Lumbar disc degeneration in relation to occupation

Angiogenic growth factors are essential for cancer metastasis, and the growth of metastatic foci also depends on these angiogenic growth factors as well as autocrine or paracrine growth factors. We therefore investigated whether vascular endothelial growth factor (VEGF) and thymidine phosphorylase (dThdPase) are localized more often in primary tumors with hepatic metastasis than in those without such metastasis and whether transforming growth factor (TGF-alpha) and epidermal growth factor receptor (EGF-R) are coexisted more often in hepatic metastases than in primary tumors of gastric cancer. Resected specimens from 82 patients with gastric cancer were examined immunohistochemically. The primary antibodies used were anti-VEGF, anti-dThdPase, anti-TGF-alpha and anti-EGF-R. VEGF expression was found to be higher in primary cancers with than in those without hepatic metastasis (p < 0.001), while VEGF was frequently observed in both hepatic metastases and in the primary tumors. Localization of dThdPase was also higher in advanced than in early gastric cancers (p = 0.021). High co-presence of TGF-alpha and EGF-R was detected more frequently in cancers with deep gastric wall invasion than in those without such invasion (p = 0.050), and also more often in cancers with venous invasion (p = 0.007) and those in the advanced stage (p = 0.020). Co-presence of TGF-alpha and EGF-R was found to be higher, though not significantly, in hepatic metastases (58.8%) than in primary tumors (29.4%). These findings suggest that localization of VEGF may play an important role in hepatic metastasis, and that the expression of VEGF, dThdPase and the TGF-alpha/EGF-R pathway may be responsible for the growth of hepatic metastasis.     

Crisis response strategies in Finland and Spain

Crises are common in today's unpredictable environment rising the importance of crisis response strategies. Two societies in Europe are chosen: Finland, where trust in society is generalized to institutions, and Spain, where trust in society remains on the level of individuals. Using the results of the European Communication Monitor 2013 survey on crisis communication, we explored three hypotheses: “certain types of crises are often met with certain types of strategies,” “cultural context makes some crises more likely than others,” and “cultural context makes some response strategies more likely than others.” We find evidence for all three hypotheses and discuss our findings about perceived differences in the two societies. The results show that the cultural context plays an important role for crisis communication.     

Linking business and requirements engineering: is solution planning a missing activity in software product companies?

A strong link between strategy and product development is important, since companies need to select requirements for forthcoming releases. However, in practice, connecting requirements engineering (RE) and business planning is far from trivial. This paper describes the lessons learned from four software product companies that have recognized the need for more business-oriented long-term planning. The study was conducted using the action research approach. We identified five practices that seem to strengthen the link between business decisions and RE. These are (1) explicating the planning levels and time horizons; (2) separating the planning of products’ business goals from R&D resource allocation; (3) planning open-endedly with a pre-defined rhythm; (4) emphasizing whole-product thinking; and (5) making solution planning visible. To support whole-product thinking and solution planning, we suggest that companies create solution concepts. The purpose of the solution concept is to provide a big picture of the solution and guide RE activities.     

Chemical composition distribution study in ethylene/1‐hexene copolymerization to produce LLDPE material using MgCl2‐TiCl4‐based Ziegler‐Natta catalysts

The characteristic features of LLDPE polymerization with ZN catalyst are the time drift effect during polymerization and the bending effect when trying to decrease density of the copolymer by adding more comonomer to the polymerization. The time drift in LLDPE polymerization is revealed by a constant decrease of comonomer incorporation during polymerization time. The bending is revealed by difficulties in lowering the density of LLDPE material below the density of 920 kg/m³. With increasing comonomer content during polymerization, the density does not decrease, but the soluble fraction increases. To try to observe if these phenomena are connected, two types of catalysts, SiO₂ supported and precipitated MgCl₂ ZN catalysts, were studied. A short time (10 min) and an extended time (60 min) copolymerization test series where the polymerizations were performed in the presence of a gradually increasing comonomer amount. Both catalysts show a strong bending when density is presented as a function of 1‐hexene both in 10‐ and 60‐min polymerization, indicating no connection between time drift and bending. The density, melting point, and crystallinity results all indicate that both catalysts are making similar copolymer material with identical chemical composition distribution. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Tailoring the Separation Behavior of Hybrid Organosilica Membranes by Adjusting the Structure of the Organic Bridging Group

Hybrid organically linked silica is a highly promising class of materials for the application in energy‐efficient molecular separation membranes. Its high stability allows operation under aggressive working conditions. Herein is reported the tailoring of the separation performance of these hybrid silica membranes by adjusting the size, flexibility, shape, and electronic structure of the organic bridging group. A single generic procedure is applied to synthesize nanoporous membranes from bridged silsesquioxane precursors with different reactivities. Membranes with short alkylene (CH₂ and C₂H₄) bridging groups show high H₂/N₂ permeance ratios, related to differences in molecular size. The highest CO₂/H₂ permeance ratios, related to the affinity of adsorption in the material, are obtained for longer (C₈H₁₆) alkylene and aryl bridges. Materials with long flexible alkylene bridges have a hydrophobic surface and show strongly temperature‐dependent molecular transport as well as a high n‐butanol flux in a pervaporation process, which is indicative of organic polymerlike properties. The versatility of the bridging group offers an extensive toolbox to tune the nanostructure and the affinity of hybrid silica membranes and by doing so to optimize the performance towards specific separation challenges. This provides excellent prospects for industrial applications such as carbon capture and biofuel production.     

