Pharmaceutical Standardization and Physicochemical Characterization of Traditional Ayurvedic Marine Drug: Incinerated Conch Shell (Shankha Bhasma).

Natural resources such as plants, animals and minerals have always been used by mankind to develop drugs and marine world is no exception. Marine by-products like conches, pearls, mother of pearl shells, corals and so forth have been used by traditional Ayurvedic practitioners for centuries. The unique methods of these preparations are scientifically designed to eliminate unwanted impurities and convert them into bioavailable form. In this study, Conch (Xanchus pyrum) was used as a marine resource of calcium carbonate and was converted pharmaceutically from its aragonite form to calcite. All the steps of preparations and changes in the properties therein were documented and validated. Further, traditional as well as modern analytical tools were used to study its physical and chemical characters to develop a monograph. The physical characterization included particle size, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Fourier Transform Infra-red (FTIR). Metal composition and heavy metal limits were determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICPOES). This study revealed the rearrangement of aragonite crystals into calcite form by grinding, trituration with aloe vera juice and incineration under controlled conditions. Moreover, the finished product was found to be devoid of organic matrix that is nacre. This study creates a foundation for the development of a master formula for commonly used Shankha Bhasma in Ayurvedic medicines.

Influence of pore structure on compressive strength of cement mortar.

This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure.

Management of hyperphosphataemia in chronic kidney disease: summary of National Institute for Health and Clinical Excellence (NICE) guideline.

Bone disease and ectopic calcification are the two main consequences of hyperphosphataemia of chronic kidney disease (CKD). Observational studies have demonstrated that hyperphosphataemia in CKD is associated with increased mortality. Furthermore, the use of phosphate binders in dialysis patients is associated with significantly lower mortality. The UK Renal Registry data show significant underachievement of phosphate targets in dialysis patients. It is believed to be due to wide variation in how management interventions are used. The National Institute for Health and Clinical Excellence (NICE) has developed a guideline on the management of hyperphosphataemia in CKD. This is based on the evidence currently available using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. This review outlines the recommendations including research recommendations and discusses methodology, rationale and challenges faced in developing this guideline and the health economic model used to assess the cost-effectiveness of different phosphate binders.

How well do we know VPDB? Variability of delta13C and delta18O in CO2 generated from NBS19-calcite.

In order to generate a local daughter scale from the material defining the international delta13C and delta18O stable isotope ratio scales (NBS19-calcite),1,2 the carbon and oxygen must be liberated to the gas phase, usually as CO2, using acid digestion of the calcite with H3PO4. It is during this conversion step that systematic errors can occur, giving rise to commonly observed discrepancies in isotopic measurements between different stable isotope laboratories. Scale consistency is of particular importance for air-CO2 isotope records where very small differences in isotopic composition have to be reliably compared between different laboratories and quantified over long time periods.3 The information is vital for estimating carbon budgets on regional and global scales and for understanding their variability under the conditions of climate change. Starting from this requirement a number of CO2 preparations from NBS19 were made at Environment Canada (EC) and analyzed in our laboratories together with Narcis II, a set of well-characterized CO2 samples in sealed tubes available from the National Institute for Environmental Studies (NIES).4,5 Narcis II is very homogeneous in delta13C and delta18O with the isotopic composition close to NBS19-CO2. Among our laboratories the results for delta13C agreed to within +/-0.004 per thousand. The same level of agreement in delta13C was obtained when CO2 was generated from NBS19-calcite using different experimental procedures and conditions in the other two laboratories. For delta18O, the corresponding data were +/-0.011 per thousand when using NBS19-CO2 produced at EC, but discrepancies were enhanced by almost one order of magnitude when NBS19-CO2 was prepared by the other laboratories using slightly different reaction conditions (range=0.13 per thousand).In a second series of experiments, larger amounts of CO2 prepared from NBS19 at the Max-Planck-Institut für Biogeochemie (MPI-BGC) were analyzed together with Narcis II and then mixed into CO2-free air. The resulting artificial air samples then were measured by the same three laboratories for the stable isotopic composition of CO2 using locally established extraction and evaluation procedures. Comparison of the results with the prior CO2 values and between the laboratories revealed additional systematic differences owing to the local CO2 extraction processes and standardization procedures. For delta13C the results showed a narrow range of discrepancies of about 0.02 per thousand; for delta18O cumulative disagreements in the range of 0.1 per thousand were observed. From these results the following conclusions are inferred: NBS19-CO2 is a reliable primary anchor to the VPDB delta13C scale. Although prepared by different methods an accuracy of better than +/-0.003 per thousand has been reached. This applies to sample amounts of 5 mg calcite or more.NBS19-CO2 can be used as a general anchor to the VPDB delta18O scale only for accuracy requirements of +/-0.1 per thousand. For a higher scale resolution additional agreements regarding details of the acid digestion reaction will have to be worked out and agreed upon.Narcis II-CO2 comprises an ideal set of test samples for the VPDB scale. The delta13C value is +1.923+/-0.003 per thousand (combined uncertainty); delta18O is between -2.50 and -2.65 per thousand versus VPDB-CO2, with most of the variation in this figure depending on details of the NBS19-CO2 preparation used for the calibration. (Ampoule to ampoule homogeneity is better than 0.01 per thousand.)When mixing NBS19-CO2 into artificial air and using this to test performance between laboratories, the delta13C offsets are small with a remaining discrepancy of only 0.02 per thousand. For delta18O, systematic disagreements are considerably larger than those found for the pure CO2 comparison. Further experimental clarification is required.Artificial air samples such as NBS19-CO2 in air can be used as reliable anchors to create a unified stable isotope scale between different laboratories. An adjustment of local scales based on these air standards appears to be necessary for improving data comparability.

