Uma nova abordagem analítica sobre teores de 'Zn' por HR-CSAAS em plantas medicinais voltadas ao emagrecimento

The following research project deals with the development of new analytical procedures aimed at the identification and quantification of the element zinc in different fractions of vegetable drugs used for weight loss, using the high-resolution continuum source atomic absorption spectrometry in flame. The determination of the levels of zinc was made in an AnalytikJena ContrAA 300 spectrometer in the principal line of Zn at 213.857 nm and wavelength integrated absorbance equal to 3 pixels. Calibration curves were obtained with linear dynamic range from 0.10 to 1.00 mg L-1, correlation coefficient equal to 0.9991 and limit of detection equal to 0.020 mg L-1. The total Zn content in the samples obtained after microwave-assisted acid digestion system were: 28.06 mg kg-1 (Artichoke), 31.49 mg kg-1 (Chamomile), 77.16 mg kg-1 (Gorse), 105.38 mg kg-1 (Horsetail), 32.37 mg kg-1 (Fennel) and 5.00 mg kg-1 (Senna). The extraction in aqueous environment assisted by microwave radiation produced extracts containing: 5.40 mg kg-1 (Artichoke), 10.65 mg kg-1 (Chamomile), 14.83 mg kg-1 (Gorse), 18.90 mg kg-1 (Horsetail), 7.80 mg kg-1 (Fennel), 3.24 mg kg-1 (Senna), corresponding to 19%, 34%, 19%, 18%, 24% and 64% of their total content of Zn, respectively. The amounts of Zn in the extracted samples from some plants indicate that this metal was strongly bounded to the plant's matrix. The sequential extraction using solvents and mixtures with different polarities (n-hexane, ethyl acetate, propanol, methanol, ethanol-water 1:1 (v/v), water) aimed the separation of different Zn containing species and water was considered the most efficient extractor. The Zn contents extracted were: 14.82 mg kg-1 (Artichoke), 16.82 mg kg-1 (Chamomile), 34.09 mg kg-1 (Gorse), 4.75 mg kg-1 (Senna), corresponding to 53% in the first two samples, 44% and 95% for the last two, respectively. It was observed that Zn is found complexed under

The young stellar cluster [DBS2003] 157 associated with the H ii region GAL 331.31-00.34

We report a study of the stellar content of the near-infrared (NIR) cluster [DBS2003] 157 embedded in the extended H ii region GAL 331.31-00.34, which is associated with the IRAS source 16085-5138. JHK photometry was carried out in order to identify potential ionizing candidates, and the follow-up NIR spectroscopy allowed the spectral classification of some sources, including two O-type stars. A combination of NIR photometry and spectroscopy data was used to obtain the distance of these two stars, with the method of spectroscopic parallax: IRS 298 (O6 V, 3.35 +/- 0.61 kpc) and IRS 339 (O9 V, 3.24 +/- 0.56 kpc). Adopting the average distance of 3.29 +/- 0.58 kpc and comparing the Lyman continuum luminosity of these stars with that required to account for the radio continuum flux of the H ii region, we conclude that these two stars are the ionizing sources of GAL 331.31-00.34. Young stellar objects (YSOs) were searched by using our NIR photometry and mid-infrared (MIR) data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) survey. The analysis of NIR and MIR colourcolour diagrams resulted in 47 YSO candidates. The GLIMPSE counterpart of IRAS 16085-5138, which presents IRAS colour indices compatible with an ultracompact H ii region, has been identified. The analysis of its spectral energy distribution between 2 and m revealed that this source shows a spectral index a= 3.6 between 2 and m, which is typical of a YSO immersed in a protostellar envelope. Lower limits to the bolometric luminosity and the mass of the embedded protostar have been estimated as L= 7.7 x 10(3) L? and M= 10 M?, respectively, which correspond to a B0B1 V zero-age main sequence star.

Referencing geostrophic velocities using ADCP data at 24.5°N (North Atlantic)

[EN] Acoustic Doppler Current Profilers (ADCPs) have proven to be a useful oceanographic tool in the study of ocean dynamics. Data from D279, a transatlantic hydrographic cruise carried out in spring 2004 along 24.5°N, were processed, and lowered ADCP (LADCP) bottom track data were used to assess the choice of reference velocity for geostrophic calculations. The reference velocities from different combinations of ADCP data were compared to one another and a reference velocity was chosen based on the LADCP data. The barotropic tidal component was subtracted to provide a final reference velocity estimated by LADCP data. The results of the velocity fields are also shown. Further studies involving inverse solutions will include the reference velocity calculated here.

