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Direct laser acceleration (DLA) of electrons in plasmas of near-critical density (NCD) is a very advancing platform for high-energy PW-class lasers of moderate relativistic intensity supporting Inertial Confinement Fusion research. Experiments conducted at the PHELIX sub-PW Nd:glass laser demonstrated application-promising characteristics of DLA-based radiation and particle sources, such as ultra-high number, high directionality and high conversion efficiency. In this context, the bright synchrotron-like (betatron) radiation of DLA electrons, which arises from the interaction of a sub-ps PHELIX laser pulse with an intensity of 1019 W/cm2 with pre-ionized low-density polymer foam, was studied. The experimental results show that the betatron radiation produced by DLA electrons in NCD plasma is well directed with a half-angle of 100-200 mrad, yielding (3.4 ± 0.4)·1010 photons/keV/sr at 10 keV photon energy. The experimental photon fluence and the brilliance agree well with the particle-in-cell simulations. These results pave the way for innovative applications of the DLA regime using low-density pre-ionized foams in high energy density research.

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We report on charge state measurements of laser-accelerated carbon ions in the energy range of several MeV penetrating a dense partially ionized plasma. The plasma was generated by irradiation of a foam target with laser-induced hohlraum radiation in the soft x-ray regime. We use the tricellulose acetate (C_{9}H_{16}O_{8}) foam of 2 mg/cm^{3} density and 1 mm interaction length as target material. This kind of plasma is advantageous for high-precision measurements, due to good uniformity and long lifetime compared to the ion pulse length and the interaction duration. We diagnose the plasma parameters to be T_{e}=17 eV and n_{e}=4×10^{20} cm^{-3}. We observe the average charge states passing through the plasma to be higher than those predicted by the commonly used semiempirical formula. Through solving the rate equations, we attribute the enhancement to the target density effects, which will increase the ionization rates on one hand and reduce the electron capture rates on the other hand. The underlying physics is actually the balancing of the lifetime of excited states versus the collisional frequency. In previous measurement with partially ionized plasma from gas discharge and z pinch to laser direct irradiation, no target density effects were ever demonstrated. For the first time, we are able to experimentally prove that target density effects start to play a significant role in plasma near the critical density of Nd-glass laser radiation. The finding is important for heavy ion beam driven high-energy-density physics and fast ignitions. The method provides a new approach to precisely address the beam-plasma interaction issues with high-intensity short-pulse lasers in dense plasma regimes.

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Intense particle beams generated from the interaction of ultrahigh intensity lasers with sample foils provide options in radiography, high-yield neutron sources, high-energy-density-matter generation, and ion fast ignition. An accurate understanding of beam transportation behavior in dense matter is crucial for all these applications. Here we report the experimental evidence on one order of magnitude enhancement of intense laser-accelerated proton beam stopping in dense ionized matter, in comparison with the current-widely used models describing individual ion stopping in matter. Supported by particle-in-cell (PIC) simulations, we attribute the enhancement to the strong decelerating electric field approaching 1 GV/m that can be created by the beam-driven return current. This collective effect plays the dominant role in the stopping of laser-accelerated intense proton beams in dense ionized matter. This finding is essential for the optimum design of ion driven fast ignition and inertial confinement fusion.

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More than 2500 chemically defined substances are approved as drugs in Germany. Unlike agricultural pesticides, these biologically active structures are not used in open environmental compartments and therefore their environmental toxicological data base is not nearly as complete. Nevertheless, some of them become environmental contaminants after their intended use. Therefore, from the viewpoint of environmental health protection, there are gaps in their health-related environmental risk assessment. Organic trace compounds that lack an adequate toxicological database, and their mixtures, in drinking water can be safely regulated and provisionally assessed by combining the "similar joint action" addition rule with the recommendation of the Federal Environment Agency of March 2003 "Assessing the presence of substances in drinking water without (adequate) toxicological database from the health point of view". The general precautionary value (Gesundheitlicher Orientierungswert GOW1=0.10 microg/l), which is a recommendation for weakly to not genotoxic compounds, re presents a workable compromise between preventive health protection, water management considerations and aesthetic quality claims (purity). Compliance with this value in the long term will only be possible if the chemical and biological degradation of pharmaceuticals and their metabolites in waste water and waste water treatment plants is effectively improved. Alternatively, there is the risk of drinking water degenerating into a sink for highly mobile, polar and persistent compounds. Their elimination at a stage as late as technical drinking water treatment would be neither close to the initial cause nor justifiable in terms of technical effectiveness. The risk assessment of their byproducts would give rise to further uncertainties. Possible conflicts with the therapeutic quality must be solved by developing substitute products which are environmentally sound.

