, 2009) properties Rosemary has one of the highest antioxidant a

, 2009) properties. Rosemary has one of the highest antioxidant activities of all the herbs and spices that have been investigated ( Wojdyło, Oszmian´ski, & Czemerys, 2007). The antioxidant activity of rosemary justifies

its use in a broad range of applications, including food preservatives ( Hamre, Kolås, & Sandnes, 2010), cosmetics ( Lee et al., 2011), nutraceuticals and phytomedicines ( Ibarra et al., 2010). These medicinal attributes can be related to rosemary’s high content of polyphenolic compounds, especially rosmarinic acid ( Erkan, Ayranci, & Ayranci, 2008), which is considered a chemical marker of this species. Despite rosemary’s medicinal and commercial importance, there is little information on its behaviour during processing and standardisation.

Accordingly, undertaking a study to elucidate the effects of processing factors on product properties during the manufacture of standardised dried rosemary extracts Ulixertinib is fully justified. In this work response surface methodology (RSM) was used to verify the effect of processing parameters on the chemical markers contents and “in vitro” antioxidant activities of rosemary extracts obtained via spray drying. Rosmarinic acid (98%), rutin (98%), tannic acid (98%) and 2,2-diphenyl-1-picrylhydrazyl (DPPH ) were purchased from Sigma–Aldrich (Sigma–Aldrich Co., Steinheim, Germany). Acetonitrile and methanol were of HPLC grade (Tedia Brazil, Rio de Janeiro, RJ, Brazil). Additionally, anhydrous formic acid (Impex Ltd., Diadema, SP, Brazil), ethanol (Chemis Ltda., São Paulo, SP, Brazil) selleckchem and ultrapure water from a Milli-Q system (Millipore®, Bedford, MA) were used. All other chemicals were of reagent grade and were used without further purification. Samples of rosemary leaves were collected from specimens located in the medicinal plants garden of Hospital de Medicina Alternativa da Secretaria Estadual da Saúde do Estado de Goiás (863 m, 16°43′50.3″ South, 49°14′32.9″ West/Goiânia, DNA Synthesis inhibitor GO, Brazil). Once identified, a voucher specimen was prepared and deposited in the Universidade Federal de Goiás (UFG) Herbarium under the registration identification UFG – 43206. The leaves were dried at room temperature

and ground in a knife mill TE-625 (Tecnal Ltda, Piracicaba, SP, Brazil). Powdered material was stored sheltered from light and moisture for subsequent use in the extraction procedure. The hydroalcoholic rosemary extract (HRE) was obtained by percolation of the powdered material (mean particle size of 438 ± 7.00 μm), using ethanol:water solution (80:20 v/v) as solvent mixture. Briefly, 3 kg of powdered material were placed in contact with 1 L of solvent in a glass flask. After an incubation period of 2 h (pre-swelling phase), this material was carefully transferred to a 10L percolator (Revitec Ltda, São Paulo, SP, Brazil) and solvent was added to volume. This system remained in contact with the powdered material for 24 h (intermediate maceration phase).

Immediately before LC–MS analysis each sample was filtered using

Immediately before LC–MS analysis each sample was filtered using 0.25 μm filter discs with a low protein binding Durapore polyvinylidene fluoride (PVDF) membrane Fasudil cell line (Millex; EMD Millipore, Billerica, MA, USA) and diluted with 9 ml of HPLC-grade water. Samples were run in a random order with QC samples (Dunn, Wilson, Nicholls, & Broadhurst, 2012). An external reference standard of sinigrin hydrate was also prepared for quantification of GSL compounds, and isorhamnetin