Bioremediation of PAHs - Limitations and soultions

Introduction 1.1 Occurrence of polycyclic aromatic hydrocarbons (PAH) in the environment Worldwide industrial and agricultural developments have released a large number of natural and synthetic hazardous compounds into the environment due to careless waste disposal, illegal waste dumping and accidental spills. As a result, there are numerous sites in the world that require cleanup of soils and groundwater. Polycyclic aromatic hydrocarbons (PAHs) are one of the major groups of these contaminants (Da Silva et al., 2003). PAHs constitute a diverse class of organic compounds consisting of two or more aromatic rings with various structural configurations (Prabhu and Phale, 2003). Being a derivative of benzene, PAHs are thermodynamically stable. In addition, these chemicals tend to adhere to particle surfaces, such as soils, because of their low water solubility and strong hydrophobicity, and this results in greater persistence under natural conditions. This persistence coupled with their potential carcinogenicity makes PAHs problematic environmental contaminants (Cerniglia, 1992; Sutherland, 1992). PAHs are widely found in high concentrations at many industrial sites, particularly those associated with petroleum, gas production and wood preserving industries (Wilson and Jones, 1993). 1.2 Remediation technologies Conventional techniques used for the remediation of soil polluted with organic contaminants include excavation of the contaminated soil and disposal to a landfill or capping - containment - of the contaminated areas of a site. These methods have some drawbacks. The first method simply moves the contamination elsewhere and may create significant risks in the excavation, handling and transport of hazardous material. Additionally, it is very difficult and increasingly expensive to find new landfill sites for the final disposal of the material. The cap and containment method is only an interim solution since the contamination remains on site, requiring monitoring and maintenance of the isolation barriers long into the future, with all the associated costs and potential liability. A better approach than these traditional methods is to completely destroy the pollutants, if possible, or transform them into harmless substances. Some technologies that have been used are high-temperature incineration and various types of chemical decomposition (for example, base-catalyzed dechlorination, UV oxidation). However, these methods have significant disadvantages, principally their technological complexity, high cost , and the lack of public acceptance. Bioremediation, on the contrast, is a promising option for the complete removal and destruction of contaminants. 1.3 Bioremediation of PAH contaminated soil & groundwater Bioremediation is the use of living organisms, primarily microorganisms, to degrade or detoxify hazardous wastes into harmless substances such as carbon dioxide, water and cell biomass Most PAHs are biodegradable unter natural conditions (Da Silva et al., 2003; Meysami and Baheri, 2003) and bioremediation for cleanup of PAH wastes has been extensively studied at both laboratory and commercial levels- It has been implemented at a number of contaminated sites, including the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, the Mega Borg spill off the Texas coast in 1990 and the Burgan Oil Field, Kuwait in 1994 (Purwaningsih, 2002). Different strategies for PAH bioremediation, such as in situ , ex situ or on site bioremediation were developed in recent years. In situ bioremediation is a technique that is applied to soil and groundwater at the site without removing the contaminated soil or groundwater, based on the provision of optimum conditions for microbiological contaminant breakdown.. Ex situ bioremediation of PAHs, on the other hand, is a technique applied to soil and groundwater which has been removed from the site via excavation (soil) or pumping (water). Hazardous contaminants are converted in controlled bioreactors into harmless compounds in an efficient manner. 1.4 Bioavailability of PAH in the subsurface Frequently, PAH contamination in the environment is occurs as contaminants that are sorbed onto soilparticles rather than in phase (NAPL, non aqueous phase liquids). It is known that the biodegradation rate of most PAHs sorbed onto soil is far lower than rates measured in solution cultures of microorganisms with pure solid pollutants (Alexander and Scow, 1989; Hamaker, 1972). It is generally believed that only that fraction of PAHs dissolved in the solution can be metabolized by microorganisms in soil. The amount of contaminant that can be readily taken up and degraded by microorganisms is defined as bioavailability (Bosma et al., 1997; Maier, 2000). Two phenomena have been suggested to cause the low bioavailability of PAHs in soil (Danielsson, 2000). The first one is strong adsorption of the contaminants to the soil constituents which then leads to very slow release rates of contaminants to the aqueous phase. Sorption is often well correlated with soil organic matter content (Means, 1980) and significantly reduces biodegradation (Manilal and Alexander, 1991). The second phenomenon is slow mass transfer of pollutants, such as pore diffusion in the soil aggregates or diffusion in the organic matter in the soil. The complex set of these physical, chemical and biological processes is schematically illustrated in Figure 1. As shown in Figure 1, biodegradation processes are taking place in the soil solution while diffusion processes occur in the narrow pores in and between soil aggregates (Danielsson, 2000). Seemingly contradictory studies can be found in the literature that indicate the rate and final extent of metabolism may be either lower or higher for sorbed PAHs by soil than those for pure PAHs (Van Loosdrecht et al., 1990). These contrasting results demonstrate that the bioavailability of organic contaminants sorbed onto soil is far from being well understood. Besides bioavailability, there are several other factors influencing the rate and extent of biodegradation of PAHs in soil including microbial population characteristics, physical and chemical properties of PAHs and environmental factors (temperature, moisture, pH, degree of contamination). Figure 1: Schematic diagram showing possible rate-limiting processes during bioremediation of hydrophobic organic contaminants in a contaminated soil-water system (not to scale) (Danielsson, 2000). 1.5 Increasing the bioavailability of PAH in soil Attempts to improve the biodegradation of PAHs in soil by increasing their bioavailability include the use of surfactants , solvents or solubility enhancers.. However, introduction of synthetic surfactant may result in the addition of one more pollutant. (Wang and Brusseau, 1993).A study conducted by Mulder et al. showed that the introduction of hydropropyl-ß-cyclodextrin (HPCD), a well-known PAH solubility enhancer, significantly increased the solubilization of PAHs although it did not improve the biodegradation rate of PAHs (Mulder et al., 1998), indicating that further research is required in order to develop a feasible and efficient remediation method. Enhancing the extent of PAHs mass transfer from the soil phase to the liquid might prove an efficient and environmentally low-risk alternative way of addressing the problem of slow PAH biodegradation in soil.

