Synthesis and X-ray Crystal Structures of New Tetrahedral Arylethynyl Substituted Silanes

The tetrakis(arylethynyl)silanes 1–4 of which 2–4 are new compounds have been synthesized and determined by single crystal structure analysis to show their tetrahedral molecular geometries reflected in slightly disturbed S₄ symmetry in the crystal lattices. The lattice structures are mainly determined by close packing effects while the interactions of π-stacking type or C–H···π contacts are rather secondary. A similar behaviour is found for the crystal structure of the comparative compound 5 with reference to 4 which lacks the ethynylene units. It is demonstrated that the given molecular constructions are distinguished by a high degree of tetrahedral persistency governing the packing structures.     

Short- and long-term effectiveness of an empirically supported treatment for agoraphobia.

This study examined the effectiveness of individual high-density exposure (2–3 weeks, all day) for panic disorder with agoraphobia (PDAG). Participants were 416 unselected patients with a primary diagnosis of PDAG who were treated by 52 therapists in 3 outpatient clinics of the Christoph-Dornier Foundation of Clinical Psychology in Germany. Results 6 weeks after the end of therapy and at the 1-year follow-up showed highly significant reductions in anxiety symptoms, anxious cognition, agoraphobic avoidance, general symptomatology, and depressive symptoms. Results did not differ significantly between the 3 outpatient clinics and are comparable with the average effect sizes reported by meta-analytic studies of controlled efficacy research, using selected patients and specifically trained therapists. Effectiveness was not dependent on duration of disorder, number of treatment sessions, and therapist experience. The study suggests that high-density exposure can be transported from research settings to the mental health field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therban® – The High Performance Elastomer for the New Millennium

Hydrogenated nitrile rubber (Therban) was introduced in the early 80's by Bayer as an oil‐resistant elastomer for permanent exposure to temperatures between –25°C and 150°C. By specific modification of micro‐ and macrostructural features the service temperature range could be extended. The introduction of bulky side groups hinders the crystallization of methylene sequences along the polymer backbone. The inability to crystallize leads to superior dynamic‐mechanical properties at low service temperatures. High temperature properties are determined by the plateau of rubber elasticity and are mainly influenced by the network density and structure of the crosslinked polymer matrix as well as by the polymer‐filler interactions. The temperature dependence of the latter causes a decline in the reinforcement properties of filler and polymer matrix at elevated temperatures. Above 150°C a deterioration of the polymer network is observed for standard HNBR grades. This service temperature limit can be increased by ca. 10°C being equivalent to a doubling of the service life‐time by the proper use of Therban HT.     

Review of the effects of food processing and formulation on flavonol and anthocyanin behaviour

In spite of the growing interest over the last few years in flavonoids and their antioxidant capacity, little work has been devoted to investigate the effect of the processes on the structure and the activities of these molecules during processing and storage steps. Most of the studies concern the characterization and analyses of these compounds in raw materials before their processing. Flavonoids are sensitive to heat and to the physico-chemical environment; thus the steps of processing (heating, mechanical and domestic processes), of formulation (food matrix) and the storage period and conditions may lead to a degradation of the flavonoids and an alteration of their antioxidant properties. In this paper, we review the main studies describing the effects of processing, formulation and storage on flavonol and anthocyan content and we also report the models describing the degradation kinetics under a wide range of temperature and operating conditions.     

Effects of direct-electric-current on secondary plant compounds and antioxidant activity in harvested tomato fruits (Solanum lycopersicon L.)

The effects of direct-electric-current (DC) on secondary plant compounds and antioxidant activity in harvested tomato fruits were investigated. A new technology was developed to supply DC to the tomatoes. Different intensities of DC (100–500 mA) with varied application times (15–60 min) were applied during postharvest. Almost all DC treatments significantly affected the secondary metabolism, resulting in an accumulation of carotenoids, phenolic compounds, and antioxidant activity in tomatoes. In the present study, optimal DC treatments were found in order to obtain the highest content of all investigated secondary plant compounds. After an adaptation time (AT) of 2 h, the maximum contents of lycopene (122.4%), ß-carotene (140.4%), total phenol (120.0%), and antioxidant activity (126.5%) were attained with a DC treatment of 500 mA for 15 min. The results changed after an adaptation time of 24 h (AT 24 h), where the highest contents of lycopene (128.7%), ß-carotene (129.6%), total phenol (113.6%), and antioxidant activity (120.9%) were obtained using the same DC treatment (500 mA), but with an application time of 30 min. Therefore, the application of DC in harvested tomato fruits may be appropriate to improve the health-promoting properties of tomatoes.     