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Nitro compounds are important industrial chemicals with a broad range of applications. During their commercial production or practical use and through leaching from military waste sites they may be released into the environment and thus lead to a contamination of drinking water resources. In the last 15-20 years, the wider public first became aware of nitro compounds as contaminants in groundwater and drinking water resources that originated from manufacturing and processing of secondary explosives during World War II. In 1980, the former Bundesgesundheitsamt (BGA; Federal Health Office) had based its first risk assessment of monocyclic nitro compounds in drinking water on the known carcinogenicity of some aromatic amines in the working environment. On this basis, the BGA recommended for metabolites of aromatic nitro compounds a guide value of 0.1 mug/l for the sum of aromatic amines. From the beginning to the middle of the 1990s, the BGA established a more specific health-related assessment for the individual compounds, but not on the basis of tolerable or acceptable body doses but of dimensionless risk assessment scores ranking their combined toxic and carcinogenic potential on a scale from 1 to 100. In this contribution, we derived new health-based drinking water guide values for 19 nitro(aromatic) compounds and nitramines, including hexogen, octogen, and tetryl as well as the O-nitro compound PETN. All compounds under consideration have been detected within the last 15 years in Germany at contaminated sites close to or directly in groundwater resources for drinking water. For toxicological evaluation and derivation of guideline values for the nitro compounds of interest, the tolerable daily intake (TDI) approach was used for chemicals exhibiting a threshold for toxic effects. This was done by using established tolerable body doses for humans based on an identified NOAEL/LOAEL for the most sensitive toxic endpoint. In the case of non-threshold chemical substances, suitable estimates of excess lifetime cancer risk have been applied.

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A method for beam shaping based on fitting the power moments of the final beam intensity distribution and independent of the optical system particularities is suggested. It is shown how one can analytically calculate any moment of the final phase space distribution using the moments of the initial distribution and the optical system transfer map. Numerical tests carried out for a final focus system have demonstrated the usefulness of the approach developed here.

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In order to secure a safe drinking water supply, the setting of tolerable/acceptable ceilings of drinking water hygiene is required with regard to xenobiotics resulting from several anthropogenic impacts. This is done in practice by using drinking water guidelines or standards as quantitative objectives. The list of the new EU Directive or the German drinking-water standards is limited to those parameters that have the highest relevance for drinking water quality; nitro compounds (NCs) are not regulated. Because other substances contained in water can also represent a hazard for human health, the German Drinking Water Ordinance clarifies that specific actions must be implemented if compounds other than those regulated appear at concentrations that may be a cause for concern regarding human health. NCs serve as intermediates for dyes, pharmaceuticals, and synthetic materials; they themselves are used as solvents, explosives, and pesticides. During their commercial production or from their use, they may be released to the environment and lead to a contamination of aquatic systems and thus also of drinking water resources. In practice, therefore, a need for assessment is frequently given for relevant NCs. For 19 nitro-, amino-, and aminonitroaromatics, nitramines, and nitrate esters health-based drinking water guide values have been derived. For toxicological evaluation and derivation of guideline values for the NCs of interest, the tolerable daily intake approach was used for chemicals exhibiting a threshold for toxic effects. This was done by using established tolerable body doses for humans based on an identified no-observed-adverse-effect level/low-observed-effect-level for the most sensitive indicator for toxicity. In the case of nonthreshold chemical substances, suitable estimates of excess lifetime cancer risk have been applied.

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Copper (Cu) is an essential trace element with many physiological functions. Homeostatic mechanisms exist to allow Cu to act as a cofactor in enzymatic processes and to prevent accumulation of Cu to toxic levels. The aim of this commentary is to better understand the role of dietary Cu supply in deficiency and under physiological and pathological conditions. The essentiality of Cu can be attributed to its role as a cofactor in a number of enzymes that are involved in the defence against oxidative stress. Cu, however, has a second face, that of a toxic compound as it is observed with accumulating evidence in hepatic, neurodegenerative and cardiovascular diseases. The destructive potential of Cu can be attributed to inherent physico-chemical properties. The main property is its ability to take part in Fenton-like reactions in which the highly reactive and extremely deleterious hydroxyl radical is formed. Diseases caused by dietary Cu overload could be based on a genetic predisposition. Thus, an assessment of risk-groups, such as infants with impaired mechanisms of Cu homeostasis regarding detoxification, is of special interest, as their Cu intake with resuspended formula milk may be very high. This implies the need for reliable diagnostic markers to determine the Cu status. These topics were introduced at the workshop by the participants followed by extensive group discussion. The consensus statements were agreed on by all members. One of the conclusions is that a re-assessment of published data is necessary and future research is required.