for flavonol compounds. Preparation was as follows: A 12 mM solution was prepared in 70% methanol. A dilution series of concentrations was prepared as an external calibration curve with HPLC-grade water (200, 150, 100, 56, 42, 28, 14 and 5.6 ng μl; sinigrin correlation coefficient: y = 12.496x − 15.012; r2 = 0.993, isorhamnetin correlation coefficient: y = 0.3205x − 5.3833, r2 = 0.921). Standard response factors were used in the calculation of GSL concentration where available ( Wathelet, Iori, Leoni, Quinsac, & Palmieri, 2004). Where such data could not be found for intact GSLs, response factors were assumed to be 1.00 ( Lewis & Fenwick, 1987). LC–MS analysis was performed in the negative ion mode on an Agilent 1200 Series LC system equipped with a binary pump, degasser, autosampler, thermostat, column heater, photodiode array detector and Agilent 1100 Series LC/MSD mass trap spectrometer.

Separation of samples was achieved find more on a Zorbax SB C18 column (2.1 × 100 mm; 1.8 μm; Agilent, Santa Clara, CA, USA) with precolumn filter. Myosin Both GSLs and flavonols

were separated in the same sample during a 40-min chromatographic run. Mobile phases consisted of ammonium formate (0.1%) and acetonitrile with a gradient of 95% and 5% respectively at a flow rate of 0.3 ml/min, with a column temperature of 30 °C. 5 μl of sample was injected. MS analysis settings were as follows: ESI was carried out at atmospheric pressure in negative ion mode (scan range m/z 50–1050 Da). Nebulizer pressure was set at 50psi, gas-drying temperature at 350 °C, and capillary voltage at 20,000 V. Compounds were identified using their nominal mass and characteristic fragment ions, and by comparing data with those published in the literature (see Table 1 and Table 2). GSLs were quantified at a wavelength of 229 nm, and flavonols at 330 nm. All data were analysed using Bruker Daltronics software. The results reported are the averages of three biological replicates and three separately extracted technical replicates (n = 9). Processed GSL and flavonol data were analysed with ANOVA and Tukey’s HSD test, and principal component analysis (PCA) was performed in XL Stat (Addinsoft, New York City, New York, USA). Table 1 lists all of the GSL compounds identified across all rocket samples, including systematic names, common names and the identifying ions. Unlike previous studies, the GSL profiles of each rocket accession were markedly different in some cases.

For instance, the parietal cortex seems to be the neural region l

For instance, the parietal cortex seems to be the neural region linked to self-perception; while sense of ownership in action execution may be located within the inferior parietal lobe and the temporoparietal junction (Farrer et al.,

2003 and Ruby and Decety, 2001). According to Jeannerod (2003) SoA and the integrated SoO implies an active organism, i.e. an agent with plans, desires, MAPK Inhibitor high throughput screening and actions. Particularly intriguing to us is the self-perception of controlling one’s own volitional actions. This statement may well be the necessary link in TBM between the idea of possessing FW and the rise of SoA and SoO. Moreover, following intentionally caused actions, the sense of agency triggers (in the subject) an interesting illusion concerning the timing of events. By means of Libet’s paradigm (Libet, 1983 and Libet, 2004), Haggard and others demonstrated that when an event is causally linked to a subject’s intentional action, the perception of the time separating the decisions from the outcomes of an action is reduced (Haggard, Clark, & Kalogeras, 2002). This sort of binding effect between the two events is strongly correlated to the SoA (Haggard, Cartledge, Dafydd, & Oakley, 2004). Thus, the feeling of exercising FW is fundamental to the sense of self. Altered perceptions of this feeling (generated by hypnosis or

by some psychopathological conditions, for instance) may exert an anomalous control of “voluntary” acts, so that the agent reports a distorted perception of the binding effect. Elsewhere http://www.selleckchem.com/products/pd-0332991-palbociclib-isethionate.html (Bignetti, 2001 and Bignetti, 2003), the inherent excitability and firing potential of each single neuron (Katz, 1966) is understood as the intrinsic “desire to think,” motivating

