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Covered anaerobic lagoons (CALs) are Latin America's main livestock waste treatment systems. Mexico has 680 CALs that present low biogas yields (0.05 m3 m−3 digester d−1) and low COD removal rates (< 60%). This work focused on diagnosing CAL´s low performance in dairy farms by determining and analyzing operational parameters. Seven CALs located in the main dairy basin of Mexico were analyzed. The sampling areas for each CAL were the supernatant, the active zone, settled sludge, and digester inlet and outlet. The variation of the process parameter values corroborated that CALs appeared stratified and not working as expected. The sludge zone, comprising 50–58% of total solids content and 1–15% of total CALs volume, showed an elemental compounds content suitable for organic fertilizer (340, 48, and 5 kg t−1 of C, N, and S, respectively). However, this zone contained, at least, 85% of the slowly hydrolysable material; the methanogenic potential was less than 87 mL CH4 g VS−1, and the C/N ratio ranged from 4.9 to 17, outside of the optimal range. The biogas produced did not exceed 60% of methane content and more than 3000 ppm of H2S. The sludge zone significantly influences the lagoon's dynamics since it is a nutrient sink. Furthermore, the lack of agitation is the leading cause for the low energy yield and the low removal of organic matter rate. This work provides valuable information to address the operational problems within the CALs improving our understanding that shall allow proposing reactivation alternatives. [ABSTRACT FROM AUTHOR]

The Verbesina gender represents the second most diverse group from the Asteraceae family in Mexico; Verbesina sphaerocephala is one of the most distributed species along the Mexican territory. This species has been poorly studied, reporting the presence of some bioactive compounds with antioxidant and antibacterial activity. In this study, phenolic and flavonoid contents and composition, antioxidant and antifungal activities of aqueous extracts of the stem of V. sphaerocephala and its fractions were determined. The results showed that the highest antifungal activity against Botrytis cinerea was shown by the aqueous extract (IC50: 0.10 mg/mL) and the ethyl acetate fraction (IC50: 14.8 mg/mL). In addition, the aqueous extract and the ethyl acetate fraction exhibited the highest phenolic (21.40 and 21.26 mg gallic acid equivalents per gram of dry extract, respectively) and flavonoid contents (11.53 and 3.71 mg rutin equivalents, respectively) and high antioxidant activity determined by the Total Antioxidant Capacity (20.62 and 40.21 mg ascorbic acid equivalents per gram of dry extract, respectively), Ferric Reducing Power (74.76 and 129.57 mg gallic acid equivalents per gram of dry extract, respectively), DPPH (IC50: 12.38 and 7.36 mg/mL, respectively), and ABTS (IC50: 5.60 and 7.76 mg/mL, respectively) methods. Twelve phenolic compounds were detected in the aqueous extract using UPLC-MS analysis, of which the major ones were protocatechuic, vanillic, and hydroxybenzoic acid, while in the ethyl acetate fraction, the presence of 18 phenolic compounds were identified, of which the majority were vanillin, rutin, and hydroxybenzoic acid. The results of this research demonstrate that the aqueous extract of V. sphaerocephala stems has phenolic compounds with antifungal and antioxidant activity. [ABSTRACT FROM AUTHOR]

Copyright of Middle Atlantic Review of Latin American Studies is the property of Middle Atlantic Council of Latin American Studies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Native corn in Cherán, Michoacán, southwestern Mexico, represents a high-impact economic, social, and religious support, although its yield is low due to fungal diseases. Fungicides are mainly used for their control, but the fungi involved create resistance. The aims of this study are to determine the incidence of foliar diseases in the field, isolate the causal fungi, evaluate the in vitro effect of the essential oil of rue (Ruta graveolens) on them, and identify the secondary metabolites. The essential oil was obtained using the steam distillation technique on fresh plants. Also used was an industrial-grade chitosan, and the commercial fungicide benomyl was used as a positive control. Rue essential oil was characterized by mass spectrometry with ultra-high-performance liquid chromatography with electrospray ionization (UHPLC-ESI). The highest incidence of disease was obtained for leaf rust (35%), followed by gray leaf spot (GLS) (24%) and leaf blight (19%). Rue essential oil inhibited 100% of the mycelial growth of Coniothyrium phyllachorae and 96% of the mycelium of Exseroilum turcicum. The benomyl fungicide effectively inhibited C. phyllachorae (86 to 91%), but not E. turcicum, with the opposite effect when using chitosan by inhibiting 89 to 90% of the latter's mycelial development. The majority compound of the essential oil of R. graveolens was 2-(3-phenylprop-2-enoyl)chromen-4-one; however, fatty acids were also detected: linoleic, palmitic, and retinoic acid. [ABSTRACT FROM AUTHOR]