Changes of life satisfaction in the transition to retirement: A latent-class approach.

Contradictory positions have been advanced as to whether retirement has negative, positive, or no effects on subjective well-being. The authors investigated changes in life satisfaction in 1,456 German retirees. Using latent growth mixture modeling, the authors found 3 groups of people who experienced retirement differently. In Group 1, satisfaction declined at retirement but continued on a stable or increasing trajectory thereafter. Group 2 demonstrated a large increase in satisfaction at retirement but overall declining satisfaction. In Group 3, satisfaction showed a temporary very small increase at retirement. Groups differed by retirement age, gender, socioeconomic status, marital status, health, unemployment before retiring, and region. Thus, retirement is not a uniform transition, and resource-rich individuals are less likely to experience retirement-related change in satisfaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Steelmaking / U.S.A.

Part II of a four-part series on the history of steelmaking in the US, points out the inadequate safety and living conditions that existed in steel mills at the turn of the Century. Also defined are furnace and process developments.     

Nitrification activity and community structure of nitrite-oxidizing bacteria in the bioreactors operated with addition of pharmaceuticals

Pharmaceuticals represent a group of the new emerging contaminants, which might influence microbial communities in the activated sludge. Nitrification activity and Nitrospira community structure in the small-scale reactors supplied with different concentrations (0, 50, 200, 500 μg L(-1)) of the selected pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac and clofibric acid) were evaluated. Ammonia removal was not influenced by selected pharmaceuticals. However, in the two reactors operated with 50 μg L(-1) of pharmaceuticals (R50 and R50P), the effluent concentration of N-(NO(2)(-)+NO(3)(-)) was significantly higher than in the other reactors. Nitrospira community structure was assessed by terminal restriction fragment length polymorphism (T-RFLP) and by cloning and sequencing of the partial genes for 16S rRNA. Nitrospira spp. were detected in all reactors. The two dominant T-RFs represented the sublineages I and II of the genus Nitrospira. Main shifts were observed in the reactors R50 and R50P, where the T-RF representing sublineage II was much higher as compared to the other reactors. Consistent with this, the Nitrospira sublineage II was detected only in the clone libraries from the reactors R50 and R50P. Our results suggest that the relative abundance of Nitrospira sublineage II could be related to the effluent N-(NO(2)(-)+NO(3)(-)) concentration.     

Development and Biochemical Characterization of Self-Immolative Linker Containing GnRH-III-Drug Conjugates

The human gonadotropin releasing hormone (GnRH-I) and its sea lamprey analogue GnRH-III specifically bind to GnRH receptors on cancer cells and can be used as targeting moieties for targeted tumor therapy. Considering that the selective release of drugs in cancer cells is of high relevance, we were encouraged to develop cleavable, self-immolative GnRH-III-drug conjugates which consist of a p-aminobenzyloxycarbonlyl (PABC) spacer between a cathepsin B-cleavable dipeptide (Val-Ala, Val-Cit) and the classical anticancer drugs daunorubicin (Dau) and paclitaxel (PTX). Alongside these compounds, non-cleavable GnRH-III-drug conjugates were also synthesized, and all compounds were analyzed for their antiproliferative activity. The cleavable GnRH-III bioconjugates revealed a growth inhibitory effect on GnRH receptor-expressing A2780 ovarian cancer cells, while their activity was reduced on Panc-1 pancreatic cancer cells exhibiting a lower GnRH receptor level. Moreover, the antiproliferative activity of the non-cleavable counterparts was strongly reduced. Additionally, the efficient cleavage of the Val-Ala linker and the subsequent release of the drugs could be verified by lysosomal degradation studies, while radioligand binding studies ensured that the GnRH-III-drug conjugates bound to the GnRH receptor with high affinity. Our results underline the high value of GnRH-III-based homing devices and the application of cathepsin B-cleavable linker systems for the development of small molecule drug conjugates (SMDCs).