Semi-interpenetrating polymer network (IPN) microspheres of natural polymers, viz., gelatin and sodium carboxymethyl cellulose (NaCMC) were prepared by using glutaraldehyde (GA) as a crosslinker. ...Ketorolac tromethamine (KT), an anti-inflammatory and analgesic agent, was successfully encapsulated into IPN microspheres. Various formulations were prepared by varying the ratio of gelatin and NaCMC, % drug loading, and amount of GA. Microspheres were characterized by Fourier transform infrared spectroscopy (FTIR) to understand the formation of IPN structure and to confirm the absence of chemical interactions between drug, polymer, and crosslinking agent. Scanning electron microscopy (SEM) was used to study the surface morphology of the microspheres. SEM showed that particles have slightly rough surfaces. Particle size as measured by using laser light scattering technique gave an average size ranging from 247 to 535
μm. Differential scanning calorimetry (DSC) and X-ray diffraction (X-RD) studies were performed to understand the crystalline nature of the drug after encapsulation into IPN microspheres. Drug encapsulation of up to 67% was achieved as measured by the UV method. Both equilibrium and dynamic swelling experiments were performed in water. Diffusion coefficients (
D) of water transport through the microspheres were determined using an empirical equation. Values of
D decrease with increasing crosslinking as well as increasing content of NaCMC in the matrix. In vitro release studies indicated a dependence of release rate on both the extent of crosslinking and the amount of NaCMC used to produce microspheres, but slow release was extended up to 10
h. Cumulative release data were fitted to an empirical equation to compute diffusional exponent (
n), which indicated the non-Fickian trend for drug release.
Systemic delivery of therapeutic agents to solid tumors is hindered by vascular and interstitial barriers. We hypothesized that prostate tumor specific epigallocatechin-gallate (EGCg) functionalized ...radioactive gold nanoparticles, when delivered intratumorally (IT), would circumvent transport barriers, resulting in targeted delivery of therapeutic payloads. The results described herein support our hypothesis. We report the development of inherently therapeutic gold nanoparticles derived from the Au-198 isotope; the range of the ¹⁹⁸ Au β-particle (approximately 11 mm in tissue or approximately 1100 cell diameters) is sufficiently long to provide cross-fire effects of a radiation dose delivered to cells within the prostate gland and short enough to minimize the radiation dose to critical tissues near the periphery of the capsule. The formulation of biocompatible ¹⁹⁸ AuNPs utilizes the redox chemistry of prostate tumor specific phytochemical EGCg as it converts gold salt into gold nanoparticles and also selectively binds with excellent affinity to Laminin67R receptors, which are over expressed in prostate tumor cells. Pharmacokinetic studies in PC-3 xenograft SCID mice showed approximately 72% retention of ¹⁹⁸AuNP-EGCg in tumors 24 h after intratumoral administration. Therapeutic studies showed 80% reduction of tumor volumes after 28 d demonstrating significant inhibition of tumor growth compared to controls. This innovative nanotechnological approach serves as a basis for designing biocompatible target specific antineoplastic agents. This novel intratumorally injectable ¹⁹⁸AuNP-EGCg nanotherapeutic agent may provide significant advances in oncology for use as an effective treatment for prostate and other solid tumors.
In present study, impact of CaO doping on microstructure and phase electrical properties of a ZnO varistor is being reported. The doped ZnO nanopowders were prepared by solution combustion followed ...by conventional sintering. The ZnO particle size of powders decreased from 22 to 17 nm with CaO doping was noted. Decrease in grain size of the sintered samples from 4.54 to 1.19 μm with CaO doping was observed. This is attributed to Ca4Bi6O13 and Ca0.89Bi3.11O5.58 secondary phase formations apart from pyrochlore and spinel phases. A breakdown field as high as 21 kVcm−1 in X = 1.00 sample was obtained. The Coefficient of nonlinearity (α) decreased from 95 to 42 is due to decrease in carrier concentrations. Increase in resistivity with CaO doping and decrease in resistivity beyond X = 2.5 were noted. The electric modulus plots yielded two relaxations at a temperature in the range 100–300 °C and frequency in the range 0.1 Hz-1MHz. Activation energy (Ea) decreased from 0.65 to 0.50 eV for a region I and from 0.89 to 0.75 eV for region II with CaO doping was observed.
Effect of CaO doping on ZnO varistor properties are displayed in left side of the figure. It can be seen that the breakdown field increased with CaO doping, reaches a maximum at 20.3 ± 1 kVcm−1 in X = 1.00 CDV sample, after that decreased and then remain almost constant. Increase in breakdown field is due to a decrease in ZnO grain size. It can be seen in right side of the figure that the average grain size for CaO free varistor (X = 0.00) sample is around 4.5 μm where as CaO added sample (X = 1.00) the grain size is approximately 1 μm which is attributed to Ca0.89Bi3.11O5.58 phase apart from spinel and pyrochlore phases. Display omitted
•For the very first time in complex ZnO varistors system effect of CaO doping on phase, microstructure, dielectric and electrical properties has been reported in this study.•Two new phase Ca4Bi6O13 and Ca0.89Bi3.11O5.58 have been reported in the varistor system, the phase and microstructure have been correlated with dielectric and electrical properties of the varistor.•A high breakdown field 21 kVcm−1 was obtained in the CaO doped (1 wt%) ZnO varistor sample, which is order magnitude higher than commercial.•The complex impedance data have analysed with different formulations for the interpretation. The experiment data are fitted into two parallel RC circuit model to extract electrical properties like capacitance and resistance.
