CD Data Research Articles

The disruption index suffers from citation inflation: Re-analysis of temporal CD trend and relationship with team size reveal discrepancies

Measuring the rate of innovation in academia and industry is fundamental to monitoring the efficiency and competitiveness of the knowledge economy. To this end, a disruption index (CD) was recently developed and applied to publication and patent citation networks (Wu et al., 2019; Park et al., 2023). Here we show that CD systematically decreases over time due to secular growth in research production, following two distinct mechanisms unrelated to innovation – one behavioral and the other structural. Whereas the behavioral explanation reflects shifts associated with techno-social factors (e.g. self-citation practices), the structural explanation follows from ‘citation inflation’ (CI), an inextricable feature of real citation networks attributable to increasing reference list lengths, which causes CD to systematically decrease. We demonstrate this causal link by way of mathematical deduction, computational simulation, multi-variate regression, and quasi-experimental comparison of the disruptiveness of PNAS versus PNAS Plus articles, which differ primarily in their lengths. Accordingly, we analyze CD data available in the SciSciNet database and find that disruptiveness incrementally increased from 2005-2015, and that the negative relationship between disruption and team-size is remarkably small in overall magnitude effect size, and shifts from negative to positive for team size ≥ 8 coauthors.

Molecular mechanism of alpha- and beta-cyclodextrin assisted refolding of SDS-induced amyloid fibrils of myoglobin

The formation of amyloids arises from the misfolding or unfolding of various proteins. This study investigated the impact of chemical chaperones, alpha-cyclodextrin (α-CD) and beta-cyclodextrin (β-CD), on the solubilization and defibrillation of sodium dodecyl sulfate (SDS)-induced myoglobin (Mb) amyloid fibrils. Amyloid fibril was developed in Mb in the presence of 0.8 mmol dm−3 SDS at pH 4.5. Subsequently, SDS-induced Mb amyloid was incubated with varying concentrations of α-CD and β-CD at the same pH. Our turbidity, intrinsic fluorescence, SDS-PAGE, and transmission electron microscope data showed that α-CD (2.1 mmol dm−3) was more efficiently solubilized the SDS-treated Mb aggregates than β-CD (4.0 mmol dm−3). But, another interesting phenomenon was observed with β-CD. The ThT fluorescence and far-UV CD data suggested that amyloid defibrillation by β-CD (0.6 mmol dm−3) was more effective than α-CD (0.9 mmol dm−3). The intrinsic fluorescence and far-UV CD data also showed that SDS-treated Mb regained native-like structure at lower α-CD compared to β-CD. Overall our data suggest that α-CD was more efficient in aggregate solubilization while β-CD was more effective in amyloid defibrillation. Understanding the mechanisms underlying cyclodextrins’ actions may serve as a basis for identifying potential drugs to suppress amyloid fibril formation effectively. This research provides valuable insights into mitigating amyloid-related pathologies.

New Flavan Derivatives from the Leaves and Stems of Cassia Nodosa.

Three new flavan derivatives including two methylene-linked flavan-3-ol dimers, bis(8-epiafzelechinyl)methane (1), and 8,8-(epiafzelechin-afzelechin)methane (2), a flavan-3-ol monomer, (-)-3-O-acetyl-epiafzelechin (3) and four known related compounds (4-7) were isolated from the leaves and stems of Cassia nodosa. Their structures were elucidated by extensive spectroscopic analyses and CD data. The isolates were evaluated for their antioxidant, α-glucosidase inhibitory, cytotoxic and neuroinflammatory activities, and compound 3 exhibited remarkable radical scavenging activities in both the DPPH and ABTS models with IC50 values of 2.65±1.25, and 4.78±0.91 μg/mL, respectively.

