Organoclay embedded polysulfone (PSf) nanocomposite membranes were prepared for arsenate removal from contaminated surface water. Prepared membranes consisted of different weight ratios of organoclay ...to polymer, ranging from 0 to 2.0wt% and were characterized by FE-SEM, XRD, AFM, pure water flux, mechanical strength, contact angle measurement and adsorption experiments. Obtained results showed that pure water flux, surface hydrophilicity, roughness and mechanical strength of the membranes increased as organoclay content increased from 0 to 2.0wt%. XRD analysis confirmed the exfoliated structure of organoclay in membrane when its content increased from 0.5–1.5wt%. Further increase in organoclay content; up to 2.0wt%, resulted in the intercalated structure of dispersed organoclays in membrane matrix. Adsorption kinetic of arsenate was found to follow pseudo-second-order kinetic model and equilibrium data showed good correlation with the Langmuir model. The obtained results also revealed that the arsenate adsorption was most favorable in the neutral pH. Moreover, membrane reusability of the 1.5wt% and 2.0wt% organoclay embedded PSf membranes was assessed by conducting five cycles of adsorption experiments and membrane regeneration in dead-end filtration. Obtained results confirmed the applicability of the prepared membrane for multiple cycles.
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•PSf/organoclay adsorptive nanocomposite membranes were fabricated for As(V) removal.•Prepared nanocomposite membranes had high adsorption capacity for As(V) solutions.•Equilibrium data showed good correlation with the Langmuir model.•Prepared nanocomposite membranes are re-generable and easy for multiple applications.
Neat and arginine modified montmorillonite, Mt and Mt-Arg, were embedded into polysulfone (PSf) to prepare adsorptive mixed matrix membranes (AMMMs) for arsenate removal from contaminated water. ...Prepared membranes were characterized by FE-SEM, XRD, AFM, pure water flux and contact angle measurement. Equilibrium adsorption capacity and adsorption kinetic of AMMMs were determined using batch adsorption experiments. In addition, dynamic adsorption and regeneration studies were also investigated in dead-end filtration setup. Adsorption kinetic of arsenate was found to follow pseudo-second-order kinetic model and equilibrium data showed good correlation with the Langmuir model for AMMMs. The obtained results revealed that the arsenate adsorption was favorable for PSf/Mt-Arg. Regeneration capability of the Mt-Arg embedded PSf membranes was assessed by conducting ten cycles of adsorption-desorption experiments. Arg modified Mt provides interesting properties to adsorb As(V) from water in neutral pH and desorb in alkaline condition; pH=9, due to negative side group. The obtained results confirmed the applicability of the prepared PSf/Mt-Arg in As(V) removal for multiple cycles.
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•Arginine modified Mt was incorporated into PSf to prepare adsorptive membranes.•Adsorptive membranes were used for As(V) removal from water.•PSf/Mt-Arg membrane showed higher adsorption capacity than PSf/Mt membrane.•Mt-Arg provides interesting properties to adsorb and desorb As(V).•PSf/Mt-Arg membrane was re-generable and easy for multiple applications.
Data-driven functional connectivity density (FCD) mapping is being increasingly utilized to assess brain connectomics at rest in the healthy brain and its disruption in neuropsychiatric diseases with ...the underlying assumption that the spatiotemporal hub distribution is stationary. However, recent studies show that functional connectivity is highly dynamic. Here we study the temporal variability of the local FCD (lFCD) at high spatiotemporal resolution (2-mm isotropic; 0.72s) using a sliding-window approach and 'resting-state' datasets from 40 healthy subjects collected under the Human Connectome Project. Prominent functional connectivity hubs in visual and posterior parietal cortices had pronounced temporal changes in local FCD. These dynamic patterns in the strength of the lFCD hubs occurred in cortical gray matter with high sensitivity (up to 85%) and specificity (> 85%) and showed high reproducibility (up to 72%) across sessions and high test-retest reliability (ICC(3,1) > 0.5). The temporal changes in lFCD predominantly occurred in medial occipitoparietal regions and were proportional to the strength of the connectivity hubs. The temporal variability of the lFCD was associated with the amplitude of the low frequency fluctuations (ALFF). Pure randomness did not account for the probability distribution of lFCD. Shannon entropy increased in proportion to the strength of the lFCD hubs suggesting high average flow of information per unit of time in the lFCD hubs, particularly in medial occipitoparietal regions. Thus, the higher dynamic range of the lFCD hubs is consistent with their role in the complex orchestration of interacting brain networks.
Abstract
In this work, montmorillonite (Mt) was modified by environmentally friendly arginine (Arg) and lysine (Lys) amino acids with di-cationic groups for arsenic removal from contaminated water. ...The modified Mts were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential and thermal analysis. The adsorption of As(V) onto modified Mts as a function of initial As(V) concentration, contact time and solution pH was investigated. The removal efficiency was increased with increasing the As(V) concentration and contact time; however, it was decreased with increasing solution pH. The maximum As(V) adsorption capacities of Mt-Arg and Mt-Lys were 11.5 and 11 mg/g, respectively, which were five times larger than pristine Mt. The high adsorption capacity makes them promising candidates for arsenic removal from contaminated water. The regeneration studies were carried out up to 10 cycles for both modified Mts. The obtained results confirmed that the modified adsorbents could also be effectively used for As(V) removal from water for multiple adsorption – desorption cycles.
