Das Leitbild Nachhaltigkeit und das Konzept Technikbewertung

Sustainable Development and Technology Assessment . Changes in the environmental consciousness of wealthy western societies began t o appear in the 1960s. These changes manifested themselves in three ways. First, in the mid-1960s the term “Technology Assessment” (TA) was coined in the USA. The TA discussion in Germany – as well as in other comparable countries – lead t o growing TA activities and the opening of institutions connected with Technology Assessment. Secondly, in 1968, the Club of Rome was founded, which in 1972 brought out its first study “The Limits to Growth”. Thirdly, the sustainability debate followed and intensified with the report in 1980 “Global 2000” and the Brundtland report in 1987 “Our Common Future”, which formulated the concept of sustainable development. Debates intensified further in 1992 with the “Agenda 21”. the closing document of the Rio Conference for Environment and Development. The following will show both that the diffuse idea of sustainability can be operationalised with the technology assessment concept; and – as has recently taken place at the TU Clausthal – that technology assessment should be established in research and teaching at the university level.     

Selective improvement of porcine fat firmness by a diet enriched in medium-chain fatty acids

The effects of 4% fat either rich in medium-chain fatty acids (MCFA; saturated fat) or in polyenoic fatty acids (PUFA; unsaturated fat) isoenergetically exchanging carbohydrates of a low-fat diet (control) on performance and product quality were evaluated with 180 growing pigs. Growth, carcass and meat quality were not affected by the fat treatments. Although elevated in blood serum, cholesterol was not increased in belly meat when the MCFA-rich diet was fed. Fatty acid composition of backfat reflected dietary fat composition. The significantly lowest shelf life and melting temperatures were found with the unsaturated-fat diet. When compared with control, fat tissue PUFA contents were slightly higher in the saturated-fat diet, and fat melting temperatures were somewhat lower. In contrast, the use of this MCFA-enriched diet increased penetrometer firmness in pure 4°C temperated backfat by more than 50% as compared with control and to about the tenfold level of the firmness obtained in the unsaturated-fat diet. Impression of flavour and odor in lean and fatty meat were not systematically affected by the diets. The present results show a high potential of MCFA-enriched diets to selectively increase fat firmness in pigs without greater undesired side effects on other traits of product quality.     

Voltammetric and Scanning Electrochemical Microscopic Studies of the Adsorption Kinetics and Self-Assembly of n-Alkanethiol Monolayers on Gold

The adsorption kinetics and self-assembly of hexadecyl mercaptan on gold have been investigated by scanning electrochemical microscopy (SECM), chronoamperometry, and cyclic voltammetry. The developed methodology allows one to evaluate the surface coverage and the average size of the defects in the monolayer film from the effective rate constant of electron transfer. Two kinetic regimes of self-assembly were identified: a rapid initial adsorption of hexadecyl mercaptan onto a clean gold surface from 5 mM solution (more than 90% coverage obtained in 1 to 5 min), and a slower subsequent annealing of a thiol monolayer resulting in a more compact film. Typically, a long-chain-length thiol-treated gold surface acts as an electronically insulating surface after about 1 h. The SECM images of partially covered gold surfaces were always featureless, suggesting that the defects in the film were smaller than 0.5 μm for any exposure time ≥ 1 min.     

In Situ Reacted Rare-Earth Hexaaluminate Interphases

A novel in situ reaction between a ceria-doped zirconia interphase coating on Saphikon fibers and an outer alumina coating has resulted in the formation of oriented hexaaluminate platelets which can act as a low fracture energy interface barrier for crack deflection in oxide-oxide ceramic-matrix composites (CMCs). The reaction proceeds only in reducing environments where the reduction of the cerium and zirconium ions to their 3+ valent state causes a destabilization phenomenon consistent with previously reported findings. The diffusion of the cerium from the zirconia into solid solution with the alumina can stabilize the layered hexaaluminate structure. Preferred orientational growth of the hexaaluminate parallel to the coating interface was observed which is the required orientation for enhanced debonding at the fiber/matrix interface in long-fiber-reinforced CMCs.     