Cosmos sulphureus Cav. (Asteraceae), and endemic plant of Mexico is used in herbal medicine. In this study, the phytochemical composition, phenolic content, and antioxidant activity of ethanolic and methanolic extracts from C. sulphureus leaves and flowers were determined. The phytochemical analysis showed the presence of compounds such as terpenoids, phenolic compounds, tannins, and flavonoids and the absence of alkaloids, saponins, glycosides, and anthraquinones. The experimental results showed that the extracts have high contents of phenolic, flavonoid, and condensed tannins contents. The phenolic compounds identified in the C. sulphureus extracts by high-performance thin-layer chromatography (HPTLC) include phenolic acids such as chlorogenic acid and caffeic acid as well flavonoids such as rutin and quercetin. The C. sulphureus extracts showed a relevant free radical scavenging activity, ferric-reducing antioxidant power, lipid peroxidation inhibition ability, and oxygen radical antioxidant capacity. This research highlights the phytochemical profile and antioxidant activity of phenolic compounds-rich extracts from C. sulphureus leaves and flowers. [ABSTRACT FROM AUTHOR]

Copyright of Revista Medica del IMSS is the property of Direccion de Prestaciones Medicas - IMSS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gaceta Médica de Caracas is the property of Academia Nacional de Medicina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Current society is characterized by the increasing impact of online communication tools. In recent years, researchers have dedicated their efforts to the study of addictive behavior to internet and social networks as it is essential to know both the benefits and possible issues that the internet could hold for the youth and new generations. Moreover, it is fundamental to inquire about the personality traits that have influence over addictive behavior. As such the objective of this study was to measure the link between the model of five personality traits and the problematic use of social networks. In this regard, different surveys were applied online to a sample of 251 university students between the age of 18 and 24 years old. The surveys used are as follows: a questionnaire that collects socio-demographic data, the big five inventory (BFI) and the social networking addiction questionnaire (SNA). The results are: (1) a positive correlation between the neuroticism and addictive behavior to social networks, (2) a notable yet negative correlation between responsibility and kindness and (3) there was no link found between extroversion and openness to experience. In conclusion, the obtained results contribute empirical evidence of the relation between the personality and the addictive behavior to the social networks. [ABSTRACT FROM AUTHOR]

Copyright of Neotropical Ichthyology is the property of Neotropical Ichthyology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The family Pseudopimelodidae is widely distributed in South America and includes 51 described species organized in seven genera. Only two of four species of the genus Pseudopimelodus have been recorded for the trans-Andean basins of Colombia, Pseu- dopimelodus bufonius and P. schultzi, whose similarity in external morphology make their identification difficult. We performed a phylogenetic analysis using a fragment of the Cytochrome C Oxidase subunit 1 gene (COI), and analyzed osteological and traditional morphometric characters to study Pseudopimelodus from the Colombian trans-Andean region. Results provided strong support for two clades phylogenetically related to Pseudopimelodus, that showed clear-cut molecular, osteological, and morphometric differences from previously described bumblebee catfishes. Based on these results, we describe two Pseudopimelodus species from the Magdalena-Cauca River Basin: P. magnus sp. nov. with 43-44 vertebrae, dorsal-fin spine with serrations on its anterior margin; lateral margin of transverse process of the fourth vertebra of the Weberian complex forming an acute angle in ventral view and P. atricaudus sp. nov. with 39 vertebrae, dorsal-fin spine smooth on its anterior margin and a dark, vertical band covering 3/4 of the caudal fin with base of rays and tip of caudal-fin lobes hyaline. [ABSTRACT FROM AUTHOR]