Partial volume correction incorporating Rb-82 positron range for quantitative myocardial perfusion PET based on systolic-diastolic activity ratios and phantom measurements.

BACKGROUND: Quantitative myocardial PET perfusion imaging requires partial volume corrections. METHODS: Patients underwent ECG-gated, rest-dipyridamole, myocardial perfusion PET using Rb-82 decay corrected in Bq/cc for diastolic, systolic, and combined whole cycle ungated images. Diastolic partial volume correction relative to systole was determined from the systolic/diastolic activity ratio, systolic partial volume correction from phantom dimensions comparable to systolic LV wall thicknesses and whole heart cycle partial volume correction for ungated images from fractional systolic-diastolic duration for systolic and diastolic partial volume corrections. RESULTS: For 264 PET perfusion images from 159 patients (105 rest-stress image pairs, 54 individual rest or stress images), average resting diastolic partial volume correction relative to systole was 1.14 ± 0.04, independent of heart rate and within ±1.8% of stress images (1.16 ± 0.04). Diastolic partial volume corrections combined with those for phantom dimensions comparable to systolic LV wall thickness gave an average whole heart cycle partial volume correction for ungated images of 1.23 for Rb-82 compared to 1.14 if positron range were negligible as for F-18. CONCLUSION: Quantitative myocardial PET perfusion imaging requires partial volume correction, herein demonstrated clinically from systolic/diastolic absolute activity ratios combined with phantom data accounting for Rb-82 positron range.

An die Urwähler des 82. Bezirks: Wir unterzeichnete Urwähler des 82. Bezirks erblicken in der constitutionellen Monarchie ...

Welsch (Projektbearbeiter): Appell von 50 Urwählern des Berliner 82. Bezirks, nur solche Wahlmänner zu wählen, die zur konstitutionellen Monarchie und zur Verfassung vom 5. Dezember 1848 stehen. Letztere ist aufgrund der Möglichkeit der Revision nicht unbedingt oktroyiert zu nennen.

Ms. Praed. 82 - Acta capitulorum generalium ordinis praedicatorum

Vorbesitzer: Dominikanerkloster Frankfurt am Main

Deutsche Kolonisation in Ostafrika : aus Briefen und Tagebüchern des am 24. September 1888 zu Kilwa umgekommenen Beamten der Deutsch-Ostafrikanischen Gesellschaft

Heinrich Hessel. Veröffentl. von Karl Hessel

Physical oceanography from the TRACTOR project

Primary Objectives - Describe and quantify the present strength and variability of the circulation and oceanic processes of the Nordic Seas regions using primarily observations of the long term spread of a tracer purposefully released into the Greenland Sea Gyre in 1996. - Improve our understanding of ocean processes critical to the thermaholine circulation in the Nordic Seas regions so as to be able to predict how this region may respond to climate change. - Assess the role of mixing and ageing of water masses on the carbon transport and the role of the thermohaline circulation in carbon storage using water transports and mixing coefficients derived from the tracer distribution. Specific Objectives Perform annual hydrographic, chemical and SF6 tracer surveys into the Nordic regions in order to: - Measure lateral and diapycnal mixing rates in the Greenland Sea Gyre and in the surrounding regions. - Document the depth and rates of convective mixing in the Greenland Sea using the SF6 and the water masses characteristics. - Measure the transit time and transport of water from the Greenland Sea to surrounding seas and outflows. Document processes of water mass transformation and entrainment occurring to water emanating from the central Greenland Sea. - Measure diapycnal mixing rates in the bottom and margins of the Greenland Sea basin using the SF6 signal observed there. Quantify the potential role of bottom boundary-layer mixing in the ventilation of the Greenland Sea Deep Water in absence of deep convection. Monitor the variability of the entrainment of water from the Greenland Sea using time series auto-sampler moorings at strategic positions i.e., sill of the Denmark Strait, Labrador Sea, Jan Mayen fracture zone and Fram Strait. Relate the observed variability of the tracer signal in the outflows to convection events in the Greenland Sea and local wind stress events. Obtain a better description of deepwater overflow and entrainment processes in the Denmark Strait and Faeroe Bank Channel overflows and use these to improve modelling of deepwater overflows. Monitor the tracer invasion into the North Atlantic using opportunistic SF6 measurements from other cruises: we anticipate that a number of oceanographic cruises will take place in the north-east Atlantic and the Labrador Sea. It should be possible to get samples from some cruises for SF6 measurements. Use process models to describe the spread of the tracer to achieve better parameterisation for three-dimensional models. One reason that these are so resistant to prediction is that our best ocean models are as yet some distance from being good enough, to predict climate and climate change.