Grain-scale heterogeneities in the stable carbon and oxygen isotopic compositions of the international standard calcite materials (NBS 19, NBS 18, IAEA-CO-1, and IAEA-CO-8).

We determined grain-scale heterogeneities (from 6 to 88 microg) in the stable carbon and oxygen isotopic compositions (delta(13)C and delta(18)O) of the international standard calcite materials (NBS 19, NBS 18, IAEA-CO-1, and IAEA-CO-8) using a continuous-flow isotope ratio mass spectrometry (CF-IRMS) system that realizes a simultaneous determination of the delta(13)C and the delta(18)O values with standard deviations (S.D.) of less than 0.05 per thousand for CO(2) gas. Based on the S.D. of the delta(13)C and delta(18)O values determined for CO(2) gases evolved from the different grains of the same calcite material, we found that NBS 19, IAEA-CO-1, and IEAE-CO-8 were homogeneous for delta(13)C (less than 0.10 per thousand S.D.), and that only NBS 19 was homogeneous for delta(18)O (less than 0.14 per thousand S.D.). On the level of single grains, we found that both IAEA-CO-1 and IAEA-CO-8 were heterogeneous for delta(18)O (1.46 per thousand and 0.76 per thousand S.D., respectively), and that NBS 18 was heterogeneous for both delta(13)C and delta(18)O (0.34 per thousand and 0.54 per thousand S.D., respectively). Closer inspection of NBS 18 grains revealed that the highly deviated isotopic compositions were limited to the colored grains. By excluding such colored grains, we could also obtain the homogeneous delta(13)C and delta(18)O values (less than 0.18 per thousand and less than 0.16 per thousand S.D., respectively) for NBS 18. We conclude that NBS 19, IAEA-CO-1, or pure grains in NBS 18 are suitable to be used as the standard reference material for delta(13)C, and that either NBS 19 or pure grains in NBS 18 are suitable to be used as the reference material for delta(18)O during the grain-scale isotopic analyses of calcite.

Comparison of Amberlite IR 120 and dolomite's performances for removal of heavy metals.

The presence of heavy metals in the environment is major concern due to their toxicity. Contamination of heavy metals in water supplies has steadily increased over the last years as a result of over population and expansion of industrial activities. A strong cation-exchange resin, Amberlite IR 120 and a natural zeolite, dolomite were used for the removal of lead(II) and cadmium(II). The optimum conditions were determined in a batch system as concentration range was between 5 and 100 mg/L, pH range between 1 and 8, contact time between 5 and 90 min, and the amount of adsorbent was from 0.1 to 1g. A constant stirring speed, 2000 rpm, was chosen during all of the experiments. The optimum conditions were found to be a concentration of 20 mg/L, pH of 5, contact time of 60 min and 0.5 g of adsorbent. Also, for investigation of exchange equilibria different amounts of ion exchange resin and dolomite were contacted with a fixed volume and concentration of a heavy metal bearing solutions. Sorption data have been interpreted in terms of Langmuir and Freundlich equations. The effect of adsorption temperature on the heavy metals adsorption onto dolomite was investigated at three different temperatures (20, 40 and 60 degrees C). Thermodynamic parameters were calculated. The results obtained show that the Amberlite IR 120 strong cation-exchange resin and dolomite performed well for the removal of these heavy metals. As a low cost adsorbent, dolomite can preferable for removal of heavy metals from wastewaters.

Surface consolidation of Pentelic marble: criteria for the selection of methods and materials. The Acropolis case.