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In our study, it was found that solid–liquid extraction solvent influenced the phenolic content in leaf extracts of Stevia origanoides, S. ovata and S. viscida. The highest total phenolic and flavonoids contents, the highest scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical, and the highest total antioxidant capacity values were observed when 50% ethanol was used. The phenolic compounds identified in the Stevia leaf extracts by high-performance liquid chromatography with diode array detection (HPLC-DAD) include phenolic acids such as chlorogenic, caffeic, p-coumaric and vanillic acid, as well as flavonoids such as quercetin and kaempferol. [ABSTRACT FROM AUTHOR]

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The total phenolic and flavonoid content, phenolic composition, and in vitro antioxidant capacity of ethanolic extracts of Ximenia parviflora Benth. var. parviflora fruits collected at Zinaparo, Michoacan (in central Mexico) were determined. Fruit extracts present a high scavenging activity of 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] radicals (71.49 ± 0.11% and 85.00 ± 1.29% inhibition, respectively). The four phenolic compounds identified in fruit extracts by high-performance liquid chromatography with diode array detection were gallic acid, chlorogenic acid, caffeic acid, and quercetin. X. parviflora fruits may be used as a starting material for the extraction of high value antioxidant phenolic compounds with potential applications in the pharmaceutical and dietary supplement industries. [ABSTRACT FROM AUTHOR]

The main objective of this study was to analyze the direct and indirect relationships among sexting, cybervictimization, depression, and suicidal ideation. The sample consisted of 303 university students from Mexico (mean age = 19.73, SD = 1.73) who completed a questionnaire about the variables of interest. The relationships among the variables were analyzed using structural equation modeling. The results show that sexting was associated with being the victim of cyberbullying, which, in turn, was related to depressive symptoms. In addition, sexting, cybervictimization, and depressive symptoms were significantly associated with suicidal ideation. These results contribute to a better understanding of the relationship between online risk behaviors, such as sexting, and their possible negative consequences, such as cybervictimization, depression, and suicidal ideation. [ABSTRACT FROM PUBLISHER]

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Solanum ferrugineumJacq. is a wild species that in previous analysis reported a significant antioxidant capacity. The aim of our research was to determine total phenolic content (TPC) and total flavonoid content (TFC), and the phenolic composition by HPLC-DAD and HPLC/ESI-MS/TOF of methanolic extracts ofS. ferrugineumfruits, collected from Paredones, Jiquilpan, and Fray Dominguez, Pajuacarán in the Mexican state of Michoacán. TPC and TFC were determined by the spectrophotometric Folin–Ciocalteu reagent and the AlCl3method, respectively. TPC inS. ferrugineumfruit [31.41 ± 0.91 mg gallic acid equivalent/g dry tissue (DT)] was similar to those reported for Turkey berry (Solanum torvumSw.) and eggplant (Solanum melongenaL.) fruits. The TFC values ofS. ferrugineumfruits (29.14 ± 4.99 mg catechin equivalent /g DT) corresponded to 80.24% of the TPC. Eight phenolic compounds (PC) were identified by HPLC analysis. The main PC identified inS. ferrugineumfruits were chlorogenic acid, caffeic acid,p-coumaric acid, gallic acid, quercetin, and kaempferol.S. ferrugineumfruits could be used as a starting material for the extraction of high-value PC with potential applications. [ABSTRACT FROM PUBLISHER]

In this research, the production of granular activated carbon from coffee waste (CW) by chemical activation with zinc chloride was studied by using a 2³ factorial design with the three responses (surface area, yield, and hardness) and studying three factors (the activation temperature, activation time, and impregnation ratio). The findings expose that after the experimental design, the highest response values were achieved at an activation temperature of 600°C, an activation time of 40 min, and an impregnation ratio of 1.5 g ZnCl2 g-1 CW. At these conditions, the experimental tests produced a surface area of 1,279 m² g-1. Batch studies of phenol adsorption onto coffee waste-activated carbon (CW-GAC) were performed at different solution pH, stirring speeds, and initial phenol concentrations. The maximum phenol adsorption capacity onto CW-GAC was 160.52 mg g-1 at pH 7. The adsorption kinetics was affected by stirring speed, the required time to achieve equilibrium decreased from 150 to 120 min when stirring speed varied from 200 to 400 min-1. Film and intraparticle diffusion mechanisms controlled the adsorption of phenol onto CW-GAC. Finally, the porous material developed in this research is capable of sequestering phenol from aqueous solutions to a higher extent than similar lignocellulosic-based activated carbons. [ABSTRACT FROM AUTHOR]