the neuron to contribute to the thinking process. The expression “desire to think” was provocatively coined for those opposed to the reductionist view of the thinking process. The epistemology of Buddhism considers “desire” to be the insatiable tendency of an individual mind to extinguish Afatinib in vivo all painful stimuli of life (RadhaKrishnan, 1991); again, this can be seen by thermodynamics as any other physical–chemical system which needs to spontaneously evolve to dissipate Gibbs’ free energy. However, the question remains as to how the brain can manage the activity of so many neurons in order to be able to execute a goal-directed thought. To identify the mind’s “driver” or “organiser” we can either go back to the metaphysical idea of mind–body duality, or try to introduce some type of biophysical mechanism by sorting and integrating a bundle of coherent memories accumulated during the course of a life which may give rise to a virtual personal identity. Scientifically speaking, we prefer this second hypothesis, but from the agent’s first-person perspective, the question of self-ontogeny is irrelevant.

The latter could not be unambiguously attributed to management B

The latter could not be unambiguously attributed to management. Because this Protease Inhibitor Library manufacturer case study is exclusively based on neutral markers, the effect of ISS on the adaptive potential of the studied beech stand remains unknown. The study was part of the target developmental project V4-1140, financed by the Ministry of Agriculture and the Environment and co-financed by the Slovenian Research Agency (SRA), and of the Research Programme P4-0107 financed by the SRA. We would like to thank Melita Hrenko, Barbara Štupar and Marko Bajc

for their help in the laboratory and Igor Ahej, Peter Železnik and Matej Rupel for their help with the field work. We thank Tomaž Hartman, Gorazd Mlinšek, Andrej Breznikar and Matjaž Zupanič from the Slovenian Forestry Service for answering all our questions. We also thank Filippos Aravanopoulos, An Vanden Broeck and two anonymous reviewers for critical

reading and valuable comments on the manuscript. Open Access is supported by EUFORINNO REGPOT-2012-2013-1. “
“Budworms in the genus Choristoneura (Lepidoptera: Tortricidae) that feed on conifers periodically experience population outbreaks that extend over large geographical areas in North America. Notable in Talazoparib molecular weight this regard is the western spruce budworm (WSB; Choristoneura occidentalis Freeman), a widespread and destructive defoliator in western North America ( Fellin and Dewey, 1982) that primarily feeds on Douglas-fir (Pseudotsuga menziesii var. glauca Beissn. Franco), but also on true firs (Abies spp.), Engelmann spruce (Picea engelmanni Parry ex Engelm.) and western larch (Larix occidentalis

Nutt.) ( Furniss and Carolin, 1977 and Fellin and Dewey, 1982). Repeated and/or sustained WSB outbreaks can result in large timber volume losses, stem defects, mortality primarily in understory trees, and regeneration delays due to budworm feeding on developing cones ( Alfaro et al., 1982, Fellin and Dewey, 1982, van Sickle et al., 1983, Alfaro NADPH-cytochrome-c2 reductase and Maclauchlan, 1992, Hadley and Veblen, 1993 and Maclauchlan and Brooks, 2009). Since the early-1900s documented WSB outbreaks in the Douglas-fir forests of British Columbia (BC) has resulted in the defoliation of over 5.6 million hectares (Maclauchlan et al., 2006). Despite the fact that Douglas-fir is one of the most commercially valuable conifer species in BC, attention to WSB outbreak dynamics has primarily been confined to the southern interior of the province (Harris et al., 1985 and Maclauchlan et al., 2006) where tree-ring studies show that over the last 500 years WSB outbreaks have occurred repeatedly, with a mean return interval of approximately 33 years (Campbell et al., 2006 and Alfaro et al., 2014).

