Graphene nanoplatelets (GNPs) are extremely useful nanofillers in epoxy in carbon fiber‐reinforced polymer (CFRP) composites as they make CFPRs sustain higher loads before failure in different kinds ...of loading for example flexural, tensile and fatigue. The current study aims to investigate the effect of GNP coating on carbon fibers on the deformation modes of CFRPs under flexural loading. Laminates have been fabricated using vacuum‐assisted resin transfer molding (VARTM) after spray coating GNPs on unidirectional carbon fiber fabrics. One set of flexural tests were carried out where the strain was recorded using DIC and the other set had in‐situ deformation while recording optical images to monitor deformation. Since, the most probable causes of failure under flexural loading are local compression, shear or contact stresses due to a sharp ram, other mechanical tests like compression test and nano‐indentation were also carried out on the composites. Compressive stress–strain response was ascertained using combined loading compression (CLC) fixture and digital image corelation (DIC) while contact response was evaluated using nanoindentation. GNP‐coated CFRPs were shown to have an increase in compressive modulus of 16% and failure strain of 6%, respectively. Axial and transverse strains measured through DIC were more than two times higher in GNP‐coated CFRPs. Nano‐indentation tests across the entire composite showed some data with intermediate modulus (~10–45 GPa) and hardness (~1–5 GPa) between the epoxy and the fiber and this corresponded to an interphase region which was thicker in 0.4GNP laminate compared to pristine laminate. Flexural strength, flexural modulus and strain at maximum stress improved by 10%, 8%, and 9% respectively in GNP‐coated CFRPs compared to uncoated CFRPs. In addition, while pristine laminates showed non‐uniform distribution of strains during flexural loading, the distribution of strains was much more uniform in GNP‐coated laminate. However, in both kinds of laminates, the failure initiation was in the region of compressive bending stresses.
Highlights
GNP‐added laminate showed an intermediate modulus and hardness interphase through a nanoindentation test.
Digital image correlation analysis has been performed to obtain the strain maps during compressive and flexural loading.
GNP‐added laminates showed higher failure strains compared to pristine laminates under the compressive loads.
GNP‐added laminates performed well under flexural loading.
Flexural response and damage evolution in GNP‐coated carbon fiber epoxy composites manufactured through VARTM technique.
A proposal for staging COVID‐19 coagulopathy Thachil, Jecko; Cushman, Mary; Srivastava, Alok ...
Research and practice in thrombosis and haemostasis,
July 2020, Volume:
4, Issue:
5
Journal Article
Peer reviewed
Open access
Coronavirus disease 2019 (COVID‐19) is associated with significant hypercoagulability. However, despite prophylactic anticoagulation, critically ill patients with this condition develop thromboses. ...This forum discusses the lungs as the epicenter for the hemostatic issues, puts forward a proposal for staging COVID‐19 coagulopathy based on available diagnostic markers, and suggest considering current and future treatment options based on these different stages.
Allogeneic hematopoietic stem cell transplantation has been well established for several decades as gene replacement therapy for patients with thalassemia major, and now offers very high rates of ...cure for patients who have access to this therapy. Outcomes have improved tremendously over the last decade, even in high-risk patients. The limited data available suggests that the long-term outcome is also excellent, with a >90% survival rate, but for the best results, hematopoietic stem cell transplantation should be offered early, before any end organ damage occurs. However, access to this therapy is limited in more than half the patients by the lack of suitable donors. Inadequate hematopoietic stem cell transplantation services and the high cost of therapy are other reasons for this limited access, particularly in those parts of the world which have a high prevalence of this condition. As a result, fewer than 10% of eligible patients are actually able to avail of this therapy. Other options for curative therapies are therefore needed. Recently, gene correction of autologous hematopoietic stem cells has been successfully established using lentiviral vectors, and several clinical trials have been initiated. A gene editing approach to correct the β-globin mutation or disrupt the BCL11A gene to increase fetal hemoglobin production has also been reported, and is expected to be introduced in clinical trials soon. Curative possibilities for the major hemoglobin disorders are expanding. Providing access to these therapies around the world will remain a challenge.
