1,064 research outputs found
Cellulose Ether-Based Liquid Crystal Materials: Review Article
The development of liquid crystal materials via nanotechnology has become an interesting subject of research in optical material chemistry. One of the significant nanomaterials is cellulose-based nanoparticles. In this review article, we highlighted the classification of liquid crystal materials (LCs), and types of cellulose-NPs and their characterization as LCs materials. Finally, we present our promising data on the synergistic effect of cellulose-NPs on liquid crystal behavior of ethyl cellulose- and hydroxypropyl cellulose- nanocomposites
Reliability of candida skin test in the evaluation of T-cell function in infancy
Background: Both standardized and non-standardized candida skin tests are used in clinical practice for functional in-vivo assessment of cellular immunity with variable results and are considered not reliable under the age of 1 year. We sought to investigate the reliability of using manually prepared candida intradermal test in the evaluation of T cell function in infants during their second year of life.Methods: Twenty-five healthy infants were tested with manually prepared intradermal candida test. Cultured lymphocytes were stimulated with phytohemagglutinin (PHA) and gamma interferon (IFN-γ) levels were measured in the culture supernatant of stimulated and non-stimulated samples using ELISA.Results: The enrolled infants were 14 to 24 months old (mean 19.2 ± 3.13 months). They were 17 boys (68 %) and 8 girls (32 %). Candida skin test was positive in 17 out of the 25 infants (68%). All infants showed increased IFN-γ levels after PHA stimulation (mean ± SD: 0.83±0.29 ng/ml) compared to basal levels (mean ± SD = 0.16 ± 0.16 ng/ml). The increase of IFN γ levels after PHA stimulation ranged from 1.54 to 38 folds. Infants with positive and negative candida tests showed comparable results in terms of clinical and immunological assessment except for weight percentiles for age that were higher among candida positive group.Conclusion: Candida intradermal test is a cost-effective simple test for evaluation of T cell function with 70 % sensitivity in healthy infants above the age of one year.Keywords: Candida, IFN-γ, infants, intradermal, lymphocyte proliferation, PHA stimulation, T cell, Tuberculi
Immobilization of glucose isomerase onto radiation synthesized P(AA-co-AMPS) hydrogel and its application
AbstractIsomerization of glucose to fructose was carried out using Glucose isomerase (GI) that immobilized by entrapment into Poly(acrylic acid) P(AA) and Poly(acrylic acid-co-2-Acrylamido 2-methyl Propane sulfonic acid) P(AA-co-AMPS) polymer networks, the enzyme carriers were prepared by radiation induced copolymerization in the presence of (Methylene-bisacrylamide) (MBAA) as a crosslinking agent. The maximum gel fraction of pure P(AA) and P(AA-co-AMPS) hydrogel was found to be 95.2% and 89.6% for P(AA) and P(AA-co-AMPS), respectively at a total dose of 20 kGy. Effects of immobilization conditions such as radiation dose, MBAA concentration, comonomer composition and amount of GI were investigated. The influence of reaction conditions on the activity of immobilized GI were studied, the optimum pH value of the reaction solution is 7.5 and reaction temperature is 65 °C. The immobilized GI into P(AA-co-AMPS) and P(AA) polymer networks retained 81% and 69%, respectively of its initial activity after recycled for 15 times while it retained 87% and 71%, respectively of its initial activity after stored at 4 °C for 48 days. The Km values of free and immobilized GI onto P(AA-co-AMPS) and onto P(AA) matrices were found to be 34, 29.2 and 14.5 mg/mL, respectively while the Vmax Values calculated to be 3.87, 1.6 and 0.79 mg/mLmin, respectively. GI entrapped into P(AA-co-AMPS) hydrogel show promising behavior that may be useful as the newly glucose isomerase reactor in biomedical applications
Mathematical Description of the Change in Properties of Casuarina Wood Upon Exposure to Gamma Radiation. 1. Changes in the Compressive and Tensile Strength
