SciCombinator

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The adsorption of oligonucleotides on citrate-coated gold nanoparticles (AuNPs) is studied in conditions “right after the synthesis”, i.e. in a weak citrate solution at pH value close to neutral (5.8±0.2). We found that short-term elevation of reaction temperature under these conditions provides fast and strong adsorption of oligonucleotides on the surface of AuNPs. The affinity of oligonucleotides to AuNPs depends on the length of the oligonucleotide and its nucleotide composition. The shortest oligonucleotide in this study - T6 is the most affine, having the equilibrium binding constant KD=0,10±0,04 nM, and the highest surface density - up to 200 molecules per one particle. Olygothymidylates are at least as affine to AuNPs as oligoadenylates, while oligocytidilates show the lowest affinity. We also studied the interaction of resulting DNA/AuNPs with a series of low- and high-molecular thiols, which provide a variety of operations with adsorbed oligonucleotides: displacement (complete or partial) and encapsulation in a secondary shell. These experiments imitate someway the conditions in a living cell or serum, and show that DNA/AuNPs obtained by this method can be applied in a number of bionanotechnological applications, including delivery of nucleic acid therapeutics and theranostics.

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Effects of calcium ions (Ca2+) on the solubility, aggregate structure and rheological behavior of a C22-tailed zwitterionic surfactant, erucyl dimethyl amidopropyl hydroxyl sulfobetaine (EHSB), have been investigated in aqueous solution. In comparison with sodium ions (Na+), Ca2+ ions exhibit much higher efficiency in decreasing the Krafft temperature (TK) of EHSB. Specifically, contrary to Na+ ions which have no obvious effect on the rheological properties of the EHSB solution, Ca2+ ions increase the viscosity of the EHSB solution at lower EHSB concentration, and enhance its elasticity at higher EHSB concentration. Moreover, Ca2+ ions raise the temperature needed for the elastic-to-viscous transition of the EHSB solution at higher concentration. At lower EHSB concentration, the hydrophobic interaction between the ultra-long hydrocarbon chains induces a tighter packing of the hydrophobic chains by forming more stretched configuration, while at higher EHSB concentration, the electrostatic attraction between Ca2+ ions and the sulfonate groups of EHSB induces a tighter packing of the headgroups by forming Ca2+-mediated bridges among the EHSB headgroups. Besides, the above interactions may strengthen the hydrogen bonding of OH groups and/or of C=O amide groups, which in turn facilitates the compact packing of the surfactant molecules in aggregates and promotes the growth and entanglement of wormlike micelles. Thus the EHSB solution shows Ca2+-dependent rheological behaviors. The solubility and rheological properties of the ultra-long chain surfactant solution can be simultaneously improved with the addition of divalent Ca2+ ions.

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Using glucose oxidase (GOx) and α-Zr(IV)phosphate nanoplates (α-ZrP) as a model system, a generally applicable approach to control enzyme-solid interactions via chemical modification of amino acid side chains of the enzyme is demonstrated. Net charge on GOx was systematically tuned by appending different amounts of polyamine to the protein surface to produce chemically modified GOx(n), where n is the net charge on the enzyme after the modification and ranged from -62 to +95 electrostatic units in the system. The binding of GOx(n) with α-ZrP nanosheets was studied by isothermal titration calorimetry (ITC) as well as by surface plasmon resonance (SPR) spectroscopy. Pristine GOx showed no affinity for the α-ZrP nanosheets, but GOx(n) where n ≥ -20 showed binding affinities exceeding (2.1 ± 0.6) x 106 M-1, resulting from the charge modification of the enzyme. A plot of GOx(n) charge vs Gibbs free energy of binding (ΔG) for n = +20 to n = +65 indicated an overall increase in favorable interaction between GOx(n) and α-ZrP nanosheets. However, ΔG is less dependent on the net charge for n > +45 as evidenced by the decrease in the slope as charge increased further. All modified enzyme samples and enzyme/α-ZrP complexes retained significant amount of folding structure (examined by circular dichroism) as well as enzymatic activities. Thus, strong control over enzyme-nanosheet interactions via modulating the net charge of enzymes may find potential applications in biosensing and biocatalysis.

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Little is known about the language trajectories of minimally verbal school-aged children with autism spectrum disorders. The present investigation conducted observations across two elementary schools over an entire school year to analyze the vocal language development of nine minimally verbal children with autism spectrum disorder between the ages of 6 and 10 years, and their educational service providers. A Language Environment Analysis™ device automatically recorded and disaggregated over 743 h of data on child vocalizations, and vocal interactions with adults. Vocalizations did not increase for eight of the nine participants, and conversational counts between participants and adults were near zero across the entire year. These results speak to the need for additional research examining language development and potential intervention strategies among minimally verbal children with autism spectrum disorder.

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Nanomedicine is an application of nanotechnology that provides solutions to unmet medical challenges. The unique features of nanoparticles, such as their small size, modifiable components and diverse functionality, make them attractive and suitable materials for novel diagnostic, therapeutic or theranostic applications. Cardiovascular diseases (CVDs) are the major cause of non-communicable illness in both developing and developed countries. Nanomedicine offers novel theranostic options for the treatment of CVDs. Recent Advances. Many innovative nanoparticles to target reactive oxygen species (ROS) have been developed. In this article, we review the characteristics of nanoparticles that are responsive to ROS, their limitations, and their potential clinical uses. Significant advances made in diagnosis of atherosclerosis and treatment of acute coronary syndrome using nanoparticles are discussed.

