Microwave pyrolysis of pecan nut shell and thermogravimetric, textural and spectroscopic characterization of carbonaceous products

In the present work, the pyrolysis of pecan nut shell was studied using microwave technology at different input power and exposure time. The carbonaceous products were characterized using elemental analysis, potentiometric titration, thermogravimetric analysis, N2 adsorption isotherms at −196 °C and FT-IR spectroscopy. The characteristics of microwave carbonaceous products were compared with carbons prepared by conventional heating and commercial carbons and finally, the interaction of textile dyes with the carbonaceous materials was studied. The results are indicating that it is possible to obtain carbonaceous materials with similar textural parameters in conventional and microwave systems, but for microwave heating the processing times are short (3 min). Also, the exposure time of 2 min of microwave are not enough for the complete depolymerization of the lignocellulosic matrix of the pecan nut shell and significant amount of cellulose and hemicelluloses remain in char after microwave treatment. Finally, all the carbons obtained by microwave heating are microporous materials with a high number of basic groups on their surface and the high molecular size of dyes is controlling the adsorption on these materials

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature

Putting a MOOC for Human Rights in the hands of Kenyans : The Haki Zangu case for non-formal learning

The research goal of this project was to explore the use and effects of non-formal education and incentives in the context of a developing country. The practical aim of this project was to create, implement, and evaluate a platform about human rights that was available to any Kenyan for free in order to increase knowledge and engagement. Therefore, a non-formal massive open online course (MOOC) about human rights was designed and launched. The course was free and open to anyone in Kenya and offered both a digital badge and certificate from Stockholm University in Sweden upon completion. The course was called Haki Zangu (Kiswahili for “My Rights”), and it explored how using incentives such as a digital badge and certificate of completion affected learning outcomes. This course offered ubiquitous access based on principles of responsive web design and used audio recordings of the entire course content. The course is perpetual and still on-going, but after six months there were 160 participants who had enrolled, and ten participants had completed the course and received certificates and digital badges. The participants showed extensive enthusiasm and engagement for human rights issues, and they expressed desires to learn more and further spread knowledge about human rights. The current findings suggest that the availability of digital badges and certificates increased interest for participation and positively affected learning outcomes. Moreover, the use of a Massive Open Online Course (MOOC) format with incentives proved successful, combined with the contextualization and accessibility of the course content. Furthermore, the technical platform proved adequate for disseminating education for free in a developing country, and allowed for unencumbered access regardless of device. Lastly, a key challenge for future non-formal learning efforts in developing countries is the cost of Internet access

Advanced-stage mycosis fungoides: role of the signal transducer and activator of transcription 3, nuclear factor-kB and nuclear factor of activated T cells pathways

BACKGROUND: The malignant mechanisms that control the development of cutaneous T-cell lymphoma (CTCL) are beginning to be identified. Recent evidence suggests that disturbances in specific intracellular signalling pathways, such as RAS-mitogen-activated protein kinase, T-cell receptor (TCR)-phospholipase C gamma 1 (PLCG1)-nuclear factor of activated T cells (NFAT) and Janus kinase (JAK)-signal transducer and activator of transcription (STAT), may play an essential role in the pathogenesis of CTCL. OBJECTIVES: To investigate the mechanisms controlling disease development and progression in mycosis fungoides (MF), the most common form of CTCL. METHODS: We collected 100 samples that were submitted for diagnosis of, or a second opinion regarding, MF between 2001 and 2018, 80% of which were in the early clinical stages of the disease. Formalin-fixed paraffin-embedded tissues were used for histological review and to measure the expression by immunohistochemistry of surrogate markers of activation of the TCR-PLCG1-NFAT, JAK-STAT and NF-?B pathways. Folliculotropism and large-cell transformation were also examined. RESULTS: NFAT and nuclear factor kappa B (NF-?B) markers showed a comparable activation status in early and advanced stages, while STAT3 activation was more frequent in advanced stages and was associated with large-cell transformation. Consistently with this observation, STAT3 activation occurred in parallel with MF progression in two initially MF-negative cases. A significant association of NFAT with NF-?B markers was also found, reflecting a common mechanism of activation in the two pathways. Genomic studies identified nine mutations in seven genes known to play a potential role in tumorigenesis in T-cell leukaemia/lymphoma, including PLCG1, JAK3 and STAT3, which underlies the activation of these key cell-survival pathways. A higher mutational allele frequency was detected in advanced stages. CONCLUSIONS: Our results show that STAT3 is activated in advanced cases and is associated with large-cell transformation, while the activation of NFAT and NF-?B is maintained throughout the disease. These findings could have important diagnostic and therapeutic implications. What's already known about this topic? Mycosis fungoides is characterized by a clonal expansion of T cells in the skin. The mechanisms controlling disease development and progression are not fully understood. What does this study add? An association of the nuclear factor of activated T cells and nuclear factor kappa B pathways was found, which could reflect a common mechanism of activation. These pathways were activated in early and advanced stages at the same level. Signal transducer and activator of transcription 3 activation was associated with large-cell transformation and was more frequent in advanced stages. A genomic analysis of cutaneous T-cell lymphoma-associated genes was performed. Nine mutations were detected. What is the translational message? These results could have important implications for the treatment of MF in the near future.Funding: This study has been supported by grants from the Instituto de Salud Carlos III, from the Ministerio de Economía, Industria y Competitividad (SAF2013-47416-R, CIBERONC-ISCIII, ISCIII-MINECO-AES-FEDER (Plan Estatal I + D + I 2013–2016): PI14/00221, PIE14/0064, PIE15/0081, PIE16/01294, and FIS 17/0957)), Asociación española contra el Cáncer (AECC), Comunidad Autónoma de Madrid and from the Instituto Formación e Investigación Hospital Universitario Marqués de Valdecilla (IDIVAL): NVAL16/18

Study of the adsorption-desorption of Cu2+, Cd2+ and Zn2+ in single and binary aqueous solutions using oxygenated carbons prepared by Microwave Technology

In the present work was studied the adsorption-desorption of heavy metals from aqueous solutions using carbonaceous materials prepared with a technology that combines radiant and microwave heating. Three optimum carbons O-Cu, O-Cd and O-Zn were prepared and characterized using elemental analysis, potentiometric titration, nitrogen adsorption isotherms at - 196 °C, SEM/EDX analysis, and temperature programmed desorption (TPD). The three optimum carbons had very high oxygen contents mainly ascribed to surface functional groups of acidic nature. In contrast, the porosity of the carbons was very limited with specific surface areas being < 50 m2/g. Liquid adsorption isotherms were carried out and capacities of the three optimum carbons were 67, 26 and 24 mg/g for Cu2 +, Cd2 + and Zn2 +, respectively. The higher capacity of the O-Cu carbon was explained in terms of the higher electronegativity of metallic Cu and the theory of hard and soft acids and bases (HSAB) defined by Pearson, when compared with both Cd and Zn atoms. Additionally, the desorption percentage of heavy metals was lower than 10%