136 research outputs found

    Harnessing the power of metal-organic frameworks to develop microplastic fouling resistant forward osmosis membranes

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    With the gradual increase of microplastics (MPs) in water and wastewater streams, it is imperative to investigate their removal using tertiary treatment systems to minimize and preferably prevent their entrance into aquatic environments. Forward osmosis (FO) is a non-pressurized membrane process with potential applications in MPs removal from wastewater. However, efficient application of FO systems relies on developing high-performance FO membranes with low fouling tendency. MPs are proven as emerging foulants in membrane systems, diminishing their performance and lifetime and this highlights the need to consider MP fouling in developing sustainable membranes. The current study focuses on a novel modification of thin film composite (TFC) FO membranes by MIL-53(Fe) as a water-stable and hydrophilic metal-organic framework. Experimental results demonstrated that the optimized FO membrane (0.2 wt% MIL-53(Fe)) achieved a significantly higher water flux (90% increase) with a 23% less reverse salt flux. The modified membrane also had significantly less flux decline in fouling experiments and higher flux recovery after physical cleaning compared to the control membrane affirming its higher antifouling efficiency. MIL-53(Fe) integration in the FO substrate proved to be a practical method for developing high-performance TFC FO membranes with improved antifouling properties against MPs and organic foulants

    Association between plasma tau and postoperative delirium incidence and severity: a prospective observational study

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    BACKGROUND: Postoperative delirium is associated with increases in the neuronal injury biomarker, neurofilament light (NfL). Here we tested whether two other biomarkers, glial fibrillary acidic protein (GFAP) and tau, are associated with postoperative delirium. METHODS: A total of 114 surgical patients were recruited into two prospective biomarker cohort studies with assessment of delirium severity and incidence. Plasma samples were sent for biomarker analysis including tau, NfL, and GFAP, and a panel of 10 cytokines. We determined a priori to adjust for interleukin-8 (IL-8), a marker of inflammation, when assessing associations between biomarkers and delirium incidence and severity. RESULTS: GFAP concentrations showed no relationship to delirium. The change in tau from preoperative concentrations to postoperative Day 1 was greater in patients with postoperative delirium (P<0.001) and correlated with delirium severity (ρ=0.39, P<0.001). The change in tau correlated with increases in IL-8 (P<0.001) and IL-10 (P=0.0029). Linear regression showed that the relevant clinical predictors of tau changes were age (P=0.037), prior stroke/transient ischaemic attack (P=0.001), and surgical blood loss (P<0.001). After adjusting for age, sex, preoperative cognition, and change in IL-8, tau remained significantly associated with delirium severity (P=0.026). Using linear mixed effect models, only tau (not NfL or IL-8) predicted recovery from delirium (P<0.001). CONCLUSIONS: The change in plasma tau was associated with delirium incidence and severity, and resolved over time in parallel with delirium features. The impact of this putative perioperative neuronal injury biomarker on long-term cognition merits further investigation. CLINICAL TRIAL REGISTRATION: NCT02926417 and NCT03124303

    Tolerance of some wheat varieties to boron toxicity

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    Boron (B) toxicity is an important problem in low rainfall and highly alkaline soils of central and southern part of Iran. We evaluated B toxicity tolerance of 10 Iranian wheat varieties in a greenhouse experiment. Experimental design was factorial Completely Randomized Design (CRD) with 10 wheat varieties Γ— six B levels (0, 2.5, 5, 10, 20 and 40 mg B kgβˆ’1 soil) in three replications. The results showed a great range of tolerance among wheat varieties. Arg was the most tolerant one and Chamran showed the least tolerance. It seems that different mechanisms involved in B toxicity tolerance, namely exclusion of B from root, redistribution of B within leaves and integration of these two mechanisms. Significant negative linear correlation observed between shoot B concentration and shoot dry weight (r = 0.85, p < 0.01) and positive linear correlation between shoot B concentration and shoot dry weight reduction percentage (r = 0.82, p < 0.01)

    Cohort study of electroencephalography markers of amyloid-tau-neurodegeneration pathology