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A mathematical model for the pyrolysis process of pecan nutshells in a thermogravimetric balance was developed. The model included the application of mass and energy conservation equations that assumed that the milled nutshell had a spherical shape. A kinetic progressive conversion model (PCM) for the main biomass components was proposed in this work. The pecan nutshell was characterized through elemental and ultimate analyses. Additionally, thermogravimetry (TG) and differential scanning calorimetry (DSC) studies were conducted under pyrolytic conditions. The kinetic parameters and mass transport properties were obtained as a function of the particle size by adjusting the proposed model to fit the TG and DSC experimental data through a simplex optimization method. The best fitting of the proposed model was for particle diameters of 3 and 4 mm. The calculated activation energy values for hemicellulose were found to be very high when compared with values from other works, while the values for the cellulose and lignin were more similar. These results can be helpful in scaling up a pyrolytic pecan nut process, as well as improving the understanding of the phenomena involved during the pyrolysis. [ABSTRACT FROM AUTHOR]

In this study, amberlite XAD-16 (XAD-16) bed column system was used to remove ferulic acid (FA) from aqueous solutions. Laboratory-scale column experiments were conducted in downflow fixed bed at initial FA concentration of 1 g/L, initial pH 3, and 25°C. The performance of the adsorbent bed under different flow rates (1.3–7.7 mL/min) was studied. The bed utilization efficiency was in the range of 64.64–72.21% at the studied flow rates. A mass transfer model considering both axial dispersion and intraparticle diffusion was developed to predict the breakthrough curves of FA adsorption on XAD-16. This model predicted the experimental data better than Bohart–Adams model and Thomas model, based on the low deviation between predicted and experimental data. The axial dispersion coefficient value varied from 6.45 × 10−6to 1.10 × 10−6 m2/s at flow rate from 1.3 to 7.7 mL/min, whereas the intraparticle diffusion coefficient was 1.04 × 10−10 m2/s, being this last resistance the rate-limiting step. In conclusion, axial dispersion and intraparticle diffusion phenomena play the major role in predicting the adsorption of FA onto XAD-16 in fixed-bed columns. [ABSTRACT FROM PUBLISHER]

Background: Cirrhosis and severe sepsis are factors associated with increased mortality in intensive care unit (ICU), but chronic hepatitis C (CHC) has been less studied in ICU. The aim of this study was to analyze the impact of CHC on the mortality of cirrhotic patients admitted to ICU according to severe sepsis and decompensated cirrhosis.Methods: We carried out a retrospective study based on CHC-cirrhotic patients (CHC-group) admitted to ICU (n = 1138) and recorded in the Spanish Minimum Basic Data Set (2005-2010). A control-group (randomly selected cirrhotic patients without HIV, HBV, or HCV infections) was also included (n = 4127). The primary outcome variable was ICU mortality. The cumulative mortality rate on days 7, 30, and 90 in patients admitted to the ICUs was calculated by dividing the number of deaths by the number of patients admitted to the ICU. The adjusted hazard ratio (aHR) for death in the ICU was estimated through a semi-parametric Bayesian model of competing risk.Results: The CHC-group had a higher cumulative incidence of severe sepsis than the control-group in compensated cirrhosis (37.4 vs. 31.1%; p = 0.024), but no differences between the CHC-group and the control-group in decompensated cirrhosis were found. Moreover, a higher cumulative incidence of severe sepsis was associated with decompensated cirrhosis compared to compensated cirrhosis in the control-group (40.1 vs. 31.1%; p < 0.001) whereas this was not observed in the CHC group (38.1 vs. 37.4%; p = 0.872). The CHC-group had higher cumulative mortality than the control-group by days 7 (47 vs. 41.3%; p < 0.001), 30 (78.5 vs. 73.5%; p < 0.001), and 90 (96.3 vs. 95.9%; p < 0.001). In a competitive risk model, the CHC-group had a higher risk of dying if the ICU course was complicated by severe sepsis (adjusted hazard ratio (aHR) = 1.19; p = 0.003), but no significant values in patients with absence of severe sepsis were found (aHR = 1.09; p= 0.068). When patients were stratified by cirrhosis stage and severe sepsis, CHC patients with compensated cirrhosis had the higher risk of death if they had severe sepsis (aHR = 1.35; p = 0.002). Moreover, the survival was low in patients with decompensated cirrhosis and severe sepsis but we did not find significant differences between CHC-group and control-group.Conclusions: CHC was associated with an increased risk of death in cirrhotic patients admitted to ICUs, particularly in patients with compensated cirrhosis and severe sepsis. [ABSTRACT FROM AUTHOR]