In situ aircraft measurements of cloud microphysical properties and aerosol during the 1st phase of the Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX‐I) over the Indian ...sub‐continent provided initial opportunities to investigate the dispersion effect and its implications for estimating aerosol indirect effects in continental cumuli. In contrast to earlier studies on continental shallow cumuli, it is found that not only the cloud droplet number concentration but also the relative dispersion increases with the aerosol number concentration in continental cumuli. The first aerosol indirect effect estimated from the relative changes in droplet concentration and effective radius with aerosol number concentration are 0.13 and 0.07, respectively. In‐depth analysis reveals that the dispersion effect could offset the cooling by enhanced droplet concentration by 39% in these continental cumuli. Adiabaticity analysis revealed aerosol indirect effect is lesser in subadiabatic clouds possibly due to inhomogeneous mixing processes. This study shows that adequate representation of the dispersion effect would help in accurately estimating the cloud albedo effect for continental cumuli and can reduce uncertainty in aerosol indirect effect estimates.
Key Points
Aerosols increase the relative dispersion of continental cumuli
Droplet dispersion offsets the cooling up to 39% in continental cumuli
AIE is lesser in sub‐adiabatic clouds due to inhomogeneous mixing
Ethanol (1 and 2 g/kg, i.p.) and MK-801 (1 mg/kg, i.p.), N-methyl-D-aspartate (NMDA) receptor antagonist, offered protection against caffeine-induced convulsions in mice. Subeffective doses of ...ethanol (0.5-g/kg, i.p.) and MK-801 (0.5 mg/kg, i.p.) when administered concurrently, did not provide a facilitatory anticonvulsant action against caffeine-induced convulsions. Ethanol (0.5 g/kg, i.p.) when administered concurrently with adenosine (100 mg/kg, i.p.) or dipyridamole (5 mg/kg, i.p.) elicited a facilitatory anticonvulsant action. However, concurrent administration of subeffective doses of MK-801 (0.5 mg/kg i.p.) with adenosine (100 mg/kg, i.p.) did not offer a facilitatory anticonvulsant action against caffeine-induced convulsions. The protective effect of ethanol (1 g/kg, i.p.) against caffeine-induced convulsions was reversed by an imidazobenzodiazepine, Ro 15-4513 (4 mg/kg, i.p.). Ro 15-4513 did not produce any proconvulsant effect with caffeine. It is suggested that ethanol and MK-801 elicit their anticonvulsant actions against caffeine-induced convulsions through different receptor mechanisms and that the anticonvulsant action of ethanol may be partly attributed to its ability to act via central adenosinergic mechanisms.
Macroporous polymer particles containing surface epoxy groups were synthesized for immobilization of
Candida rugosa lipase (CRL). The effect of incorporation of two different sets of monomers allyl ...glycidyl ether (AGE) and glycidyl methacrylate (GMA) and the effect of crosslinking density on immobilization of lipase were studied. AGE-co-EGDM polymers gave higher binding and expression of lipase than GMA-co-EGDM polymers. Optimization of immobilization parameters was done with respect to immobilization time and enzyme loading. Amongst AGE-co-EGDM polymer series, AGE-150 polymer found to give maximum lipase activity yield and therefore evaluated for temperature, pH and storage stability. Under optimum conditions, AGE-150 polymer gave 78.40% of activity yield. Immobilized lipase on AGE-150 showed a broader pH, higher temperature and excellent storage stability.
Submarine groundwater discharge (SGD) is now recognized as an important pathway between land and sea. As such, this flow may contribute to the biogeochemical and other marine budgets of near-shore ...waters. These discharges typically display significant spatial and temporal variability making assessments difficult. Groundwater seepage is patchy, diffuse, temporally variable, and may involve multiple aquifers. Thus, the measurement of its magnitude and associated chemical fluxes is a challenging enterprise.
A joint project of UNESCO and the International Atomic Energy Agency (IAEA) has examined several methods of SGD assessment and carried out a series of five intercomparison experiments in different hydrogeologic environments (coastal plain, karst, glacial till, fractured crystalline rock, and volcanic terrains). This report reviews the scientific and management significance of SGD, measurement approaches, and the results of the intercomparison experiments. We conclude that while the process is essentially ubiquitous in coastal areas, the assessment of its magnitude at any one location is subject to enough variability that measurements should be made by a variety of techniques and over large enough spatial and temporal scales to capture the majority of these changing conditions.
We feel that all the measurement techniques described here are valid although they each have their own advantages and disadvantages. It is recommended that multiple approaches be applied whenever possible. In addition, a continuing effort is required in order to capture long-period tidal fluctuations, storm effects, and seasonal variations.
Primary diffuse leptomeningeal primitive neuroectodermal tumor is a rare meningeal neoplasm which can masquerade as chronic meningitis. While the clinical presentation and radiological features may ...provide a clue to this condition, meningeal biopsy is essential to clinch the diagnosis. A high index of suspicion and a low threshold for re-evaluating cases of neuroinfection that do not respond to empirical therapy are essential in this scenario. We present the case of a nine year old boy who was initiated on antituberculous treatment for chronic meningitis with hydrocephalus. Meningeal biopsy revealed a primary diffuse leptomeningeal primitive neuroectodermal tumor.
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