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    Electroencephalography signatures of amyloid-Ξ², tau and neurodegenerative pathologies would aid in screening for, tracking progression of, and critically, understanding the pathogenesis of dementia. We hypothesized that slowing of the alpha peak frequency, as a signature of hyperpolarization-activated cyclic nucleotide gated β€˜pacemaker’ channel activity, would correlate with amyloid and tau pathology burden measured by amyloid (Pittsburgh Compound B) and tau (MK-6240) positron emission tomography or CSF biomarkers. We also hypothesized that EEG power would be associated with neurodegeneration (CSF neurofilament light and hippocampal volume). Wakeful high-density EEG data were collected from 53 subjects. Both amyloid-Ξ² and tau pathology were associated with slowing in the alpha peak frequency [Pittsburgh Compound B (+) vs. Pittsburgh Compound B (βˆ’) subjects, P = 0.039 and MK-6240 (+) vs. MK-6240 (βˆ’) subjects, P = 0.019]. Furthermore, slowing in the peak alpha frequency correlated with CSF AΞ²42/40 ratio (r2 = 0.270; P = 0.003), phosphoTau (pTau181, r2 = 0.290; P = 0.001) and pTau181/AΞ²42 (r2 = 0.343; P < 0.001). Alpha peak frequency was not associated with neurodegeneration. Higher CSF neurofilament light was associated with lower total EEG power (r2 = 0.136; P = 0.018), theta power (r2 = 0.148; P = 0.014) and beta power (r2 = 0.216; P = 0.002); the latter was also associated with normalized hippocampal volume (r2 = 0.196; P = 0.002). Amyloid-tau and neurodegenerative pathologies are associated with distinct electrophysiological signatures that may be useful as mechanistic tools and diagnostic/treatment effect biomarkers in clinical trials

    Adult ADHD screening scores and hospitalization due to pedestrian injuries: A case-control study

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    Background: The aim of this study was to investigate the association between adult ADHD screening scores and hospitalization due to pedestrian injuries in a sample of Iranian pedestrians. Methods: Through a case-control study, a case population of 177 pedestrians injured by the vehicles in road traffic crashes were compared with 177 controls who lacked a record of intentional or unintentional injuries enrolled from various wards of Imam Reza University Hospital which is a specialty teaching hospital located in the same city with similar referral level. The cases and controls had an age range of 18-65 years and were matched on gender and age. ADHD symptom profile was assessed using the Persian Self-report Screening Version of the Conner's Adult ADHD Rating Scales (CAARS-S:SV). The association of ADHD screening score and pedestrian injuries was investigated using multiple binary logistic regression to investigate the independent effect of ADHD index score on belonging to case group. Both crude and adjusted odds ratios were reported. Results: Men comprised 86.4 of the study subjects. The crude odds ratios for all the four ADHD subscales to be associated with pedestrian injuries were 1.05, 1.08, and 1.04 for the subscales A (attention deficit), B (hyperactivity/impulsiveness) and ADHD index respectively. However, the association for subscale A was not statistically significant with a borderline p-value. The final multivariate analysis showed that variables associated with pedestrian injuries in the road traffic crashes were ADHD Index score (OR = 1.06, 95 CI: 1.01-1.12); economic status (including household income and expenditure capacity); educational level and total walking time per 24 h. Conclusions: Adult ADHD screening score can predict pedestrian injuries leading to hospitalization independently from sex, age, economic status, educational level and pedestrian exposure to traffic environment (average walking time). © 2020 The Author(s)

    A Comparative Study of Convolutional Neural Networks and Conventional Machine Learning Models for Lithological Mapping Using Remote Sensing Data

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    Lithological mapping is a critical aspect of geological mapping that can be useful in studying the mineralization potential of a region and has implications for mineral prospectivity mapping. This is a challenging task if performed manually, particularly in highly remote areas that require a large number of participants and resources. The combination of machine learning (ML) methods and remote sensing data can provide a quick, low-cost, and accurate approach for mapping lithological units. This study used deep learning via convolutional neural networks and conventional ML methods involving support vector machines and multilayer perceptron to map lithological units of a mineral-rich area in the southeast of Iran. Moreover, we used and compared the efficiency of three different types of multispectral remote-sensing data, including Landsat 8 operational land imager (OLI), advanced spaceborne thermal emission and reflection radiometer (ASTER), and Sentinel-2. The results show that CNNs and conventional ML methods effectively use the respective remote-sensing data in generating an accurate lithological map of the study area. However, the combination of CNNs and ASTER data provides the best performance and the highest accuracy and adaptability with field observations and laboratory analysis results so that almost all the test data are predicted correctly. The framework proposed in this study can be helpful for exploration geologists to create accurate lithological maps in other regions by using various remote-sensing data at a low cost.</jats:p