Urinary concentrations of non-essential and essential elements during weaning in infants from the NELA cohort in Spain

Infancy is a period of continuous growth and development, where inadequate intake of essential elements and exposure to non-essential elements may have lifelong health consequences. Thus, the aim of this study is to evaluate the urine concentration of essential and non-essential elements as a proxy for internal exposure during the weaning period, from 3 to 18 months of age. The Nutrition in Early Life and Asthma (NELA) birth cohort generated the data for this study. Sociodemographic, dietary, and urine concentration of essential (Co, Cu, Mo, I, Fe, Mn, Se, Zn, and Ni) and non-essential elements (Al, V, As, Cd, Sb, Tl, and Pb) data were available for 490 participants at 3 months of age and 216 participants at 18 months of age. Paired urine samples at both time periods were available for 175 infants. At 3 months of age, exclusively breastfed infants had lower urine concentrations of Al, V, Fe, Co, Se, Sb, and Tl. Notably, the concentration of Mo had a median (IQR) of 0.60 (0.40–2.10) μg/L compared to a median (IQR) of 39.80 (25.00–56.40) μg/L observed in infants exclusively fed with formula. When we analyzed the change in urine elements concentrations between 3 and 18 months of age, we observed increased As (0.75 vs. 18.60 μg/L), Co (0.05 vs. 0.24 μg/L), Mo (1.98 vs. 50.0 μg/L), Pb (0.15 vs. 0.69 μg/L), Se (11.3 vs. 23.1 μg/L), Tl (0.02 vs. 0.11 μg/L), and V (0.05 vs. 0.11 μg/L). For Cu, lower urine concentrations were observed at 18 months of age in comparison with concentrations at 3 months (5.77 vs. 4.41 μg/L). Among the main food items identified as driving the changes in urine concentration between 3 and 18 months of age were white fish, rice and pasta, potato chips, custard, small blue fish, and legumes. Exclusively breastfed infants showed lower exposure to non-essential elements compared to those who were fed with a mixture or formula. With the introduction of solid foods, the exposure to some non-essential elements increased drastically, as in the case of As and Pb. In addition, exposure to the essential metal Mo also increased substantially with the introduction of solid food.

Terpenoids and steroids from aerial parts of Achillea alpina L. as PTP1B inhibitors: Kinetic analysis and molecular docking studies

Achillea alpina L. (Alpine yarrow) is a noteworthy herb in the genus Achillea with many uses in vegetables and traditionally used to treat stomach disorders. In our continuous research on the chemical constituents and biological activities of medicinal plants, ten previously undescribed terpenoids including eight eudesmane-type sesquiterpenes (1–8), one nor-eudesmane-type sesquiterpene (9), one cyclo-geraniol derivative (10), and twenty-one known compounds were isolated and structurally elucidated from the aerial parts of A. alpina. Structures and absolute configurations of the undescribed terpenoids were identified using comprehensive spectroscopic analysis (NMR, HRESI-MS, and CD data) and computational methods (ECD and NMR calculation). Enzyme inhibitory assays showed that the isolated sesquiterpene (19), triterpene (22), and sterol (26) were protein tyrosine phosphatase 1B (PTP1B) inhibitors with IC50 values ranging from 14.87 to 23.09 μM in comparison with positive control - ursolic acid, showing IC50 value of 5.93 ± 0.16 μM. Further enzyme kinetics and molecular docking studies were performed to provide valuable insights into their mechanism of action.

A hierarchical progressive recognition network for building change detection in high‐resolution remote sensing images

AbstractBuilding change detection (BCD) plays a crucial role in urban planning and development. However, several pressing issues remain unresolved in this field, including false detections of buildings in complex backgrounds, the occurrence of jagged edges in segmentation results, and detection blind spots in densely built‐up areas. To address these challenges, this study innovatively proposes a Hierarchical Adaptive Gradual Recognition Network (HAGR‐Net) to improve the accuracy and robustness of BCD. Additionally, this research is the first to employ the Reinforcement Learning Optimization Algorithm Based on Particle Swarm (ROPS) to optimize the training process of HAGR‐Net, thereby accelerating the training process and reducing memory overhead. Experimental results indicate that the optimized HAGR‐Net outperforms state‐of‐the‐art methods on the WHU_CD, Google_CD, and LEVIR_CD data sets, achieving F1 scores of 93.13%, 85.31%, and 91.72%, and mean intersection over union (mIoU) scores of 91.20%, 85.99%, and 90.01%, respectively.

Tailoring the Molecular Structure of 6-Gingerol for Targeting the Phase Separation in Human Lysozyme.