Tape Casting of Lanthanum Chromite

The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycinenitrate-synthesized La_0.7Ca_0.31CrO₃ powder. An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of green tapes, and the sintered microstructure. The tape casting formulation incorporated 66:34 methyl ethyl ketone/ethyl alcohol solvent, an aliphatic phosphate ester dispersant, and 80 wt% (35 vol%) solids. The best binder/plasticizer system was 12 wt% (15 vol%) poly(isobutyl methacrylate) and 5 wt% (6.3 vol%) benzyl butyl phthalate plasticizer (binder:plasticizer = 2.3). Cast tapes were sintered at 1300°C for 2 h, producing a bulk density of 96.2% theoretical, with linear shrinkage of 22% and an approximate grain size of 1.3 μm.     

Orthoamide. L. Beiträge zur Chemie von Propiolaldehydaminalen – Synthesen und Umsetzungen zu Push–Pull-substituierten Buta-1,3-dienen,Cyclobutanen sowie vinylogen Amidiniumsalzen und 1,2,3-Triazolen

Orthoamides. L. Contribution to the Chemistry of Propiolaldehydaminales – Synthesis and Transformations to Push–Pull-substituted Buta-1,3-dienes, Cyclobutanes, Vinylogous Amidinium Salts and 1,2,3-Triazoles Tert-butylaminalester 5 reacts with terminal alkynes to give aminals of substituted propiolaldehydes 3c, d . The aminal 3a is accessible from N,N,N′,N′-tetramethylformamidinium chloride (7b) and sodium acetylide. The aminals 3b,c can also be prepared from bis(dimethylamino)acetonitrile 8 and terminal alkynes in the presence of sodium hydride. The nitrile 8 is also useful for the preparation of the bis-aminal of acetylenedialdehyde 6 . The aminal 3e can be transaminated by heating with secondary amines to give the aminals 3f–i . The aminals 3a–i react with strong CH₂-acidic compounds (pK_a between 9 and 14) to give the 1-dialkylamino-1,3-butadienes 10 . The isomeric 1-dialkylamino-butadienes 18 can be obtained from the condensation of the CH-acidic cinnamic acid derivatives 19 with dimethylformamidedimethylacetal. CH and NH-acidic compounds as cyanacetamide react with the aminals 3c,e exclusively with the acidic methylene group to produce the enamines 10h,t . The acylformamidine 21 can be obtained from 10t and tert-butylaminalester 5 . The pyridone 22 is accessible from the condensation product 10h by thermal cyclization. The pyrido[2,3-d]pyrimidine 26 is formed in the reaction of the 6-amino-uracile 23 with the aminal 3a . In an unexpected reaction the 1,2-bis(cyano-dialkylaminomethylene)-cyclobutanes 28a–d result from the action of trimethylsilylcyanide on the aminals 3e–h . The corresponding reaction with trimethylsilylisothiocyanate affords the vinylogous amidinium thiocyanates 34a, b . In the reaction of trimethylsilylazide and the aminals 3 are produced the 4-(dialkylaminomethylene)-4H-1,2,3-triazoles 38 .     

Trans Fatty Acid Intakes and Food Sources in the U.S. Population: NHANES 1999–2002

Because of efforts to decrease trans fatty acids (TFA) in the food supply, intake should be assessed in the population to establish a baseline TFA intake. The 1999?C2002 National Health and Nutrition Examination Survey (NHANES) was used to identify a benchmark for TFA intake. TFA was estimated by mean, median, and quintile of intake, TFA intake data were weighted using the NHANES 4-year sample weights. The main outcome measures included TFA intake in grams per day and percentage of energy in the top 25 food sources of TFA. Data are reported for 16,669 individuals ??3 years of age. Median TFA intake was 2.3?% of calories (5?g/day) with 0.9?C4.5?% of energy (1.5?C13.1?g/day) over different quintiles of intake. Mean TFA intake was 2.5?% of energy (6.1?g/day). The range of TFA intake in the fifth quintile was very large, i.e., 3.5?C12.5?% of energy or 8.8?C92.4?g/day. Increasing quintiles of TFA intake were associated with increases in total fat (26.7?C37.6?% of energy), saturated fat (7.6?C10.5?% of energy), and calories (for those >20?years of age: 2,416?C2,583 for men and 1,679?C1,886 for women). Major food sources of dietary TFA were cakes, cookies, pies, and pastries. Based on current dietary guidance to consume as little industrial TFA as possible, much progress is needed to attain this goal, including food industry efforts to remove TFA from the food supply and educating the public about making healthy food choices.     