    Immunolocalisation of P2Y receptors in the rat eye

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    Nucleotides present an important role in ocular physiology which has been demonstrated by recent works that indicate their involvement in many ocular processes. P2Y are important among P2 receptors since they can control tear production, corneal wound healing, aqueous humour dynamics and retinal physiology. Commercial antibodies have allowed us to investigate the distribution of P2Y receptors in the cornea, anterior and posterior chamber of the eye and retina. The P2Y1 receptor was present mainly in cornea, ciliary processes, and trabecular meshwork. The P2Y2 receptors were present in cornea, ciliary processes and retinal pigmented epithelium. P2Y4 was present in cornea, ciliary processes, photoreceptors, outer plexiform layer and ganglion cell layer. The P2Y6 presented almost an identical distribution as the P2Y4 receptor. The P2Y11 was also detectable in the retinal pigmented epithelium. The detailed distribution of the receptors clearly supports the recent findings indicating the relevant role of nucleotides in the ocular function

    Cataract-Causing Defect of a Mutant Ξ³-Crystallin Proceeds through an Aggregation Pathway Which Bypasses Recognition by the Ξ±-Crystallin Chaperone

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    Background: The transparency of the eye lens depends upon maintenance of the native state of the Ξ³- and Ξ²-crystallins, which is aided by the abundant chaperones Ξ±A- and Ξ±B-crystallin. Mature onset cataract, the leading cause of blindness worldwide, involves the polymerization of covalently damaged or partially unfolded crystallins into light-scattering aggregates. A number of single amino acid substitutions and truncations of Ξ³-crystallins result in congenital cataract in both humans and mice, though in many cases the coupling between the protein alterations and the accumulation of aggregates is poorly defined. Methodology/Principal Findings: We have studied the aggregation properties and chaperone interactions of human Ξ³D-crystallin carrying substitutions of two buried core mutants, I90F and V75D, which cause congenital cataract in mice. The in vitro aggregation pathway competing with productive refolding was not altered by either substitution. Furthermore, this aggregation pathway for both mutant proteins–originating from a partially folded intermediate–was efficiently suppressed by Ξ±B-crystallin. Thus the cataract pathology was unlikely to be associated with a direct folding defect. The native state of wild-type human Ξ³D-crystallin exhibited no tendency to aggregate under physiological conditions. However both I90F and V75D native-like proteins exhibited slow (days) aggregation to high molecular weight aggregates under physiological conditions. The perturbed conformation of I90F was recognized and bound by both Ξ±A and Ξ±B chaperones. In contrast, the aggregation derived from the perturbed state of V75D was not suppressed by either chaperone, and the aggregating species were not bound by the chaperone. Conclusions/Significance: The cataract phenotype of I90F in mice may be due to premature saturation of the finite Ξ±- crystallin pool. The V75D aggregation pathway and its escape from chaperone surveillance and aggregation suppression can account for the congenital cataract pathology of this mutant. Failure of chaperone recognition may be an important source of pathology for many other protein folding defects.National Eye Institute (Grant no. EY015834 )National Institutes of Health (U.S.) (Grant no. GM17980

    Ligand-Dependent Conformations and Dynamics of the Serotonin 5-HT2A Receptor Determine Its Activation and Membrane-Driven Oligomerization Properties

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    From computational simulations of a serotonin 2A receptor (5-HT2AR) model complexed with pharmacologically and structurally diverse ligands we identify different conformational states and dynamics adopted by the receptor bound to the full agonist 5-HT, the partial agonist LSD, and the inverse agonist Ketanserin. The results from the unbiased all-atom molecular dynamics (MD) simulations show that the three ligands affect differently the known GPCR activation elements including the toggle switch at W6.48, the changes in the ionic lock between E6.30 and R3.50 of the DRY motif in TM3, and the dynamics of the NPxxY motif in TM7. The computational results uncover a sequence of steps connecting these experimentally-identified elements of GPCR activation. The differences among the properties of the receptor molecule interacting with the ligands correlate with their distinct pharmacological properties. Combining these results with quantitative analysis of membrane deformation obtained with our new method (Mondal et al, Biophysical Journal 2011), we show that distinct conformational rearrangements produced by the three ligands also elicit different responses in the surrounding membrane. The differential reorganization of the receptor environment is reflected in (i)-the involvement of cholesterol in the activation of the 5-HT2AR, and (ii)-different extents and patterns of membrane deformations. These findings are discussed in the context of their likely functional consequences and a predicted mechanism of ligand-specific GPCR oligomerization
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