Casuarina cunninghamiana specimens were exposed to gamma-radiation doses ranging from 104 to 108 rad and tested in compression and tension parallel to grain. The percentage values of the irradiated specimens relative to that of the matched control (Y) were determined. The relationship between (Y) and log gamma radiation dose (X) was represented mathematically by the equation: Y = aXbcx. This equation described the change in compressive and tensile strength very well as was detected from the high correlation coefficients. Generally these properties increased slightly at low levels of radiation, reached a maximum, then decreased gradually thereafter. The reduction in tensile strength was more pronounced than in compressive strength.The threshold dose, i.e., the dose beyond which the properties began to decrease, was calculated. This dose ranged from 3.69 x 106 to 3.76 x 106 rad for compressive strength properties and from 1.51 x 106 to 1.70 x 106 rad for tensile strength properties. This indicated that irradiated casuarina wood had a greater resistance to compression than to tension
The Accuracy Degree of CFD Turbulence Models for Butterfly Valve Flow Coefficient Prediction
Abstract Although engineers are mainly interested in the prediction of mean flow behavior, the turbulence cannot be ignored, because the fluctuations give rise to the extra Reynolds stresses on the mean flow. These extra stresses must be modeled in commercial CFD by selecting convenient turbulence model. The flow inside the control valve is complex and the control valves performance is precisely evaluated by determining the valve coefficient named, flow coefficient. Hence, aim of the present study is to investigate the effect of turbulence model type on the solution accuracy for the valve disk angles 40° and 60° as well as to implement the degree of agreement between experimental and numerical results. The numerical verification has been investigated by FLUENT 6.3 and the valve is meshed by GAMBIT 2. The mesh independent test has been carried out only by standard k-ε to evaluate the mesh effectiveness and attain the best accuracy. Among from these several turbulence models which have been studied here are standard k-ε, realized k-ε, k-ω, and RSM. Butterfly valve, STC model and (DN 50) diameter is chosen to be the test specimen in this research. The results showed that, there is no general turbulent model that can deal successfully with all cases. Numerical and experimental results are in general in good agreement, however are different in details, and showed that, RSM model is the most efficient numerical solver when applied to butterfly valve flow coefficient evaluation. For the future, a significant amount of work still needs to be undertaken in experimental unsteady butterfly valve flow analysis with RSM numerical model
Molecular hybridization design and synthesis of novel spirooxindole-based MDM2 inhibitors endowed with BCL2 signaling attenuation:A step towards the next generation p53 activators
Despite the achieved progress in developing efficient MDM2-p53 protein-protein interaction inhibitors (MDM2 inhibitors), the acquired resistance of tumor cells to such p53 activators posed an argument about the druggability of the pathway. Combination studies disclosed that concomitant inhibition of MDM2 and BCL2 functions can sensitize the tumor cells and synergistically induce apoptosis. Herein, we employed a rapid combinatorial approach to generate a novel series of hybrid spirooxindole-based MDM2 inhibitors (5a-s) endowed with BCL2 signaling attenuation. The adducts were designed to mimic the thematic features of the chemically stable potent spiro[3H-indole-3,2′-pyrrolidin]-2(1H)-ones MDM2 inhibitors while installing a pyrrole ring on the core via a carbonyl spacer inspired by the natural product marinopyrrole A that efficiently inhibits BCL2 family functions by various mechanisms. NCI 60 cell-line panel screening revealed their promising broad-spectrum antiproliferative activities. The NCI-selected derivatives were screened for cytotoxic activities against normal fibroblasts, MDA-MB 231, HepG-2, and Caco-2 cells via MTT assay, subjected to mechanistic apoptosis studies for assessment of p53, BCL2, p21, and caspase 3/7 status, then evaluated for potential MDM2 inhibition utilizing MST assay. The most balanced potent and safe derivatives; 5i and 5q were more active than 5-fluorouracil, exhibited low μM range MDM2 binding (KD =1.32 and 1.72 μM, respectively), induced apoptosis-dependent