In India, Ayurveda has made a major contribution to the drug discovery process with new means of identifying active compounds. Recent advancement in bioavailability enhancement of drugs by compounds of herbal origin has produced a revolutionary shift in the way of therapeutics. Thus, bibliographic investigation was carried out by analyzing classical text books and peer-reviewed papers, consulting worldwide-accepted scientific databases from last 30 years. Herbal bioenhancers have been shown to enhance bioavailability and bioefficacy of different classes of drugs, such as antibiotics, antituberculosis, antiviral, antifungal, and anticancerous drugs at low doses. They have also improved oral absorption of nutraceuticals like vitamins, minerals, amino acids, and certain herbal compounds. Their mechanism of action is mainly through absorption process, drug metabolism, and action on drug target. This paper clearly indicates that scientific researchers and pharmaceutical industries have to give emphasis on experimental studies to find out novel active principles from such a vast array of unexploited plants having a role as a bioavailability and bioefficacy enhancer. Also, the mechanisms of action by which bioenhancer compounds exert bioenhancing effects remain to be explored.

Creation of affordable materials for constant release of silver ions in water is one of the most promising ways to provide microbially safe drinking water for all. Combining the capacity of diverse nanocomposites to scavenge toxic species such as arsenic, lead, and other contaminants along with the above capability can result in affordable, all-inclusive drinking water purifiers that can function without electricity. The critical problem in achieving this is the synthesis of stable materials that can release silver ions continuously in the presence of complex species usually present in drinking water that deposit and cause scaling on nanomaterial surfaces. Here we show that such constant release materials can be synthesized in a simple and effective fashion in water itself without the use of electrical power. The nanocomposite exhibits river sand-like properties, such as higher shear strength in loose and wet forms. These materials have been used to develop an affordable water purifier to deliver clean drinking water at US $2.5/y per family. The ability to prepare nanostructured compositions at near ambient temperature has wide relevance for adsorption-based water purification.hybrid | green | appropriate technology | frugal science | developing world S afe drinking water is a significant, but simple indicator of development. Its availability at point of use can save over 2 million human lives (1) (of the 3.575 million deaths caused by water, sanitation, and hygiene issues, 42.6% are due to diarrhea alone: 3.575 million × 0.426 = 1.523 million lives), can avoid over 2 billion diarrheal infections (2), and can contribute over $4 billion to the global gross domestic product (3) (formula used: Σ (number of deaths attributed to diarrhea in each country × corresponding country's per capita gross domestic product). Considering the challenges associated with traditional disinfectants (4), solutions based on state-of-the-art science and technology hold the key for safe drinking water (5) and novel approaches are being looked at (6, 7). It has been long known that silver, especially in nanoparticle form, is an effective disinfectant and works for a wide spectrum of bacteria and viruses (8, 9). Numerous approaches are available for the synthesis of biocidal silver nanoparticles or colloids, including the use of matrices (10-12). The biocidal property of silver nanoparticles, usually in the size range of 10-20 nm, is attributed to the release of trace quantities of silver ions in water (13-16), which, although being sufficient for microorganism killing, does not exhibit toxicity to humans (17,18). [Toxicity due to silver nanoparticles themselves is also known (16)]. Although a number of silver-based biocidal compositions have been synthesized, those have not been able to reach the masses in large volumes (e.g., silver nanoparticleloaded ceramic candles) (19). Massive deployment has been hampered due to the following reasons: (a) Drinking water contains many species (e.g., inorganic ions and organics) that anchor on the sur...

Arsenic-free drinking water, independent of electrical power and piped water supply, is possible only through advanced and affordable materials with large uptake capacities. Confined metastable 2-line ferrihydrite, stable at ambient temperature, shows continuous arsenic uptake in the presence of other complex species in natural drinking water and an affordable water-purification device is made using the same.

Cl atom initiated photo-oxidation of monochlorinated propanes to form the carbonyl compounds was investigated. Propionaldehyde and acetone were identified to be major products in the oxidation of 1-chloropropane and 2-chloropropane, respectively. The complete product analyses were carried out using gas chromatography–mass spectrometry (GC–MS) and gas chromatography–infrared spectroscopy (GC–IR) as analytical tools, and an appropriate oxidation mechanism was proposed on the basis of the product analyses. The temperature dependent rate coefficients for the reactions of Cl atoms with 1-chloropropane (1-CP) and 2-chloropropane (2-CP) were measured experimentally in the gas phase, using the relative rate method in the temperature range 268–363 K and at 1 atm pressure. Ethane, ethylene, and ethyl acetate were used as reference compounds. The obtained rate coefficients for the reactions of Cl atoms with 1-CP and 2-CP at room temperature (298 K) and at 1 atm pressure were (4.64 ± 0.70) × 10–11 and (2.57 ± 0.44) × 10–11 cm3 molecule–1 s–1, respectively. Furthermore, to complement our experimentally obtained results, computational calculations were performed for these reactions using canonical variational transition state theory (CVT) with small curvature tunneling (SCT) in combination with the CCSD/cc-pVDZ//MP2/6-31+G­(d,p) level of theory. Detailed discussion on feasibility of the reactions, branching ratios, degradation mechanism, and atmospheric implications are discussed in this manuscript.

We investigate the adsorption of hexavalent uranium, U(VI), on phosphorylated cellulose nanofibers (PHO-CNF) and compare the results with those for native and TEMPO-oxidized nanocelluloses. Batch adsorption experiments in aqueous media show that PHO-CNF is highly efficient in removing U(VI) in the pH range between 3 and 6. Gelling of nanofiber hydrogels is observed at U(VI) concentration of 500 mg/L. Structural changes in the nanofiber network (scanning and transmission electron microscopies) and the surface chemical composition (X-ray photoelectron spectroscopy) gave insights on the mechanism of adsorption. The results from batch adsorption experiments are fitted to Langmuir, Freundlich, and Sips isotherm models, which indicate a maximum adsorption capacity of 1550 mg/g, the highest value reported so far for any bioadsorbent. Compared to other metals (Zn, Mn, and Cu) and typical ions present in natural aqueous matrices the phosphorylated nanofibers are shown to be remarkably selective to U(VI). The results suggest a solution for the capture of uranium, which is of interest given its health and toxic impacts when present in aqueous matrices.