UNLABELLED: GOAL AND SCOPE: In order to realize surface consolidation of Pentelic marble on the Acropolis monuments, we have collected the criteria that have to be fulfilled by the methods and materials without side effects on the marbles (and other stones). When the existing methods and materials did not satisfy the requirements (criteria), we invented new ones. METHODS: The criteria were collected from the literature, by thermodynamic and kinetic viewpoints, by laboratory experiments and in situ observations on monuments, both in Greece and in several countries in which the various methods and materials were applied. Concerning our method of 'Inversion of sulfation', performed by spraying a K2CO3 solution, its concentration and its temperature were controlled in order to have a total inversion (certified by liquid crystals) of gypsum back to CaCO3. For the new material of ours, 'Reinforced Lime', in order to eliminate the disadvantages of plain lime (low carbonation rate, low mechanical properties of CaCO3 formed, lack of carbonation in the bulk of lime), measurements of the rate of carbonation were performed in plain lime and in lime with a different CaCO3 concentration beforehand as well as in a different CO2 environments, using DTG and XRD to measure the rate of carbonation. The detachment (kg/cm2) of marble specimens stuck by lime in each case was also measured. A microscope was also used to measure the dimensions of the grain in each case as well as ammonium citrate and thymolphthalein to certify the depth of carbonation in each case. Part of the work was communicated in an international congress. RESULTS: A table with the criteria of the selection of the methods and materials for the consolidation of Pentelic marble surfaces (and other stones) was established. None of the employed methods and materials fulfilled the criteria. Only the 'Inversion of gypsum' and the 'Reinforced Lime' were adopted and applied to the Acropolis monuments and to other monuments in Greece and in several other countries. RECOMMENDATION AND OUTLOOK: All criteria must be used for the selection of methods and materials for the consolidation of the monument surfaces. This is why we have already studied with the same procedures, methods and materials for restoration, surface cleaning and protection.

Applicability of Iceland spar as a stone model standard for lithotripsy devices.

The identification of a universal stone model standard would enable reproducible fragmentation data useful for the design, evaluation, and comparison of various lithotripsy devices. The clinical benefits of such a stone model include the elucidation of setting parameters that would optimize fragmentation strategies. Iceland spar is a pure form of calcite (CaCO3) that was subjected to experimental disintegration by electrohydraulic lithotripsy and extracorporeal shockwave lithotripsy. Iceland spar was fragmented with both lithotripsy methods in a reproducible fashion. The degree of fragmentation was directly related to alterations in either power or shock frequency. Iceland spar is radiopaque, inexpensive, easily obtained, homogenous in composition, and sizable. Iceland spar meets a variety of stone model criteria, warranting its continued investigation as a potential stone model standard.

Effectiveness of slow release formulations of fenthion (Baytex) in the control of Mansonia breeding in polluted pond habitats.

Effectiveness of two types of granular formulations of fenthion (Baytex) was evaluated in controlling the breeding of Mansonia mosquitos in polluted pond habitats. Calcium carbonate and sand granular formulations, when applied at 2.50 g/m2 surface area with an average depth of 0.5 m were found to be effective in keeping the habitats completely free from Mansonia breeding for 14 days and 18 days respectively. Release of insecticide was slow and the effective duration of control after a single application was relatively longer in the sand formulation when compared to the calcium carbonate formulation. Single application of calcium carbonate and sand granular formulations of fenthion could effectively prevent Mansonia adult emergence for 23 and 30 days, respectively in polluted pond habitats, without causing any adverse effect on non-target insects.

Control of predialytic hyperphosphatemia by oral calcium acetate and calcium carbonate. Comparable efficacy for half the dose of elemental calcium given as acetate without lower incidence of hypercalcemia.

Since Mai et al. found, with the intestinal lavage technique, that the same dose of elemental calcium given as acetate (Ca Ac) complexed in the gut of uremic patients twice as much phosphate as calcium carbonate (CaCO3) while inducing a rather low calcium absorption, we wanted to see if half the dose of elemental calcium given as Ca Ac could control, on medium term, the predialysis plasma phosphate as well as CaCO3 while inducing less frequent hypercalcemia. This was evaluated in a cross-over study of 3 periods of 10 weeks according to the sequence Ca Ac, CaCO3 and Ca Ac, in 12 compliant patients on chronic dialysis previously treated by CaCO3. Because of poor tolerance of Ca Ac during the first period, 4 patients were excluded and the results were assessed only on the 8 patients who completed the study. For half the doses of elemental calcium (620 +/- 250 mg versus 1,310 +/- 560 mg versus 710 +/- 200 mg/day), Ca Ac allowed the same control of predialytic hyperphosphatemia (1.67 +/- 0.34; 1.74 +/- 0.32; 1.75 +/- 0.38) with paradoxically comparable normal mean plasma calcium concentration (2.61 +/- 0.14; 2.56 +/- 0.13; 2.55 +/- 0.14 mmol/l). Plasma alkaline phosphatases and intact PTH concentrations remained also stable during the 3 periods. The frequency of hypercalcemia greater than 2.75 mmol/l (12; 9; 20%) and of hyperphosphatemia greater than 2 mmol/l (17; 22; 27%) were comparable with the 2 treatments. In conclusion, Ca Ac controls predialytic hyperphosphatemia as efficiently as CaCO3 for half the dose of elemental calcium without, however, decreasing the frequency of hypercalcemia.(ABSTRACT TRUNCATED AT 250 WORDS)