Human lysozyme undergoes a phase-separation process to form insoluble amyloid-architects that cause several pathologies including systemic amyloidosis. Here we have tailored 6-gingerol by extending its molecular framework with active functional groups to specifically target lysozyme phase-transition events. Aggregation assay revealed that tailored 6-gingerol with 4-aromatic moieties (MTV4) substantially suppressed the conversion of the lysozyme low-density liquid phase (LDLP) to solid-phase structured amyloids. The data obtained from biophysical, computational, and microscopic imaging tools suggest direct intervention of MTV4 with the liquid-liquid phase separation. The CD data suggest that MTV4 was able to retain the native conformation of lysozyme. Both biomolecular and computational data reveal the interference of MTV4 with the aggregation-prone hydrophobic stretches within the lysozyme, thereby retaining the native structure and reversing the misfolded intermediates to active monomers. Also, MTV4 was able to induce rapid dissolution of preformed-toxic amyloid fibrils. These results reinforce the importance of the aromatic-aromatic interaction in preventing human lysozyme phase separation.

Quantitative Soil Characterization for Biochar-Cd Adsorption: Machine Learning Prediction Models for Cd Transformation and Immobilization.

Soil pollution with cadmium (Cd) poses serious health and environmental consequences. The study investigated the incubation of several soil samples and conducted quantitative soil characterization to assess the influence of biochar (BC) on Cd adsorption. The aim was to develop predictive models for Cd concentrations using statistical and modeling approaches dependent on soil characteristics. The potential risk linked to the transformation and immobilization of Cd adsorption by BC in the soil could be conservatively assessed by pH, clay, cation exchange capacity, organic carbon, and electrical conductivity. In this study, Long Short-Term Memory (LSTM), Bidirectional Gated Recurrent Unit (BiGRU), and 5-layer CNN Convolutional Neural Networks (CNNs) were applied for risk assessments to establish a framework for evaluating Cd risk in BC amended soils to predict Cd transformation. In the case of control soils (CK), the BiGRU model showed commendable performance, with an R2 value of 0.85, indicating an approximate 85.37% variance in the actual Cd. The LSTM model, which incorporates sequence data, produced less accurate results (R2=0.84), while the 5-layer CNN model had an R2 value of 0.91, indicating that the CNN model could account for over 91% of the variation in actual Cd levels. In the case of BC-applied soils, the BiGRU model demonstrated a strong correlation between predicted and actual values with R2 (0.93), indicating that the model explained 93.21% of the variance in Cd concentrations. Similarly, the LSTM model showed a notable increase in performance with BC-treated soil data. The R2 value for this model stands at a robust R2 (0.94), reflecting its enhanced ability to predict Cd levels with BC incorporation. Outperforming both recurrent models, the 5-layer CNN model attained the highest precision with an R2 value of 0.95, suggesting that 95.58% of the variance in the actual Cd data can be explained by the CNN model's predictions in BC-amended soils. Consequently, this study suggests developing ecological soil remediation strategies that can effectively manage heavy metal pollution in soils for environmental sustainability.

De Novo Synthesis and Structural Elucidation of CDR-H3 Loop Mimics.

The binding affinity of antibodies to specific antigens stems from a remarkably broad repertoire of hypervariable loops known as complementarity-determining regions (CDRs). While recognizing the pivotal role of the heavy-chain 3 CDRs (CDR-H3s) in maximizing antibody-antigen affinity and specificity, the key structural determinants responsible for their adaptability to diverse loop sequences, lengths, and noncanonical structures are hitherto unknown. To address this question, we achieved a de novo synthesis of bulged CDR-H3 mimics excised from their full antibody context. CD and NMR data revealed that these stable standalone β-hairpin scaffolds are well-folded and retain many of the native bulge CDR-H3 features in water. In particular, the tryptophan residue, highly conserved across CDR-H3 sequences, was found to extend the kinked base of these β-bulges through a combination of stabilizing intramolecular hydrogen bond and CH/π interaction. The structural ensemble consistent with our NMR observations exposed the dynamic nature of residues at the base of the loop, suggesting that β-bulges act as molecular hinges connecting the rigid stem to the more flexible loops of CDR-H3s. We anticipate that this deeper structural understanding of CDR-H3s will lay the foundation to inform the design of antibody drugs broadly and engineer novel CDR-H3 peptide scaffolds as therapeutics.