Selectivity and enhanced sensitivity for surface-enhanced Raman scattering (SERS) substrates are highly desirable attributes for their analytical applications. SERS substrate interaction with target ...molecules plays a key role in determining the enhancement magnitude and spectral profile of the SERS signal as well as their applications. Herein, we demonstrate a SERS active substrate based on reduced graphene oxide/silver nanoparticles (rGO/Ag NPs) composite material synthesized by a facile wet chemical route. The Ag NPs decorated rGO nanosheet has been achieved by reducing AgNO3 with ethylene glycol in the presence of poly vinyl pyrrolidone (PVP) and NaCl over layered graphene oxide. The addition of PVP stimulates the nano-phase growth as well as uniform distribution of the Ag NPs on rGO nanosheet. The well synthesized rGO/Ag composite was confirmed by using various characterization techniques such as FESEM, HRTEM, XRD, FTIR and Raman. Further, the rGO/Ag NPs composite material has been utilized as a platform for SERS based selective detection of Rhodamine-6G, 4-mercapto benzoic acid, and 2,4-dinitrotoluene analytes. The rGO/Ag NPs substrate demonstrates good homogeneity, stability and nanomolar sensitivity with Raman intensity enhancement of the order of 5 for Rh-6G and 4-MBA whereas 3 for 2,4-DNT. The observed enhancement of SERS signal for all the analytes has been attributes to the cumulative effect of rGO and Ag NPs.
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•We fabricated and demonstrated a generic SERS sensor based on Ag-rGO composite.•Wet chemical process has been used for the decoration of spherical silver nanoparticles on the rGO nano sheets.•The loading density of the Ag NPs on rGO nanosheet depends on AgNO3 molar concentration.•The optimized concentration of AgNO3 and GO for highest enhancement in Raman intensities was 0.01M and 2.5mg respectively.•Synthesized nanocomposite acts as SERS sensitive substrate for the detection of Rh-6G, 4-MBA, and 2,4-DNT up to the nM range.•The enhancement factors are found to be 5 orders of magnitude for Rh-6G, 4-MBA and 3 orders of magnitude for 2,4-DNT.
In pancytopenia due to aplastic anemia (AA), bone marrow hypocellularity leads to hazardous failure of hematopoiesis. Āyurveda treatment was given to a 30-year-old male patient known case of severe ...acquired AA, considering it under Pāṇḍūroga (~anemia). A study was carried out to search the effectiveness of Āyurveda medications, especially Rasāyana (~immunomodulator) mentioned in the treatment of Pāṇḍū in the management of AA. The patient was administered Rasāyana drugs, such as Śilājatukalpa, Amṛītā-Satta, Punarnavā, and Maṇḍūr having hepatoprotective, anxiolytic, and antioxidant properties, and ĀrogyavardhanīVaṭī, TrikaṭūCūrṇa. Hematological investigations of the patient were carried out every 2 months for 2 and ½ years. Erythrocyte sedimentation rate, white blood cell, and red cell distribution width coefficient of variation were in the normal range after treatment. Red blood cells, HB, and platelets were found to be increased, which were not growing before treatment. Liver function test, kidney function test, serum sodium, and potassium were normal during treatment. Complete relief in symptoms was found. The present study concludes that the severity of pancytopenia due to AA can be managed effectively with Ayurvedic medications.
Rapid detection technologies with high sensitivity and selectivity for plant pathogens are essential to prevent disease spread and minimize losses to assure optimal productivity and food security. ...Traditional laboratory techniques such as microscopy and culture are time-consuming, labour intensive and require complex sample handling. Immunological and molecular techniques have advanced but have some issues related to rapidity, signal strength and instrumentation. The integration of immunological and molecular diagnostics with nanotechnology systems offers an option where all detection steps can be accommodated on a portable miniaturized device for rapid and accurate detection of plant pathogens. The sensitive nature of functionalized nanoparticles can be used to design phytopathogen detection devices with smart sensing capabilities for field use. This review summarizes the current status and future prospects of nanotechnology for detection and diagnosis of plant pathogens.
