Biopolymers from Waste Biomass — Extraction, Modification and Ulterior Uses

The residues coming from woodlands and agricultural exploitation constitute the most abundant biomass available on earth. Its importance as a source of renewable energy has grown in addition to the environmental impact. Biomass waste is a lignocellulosic feedstock which contains three main biopolymers: cellulose, hemicellulose and lignin. It could be utilized for the production of a number of value-added products due to their chemical composition, but it is necessary to efficiently recover the valuable biopolymer as intact as possible by different processing techniques.For different applications, the principal objective of pre-treatment is to keep the cellulose intact, meanwhile hemicellulose and lignin are removed. The yields of the fractions depend on the pre-treatment method, which is the most expensive step in biomass conversion. Traditionally, cellulose is obtained by kraft, sulphite and soda treatments. These methods are non-environmentally friendly and generate huge quantities of toxic wastes. Recently developed models considering the environmental laws encourage the sustainable processing of biomass into value-added products. The use of ionic liquids as new solvents for biomass waste and organosolv processes is reviewed, which are used to obtain cellulose. One of the possible applications of cellulose is membrane synthesis, which has been reported for other biomass materials, such as sugarcane bagasse, mango seed and newspaper. In this chapter, some green pre-treatment methods, different sustainable routes for cellulose modification and some of the results obtained on membrane development based on waste biomass are discussed

Marco teórico en el diseño industrial

En el campo del diseño, y por la propia naturaleza del trabajo disciplinar, los conceptos que se construyen y que son propios del discurso proyectual, son los sistemas que generan formas estéticas, formas perceptuales que satisfacen necesidades, que solucionan problemas antropológicos, que conforman la cultura material y que por supuesto abonan al conocimiento del diseño. Por eso al nombrar distintos objetos como: silla, mesa, sofá, estufa, refrigerador, plancha, ordenador, escritorio, radio, grabadora, entre muchos otros que rodean la vida cotidiana de nosotros los humanos, no sólo nos referimos a la cosa tangible, material y presente, también nos referimos a la idea, al concepto, al sistema, a la imagen que formamos mentalmente y que tiene para nosotros una estructura y una apariencia exterior, una figura que nos posibilita si ya existe, o posibilitará en el porvenir la estética y con ello la asignación de significados según la circunstancia en que se encuentre

Effect of heavy metals and environmental variables on the assimilation of CO2 and stomatal conductance of Ligustrum lucidum, an urban tree from Mexico City

Urban trees reduce CO2 and pollutants that represent a risk for human health in cities. In this work, we assessed the potential effect of heavy metals and environmental variables on the CO2 assimilation (A) and the stomatal conductace (gS) of Ligustrum lucidum, a common urban tree in Mexico City. We compared two sites with contrasting pollution levels: 1) city centre (PPI-C, high pollution level); and 2) south of the city (CU-SW; low pollution level). At each site, we measured 1) phsysiological traits (A and gS); 2) environmental variables (photosynthetically active radiation, PAR; air temperature, TA; vapor pressure deficit, VPD; concentration of atmospheric CO2); and 3) morphological leaf characteristics (stomatal size and density). Concentration of the heavy metals Pb, Cd, Cr, Cu, Mn, Fe, and Zn was determined in washed (internal metals) and unwashed (external plus internal metal) leaves at both sites. CO2 assimilation at CU-SW was higher than at PPI-C. PAR had the greatest effect on A; whereas TA and VPD had the greatest effect on gS. Regarding heavy metals, although we found no significant differences in internal concentrations between sites, we found a lower stomatal density at PPI-C, which may indicate a response of the species to the local pollution conditions. This characteristic might be benefitial for the species, allowing it to maintain optimal physiological conditions by reducing the assimilation of pollutants. Our results suggest that L. lucidum is a well adapted species for the urban environment

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

•We report INICC device-associated module data of 50 countries from 2010-2015.•We collected prospective data from 861,284 patients in 703 ICUs for 3,506,562 days.•DA-HAI rates and bacterial resistance were higher in the INICC ICUs than in CDC-NHSN's.•Device utilization ratio in the INICC ICUs was similar to CDC-NHSN's. Background: We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific. Methods: During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days. Results: Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs. Conclusions: Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically