The percentage determination of Rutilus frisii kutum (200, 500 and 1000 mg) resistance to salinity, turbidity and decrease of oxygen by usage of the river water at the releasing meantime

The survey effect of salinity, turbidity and dissolved oxygen performed on Rutilus frisii Kutum juveniles with aim, which was determined about survival rate and histological changes in gill and kidney tissues. Juveniles provided from the Rajai's fish propagation center and then examined in Caspian Sea Ecology Research Center laboratory. The juveniles were investigated on three weight group (200-75%) had shown in 400-<600mg weight group with dissolve oxygen: 3.8±0.15SE mg/l. In addition, the lowest survival rates under turbidity stress (95.83%) had shown that in weight group less than 400 mg with turbidity 15600 FTU. Therefore, survival of juveniles was high. However, gill tissue of juveniles under turbidity and salinity stress became short (necrosis) and thick (edema and hyperplasia) in the end of experiments. The juveniles gill tissues were not changes in the river clear freshwater. Therefore, the factors of gill tissue deformation were salinity and suspended particles in the water. However, the structures of kidney in the different groups of juveniles were similar. Nevertheless, juveniles glomerular diameter increased with increasing weight (p<0.05, Duncan test). Furthermore, there was a increasing the internal cavity of the proximal and distal tubules and decreasing of glomeruli in diameter in the transfer of juveniles from freshwater to brackish water. Although the survival rate of juveniles is acceptable in this study, but there was abnormal changes in the structure of them gills. It appears that this change will cause a disruption in trend of juvenile's growth

Determination of sediment nutrients in the cage fish culture area (before breeding) of the southern Caspian Sea (Mazandaran coast-Kelarabad)

This study was conducted to determine phosphorous and nitrogen species at the surface sediment in the southern Caspian Sea (Mazandaran Coast, Kelarabad). Surface sediments samples were collected at three stations from autumn of 2011 to winter of 2012. All samples were prepared by digesting and extracting processes and then phosphorous and nitrogen species concentrations determined using spectroscopy instrument. Results of this study showed that annual mean of Loosely-P, Fe-P, Al-P, Bioava.-P, Ca-P, TIP, Rese.-P and TP was obtained as 5.06±0.33, 55.11±2.52, 42.38±3.74, 102.52±5.68, 172.91±7.12, 275±9.12, 333.30±28.52 and 608±52 µg/g.dw, respectively. The results also showed that inorganic phophorous was less than organic phophorous during different seasons, however, mean percentage of residue-P containing organic compounds and non-degradable compounds was more than 50 percent. Percentage of Ca-P was higher than 60, whereas Bioava.-P was less than 40 percent. In addition, Fe-P and Loosely-P attained the maximum and minimum values, respectively, among the bioavailable phophorous. The order of different forms of phosphorous were recorded as Org-P>Ca-P>FeP>Al-P>Loosely-P. Annual mean of NH4/N, NO2/N, NO3/N, TIN, TON and TN were observed as 4.23±0.50, 0.06±0.01, 0.74±0.12, 5.02±0.53, 2.48±0.63 and 7.53±0.51 µg/g.dw, respectively. Annual percentage of TIN was two folds than TON and concentration of NH4/N was also four times than NO3/N. As a conclusion, the results revealed that main causes of Bioava.-P adsorption and desorption were temperature, Eh and pH. Also, the form of NH4+/N was of a high percentage because of anaerobic condition in the sediments. According to the high ratios of nitrogen/phosphorous of sediments to nitrogen and phosphorous of bottom water, it finds that released of those from the sediments to water will be happened with high rates. Therefore, it is expected that the establishment of fish farming cages should be carried out with more precautionary approaches which not leads to increased algae bloom

Proton Transfer, Hydrogen Bonding, and Disorder: Nitrogen Near-Edge X-ray Absorption Fine Structure and X-ray Photoelectron Spectroscopy of Bipyridine-Acid Salts and Co-crystals

The sensitivity of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to Brønsted donation and the protonation state of nitrogen in the solid state is investigated through a series of multicomponent bipyridine–acid systems alongside X-ray photoelectron spectroscopy (XPS) data. A large shift to high energy occurs for the 1s → 1π* resonance in the nitrogen K-edge NEXAFS with proton transfer from the acid to the bipyridine base molecule and allows assignment as a salt (C═NH+), with the peak ratio providing the stoichiometry of the types of nitrogen species present. A corresponding binding energy shift for C═NH+ is observed in the nitrogen XPS, clearly identifying protonation and formation of a salt. The similar magnitude shifts observed with both techniques relative to the unprotonated nitrogen of co-crystals (C═N) suggest that the chemical state (initial-state) effects dominate. Results from both techniques reveal the sensitivity to identify proton transfer, hydrogen bond disorder, and even the potential to distinguish variations in hydrogen bond length to nitrogen

Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

Designing and establishment of ISO/IEC 17025 in laboratories of national inland water aquaculture center and south Iran aquaculture research center

The project was carried out between June of 2011 and November of 2012,8 laboratories of research center in Anzali (Plankton, Algae, Hydrochemistry, Physiology, Ichthyology, Bentose, Parazitology, Virology) and 7 laboratories of research center in Ahvaz (Clinical pathology, Plankton, Hydrochemistry, Physiology, Ichthyology, Bentose, Parazitology, Virology) were selected for accreditation. The main stages for establishment of the system consisted of: 1-Conducting a gap analysis to compare the present state of the laboratories with ISO/IEC 17025 2-Training General requirements for the competence of testing and calibration laboratories Validation of methods Estimation of uncertainty Internal audits 3- Performing of technical and management requirements 4-Submit of quality manual to ASCB center in England in order to accredit In August of 2012 The main results were including: 1-Increase the accuracy of measurement in laboratories 2-Improvement of the Repeatability and Reproducibility of the test methods 3-Traceability and standardization of test methods 4- Calibration of measurement instruments 6- Updating of test methods 7-Standardization of physical condition of the laboratories 8- Getting the certification from ASCB center i

Light-induced structural changes and the site of O=O bond formation in PSII caught by XFEL

Photosystem II (PSII) is a huge membrane-protein complex consisting of 20 different subunits with a total molecular mass of 350 kDa for a monomer. It catalyses light-driven water oxidation at its catalytic centre, the oxygen-evolving complex (OEC). The structure of PSII has been analysed at 1.9 Å resolution by synchrotron radiation X-rays, which revealed that the OEC is a Mn4CaO5 cluster organized in an asymmetric, 'distorted-chair' form. This structure was further analysed with femtosecond X-ray free electron lasers (XFEL), providing the 'radiation damage-free' structure. The mechanism of O=O bond formation, however, remains obscure owing to the lack of intermediate-state structures. Here we describe the structural changes in PSII induced by two-flash illumination at room temperature at a resolution of 2.35 Å using time-resolved serial femtosecond crystallography with an XFEL provided by the SPring-8 ångström compact free-electron laser. An isomorphous difference Fourier map between the two-flash and dark-adapted states revealed two areas of apparent changes: around the QB/non-haem iron and the Mn4CaO5 cluster. The changes around the QB/non-haem iron region reflected the electron and proton transfers induced by the two-flash illumination. In the region around the OEC, a water molecule located 3.5 Å from the Mn4CaO5 cluster disappeared from the map upon two-flash illumination. This reduced the distance between another water molecule and the oxygen atom O4, suggesting that proton transfer also occurred. Importantly, the two-flash-minus-dark isomorphous difference Fourier map showed an apparent positive peak around O5, a unique μ4-oxo-bridge located in the quasi-centre of Mn1 and Mn4 (refs 4,5). This suggests the insertion of a new oxygen atom (O6) close to O5, providing an O=O distance of 1.5 Å between these two oxygen atoms. This provides a mechanism for the O=O bond formation consistent with that proposed previousl