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Fruits of wild species of the genus Physalis are consumed as food and calyces and leaves are used in traditional medicine. The phenolic composition of the species of this genus have been scarcely studied. To contribute to a better knowledge for the use of all the potential of these wild species of plants, leaves, fruits, and calyces of five wild species of the genus were analyzed for their phenolic composition and antioxidant properties. Results: Important tissue- and species-dependent variations were found. Calyces of Physalis subulata showed the highest contents of phenolics (176.58 mg of gallic acid equivalents/g dry tissue), flavonoids (39.63 mg/g dry tissue), and phenolic acids (50.57 mg of quercitrin equivalents/g dry tissue), and its leaves displayed the highest total antioxidant capacity (3.59 mg of ascorbic acid equivalents/mL) and one of the highest reduction powers (0.54 µg of ascorbic acid equivalents/mL). A high performance liquid chromatography with photodiode array detection analysis revealed a total of 28 phenolic compounds in foliar tissues (mainly kaempferol-3- O-glycosides), 16 in fruits (mainly phenolic acids), and 16 in calyces (mainly kaempferol-3- O-glycosides); the profiles of these compounds in the three types of tissue were species-specific. Conclusions: The studied species of Physalis are important sources of phenolics with relevant antioxidant activity. The current results indicate that phenolic profiles are valuable specific chemical markers and can be relevant as food tracing and authenticity indicators for plant-based preparations involving species of Physalis. [ABSTRACT FROM AUTHOR]

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Actualidad Jurídica Ambiental is the property of CIEMAT, through its Centro Internacional de Estudios de Derecho Ambiental (CIEDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The presence of dyes in effluent is a matter of concern due to their toxicologic and aesthetical effects. In this research, locally available agro-industrial wastes (Zea mayspericarp, ZMP;Agave tequilanabagasse, ATB; andMedicago sativawaste, MSW) were used as alternative low-cost adsorbents for the removal of methylene blue (MB) from aqueous solutions. The adsorbents were characterized physically and chemically by Fourier transform infrared, scanning electron microscopy, potentiometric titrations, and N2physisorption. MB adsorption experiments were carried out in batch systems and experimental data were used to calculate the adsorption isotherm model parameters (Langmuir, Freundlich, and Temkin) and the adsorption kinetic model parameters (pseudo-first- and pseudo-second-order models). MB-loaded biosorbents were desorbed with deionized water, ethanol (10% and 50% v/v), hydrochloric acid (0.01 and 0.05 N), and sodium hydroxide (0.1 N) at room temperature, and the best eluent was used in various adsorption–desorption cycles. The selected agricultural wastes can be considered as promising adsorbents for dye uptake from water since they exhibit considerable MB adsorption capacity (MSW 202.6 mg g−1, ATB 156.2 mg g−1, and ZMP 110.9 mg g−1), but it is lower than that reported for activated carbon; however, the biosorbents show higher adsorption rate than powdered activated carbon. Furthermore, the adsorbents can be economically regenerated with HCl solutions and reused for seven adsorption–desorption cycles. [ABSTRACT FROM PUBLISHER]