4 g C m−2 y−1 This annual rate was much larger in genotype Skado

4 g C m−2 y−1. This annual rate was much larger in genotype Skado on the previous cropland, with 22.5 g C m−2 y−1, than in the other land use and genotype, which averaged 17.0 g C m−2 y−1 (data not shown). The higher Cr for “Skado on previous cropland” per unit of land area (i.e. m−2) compared to “Skado on previous Selleck Lumacaftor pasture” could be explained by the lower tree mortality that resulted in a higher plant density per area (Table 3). The belowground woody biomass

(Mr + Cr + Stu) increased by 30% after the first rotation. By the fourth year, the plantation had sequestered a total of 240 g C m−2 in belowground woody biomass. The Mr biomass remained constant between both sampling campaigns. The Mr biomass represented about 22% of the total root biomass. At the end ZD1839 mouse of both

rotations total (=above-plus belowground) standing woody biomass was higher in Skado than in Koster (Table 3). Although the aboveground biomass for genotype Skado was 23% higher than for Koster, there were no differences in the total belowground biomass. After the first rotation (pre-coppice), Cr and Mr represented 17% of the total standing woody biomass in Skado vs. 23% in Koster. This proportion of the total standing woody biomass dropped after coppice (i.e. in the second rotation) to 8.7% and 10.1% for Skado and Koster, respectively. In the first and in the second rotation, the Stu represented 14% and 12.5% of the total standing woody biomass Rucaparib in vitro in Skado vs. 16% and 14.4% in Koster. Thus, the Stu biomass changed much less from before to after the coppice than the roots, and it represented a higher belowground proportion for the genotype with the lower standing biomass (Koster). The root:shoot ratio exponentially decreased with basal area in a similar way for both genotypes before and after coppice (pre- and post-coppice, Fig. 6). As for Cr

biomass the genotypic differences in root:shoot ratios were attributed to differences in the BA. The small reduction of Fr biomass observed during the growing season post-coppice (2012) is comparable with the lower Fr biomass observed after harvest of the aboveground biomass in an oak plantation (Ma et al., 2013). The higher Fr productivity post-coppice partially rejected our first hypothesis, and was in line with the higher aboveground productivity measured in 2012 (post-coppice) as compared to 2011 (Verlinden et al., submitted September 2014). This 46% increase in Fr productivity post-coppice could probably be explained by the higher precipitation (19% higher) and evapotranspiration (33% higher) in 2012 as compared to 2011 (Fig. 2). The increasing Fr mortality after the coppice of the aboveground biomass partially confirmed our first hypothesis, and validates the assumption of several SRWC models (Garten et al., 2011 and Werner et al., 2012). These results contrast with the lack of change in Fr mortality after coppice observed in minirhizotrons studies (Dickmann et al.

A 5-point semi-quantitative severity-based scoring system was use

A 5-point semi-quantitative severity-based scoring system was used

to assess the degree of apoptosis: 0 = normal lung parenchyma; 1 = 1–25%; 2 = 26–50%; 3 = 51–75%; and 4 = 76–100% of examined tissue. Selleckchem GSK 3 inhibitor Quantification of murine Y chromosome in lung tissue was achieved by quantitative real-time polymerase chain reaction (PCR). Briefly, DNA was purified in a 600 μl solution of 0.2% sodium dodecyl sulfate (SDS)/proteinase K (300 μg/ml), extracted with an equal volume of phenol/chloroform/isoamyl alcohol, and centrifuged for 15 min at 14,000 rpm. The aqueous phase was transferred to a new tube. DNA was precipitated with 2 volumes of ethanol 100% and centrifuged for 15 min at 14,000 rpm. DNA was resuspended and quantified in a nanodrop spectrophotometer. 5 ng of DNA was used in a real-time PCR reaction with SYBR Green detection kit run in 7000-sequence detection system thermocycler according to manufacturer instructions (Applied Biosystems, Foster City, CA). The following PCR primers were used: forward 5′-TCA TCG GAG GGC TAA AGT G-3′; and reverse 5′-CAA CCT TCT GCA GTG GGA C-3′. Primers sequences

were defined using primer3 software based on Mus musculus sex-determining region of Chr Y (Sry) gene, gene bank accession number: NM_011564 (National Institutes of Health, NIH, Bethesda, USA). These primers amplify an 88 bp product. The relative amount of total DNA was Venetoclax ic50 calculated as a ratio (2-ΔCt) of Sry and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Primers for