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1. Acrylamide (ACR) is a potent neurotoxicant, although information on its toxic influence on the developing neural system is still limited. We examined the effect of in-ovo-injected ACR on the antioxidant system activity in the brain of new hatched chickens. This model eliminated the mother’s contribution to embryonic development. It was also recognised as an adequate model for animal embryonic development. 2. ACR was injected on day 4 of embryogenesis- in doses of 1.25 and 2.50 mg per egg (n=40 eggs per group/120 eggs). The doses corresponded well with ACR doses used in other animal studies and their concentrations in certain animal feeds. 3. Mortality and incidences of malformations were not found to increase significantly. Significant depletion of GSH was detected in the cerebellum, cerebrum and medulla oblongata of specimens exposed to the highest doses of ACR. Enzymatic activity was affected by the highest ACR doses. GPx activity increased significantly in the cerebrum, medulla oblongata and the hypothalamus. SOD activity increased significantly in hypothalamus and decreased in cerebellum and cerebrum. A significant depletion of catalase activity was detected in cerebellum. In the hypothalamus, the increased SOD/GPx and SOD/CAT ratios suggest the risk of H2O2. 4. It was concluded that ACR significantly influences the antioxidative defence in the chicken brain at doses of 1.25 and 2.50 mg per egg.

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This study aimed to understand the experiences of middle school girls who have engaged in non-suicidal self-injury (NSSI) and have received professional help for these behaviors. Participants described engaging in NSSI in response to uncomfortable feelings and invasive negative thoughts. They reported that engaging in NSSI decreased their uncomfortable feelings. While each participant had at least one person in her life who knew about her NSSI, participants did not feel supported or validated by these people. Participants were not completely honest with their therapists because they were afraid of being misunderstood, dismissed, or getting others into trouble. Despite these things, participants wanted support and understanding about who they are as unique individuals, why they are struggling, and why they self-injure. They also wanted to be in a transparent therapeutic relationship where they felt respected and accepted. Unfortunately, they did not describe relationships with their therapists as possessing these qualities. Professionals would better meet the need of adolescents by clearly discussing confidentiality, boundaries, conveying respect and acceptance, and recognizing the uniqueness of their clients. Assessing for self-harm and treatment reluctance should be done in the context of resistance to therapy and a sensitivity to judgment.

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We aimed to determine the profile of IgE reactivity to three major cat allergens, Fel d 1, Fel d 2 and Fel d 4, in cat-allergic patients in the Moscow region in Russia. sIgE levels to recombinant proteins expressed in Escherichia coli (Fel d 1 and Fel d 4) and to Fel d 2 protein purified from cat serum were measured using a microarray method developed in our laboratory. Sera from 174 anonymous subjects with a positive reaction (≥0.35 IU/mL) to cat dander extract (e1, ImmunoCAP) and 56 negative controls were used for IgE testing. Fel d 1 was recognized by 92.5%, Fel d 2 by 29.9% and Fel d 4 by 39.1% of the tested patient sera. The sensitivity to these three proteins was approximately 98% compared to cat dander extract (correlation coefficient to ImmunoCAP is 0.94 with PPV = 0.99 and NPV = 0.95). These predictive values appeared to be even more statistically significant than the divergence between the ISAC IgE test and the extract-based singleplex ImmunoCAP. The combination of the three investigated proteins (Fel d 1, Fel d 2 and Fel d 4) is suitable for in vitro molecular (serological) diagnosis of cat allergy in this region as a complement to cat dander extract. Moreover, with this method, we found distinction between Fel d 2 and other Feline sIgEs formation.

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The factors affecting the mechanical properties of biofilms formed by yeast species (Rhodotorula mucilaginosa, Candida krusei, C. kefyr and C. tropicalis) isolated from the juice processing industries have been investigated. Variables studied were: the food matrix (apple/pear juice), the sugar concentration (6/12 °Bx) and the hydrodynamic conditions (static/turbulent flow). A range of environmental cues were included as the mechanical properties of biofilms are complex. Yeast counts were significantly higher in turbulent flow compared with under static conditions. The thickness of the biofilm ranged from 38 to 148 μm, from static to turbulent flow. Yeast biofilms grown under turbulent flow conditions were viscoelastic with a predominant solid-like behavior and were structurally stronger than those grown under static conditions, indicating gel-type structures. Only the type of flow had a significant effect on [Formula: see text] and G*. Flow velocity and nutrient status modulated the biofilm thickness, the biomass and the mechanical properties. A better knowledge of the factors controlling biofilm formation will help in the development of control strategies.

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Calprotectin (myeloid-related protein 8/14) is elevated in inflammatory diseases and a correlation of serum calprotectin and disease activity in rheumatoid arthritis (RA) has been shown. In this study, we investigated plasma calprotectin as a disease marker in patients with chronic RA treated with methotrexate (MTX) monotherapy and compared plasma calprotectin with C-reactive protein (CRP) in this matter.