Impact of heavy metals exposure on herpes simplex virus type I infection: A population‐based cross‐sectional study

AbstractThis study aims to investigate the significant relationship between serum heavy metals (lead [Pb], cadmium [Cd], mercury [Hg]) and the risk of herpes simplex virus type 1 (HSV‐1) infection. Data were derived from the National Health and Nutrition Examination Survey (NHANES) conducted in the United States from 2007 to 2016. This nationally representative survey, conducted by the National Center for Health Statistics, assessed the health status of participants through interviews, physical examinations, and laboratory tests. After excluding participants lacking serum Pb, Cd, and Hg data, as well as those missing HSV‐1 testing data and pregnant women, the analysis included 13 772 participants, among whom 3363 were adolescents. A survey‐weighted multivariate logistic regression model was used to evaluate the association between heavy metal exposure and the risk of HSV‐1 infection, and to explore the dose–response relationship between them. In adults and adolescents, serum concentrations of Pb and Cd were higher in those infected with HSV‐1 than in those not infected. However, an increase in serum Hg concentration was observed only in infected adolescents. After adjusting for potential confounders, elevated serum Pb and Cd concentrations in adults were associated with an increased risk of HSV‐1 infection. Higher serum Pb and Cd concentrations were associated with an increased risk of HSV‐2 infection, irrespective of HSV‐1 infection status. In adults, serum concentrations of Pb and Hg showed an approximately linear relationship with HSV‐1 infection risk (p for nonlinearity > 0.05), whereas the dose–response relationship between serum Cd concentration and HSV‐1 infection was nonlinear (p for nonlinearity = 0.004). In adolescents, serum concentrations of heavy metals (Pb, Cd, Hg) showed an approximately linear relationship with HSV‐1 infection (p for nonlinearity > 0.05). Furthermore, the study examined the relationship between serum heavy metal levels and the risk of HSV‐1 infection across different genders, races, income levels, weight statuses, and immune statuses. In conclusion, there is a significant association between serum heavy metal concentrations and HSV‐1 infection, which warrants further investigation into the causal relationship between them.

Novel BRICHOS-related Defensin-like Antimicrobial Peptide from the Marine Polychaeta Arenicola marina

Objective: To date, polychaetes remain a poorly studied class of invertebrate animals in terms of the features of functioning of their immune system and, in particular, the biodiversity of antimicrobial peptides (AMPs). AMPs also known as host defense peptides play a key role in host protection from various pathogens and regulation of the species composition of symbiotic microbes. A study of the biosynthesis of AMPs in polychaetes resulted in the discovery of the so-called BRICHOS domain in the structure of the precursor proteins of a number of such peptides. The conserved structure of this domain makes possible the bioinformatic search for AMP precursors in polychaete transcriptomes. In this work, we found and studied a novel BRICHOS-related AMP from the lugworm Arenicola marina, representing a previously undiscovered in polychaetes a structural family of defensin-like peptides stabilized by four disulfide bonds. Methods: The peptide, designated as AmBRI-44a and containing 44 amino acid residues, was obtained by heterologous expression in Escherichia coli. The peptide secondary structure was investigated by CD spectroscopy in water and dodecylphosphocholine (DPC) micelles. The minimum inhibitory concentrations (MICs) against a wide range of bacterial pathogens were assessed using the two-fold serial dilutions method. Cytotoxicity of AmBRI-44a was studied in vitro on human erythrocytes or adherent cell line HEK293T using the hemoglobin release assay or the MTT test, respectively. The AMBRI-44a potential target was discovered by successive daily subculturing of the AmBRI-44a resistant strain followed by whole-genome sequencing. Results and Discussion: According to CD data, AmBRI-44a is a predominantly β-structured peptide. AmBRI-44a was shown to have a specific activity against a narrow spectrum of Gram-positive bacteria and pronounced cytotoxic effects on the eukaryotic cell line HEK293T. The proposed mechanism of the antibacterial action of this peptide is associated with the inhibition of bacterial cell wall biosynthesis, as indicated by the genetic and phenotypic analysis of selected AmBRI-44a-resistant bacteria Bacillus licheniformis B-511. Conclusions: The resulting data allow us to consider the discovered peptide AmBRI-44a as a candidate compound for the development of an antibiotic agent that could potentially be effective in the treatment of infectious diseases mediated by multidrug-resistant Gram-positive bacteria.