Effects of particulate matter on inflammatory markers in the general adult population

Background

Particulate air pollution is associated with increased risk of cardiovascular disease and stroke. Although the precise mechanisms underlying this association are still unclear, the induction of systemic inflammation following particle inhalation represents a plausible mechanistic pathway.

Methods

We used baseline data from the CoLaus Study including 6183 adult participants residing in Lausanne, Switzerland. We analyzed the association of short-term exposure to PM₁₀ (on the day of examination visit) with continuous circulating serum levels of high-sensitive C-reactive protein (hs-CRP), interleukin 1-beta (IL-1??), interleukin 6 (IL-6), and tumor-necrosis-factor alpha (TNF-??) by robust linear regressions, controlling for potential confounding factors and assessing effect modification.

Results

In adjusted analyses, for every 10???g/m³ elevation in PM₁₀, IL-1? increased by 0.034 (95?% confidence interval, 0.007-0.060) pg/mL, IL-6 by 0.036 (0.015-0.057) pg/mL, and TNF-?? by 0.024 (0.013-0.035) pg/mL, whereas no significant association was found with hs-CRP levels.

Conclusions

Short-term exposure to PM₁₀ was positively associated with higher levels of circulating IL-1?, IL-6 and TNF-?? in the adult general population. This positive association suggests a link between air pollution and cardiovascular risk, although further studies are needed to clarify the mechanistic pathway linking PM₁₀ to cardiovascular risk.     

Stable Synthetic Bacteriochlorins for Photodynamic Therapy: Role of Dicyano Peripheral Groups,Central Metal Substitution (2H,Zn, Pd), and Cremophor EL Delivery

A series of four stable synthetic bacteriochlorins was tested in vitro in HeLa cells for their potential in photodynamic therapy (PDT). The parent bacteriochlorin (BC), dicyano derivative (NC)₂BC and corresponding zinc chelate (NC)₂BC–Zn and palladium chelate (NC)₂BC–Pd were studied. Direct dilution of a solution of bacteriochlorin in an organic solvent (N,N‐dimethylacetamide) into serum‐containing medium was compared with the dilution of bacteriochlorin in Cremophor EL (CrEL; polyoxyethylene glycerol triricinoleate) micelles into the same medium. CrEL generally reduced aggregation (as indicated by absorption and fluorescence) and increased activity up to tenfold (depending on bacteriochlorin), although it decreased cellular uptake. The order of PDT activity against HeLa human cancer cells after 24 h incubation and illumination with 10 J cm^?2 of near‐infrared (NIR) light is (NC)₂BC–Pd (LD₅₀=25 nM ) > (NC)₂BC > (NC)₂BC–Zn ≈ BC. Subcellular localization was determined to be in the endoplasmic reticulum, mitochondria and lysosomes, depending on the bacteriochlorin. (NC)₂BC–Pd showed PDT‐mediated damage to mitochondria and lysosomes, and the greatest production of hydroxyl radicals as determined using a hydroxyphenylfluorescein probe. The incorporation of cyano substituents provides an excellent motif for the enhancement of the photoactivity and photostability of bacteriochlorins as PDT photosensitizers.     

Construction of microbial cell factories for industrial bioprocesses

The development of industrial microbial processes is gaining unprecedented momentum. Increased concern for environmental issues and the prospect of declining petroleum resources has shifted the industrial focus increasingly to microorganisms as biocatalysts. At the same time systems biology and synthetic biology supply industry and academia with new tools to design optimal microbial cell factories. Among the tools are systems biology approaches allowing the modelling of cellular networks for rational strain design, single cell analyses methods for gaining insight into population hetereogeneity, and an exciting combination of tools from structural biology and synthetic biology, permitting the catalysis of new (unnatural) enzymatic reactions or the production of new (unnatural) chemicals. This perspective article outlines recent advances and new developments within the field of microbial cell factory design. Copyright © 2012 Society of Chemical Industry