GAPDH – Forward: many 5′-CCA CCA ACT GCT TAG CCC-3′ and reverse: 5′-GAC ACC TAC AAA GAA GGG TCC A-3′, 145 bp. In order to evaluate the mechanisms related to lung remodeling, quantitative real-time reverse transcription (RT) polymerase chain reaction (PCR) was performed to measure the expression of transforming growth factor (TGF)-β, platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), and caspase-3 genes. Central slices of left lungs were cut, collected in cryotubes, quick-frozen by immersion in liquid nitrogen, and stored at −80 °C. Total RNA was extracted from the frozen tissues, using the Trizol reagent (Invitrogen, Carlsbad, CA) according to the manufacturer’s recommendations. RNA concentration was measured by spectrophotometry in Nanodrop® ND-1000. First-strand cDNA was synthesized from total RNA using M-MLV Reverse Transcriptase Kit (Invitrogen, Carlsbad, CA). PCR primers for target gene were purchased (Invitrogen, Carlsbad, CA).

Interestingly, when parental and CDV-resistant cells produced an

Interestingly, when parental and CDV-resistant cells produced an equivalent size of xenografts (i.e. 3 and 5 weeks post cell-inoculation),

the amount of neutrophils, macrophages, NK cells and inflammatory cytokines was significantly higher in the animals inoculated with the parental cells compared to those that received the CDV-resistant cells. Our data obtained by whole genome gene expression profiling of normal versus immortalized cells exposed to CDV supports the use of CDV for the treatment of non-viral induced neoplasias. Furthermore, a few reports sustain this hypothesis. For instance, CDV proved effective in reducing the growth of melanoma B16 in an experimental model in mice ( Redondo et al., 2000). The most effective treatment in this model was subcutaneous administration of 67 mg/kg on alternative days three times weekly that resulted in 90% inhibition selleck inhibitor of tumor growth. When CDV antiproliferative effects were evaluated against a series of nine HPV-negative cells, the 50% cytostatic concentrations of the drug following

7 days of incubation varied between 1.4 μg/ml (for the cervical carcinoma cell line C33A) and 43 μg/ml (for the breast carcinoma cell line BT-20) compared to 0.7–2.0 μg/ml for four different HPV-positive cell lines [SiHa and CaSki (HPV-16), HeLa (HPV-18) and CK-1 (HPV-33) (Andrei et al., 1998a). When ODE-CDV was compared to CDV, ODE-CDV proved more potent than the parent compound against the HPV-positive PD0332991 cell carcinoma cell lines HeLa, CaSki, Me-180 (HPV-68) and the C33A cervical carcinoma cells lacking HPV (Hostetler et al., 2006). Liekens et al. have demonstrated the inhibitory effects of CDV on the development of virus-independent vascular tumors originated by basic fibroblast growth factor (FGF2)-overexpressing endothelial cells (FGF2-T-MAE). The in vivo antitumor efficacy of CDV was attributed to specific induction of apoptosis in this model ( Liekens et al., 2007). next In addition, CDV treatment of FGF2-T-MAE cells resulted in a pronounced up-regulation of the tumor suppressor protein p53. However, the expression of

Bax (pro-apoptotic) and Bcl-2 (anti-apoptotic) proteins remained unchanged, and CDV did not induce the release of cytochrome c from the mitochondria. Therefore CDV appeared to inhibit the growth of FGF2-T-MAE cells via inhibition of FGF2 expression and signalling ( Liekens et al., 2007). Recently, it was shown that CDV possesses potent antineoplastic activity against both HCMV positive and negative glioblastomas (Hadaczek et al., 2013). While this activity was associated with inhibition of HCMV expression and with activation of cellular apoptosis in HCMV-positive glioblastomas, CDV was also demonstrated to induce cell death in the absence of HCMV. CDV incorporated into tumor cell DNA promoting double-strand DNA breaks and apoptosis.