Photoswitchable Superabsorbency Based on Nanocellulose Aerogels

Chemical vapor deposition of a thin titanium dioxide (TiO₂) film on lightweight native nanocellulose aerogels offers a novel type of functional material that shows photoswitching between water‐superabsorbent and water‐repellent states. Cellulose nanofibrils (diameters in the range of 5–20 nm) with native crystalline internal structures are topical due to their attractive mechanical properties, and they have become relevant for applications due to the recent progress in the methods of their preparation. Highly porous, nanocellulose aerogels are here first formed by freeze‐drying from the corresponding aqueous gels. Well‐defined, nearly conformal TiO₂ coatings with thicknesses of about 7 nm are prepared by chemical vapor deposition on the aerogel skeleton. Weighing shows that such TiO₂‐coated aerogel specimens essentially do not absorb water upon immersion, which is also evidenced by a high contact angle for water of 140° on the surface. Upon UV illumination, they absorb water 16 times their own weight and show a vanishing contact angle on the surface, allowing them to be denoted as superabsorbents. Recovery of the original absorption and wetting properties occurs upon storage in the dark. That the cellulose nanofibrils spontaneously aggregate into porous sheets of different length scales during freeze‐drying is relevant: in the water‐repellent state they may stabilize air pockets, as evidenced by a high contact angle, in the superabsorbent state they facilitate rapid water‐spreading into the aerogel cavities by capillary effects. The TiO₂‐coated nanocellulose aerogels also show photo‐oxidative decomposition, i.e., photocatalytic activity, which, in combination with the porous structure, is interesting for applications such as water purification. It is expected that the present dynamic, externally controlled, organic/inorganic aerogels will open technically relevant approaches for various applications.     

Effect of three countermeasures against the illegal crossing of railway tracks

This study was designed to investigate the effects of three countermeasures – landscaping, building a fence and prohibitive signs – on the frequency of trespassing, which in this case means crossing the track at places where it is forbidden. At each location the official route was no more than 300 m away. The main results showed that the effect of each countermeasure on the frequency of trespassing was statistically significant. Specifically, the fencing reduced trespassing by 94.6%, followed by landscaping (91.3%) and prohibitive signs (30.7%). The majority of illegal crossings were committed alone and the persons trespassing were mostly adults and men. In addition, the results demonstrated some tendencies of how the effects of the selected countermeasures can vary with the characteristics of the trespassers. The main implication of this study is that the building of physical barriers such as landscaping or fencing is recommended for reducing trespassing. However, if the required resources are not available or the site is not suitable for such measures, the use of prohibitive signs is recommended. Further, there is a need to tailor the countermeasures to the characteristics of the trespassers in order to ensure that the most appropriate countermeasures are applied.     

Structural features of a polypeptide carrier promoting secretion of a β-lactamase fusion protein in yeast

Escherichia coli β-lactamase was secreted into the culture medium of Saccharomyces cerevisiae in biologically active form, when fused to the C-terminus of the hsp150δ-carrier. The hsp150δ-carrier is an N-terminal fragment of the yeast hsp150 protein, having a signal peptide and consisting mostly of a 19 amino acid peptide repeated 11 times in tandem. Here we expressed the hsp150δ-carrier fragment alone in S. cerevisiae. Apparently due to a positional effect of the gene insertion, large amounts of the hsp150δ-carrier were synthesized. About half of the de novo synthesized carrier molecules were secreted into the culture medium, the rest remaining mostly in the pre-Golgi compartment. The extensively O-glycosylated carrier fragment was purified from the culture medium under non-denaturing conditions. Circular dichroism spectroscopy showed that it had no regular secondary structure. Nuclear magnetic resonance spectroscopy showed that a non-glycosylated synthetic peptide, the consensus sequence of the repetitive 19 amino acid peptide, also lacked secondary structure. The unstructured carrier polypeptide may facilitate proper folding and secretion of heterologous proteins attached to it.     

Trace element trophic transfer in aquatic organisms: a critique of the kinetic model approach

The bioaccumulation of trace elements in aquatic organisms can be described with a kinetic model that includes linear expressions for uptake and elimination from dissolved and dietary sources. Within this model, trace element trophic transfer is described by four parameters: the weight-specific ingestion rate (IR); the assimilation efficiency (AE); the physiological loss rate constant (ke); and the weight-specific growth rate (g). These four parameters define the trace element trophic transfer potential (TTP = IR.AE/[ke + g]) which is equal to the ratio of the steady-state trace element concentration in a consumer due to trophic accumulation to that in its prey. Recent work devoted to the quantification of AE and ke for a variety of trace elements in aquatic invertebrates has provided the data needed for comparative studies of trace element trophic transfer among different species and trophic levels and, in at least one group of aquatic consumers (marine bivalves), sensitivity analyses and field tests of kinetic bioaccumulation models. Analysis of the trophic transfer potentials of trace elements for which data are available in zooplankton, bivalves, and fish, suggests that slight variations in assimilation efficiency or elimination rate constant may determine whether or not some trace elements (Cd, Se, and Zn) are biomagnified. A linear, single-compartment model may not be appropriate for fish which, unlike many aquatic invertebrates, have a large mass of tissue in which the concentrations of most trace elements are subject to feedback regulation.