Acute and chronic alcohol exposure significantly affect behavior but the underlying neurobiological mechanisms are still poorly understood. Here, we used functional connectivity density (FCD) mapping ...to study alcohol-related changes in resting brain activity and their association with behavior. Heavy drinkers (HD, N=16, 16 males) and normal controls (NM, N=24, 14 males) were tested after placebo and after acute alcohol administration. Group comparisons showed that NM had higher FCD in visual and prefrontal cortices, default mode network regions and thalamus, while HD had higher FCD in cerebellum. Acute alcohol significantly increased FCD within the thalamus, impaired cognitive and motor functions, and affected self-reports of mood/drug effects in both groups. Partial least squares regression showed that alcohol-induced changes in mood/drug effects were associated with changes in thalamic FCD in both groups. Disruptions in motor function were associated with increases in cerebellar FCD in NM and thalamus FCD in HD. Alcohol-induced declines in cognitive performance were associated with connectivity increases in visual cortex and thalamus in NM, but in HD, increases in precuneus FCD were associated with improved cognitive performance. Acute alcohol reduced 'neurocognitive coupling', the association between behavioral performance and FCD (indexing brain activity), an effect that was accentuated in HD compared with NM. Findings suggest that reduced cortical connectivity in HD contribute to decline in cognitive abilities associated with heavy alcohol consumption, whereas increased cerebellar connectivity in HD may have compensatory effects on behavioral performance. The results reveal how drinking history alters the association between brain FCD and individual differences in behavioral performance.
Indian walnut
Aeluropus littoralis
(Gouan) Pari, well known for its salt tolerance and forage quality, is a perennial monocot grass from
Chlorideae
tribe that shows a high potential to become an ...important genetic model. Although,
Aeluropus
germplasm is very rich in Iran; but is still unexplored. In this study, 20 ecotypes of
A. littoralis
were gathered from different geographic zones and a set 16 primers (ISSRs-AFLPs combined) was used for genetic diversity evaluation. A total of 635 fragments and 594 polymorphic fragments were produced (93.5%) and modest levels of genetic similarity were found (ranging from 0.38 to 0.71) among ecotypes. The results showed an equal competition between the two markers on polymorphism detection, so both molecular techniques were able to distinguish the
A. littoralis
ecotypes. Furthermore, Dendrogram based on both the Bayesian and PCoA analysis showed a clear discrimination and significant variation among ecotypes; however, molecular clustering indicated a weak concordance with geographical grouping. The amount of molecular diversity revealed by molecular markers for
A. littoralis
in this study can be exploited for pasture conservation programs and new forage crop development.
In this study, a biopolymer-based adsorptive membrane was designed for simultaneous removal of differently charged heavy metals from water. Polylactic acid (PLA)/hydroxyapatite (HAp) adsorptive ...membranes with various content of HAp were fabricated using the non-solvent induced phase separation method. The effect of incorporating different weight content of HAp ranging from 0 to 3.0 wt% was studied on the structural morphology, hydrophilicity, porosity, mechanical properties, pure water permeability, and lead (Pb) and arsenic (As) adsorption capacity of the fabricated membranes. The results revealed that adsorptive membrane with 2.5 wt% HAp exhibited high porosity and hydrophilicity, acceptable mechanical strength, and ultrahigh pure water flux (1100 L m
−2
h
−1
). This membrane showed proper removal efficiency in batch adsorption, 97% for Pb and 82% for As solutions (100 ppb), which are comparable to most of the readily available adsorbents. Dynamic adsorption results divulged that the adsorptive membrane with 2.5 wt% HAp content provided a promising filtrate of Pb and As solutions with a concentration below 10 ppb for even four and five consequent regeneration cycles. Additionally, the adsorptive performance of the optimum HAp content membrane was better than batch adsorption, especially in Pb removal.
The vacuolar H(+)-ATPase (VHA) is a universal component of eukaryotic organisms that is responsible for establishing and maintaining intracellular pH gradients across specialized organellar ...membranes, and influences the transport of cations into the vacuoles of plant cells. A cDNA clone (AlVHA-c) encoding the c subunit of V-ATPase was isolated from the monocot halophyte Aeluropus littoralis. The DNA sequence of AlVHA-c showed significant homology with V-ATPase subunit c of millet, rice and Zea mays. The deduced amino acid sequence of AlVHA-c and other reported c subunits were compared, and sequence relationships have been drawn to know their genetic relatedness. Semi-quantitative RT-PCR analysis of salt-treated A. littoralis plants revealed that subunit c of V-ATPase is regulated by NaCl treatment at transcriptional level in a tissue-specific manner. The increased V-ATPase subunits amounts of A. littoralis provide the energy for the compartmentalization of sodium in response to salinity.
Neuroimaging studies have documented reduced striatal dopamine D2/D3 receptor (D2/D3R) availability in cocaine abusers, which has been associated with impaired prefrontal activity and vulnerability ...for relapse. However, the mechanism(s) underlying the decreases in D2/D3R remain poorly understood. Recent studies have shown that sleep deprivation is associated with a downregulation of striatal D2/D3R in healthy volunteers. As cocaine abusers have disrupted sleep patterns, here we investigated whether reduced sleep duration mediates the relationship between cocaine abuse and low striatal D2/D3R availability. We used positron emission tomography with (11)Craclopride to measure striatal D2/D3R availability in 24 active cocaine abusers and 21 matched healthy controls, and interviewed them about their daily sleep patterns. Compared with controls, cocaine abusers had shorter sleep duration, went to bed later and reported longer periods of sleep disturbances. In addition, cocaine abusers had reduced striatal D2/D3R availability. Sleep duration predicted striatal D2/D3R availability and statistically mediated the relationship between cocaine abuse and striatal D2/D3R availability. These findings suggest that impaired sleep patterns contribute to the low striatal D2/D3R availability in cocaine abusers. As sleep impairments are similarly observed in other types of substance abusers (for example, alcohol and methamphetamine), this mechanism may also underlie reductions in D2/D3R availability in these groups. The current findings have clinical implications suggesting that interventions to improve sleep patterns in cocaine abusers undergoing detoxification might be beneficial in improving their clinical outcomes.
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