Insights into cadmium induced physiological and ultra-structural disorders in Juncus effusus L. and its remediation through exogenous citric acid

This study appraised cadmium (Cd) toxicity stress in wetland plant Juncus effusus, and explored its potential for Cd phytoextraction through chelators (citric acid and EDTA). Cadmium altered morphological and physiological attributes of J. effusus as reflected by growth retardation. Citric acid in the presence of 100 μM Cd significantly countered Cd toxicity by improving plant growth. Elevated Cd concentrations reduced translocation factor that was increased under application of both chelators. Citric acid enhanced Cd accumulation, while EDTA reduced its uptake. Cadmium induced oxidative stress modified the antioxidative enzyme activity. Both levels of citric acid (2.5 and 5.0 mM) and lower EDTA concentration (2.5 mM) helped plants to overcome oxidative stress by enhancing their antioxidative enzyme activities. Cadmium damaged the root cells through cytoplasmic shrinkage and metal deposition. Citric acid restored structure and shape of root cells and eliminated plasmolysis; whereas, EDTA exhibited no positive effect on it. Shoot cells remained unaffected under Cd treatment alone or with citric acid except for chloroplast swelling. Only EDTA promoted starch accumulation in chloroplast reflecting its negative impact on cellular structure. It concludes that Cd and EDTA induce structural and morphological damage in J. effusus; while, citric acid ameliorates Cd toxicity stress.     

Thermal maturity evaluation using Raman spectroscopy for oil shale samples of USA: comparisons with vitrinite reflectance and pyrolysis methods

Thermal maturity is commonly assessed by various geochemical screening methods(e.g., pyrolysis and organic petrology).In this contribution, we attempt to establish an alternative approach to estimating thermal maturity with Raman spectroscopy,using 24 North American oil shale samples with thermal maturity data generated by vitrinite reflectance(VR_o%) and pyrolysis(T_(max))-based maturity calculation(VR_e%). The representative shale samples are from the Haynesville(East Texas), Woodford(West Texas), Eagle Ford and Pearsall(South Texas) Formations, as well as Gothic, Mancos, and Niobrara Formation shales(all from Colorado). The Raman spectra of disordered carbonaceous matter(D1 and G bands separation) of these samples were directly obtained from the rock chips without prior sample preparation. Using the Gaussian and Lorentzian distribution approach, thermal maturities from VR were correlated with carbon G and D1. We found that the Raman band separation(RBS) displayed a better correlation for equivalent VR_e%than vitrinite reflectance VR_o%.The RBS(D1–G) distance versus total organic carbon, free hydrocarbons from thermal extraction(S1), and the remaining hydrocarbon generating potential(S2)indicate that the RBS(D1–G) distance is also related to kerogen type. Data presented here from three methods of maturity determination of shale demonstrate that Raman spectroscopy is a quick and valid approach to thermal maturity assessment.     

Influence of matrix material on flexural fatigue performance of unidirectional composites

A deflection-controlled flexural fatigue study of unidirectional glass fiber reinforced epoxy and vinyl ester composites was undertaken. Damage initiation and growth for various deflection levels were evaluated. Also, quantitative assessment of damage was made by monitoring stiffness loss in the composites as a function of fatigue cycles. Results show that the glass/epoxy composite has better performance compared with the glass/vinyl ester composite, especially at low deflection amplitudes. Fatigue behavior of the composites at low deflection amplitudes is found to be primarily influenced by matric and fiber-matrix interfacial damage in the form of longitudinal splitting.     

Mucoadhesive elementary osmotic pump tablets of trimetazidine for controlled drug delivery and reduced variability in oral bioavailability

The objectives of this work was preparation and evaluation of the mucoadhesive elementary osmotic pump tablets of trimetazidine hydrochloride to achieve desired controlled release action and augmentation of oral drug absorption. The drug-loaded core tablets were prepared employing the suitable tableting excipients and coated with polymeric blend of ethyl cellulose and hydroxypropyl methylethylcellulose E5 (4:1). The prepared tablets were characterized for various quality control tests and in vitro drug release. Evaluation of drug release kinetics through model fitting suggested the Fickian mechanism of drug release, which was regulated by osmosis and diffusion as the predominant mechanism. Evaluation of mucoadhesion property using texture analyzer suggested good mucoadhesion potential of the developed osmotic systems. Solid state characterization using Fourier-transform infrared spectroscopy, differential scanning calorimetry and powder X-ray diffraction spectroscopy confirmed the absence of any physiochemical incompatibilities between drug and excipients. Scanning electron microscopy analysis showed the smooth surface appearance of the coated tablets with intact polymeric membrane without any fracture. In vivo pharmacokinetic studies in rabbits revealed 3.01-fold enhancement in the oral bioavailability vis-à-vis the marketed formulation (Vastarel MR®). These studies successfully demonstrate the bioavailability enhancement potential of the mucoadhesive elementary osmotic pumps as novel therapeutic systems for other drugs too.     

Intracranial chondromas

Biochemical and hormonal effects of oral calcium supplementation in premature and asphyxiated neonates during the first few days of life are described. Eight pairs of infants were matched for gestational age and one-minute Apgar score. One member of each pair served as a control and the other was given supplemental oral calcium (75 mg/kg/24 hr) beginning at 12 and ending at 72 hours of age. The supplemental infants had significantly higher serum calcium values both during the time of supplementation and for 36 hours after supplementation was stopped. The oral calcium supplements had no significant effect on serum concentrations of phosphate, magnesium, 25-hydroxy-vitamin D3, or parathyroid hormone, The incidence of hypocalcemia after 12 hours of age was 0 in eight supplemented infants and three in eight control infants. In patients at risk for hypocalcemia, prospective use of oral calcium supplements during the period when there is inadequate calcium intake from feedings may prevent hypocalcemia, appears to be without deleterious effect on measurable chemical and hormonal factors important in calcium homeostasis, and results in maintenance of higher serum calcium levels after supplementation has been discontinued.     

Household food security in the face of climate change in the Hindu-Kush Himalayan region

This study attempts to understand local people’s perceptions of climate change, its impacts on agriculture and household food security, and local adaptation strategies in the Hindu-Kush Himalayan (HKH) region, using data from 8083 households (HHs) from four river sub-basins (SBs), i.e. Upper Indus (Pakistan), Eastern Brahmaputra (India), Koshi (Nepal) and Salween and Mekong (China). The majority of households in SBs, in recent years, have perceived that there have been more frequent incidences of floods, landslides, droughts, livestock diseases and crop pests, and have attributed these to climate change. These changes have led to low agricultural production and income, particularly in Eastern Brahmaputra (EB) where a substantial proportion of HHs reported a decline in the production of almost all staple and cash crops, resulting in very low farm income. Consequently, households’ dependency on external food items supplied from plain areas has increased, particularly in the Upper Indus (UI) and EB. After hazards, households face transitory food insecurity owing to damage to their local food systems and livelihood sources, and constrained food supply from other areas. To cope with these, HHs in SBs make changes in their farming practices and livestock management. In EB, 11 % of HHs took on new off-farm activities within the SB and in SM, 23 % of HHs chose out-migration as an adaptation strategy. Lastly, the study proposes policy instruments for attaining sustainable food security, based on agro-ecological potential and opportunities for increasing agricultural resilience and diversity of livelihoods.