1 ; 0·23 mol m-3  h-1 vs 0·29 mol m-3  h-1 ) than strain CGA676. CONCLUSIONS: Water lettuce waste biomass can be used for biofuel production, after hydrolization, fermentation and nitrogen stripping. SIGNIFICANCE AND IMPACT OF THE STUDY: The investigation on novel, low cost and sustainable biomasses as feedstocks for biofuel production is a priority. Aquatic plants do not compete for arable land. Moreover, water lettuce is a floating and invasive weed, thus its biomass must be harvested when detrimental, and can now be biotransformed in clean hydrogen.

Is Mexico Ready for Face Transplantation?

With the limitations of surgical reconstructive procedures, the growing number of gunshot wounds, burns, and work accidents in Mexico that result in complex facial deformities leaves only 1 option-face transplantation. The National Institute of Medical Sciences and Nutrition "Salvador Zubiran" (INCMNSZ) has performed transplants since 1971. We at INCMNSZ undertook the 1st bilateral upper-limb transplantation in Latin America in 2012. We are willing to continue in this manner toward conducting face transplantation at our institute. To this end, we identified and solved various challenges. The 1st challenge was acceptance and inclusion of vascularized composite allotransplantation (VCA) within general Mexican health law and approval of the face transplantation procedure. Subsequently, the health ministry provided a license to INCMNSZ to perform the procedure. The 2nd challenge concerned who would pay for the procedure. The costs will be paid by the patient (1st-party payer), social security institutions (2nd-party payers), and the health ministry (3rd-party payer). The 3rd challenge was to maintain ongoing surgical training of the team using cadavers. The fourth challenge was to locate donors; toward this end, we developed a campaign for promoting face donation in social media, making a comic book, and training organ and tissue coordinators to further VCA. Thus, INCMNSZ has the legal, administrative, medical, and surgical wherewithal to accomplish face transplantation.

Cytotoxicity assessment of some carbon nanotubes and related carbon nanoparticle aggregates and the implications for anthropogenic carbon nanotube aggregates in the environment.

Nanotechnology and nanomaterials have become the new frontier world-wide over the past few years and prospects for the production and novel uses of large quantities of carbon nanotubes in particular are becoming an increasing reality. Correspondingly, the potential health risks for these and other nanoparticulate materials have been of considerable concern. Toxicological studies, while sparse, have been concerned with virtually uncharacterized, single wall carbon nanotubes, and the conclusions have been conflicting and uncertain. In this research we performed viability assays on a murine lung macrophage cell line to assess the comparative cytotoxicity of commercial, single wall carbon nanotubes (ropes) and two different multiwall carbon nanotube samples; utilizing chrysotile asbestos nanotubes and black carbon nanoaggregates as toxicity standards. These nanotube materials were completely characterized by transmission electron microscopy and observed to be aggregates ranging from 1 to 2 microm in mean diameter, with closed ends. The cytotoxicity data indicated a strong concentration relationship and toxicity for all the carbon nanotube materials relative to the asbestos nanotubes and black carbon. A commercial multiwall carbon nanotube aggregate exhibiting this significant cell response was observed to be identical in structure to multiwall carbon nanotube aggregates demonstrated to be ubiquitous in the environment, and especially in indoor environments, where natural gas or propane cooking stoves exist. Correspondingly, preliminary epidemiological data, although sparse, indicate a correlation between asthma incidence or classification, and exposure to gas stoves. These results suggest a number of novel epidemiological and etiological avenues for asthma triggers and related respiratory or other environmental health effects, especially since indoor number concentrations for multiwall carbon nanotube aggregates is at least 10 times the outdoor concentration, and virtually all gas combustion processes are variously effective sources. These results also raise concerns for manufactured carbon nanotube aggregates, and related fullerene nanoparticles.

Carbon nanotubes and other fullerene nanocrystals in domestic propane and natural gas combustion streams.

Carbon nanotubes and other aggregated fullerene-related multi-layer shell structures have been collected in propane and natural gas flame emissions from domestic cooking stoves and observed by transmission electron microscopy. Some aggregated nanoparticles collected on 3 mm electron microscope grids by thermal precipitation were mostly multi-walled nanotubes; many tangled and distorted, and aggregated with other closed-concentric, multi-shell forms. Such clean-burning regimes may be major contributors to complex particulate matter in indoor and outdoor air.

The Shulman syndrome.

The Shulman syndrome is a symptom complex recently described in the rheumatology literature that is characterized by eosinophilia, hypergammaglobulinemia, and a diffuse scleroderma-like process of the extremities. The onset of illness has been associated with a period of unusual physical exertion. The condition seems to respond to corticosteroid therapy for systemic effect.