anticancer activities up to 50%, activated p53 by 47-63%, downregulated the BCL2 gene to 59.8%, and reduced its protein level (13.75%) in the treated cancer cells. Further downstream p53 signaling studies revealed > 2 folds p21 upregulation and > 3 folds caspase 3/7 activation. Docking simulations displayed that the active MDM2 inhibitors resided well into the p53 binding sites of MDM2, and shared key interactions with the co-crystalized inhibitor posed by the indolinone scaffold (5i, 5p, and 5q), the halogen substituents (5r), or the installed spiro ring (5s). Finally, in silico ADMET profiling predicted acceptable drug-like properties with full accordance to Lipinski's, Veber's, and Muegge's bioavailability parameters for 5i and a single violation for 5q
Design, Synthesis, Chemical and Biochemical Insights Into Novel Hybrid Spirooxindole-Based p53-MDM2 Inhibitors With Potential Bcl2 Signaling Attenuation
The tumor resistance to p53 activators posed a clinical challenge. Combination studies disclosed that concomitant administration of Bcl2 inhibitors can sensitize the tumor cells and induce apoptosis. In this study, we utilized a rapid synthetic route to synthesize two novel hybrid spirooxindole-based p53-MDM2 inhibitors endowed with Bcl2 signaling attenuation. The adducts mimic the thematic features of the chemically stable potent spiro [3H-indole-3,2′-pyrrolidin]-2(1H)-ones p53-MDM2 inhibitors, while installing a pyrrole ring via a carbonyl spacer inspired by the natural marine or synthetic products that efficiently inhibit Bcl2 family functions. A chemical insight into the two synthesized spirooxindoles including single crystal x-ray diffraction analysis unambiguously confirmed their structures. The synthesized spirooxindoles 2a and 2b were preliminarily tested for cytotoxic activities against normal cells, MDA-MB 231, HepG-2, and Caco-2 via MTT assay. 2b was superior to 5-fluorouracil. Mechanistically, 2b induced apoptosis-dependent anticancer effect (43%) higher than that of 5-fluorouracil (34.95%) in three studied cancer cell lines, activated p53 (47%), downregulated the Bcl2 gene (1.25-fold), and upregulated p21 (2-fold) in the treated cancer cells. Docking simulations declared the possible binding modes of the synthesized compounds within MDM2
Consensus evidence-based recommendations for treat-to-target management of immunoglobulin A vasculitis
IgA vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is the most common cause of systemic vasculitis in childhood. Given its potential life-threatening systemic
complications, early and accurate diagnosis as well as management of IgAV represent a major challenge for health care professionals. This study was carried out to attain an evidence-based expert consensus on a treat-to-target management approach for IgAV using Delphi technique.
The preliminary scientific committee identified a total of 16 key clinical questions according to the patient, intervention, comparison, and outcomes (PICO) approach. An evidence-based, systematic, literature review was conducted to compile evidence for the IgAV management.
The core leadership team identified researchers and clinicians with expertise in IgAV management in Egypt upon which experts were gathered from different governorates and health centers across Egypt. Delphi process was implemented (two rounds) to reach a consensus. An online questionnaire was sent to expert panel (n = 26) who participated in the two rounds. After completing round 2, a total of 20 recommendation items, categorized into two sections were
obtained. Agreement with the recommendations (rank 7–9) ranged from 91.7–100%.
Consensus was reached (i.e. ⩾75% of respondents strongly agreed or agreed) on the wording of all the 20 clinical standards identified by the scientific committee. Algorithms for the diagnosis and management have been suggested. This was an expert, consensus recommendations for the diagnosis and treatment of IgAV and IgA vasculitic nephritis, based on best available evidence and expert opinion. The guideline presented a strategy of care with a pathway to achieve a state of remission as early as possible
Water decontamination with hydrogen production using microwave-formed minute-made ruthenium catalysts
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