Isolation and identification of three new phenylpropanoids from the culms of phyllostachys nigra var. henonis (mitford) Rendle

Three new phenylpropanoids, namely (7′R,8′R) guaiacylglycerol 4′-O-β-D-[6″-O-(4-O-β-D-glucopyranosyl)-p-hydroxyl­benzoyl]-glucopyranoside (1), (7 R,8R) guaiacylglycerol 8-O-1′-(2′,6′-dimethoxy-4′-O-β-D-glucopyranosyl)-benzene (2), (7′R,8′R) guaiacylglycerol 4′-O-β-D-[6″-O-3,5-dimethoxy-4-hydroxylbenzoyl]-gluco­pyranoside (3), along with one known phenylpropanoid (4) were isolated from the ethanol extract of Phyllostachys nigra var. henonis fresh culm. The structures of all compounds were determined by analysis of UV, 1D NMR, 2D NMR, HR-ESI-MS and CD data. All compounds were evaluated for their DPPH radical scavenging activity. Compound 2 (IC50 54.9 μM) and 3 (IC50 77.2 μM) exhibited moderate antioxidant activity compared with two positive control compounds L-ascorbic acid (IC50 15.5 μM) and 2,6-ditertbutyl-4-methyl phenol (IC50 19.1 μM).

Methotrexate for Drug Repurposing as an Anti-Aggregatory Agent to Mercuric Treated α-Chymotrypsinogen-A.

Protein aggregation is related to numerous pathological conditions like Alzheimer's and Parkinson's disease. In our study, we have shown that an already existing FDA-approved drug; methotrexate (MTX) can be reprofiled on preformed α-chymotrypsinogen A (α-Cgn A) aggregates. The zymogen showed formation of aggregates upon interaction with mercuric ions, with increasing concentration of Hg2Cl2 (0-150 µM). The hike in ThT and ANS fluorescence concomitant with blue shift, bathochromic shift and the hyperchromic effect in the CR absorbance, RLS and turbidity measurements, substantiate the zymogen β-rich aggregate formation. The secondary structural alterations of α- Cgn A as analyzed by CD measurements, FTIR and Raman spectra showed the transformation of native β-barrel conformation to β-inter-molecular rich aggregates. The native α- Cgn A have about 30% α-helical content which was found to be about 3% in presence of mercuric ions suggesting the formation of aggregates. The amorphous aggregates were visualized by SEM. On incubation of Hg2Cl2 treated α- Cgn A with increasing concentration of the MTX resulted in reversing aggregates to the native-like structure. These results were supported by remarkable decrease in ThT and ANS fluorescence intensities and CR absorbance and also consistent with CD, FTIR, and Raman spectroscopy data. MTX was found to increase the α-helical content of the zymogen from 3 to 15% proposing that drug is efficient in disrupting the β-inter-molecular rich aggregates and reverting it to native like structure. The SEM images are in accordance with CD data showing the disintegration of aggregates. The most effective concentration of the drug was found to be 120 µM. Molecular docking analysis showed that MTX molecule was surrounded by the hydrophobic residues including Phe39, His40, Arg145, Tyr146, Thr151, Gly193, Ser195, and Gly216 and conventional hydrogen bonds, including Gln73 (bond length: 2.67Å), Gly142 (2.59Å), Thr144 (2.81Å), Asn150 (2.73Å), Asp153 (2.71Å), and Cys191 (2.53Å). This investigation will help to find the use of already existing drugs to cure protein misfolding-related abnormalities.

Polyketides with α-glucosidase inhibitory and neuroprotective activities from Aspergillus versicolor associated with Pedicularis sylvatica.

Aspergillus versicolor, an endophytic fungus associated with the herbal medicine Pedicularis sylvatica, produced four new polyketides, aspeversins A-D (1-2 and 5-6) and four known compounds, O-methylaverufin (2), aversin (3), varilactone A (7) and spirosorbicillinol A (8). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by calculated electronic circular dichroism (ECD) and Mo2(AcO)4-induced CD data. Compound 5 was found to exhibit α-glucosidase inhibitory activity with an IC50 value of 25.57 μM. An enzyme kinetic study indicated that 5 was a typical uncompetitive inhibitor toward α-glucosidase, which was supported by a molecular docking study. Moreover, compounds 1-3 and 5 also improved the cell viability of PC12 cells on a 1-methyl-4-phenylpyridinium (MPP+)-induced Parkinson's disease model, indicating their neuroprotective potential as antiparkinsonian agents.