The potential use of spent coffee ground (SCG) for the removal of copper has been investigated as a low-cost adsorbent for the biosorption of heavy metals. Adsorption batch experiments were conducted to determine isotherms and kinetics. The biosorption equilibrium data were found to fit well the Freundlich model and an experimental maximum biosorption capacity of copper ions 0.214 mmol/g was achieved. The biosorption kinetics of SCG was studied at different adsorbate concentrations (0.1-1.0 mM) and stirring speeds (100-400/min). The results showed an increase in the copper ion uptake with raising the initial metal concentration and the kinetic data followed the pseudo-second order rate expression. The effect of stirring speed was a significant factor for the external mass transfer resistance at 100/min and coefficients were estimated by the Mathews and Weber model. Biosorption of copper ions onto SCG was observed to be related mainly with the release of calcium and hydrogen ions suggesting that biosorption performance by SCG can be attributed to ion-exchange mechanism with calcium and hydrogen ions neutralizing the carboxyl and hydroxyl groups of the biomass. [ABSTRACT FROM AUTHOR]

Several reactor configurations have been tested for catalytic propane dehydrogenation employing Pt-Sn/MgAl2O4 as a catalyst. Pd-Ag alloy membranes coupled to the multifunctional Two-Zone Fluidized Bed Reactor (TZFBR) provide an improvement in propane conversion by hydrogen removal from the reaction bed through the inorganic membrane in addition to in situ catalyst regeneration. Twofold process intensification is thereby achieved when compared to the use of traditional fluidized bed reactors (FBR), where coke formation and thermodynamic equilibrium represent important process limitations. Experiments were carried out at 500-575 °C and with catalyst mass to molar flow of fed propane ratios between 15.1 and 35.2 g min mmol-1, employing three different reactor configurations: FBR, TZFBR and TZFBR + Membrane (TZFBR + MB). The results in the FBR showed catalyst deactivation, which was faster at high temperatures. In contrast, by employing the TZFBR with the optimum regenerative agent flow (diluted oxygen), the process activity was sustained throughout the time on stream. The TZFBR + MB showed promising results in catalytic propane dehydrogenation, displacing the reaction towards higher propylene production and giving the best results among the different reactor configurations studied. Furthermore, the results obtained in this study were better than those reported on conventional reactors. [ABSTRACT FROM AUTHOR]

Background Limited data are available on the use of unboosted atazanavir in combination with nucleoside reverse transcriptase inhibitors (NRTIs) in treatment-experienced HIV-infected patients. Methods We conducted a multicentre, retrospective study among patients with plasma HIV-1 RNA levels <50 copies/mL under antiretroviral therapy who switched to unboosted atazanavir + NRTIs between January 2002 and December 2008. Virological failure during follow-up was defined as a confirmed plasma HIV-1 RNA level >50 copies/mL. Baseline risk factors for virological failure were identified using Cox proportional hazards models. Results A total of 886 patients were analysed. At baseline, median age was 44 years, 71.5% were males and median CD4 cell count was 490 cells/mm3. NRTIs used in combination with atazanavir were tenofovir, abacavir and emtricitabine/lamivudine in 36.9%, 44.1% and 94.4% of patients, respectively. Median follow-up was 21 months. The 3 year probability of virological failure was 20.1%. Only a history of virological failure under NRTIs [hazard ratio (HR) 1.63, P = 0.049] and under protease inhibitors (HR 2.04, P = 0.006) were significantly associated with the risk of virological failure. Among the 431 patients without a prior history of virological failure, the 3 year probability of virological failure was 11.3%, and only hepatitis C virus co-infection (HR 2.25, P = 0.026) and abacavir use (HR 0.43, P = 0.04) were associated with the risk of virological failure. Safety of the switch was satisfactory, with improvement of the lipid profile. Conclusions In patients with virological suppression and no prior history of virological failure, a switch to unboosted atazanavir in combination with NRTIs is associated with a low probability of virological failure and a good safety profile. [ABSTRACT FROM PUBLISHER]