gov under registration NCT 01292902 Inspiratory muscle strength

gov under registration NCT 01292902. Inspiratory muscle strength was evaluated using a digital manometer (MVD-300, Globalmed, Brazil) connected to a mouthpiece with a 2 mm opening. Each patient performed three maneuvers with maximum variation of up to 10% between them to achieve MIP ( Neder et al., 1999), from residual volume (RV) to total lung capacity (TLC). The best of the three maneuvers was recorded. A Cell Cycle inhibitor portable spirometer (Micro Medical, Microloop, MK8, England) was used for pulmonary function testing. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were evaluated in accordance with recommendations of the

American Thoracic Society ( American Thoracic Society, 2002). The six-minute walk test (6MWT) was used to assess functional capacity in terms of distance covered (6MWD) in accordance with protocol established by the American Thoracic Society (ATS) (2002). The following resting parameters were evaluated before testing: arterial pressure (Pa), heart rate (HR), oxygen saturation (SpO2 measured by Onyx 9500 portable pulse oximeter), respiratory rate (RR), and dyspnea scale (Borg Scale). Inspiratory loaded breathing testing was performed

with a threshold device (Threshold Inspiratory Muscle Trainer, Healthscan Products Inc., Cedar Grove, New Jersey), mostly used FK228 for inspiratory muscle training in healthy subjects (Hostettler et al., 2011) and in patients with various pathologies C1GALT1 such as CHF (Dall’Ago et al., 2006 and Chiappa et al., 2008). This device was connected the mouthpiece. During the three-minute-long test (De Andrade et al., 2005), patients breathed through the mouthpiece with their noses occluded by a noseclip, using 30% MIP. An inspiratory load

of 30% was chosen taking into consideration several studies of inspiratory muscle training for this population (Laoutaris et al., 2004, Dall’Ago et al., 2006 and Chiappa et al., 2008). During the test, the participants were encouraged to maintain respiratory frequency between 12 and 16 bpm. Testing was interrupted if HR increased more than 20% and/or SpO2 <88%. Optoelectronic plethysmography (BTS Bioengineering, Italy) measures volume changes in the thoracoabdominal system through the placement of 89 markers formed by hemispheres covered with retro-reflective paper. The location of each hemisphere is determined by anatomical references in the anterior and posterior regions of the thorax and abdomen. Markers were placed on the skin using hypoallergenic bioadhesives. Eight cameras were placed around the patient and recorded images were transmitted to a computer, where a three-dimensional model is formed based on the markers OEP capture software (BTS Bioengineering, Italy). The chest wall was divided into the following compartments (Fig.

, 2003) Most recorded sites were pointed out to researchers by l

, 2003). Most recorded sites were pointed out to researchers by locals (e.g., Nimuendaju, 2004). Though major phases of human occupation and environmental change have emerged from site research, most sites have not been investigated comprehensively, and there has been only limited coverage over Amazonia as a whole. Though only a tiny proportion of Amazonia has been examined, thousands of sites have been discovered in the diverse regions examined by researchers. As more areas are examined and more sites are found, new

regional cultures are being discovered (Fig. 1). Aerial survey was important in geographers’ early revelations about large wetland raised field systems (Denevan, 1966), but few sites of any kind have been mapped with instruments and even fewer with ground-probing geophysical technology (e.g., Bevan and Roosevelt, 2003, Roosevelt, 1991b and Roosevelt, CB-839 order 2007). this website Anthropic deposits that affect geomorphology over large areas are in principle detectable from the air or from space in many ways (e.g., El Baz and Wiseman, 2007). With such methods, we could better evaluate the patterning,

scope, and functioning of site complexes. Evidence of different cultures and land-management systems in Amazonia has come from stratigraphic analysis of sediments (e.g., Heckenberger, 2004, Iriarte et al., 2010, Morais and Neves, 2012, Neves, 2012, Piperno and Pearsall, 1998, Prumers,