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Copper is an essential element for the activity of a number of physiologically important enzymes. Enzyme-related malfunctions may contribute to severe neurological symptoms and neurological diseases: copper is a component of cytochrome c oxidase, which catalyzes the reduction of oxygen to water, the essential step in cellular respiration. Copper is a cofactor of Cu/Zn-superoxide-dismutase which plays a key role in the cellular response to oxidative stress by scavenging reactive oxygen species. Furthermore, copper is a constituent of dopamine-beta-hydroxylase, a critical enzyme in the catecholamine biosynthetic pathway. A detailed exploration of the biological importance and functional properties of proteins associated with neurological symptoms will have an important impact on understanding disease mechanisms and may accelerate development and testing of new therapeutic approaches. Copper binding proteins play important roles in the establishment and maintenance of metal-ion homeostasis, in deficiency disorders with neurological symptoms (Menkes disease, Wilson disease) and in neurodegenerative diseases (Alzheimer's disease). The Menkes and Wilson proteins have been characterized as copper transporters and the amyloid precursor protein (APP) of Alzheimer's disease has been proposed to work as a Cu(II) and/or Zn(II) transporter. Experimental, clinical and epidemiological observations in neurodegenerative disorders like Alzheimer's disease and in the genetically inherited copper-dependent disorders Menkes and Wilson disease are summarized. This could provide a rationale for a link between severely dysregulated metal-ion homeostasis and the selective neuronal pathology.

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In a multicentric retrospective clinical study with 16 pediatric centres we identified 103 cases of histologically confirmed early childhood cirrhosis (ECC) in Germany for the years 1984-1994. The most prominent diagnoses were congenital bile duct anomalies (47.5%), inborn metabolic disorders (17.5%) and unclear etiologies (17.5%). Chronic and excessive intake of copper might be discussed as an etiological factor in 8 other cases. 5 of these were proven to have coincided with very high hepatic copper contents and copper plumbing/acid well water. Their connection with copper exposure must be considered as probable, whereas 3 others were only suspected copper cases, mainly due to reliable exclusion of other etiologies. High corrosivity (base capacity) values and copper levels in the water for infants formula of 9-26.4 mg/L were determined in those probable cases for which exposure conditions could be exactly reproduced. Additional reports on copper associated ECC, either Indian Childhood Cirrhosis (ICC) from outside India or so-called Idiopathic Copper Toxicosis ( ICT ), originate from Austria, Australia, Germany, Ireland, USA.

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Limit values (LVs) are legal concentration limits for constituents, residues and contaminants in consumer products or for emissions from production processes into environmental compartments. They are a traditional regulatory aid to manage chemicals in human environments. To make them proactive, LVs should become enforced by means of a transparent and informed decision process whose starting point is the Basic Rule of Environmental Hygiene, BREH:Avoid useless exposure as far as possible, minimize useful exposure in a reasonable manner, and prevent that exposure which is dangerous. The BREH calls upon minimizing exposure not only according to on site risk potentials and acceptance, but also to off site avoidability and acceptability.

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The Basic Rule of Environmental Hygiene BREH (Dieter 1996;1998b) is a suitable starting point for proactive chemicals management.Three definitions (==> LV) for corresponding proactive LVs can be derived from the BREH: (1) Functional anthropogenic exposure of the type residues = substance group B is accepted at least at a minimal technical threshold FB > 0 to maintain desired functionality distinctly below the most sensitive adverse effect threshold Ea, (0 < FB ==> LVB < Ea). (2) Group C exposure = non functional contaminants (F c = 0) is to be tolerated only at technically low if not "zero" levels Tc, hence 0 = Fc < Tc ==> LVC < or= 0). It may be accepted or tolerated up to its upper limit NA LVA

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Aflatoxin B1 alone (0.05 mg resp. 0.037 mg/kg/d), copper alone (6.6 mg/kg/d or 200 mg/l drinking water) or a combination of both was administered orally for 6 months to young guinea pigs from the first/second day of life. In the copper group there were no pathomorphological changes. For the aflatoxin B1 group, liver damage was established. In the combined group, liver injury was more frequent and more severe compared to the aflatoxin B1 group and biliary copper excretion was diminished compared with the copper group. Histologically, only the livers of this group exhibited degeneration, atrophy and steatosis of liver cells, inflammatory processes and a more or less prominent fibrosis. For childhood cirrhosis (ICC and ICT) a combined etiology--a liver damaging agent plus elevated alimentary copper--is a plausible hypothesis.

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