Two unprecedented 2-(2-phenethyl)chromone dimers from red soil agarwood of Aquilaria crassna

Two unprecedented 2-(2-phenethyl)chromone dimers, aquicrassones A and B (1 and 2), were isolated by HPLC-MS guided method from the ethanol extract of red soil agarwood originating from Aquilaria crassna in Vietnam. Their structures were unambiguously elucidated by analysis of HR-ESI-MS, 1D and 2D NMR, CD data and by comparison with literature data. Compounds 1 and 2 were evaluated for their inhibition effect on nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells. Compound 2 displayed anti-inflammatory activity with an IC50 value of 20.36 ± 0.41 μM.

Efficient enumeration and visualization of helix-coil ensembles

Helix-coil models are routinely used to interpret circular dichroism data of helical peptides or predict the helicity of naturally-occurring and designed polypeptides. However, a helix-coil model contains significantly more information than mean helicity alone, as it defines the entire ensemble—the equilibrium population of every possible helix-coil configuration—for a given sequence. Many desirable quantities of this ensemble are either not obtained as ensemble averages or are not available using standard helicity-averaging calculations. Enumeration of the entire ensemble can allow calculation of a wider set of ensemble properties, but the exponential size of the configuration space typically renders this intractable. We present an algorithm that efficiently approximates the helix-coil ensemble to arbitrary accuracy by sequentially generating a list of the M highest populated configurations in descending order of population. Truncating this list of (configuration, population) pairs at a desired accuracy provides an approximating sub-ensemble. We demonstrate several uses of this approach for providing insight into helix-coil ensembles and folding mechanisms, including landscape visualization.

Toward Accurate Simulation of Coupling between Protein Secondary Structure and Phase Separation.

Intrinsically disordered proteins (IDPs) frequently mediate phase separation that underlies the formation of a biomolecular condensate. Together with theory and experiment, efficient coarse-grained (CG) simulations have been instrumental in understanding the sequence-specific phase separation of IDPs. However, the widely used Cα-only models are limited in capturing the peptide nature of IDPs, particularly backbone-mediated interactions and effects of secondary structures, in phase separation. Here, we describe a hybrid resolution (HyRes) protein model toward a more accurate description of the backbone and transient secondary structures in phase separation. With an atomistic backbone and coarse-grained side chains, HyRes can semiquantitatively capture the residue helical propensity and overall chain dimension of monomeric IDPs. Using GY-23 as a model system, we show that HyRes is efficient enough for the direct simulation of spontaneous phase separation and, at the same time, appears accurate enough to resolve the effects of single His to Lys mutations. HyRes simulations also successfully predict increased β-structure formation in the condensate, consistent with available experimental CD data. We further utilize HyRes to study the phase separation of TPD-43, where several disease-related mutants in the conserved region (CR) have been shown to affect residual helicities and modulate the phase separation propensity as measured by the saturation concentration. The simulations successfully recapitulate the effect of these mutants on the helicity and phase separation propensity of TDP-43 CR. Analyses reveal that the balance between backbone and side chain-mediated interactions, but not helicity itself, actually determines phase separation propensity. These results support that HyRes represents an effective protein model for molecular simulation of IDP phase separation and will help to elucidate the coupling between transient secondary structures and phase separation.

Impaired intestinal immunity and microbial diversity in common carp exposed to cadmium

Waterborne cadmium (Cd) accumulates in the fish intestine and causes irreversible toxicity by disrupting intestinal immunity and microbial diversity. To explore the toxicity of environmentally available high Cd concentration on intestinal immunity and microbial diversity of fish, we selected the widely used bioindicator model species, Common carp (Cyprinus carpio). Literature review and Cd pollution data supported sequential doses of 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg/L Cd for 30 days. Based on intestinal tissue Cd accumulation, previous studies, and environmentally available Cd data, 0.4 and 1.6 mg/L Cd were selected for further studies. Intestinal Cd bioaccumulation increased significantly to ~100 times in fish exposed to 1.6 mg/L Cd. We observed villous atrophy, increased goblet cells with mucus production, muscularis erosion, and thickened lamina propria due to intense inflammatory cell infiltration in the intestine at this Cd concentration. Cd-induced immunosuppression occurred with increased lysozyme, alkaline phosphate (AKP), and acid phosphate (ACP). High levels of catalase (CAT), total antioxidant capacity (T-AOC), malondialdehyde (MDA), and hydrogen peroxide (H2O2) suggested induced oxidative stress and poor metabolism by α-amylase and lipase suppression for Cd toxicity. Proteobacteria (41.2 %), Firmicutes (21.8 %), and Bacteroidetes (17.5 %) were the dominant bacterial phyla in the common carp intestine. Additionally, potential pathogenic Cyanobacteria increased in Cd-treated fish. The decrease of beneficiary bacteria like Aeromonas, and Cetobacterium indicated Cd toxicity. Overall, these findings indicate harmful consequences of high Cd concentration in the intestinal homeostasis and health status of fish.