2013, Roosevelt, 1991b, Roosevelt, 1997, Roosevelt et al., 1996, Rostain, 2010, Rostain, 2012 and Rostain, 2013). Excavation defines sites’ cultural components, layering, activity areas, and sequences of occupation. Soil processing to recover artifacts and ecofacts from strata gives evidence of specific past environments and economies and materials for dating. Where stratigraphy is not purposefully sampled, analyzed, and dated, questionable conclusions ensue, such as Pleistocene savannization and desertification (Whitmore and Prance, 1987) or megafaunal extinctions selleck screening library (Coltorti et al., 2012), unsupported by more comprehensive and critical studies (see Section ‘Environmental background’). And extrapolations not based on excavated cross-sections (van der Hammen and Absy, 1994:255, Fig. 2; Lombardo et al., 2013a, Fig. 2) do not accurately represent stratigraphy. Coring has been a main method for sampling offsite sediments to reconstruct past environments and land use. However, site formation processes and effectiveness of coring are seldom evaluated. Cores are often interpreted as direct evidence of regional climate change, without consideration of processes of local hydrology. For example, if an ancient water body dries up, this is interpreted as epochal climate change, though lake levels can change because of local hydrological or tectonic shifts (Colinvaux et al., 2000).

When the adsorbent surface is negatively charged, Phe is adsorbed

When the adsorbent surface is negatively charged, Phe is adsorbed in the neutral form, with the phenyl ring oriented parallel to the surface and with both amino and carboxylic groups of the Phe molecule interacting with the surface and with other Phe molecules by hydrogen bonding ( Li, Chen, Roscoe& Lipkowski, 2001). At pH 8 and 10, there is a predominance of negative charges in both adsorbent and Phe selleck products molecules with the effect of electrostatic repulsion on the adsorption performance being observed prior to 4 h. Such effect is not as significant when adsorption equilibrium is reached and is attributed to a change in the dominant adsorption mechanism from one dependent

on the solution pH (e.g., interaction of ionized groups of Phe with groups at the adsorbent PD98059 solubility dmso surface) to one that is independent, such as hydrophobic interactions, after 8 h of adsorption. pH measurements after equilibrium were close to pHPZC for all values of initial solution pH between 4 and 8, with this variation explained by the H+ ions released by the ionized carboxylic groups of Phe molecules neutralizing negative charges at the adsorbent surface, partially restoring the charge balance to a value close to pHPZC. For the case of initial pH 2, the pH value remained unaltered during the entire adsorption period, corroborating the hypothesis of

a mechanism of hydrophobic interactions between Phe and the adsorbent

surface. Rajesh, Majumder, Mizuseki, and Kawazoe (2009) demonstrated that aromatic rings of amino acids tend to orient in parallel with respect to the planes of graphene sheets, favoring π-π type interactions, because this configuration is more energetically stable than others. The influence of adsorbent dosage on Phe adsorption can be viewed in Fig. 2c. Removal efficiency increased with the increase in adsorbent dosage, given the corresponding increase in number of available active adsorption sites resulting from the increase in adsorbent mass. However, the amount of Phe adsorbed per unit mass of adsorbent decreased with increasing adsorbent mass, due to the reduction in adsorbate/adsorbent ratio. Based on these results, the remaining experiments were conducted with an adsorbent 4��8C dosage of 10 g L−1, a choice based on the fact that higher dosages led to a significant decrease in Phe loading, whereas lower dosages did not present satisfactory Phe removal percentage. The data in Fig. 3a show that an increase in Phe initial concentration led to an increase in the total amount adsorbed, given the corresponding increase in driving force (concentration gradient). Results in Fig. 3a also show that a contact time of 3 h almost assured attainment of equilibrium conditions for all evaluated initial Phe concentrations.