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•The manuscript describes the simple synthetic protocol towards potent multiple-action 2,4-thiazolidinedione derivatives.•The corroboration of the pharmacological activity with ...in-silico evaluation has also been reported.•The compounds are promising dual action or even triple action drug candidates.•Free radicals responsible for inflammation can be curbed thus tackling inflammation.
A series of thirteen novel 2,4-thiazolidinedione derivatives were synthesized through three step reaction procedure. The title compounds were synthesized by Knoevenagel condensation at the 5th position of the 2,4-thiazolidinedione ring. Various physicochemical and spectral studies were conducted to characterize the synthesized derivatives including- IR, Mass, 1H NMR, 13C NMR and elemental analysis. The derivatives were screened for in vivo anti diabetic, in vivo anti-inflammatory and in vitro free radical scavenging activities by carrageenan induced rat paw edema method, alloxan induced diabetes in wistar rats method and FRAP (ferric reducing antioxidant power) method respectively. Some of the derivatives emerged out as potent antidiabetic, anti inflammatory and free radical scavenging agents. Molecular docking was carried out to investigate some possible structural insights into the potential binding patterns of the most potent anti-diabetic molecules NB7,NB12 and NB13 with the active sites of target PPARγ (PDB ID: 2PRG) using MOE software. Dichloro derivative compound NB-7 has shown great potential in the present study as it not only has maximum antidiabetic activity but also possess excellent anti-inflammatory and antioxidant potential.
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•Quaternary Metal Oxides were directly grown over carbon fiber substrate via simple hydrothermal approach.•While fabricating the Battery Supercapacitor Hybrid device effects of ...various metals and metal ratios were observed.•NiCoMoAgOx nanostructure based electrode exhibits high specific capacitance of 530 Fg−1 at current density of 1 Ag−1.•The fabricated BSH composed of the Ni-Co-Mo-Ag oxide positive electrode and activated carbon negative electrode showed capacitance 126 Fg−1 at current density of 1 Ag−1 with a potential window of 0.4–0.5 V and 97 % capacitance retention after 300 charge /discharge cycles.•The resulting materials have tremendous potential to be used as electrodes for flexible supercapacitor.
The objective of the present study is to explore novel, cost-effective, environmental friendly electrode materials with enhanced supercapacitor performance. Cobalt and nickel oxide based materials have been widely used for supercapacitor applications. In this work, Nickel-Cobalt-Molybdenum in combination with another metal of group (Ag, Mn, Cu), based quaternary metal oxide (QMO), were directly grown over a carbon fiber via a simple hydrothermal route. Hierarchical 3-D nanostructures of QMOs were synthesized over carbon fiber and characterized to investigate the effect of different metals over electrochemical performance. The Nickel-Cobalt-Molybdenum-Silver oxide electrode attained the best electrocapacitive performance of 530 Fg−1 at current density of 1 Ag−1 owing to its unique structure and high surface area. The fabricated supercapacitor hybrid device composed of the Ni-Co-Mo-Ag oxide positive electrode and activated carbon negative electrode showed capacitance 126 Fg−1 at current density of 1 Ag−1 with a potential window of 0.4–0.5 V and the 97 % capacitance retention. This facile synthesis of novel quaternary metal oxides provides new possibilities for making flexible energy storage devices with higher electro capacitive ability.
The structural data on compounds which crystallize with the (cubic) pyrochlore structure have been analyzed to obtain a model equation that predicts their lattice constants. The model, which is based ...on the ionic radii and the electronegativities of the constituting ions, is applied to simple ternary and to more complicated mixed cation and anion pyrochlores. The average error between the experimental and calculated lattice constants is ~ 0.45% for the ternary pyrochlores and ~ 0.68% for the mixed compounds. The lattice constant of any new pyrochlore can be estimated from the model equation, which has been derived in this work.
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