Phenolic Derivatives with Anti-Acetylcholinesterase Inhibitory Activities from Galeola nudifolia in Vietnam.

A new phenolic derivative, galeomalate A (1), together with five known structurally related compounds (2-6), was isolated from the ethyl acetate extract of Galeola nudifolia collected in Vietnam. The structures were elucidated by various spectroscopic methods, including 1D and 2D NMR, HR-ESI-TOF-MS, and CD data, and chemical conversion of the sugar moiety. All isolated compounds possessed acetylcholinesterase (AChE) inhibitory activities in a dose-dependent manner. Among them, compounds 2 and 3 exhibited the first and second highest inhibitory activity on AChE with IC50 values of 122.13 and 125.49 μM, respectively. Compounds 1 and 4-6 inhibited the AChE activity by mixed modes of action comprising competitive and non-competitive modes, whereas 2 and 3 exerted their inhibitory activities in a competitive manner. Molecular docking analyses suggested that the phenyl-β-D-glucopyranoside unit of 2 and 3 bound to the active site of AChE for the competitive inhibitory activities, while the mixed inhibitory activity of 4 was due to the two binding patterns in the active-site and the active-site entrance of AChE. Furthermore, the docking studies indicated that 1, 5, and 6 would inhibit AChE in a mixed inhibitory manner by adopting three distinct binding patterns of the additional phenyl-β-D-glucopyranoside unit at the active-site entrance.

The impacts of atmospheric icing on performance and behavior of a controlled large-scale wind turbine

Icing degrades turbine performance by altering the geometry of blade airfoils, reducing turbine power output, and increasing structural loads. In this study, the impacts of atmospheric icing on the full performance and behavior of a controlled large-scale wind turbine are thoroughly investigated. Using the Mustafa Sahin bladed wind turbine simulation model, the National Renewable Energy Laboratory 5 MW turbine is simulated with and without iced blades. The turbine blades are considered fully covered by light icing at the leading edge, which causes a reduction of up to 9.27% in Cl and an increase of up to 48% in Cd data of blade airfoils. Turbine static performance and behavior are examined at different uniform winds between cut-in and cut-out wind speeds, while the dynamic performance and behavior are estimated under turbulent winds at below (region II) and above (region III) rated regions. Simulation results are presented in terms of various turbine parameters, such as rotor power, thrust, their coefficients, blade pitch angle, rotor speed, etc. Results show that such light icing alters the turbine's aerodynamic characteristics and dynamics, increasing the turbine's cut-in and rated wind speeds, and reducing the thrust and maximum power coefficients by 5.5% and 13.35%, respectively. Under the same uniform winds, due to icing, turbine static performance and behavior are drastically disrupted in below rated region, resulting in reduced rotor speed, turbine efficiency, thrust, and power output by up to 4.77%, 39.7%, 7.63%, and 40%, respectively. In region III, however, thrust increases by up to 15% although the power output, rotor speed, and turbine efficiency do not change considerably. When the dynamic responses are examined under turbulent wind with a mean of 7.9 m/s in region II, mean power and fluctuations reduce by 14.17% and 10.88%, respectively. The mean thrust decreases by 6.86%, while its fluctuations reduce by 11.33%. The mean rotor speed reduces by 3.83%, and its fluctuations decrease by 12.84%. Under turbulent wind with a mean of 15.7 m/s in region III, the mean power and fluctuations decrease by 0.053% and 1.95%, respectively. The mean thrust increases by 11.99% and its fluctuations drop by 0.84%. The mean rotor speed does not change much, but its fluctuations increase by 0.132%. The mean blade pitch angle reduces by 9.39%, while its fluctuations increase by 7.39%.