Polystyrene-poly(2-ethylhexylmethacrylate) block copolymers: Synthesis,bulk phase behavior,and thin film structure

Anionic polymerization was employed to synthesize well-defined diblock copolymers of polystyrene and poly(2-ethylhexylmethacrylate), PS-PEHMA. Diblock morphologies in bulk and in substrate-supported thin films were characterized by small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM), respectively. PS-PEHMA diblocks exhibited thermotropic order-disorder transitions; one diblock showed a thermoreversible transition between lamellae and a higher-temperature morphology assigned as perforated lamellae. Unlike PS-poly(alkylmethacrylate) diblocks where the alkyl group is n-butyl or n-pentyl, PS-PEHMA diblocks showed a typical decreasing Flory interaction parameter with increasing temperature. Thin films of PS-cylinder-forming PS-PEHMA diblocks showed a strong preference for the cylinders to lie in the plane of the film; films of incommensurate thickness readily formed terraces. Films of commensurate thickness were easily aligned over macroscopic areas through the application of mechanical shear.     

3D seismic and formation micro-imager (FMI) integrated study to delineate depositional pattern of Abu Madi (Upper Miocene) clastic reservoir rocks in El-Wastani gas field,onshore Nile Delta,Egypt

Ten wells (EW-4, EW-5, EW-6, EW-7, EW-8, EW-9, EW-10, EW-12, EW-13 and EW-15) were interpreted using the composite well logs, data of core analysis, gamma-ray logs, formation micro-imager logs (FMI), and 3D seismic data in SEGY format to understand the stratigraphy of the onshore, Nile Delta, Egypt.The amplitude analysis of 3-D seismic horizon slice of Lower Abu Madi rock unit together with the lithostratigraphic correlation through the study area depending on the gamma-ray log “HSGR” (left to right increasing), and the identification of type of bed geometry, nature of bed contacts, type of the sedimentary structures and the dominant formative paleocurrents by using some available borehole micro-resistivity images (FMI) and core photos. All of these techniques are used together to define the different depositional facies and depositional environment of the Messinian clastics (Lower Abu Madi rock unit), which is considered to be the main reservoir in the El-Wastani gas field, onshore Nile Delta, Egypt.The present study of depositional pattern of the Upper Miocene clastics reservoir (Lower Abu Madi rock unit) revealed that it is represented by high sinuous meandering channels or paleo-valley and three types of fluvial facies were defined; channel fill, channel margin, and floodplain basin.     

Estrogen content of dairy and swine wastes

Naturally occurring estrogens in animal wastes may cause negative environmental impacts, yet their abundance in animal waste treatment and storage structures is poorly documented. To better quantify estrogen concentrations in animal wastes, multiple waste samples were collected from treatment and storage structures at dairy and swine facilities and analyzed for concentrations of 17beta-estradiol (E2), estrone (E1), and 17alpha-estradiol by gas chromatography-mass spectroscopy and by enzyme linked immunosorbent assay (E2 only). Mass ratios of each estrogen to the macronutrients nitrogen, phosphorus, and potassium were also determined. Because manure application rates are typically macronutrient-based, estrogen to macronutrient ratios are proportional to areal mass application rates of estrogen to fields. Swine farrowing waste (from farrowing sows and piglets) had the highest ratios of E2 to macronutrients. Mean ratios in swine farrowing waste were roughly twice those in swine finishing waste (from growing male and nonpregnant female animals) and more than four times higher than those in dairy waste (from lactating cows in various stages of their reproductive cycles); these differences were statistically significant (alpha = 0.05). Estrone followed a similar trend. In contrast, ratios of 17alpha-estradiol to macronutrients were highest in dairy operations. These results can be used to better predict estrogen loading rates on fields receiving swine and dairy wastes.     

Chemopreventive Potential of Wild Lowbush Blueberry Fruits in Multiple Stages of Carcinogenesis

ABSTRACT: Wild lowbush blueberry fruit extract was fractionated using vacuum chromatography and analyzed for chemopreventive potential using bioassays that test the ability of compounds to inhibit the initiation, promotion, and progression stages of carcinogenesis. A fraction containing phytosterols was active against the initiation stage (quinone reductase assay). However, more polar compounds were inhibitors of later stages of carcinogenesis; a fraction containing flavan-3-ols and fractions containing mainly anthocyanins, phenolic acids, flavan-3-ols, and some proanthocyanidin dimers demonstrated activity against the promotion stage (cyclooxygenase and ornithine decarboxylase assays, respectively), and a proanthocyanidin-rich fraction demonstrated antiproliferation activity (inhibition of cancerous murine hepatocyte proliferation is associated with the progression stage). These results indicate that lowbush blueberries contain a range of compounds that have bioactivity against multiple stages of carcinogenesis, and different types of phenolic compounds are active at different stages.     

Topographic organization of connections between the hypothalamus and prefrontal cortex in the rhesus monkey

Prefrontal cortices have been implicated in autonomic function, but their role in this activity is not well understood. Orbital and medial prefrontal cortices receive input from cortical and subcortical structures associated with emotions. Thus, the prefrontal cortex may be an essential link for autonomic responses driven by emotions. Classic studies have demonstrated the existence of projections between prefrontal cortex and the hypothalamus, a central autonomic structure, but the topographic organization of these connections in the monkey has not been clearly established. We investigated the organization of bidirectional connections between these areas in the rhesus monkey by using tracer injections in orbital, medial, and lateral prefrontal areas. All prefrontal areas investigated received projections from the hypothalamus, originating mainly in the posterior hypothalamus. Differences in the topography of hypothalamic projection neurons were related to both the location and type of the target cortical area. Injections in lateral eulaminate prefrontal areas primarily labeled neurons in the posterior hypothalamus that were equally distributed in the lateral and medial hypothalamus. In contrast, injections in orbitofrontal and medial limbic cortices labeled neurons in the anterior and tuberal regions of the hypothalamus and in the posterior region. Projection neurons targeting orbital limbic cortices were more prevalent in the lateral part of the hypothalamus, whereas those targeting medial limbic cortices were more prevalent in the medial hypothalamus. In comparison to the ascending projections, descending projections from prefrontal cortex to the hypothalamus were highly specific, originating mostly from orbital and medial prefrontal cortices. The ascending and descending connections overlapped in the hypothalamus in areas that have autonomic functions. These results suggest that specific orbitofrontal and medial prefrontal areas exert a direct influence on the hypothalamus and may be important for the autonomic responses evoked by complex emotional situations.     

Recycling of L-citrulline to sustain nitric oxide-dependent enteric neurotransmission

Neurons that synthesize nitric oxide from arginine produce stoichiometric amounts of citrulline. We investigated whether nitric oxide-releasing enteric neurons have the capacity to recycle citrulline to arginine and thereby sustain nitrergic neurotransmission. Argininosuccinate synthetase-like immunoreactivity and argininosuccinate lyase-like immunoreactivity, enzymes capable of citrulline to arginine conversion, were both localized in discrete populations of myenteric and submucosal neurons in the canine proximal colon. Argininosuccinate synthetase-like immunoreactivity and argininosuccinate lyase-like immunoreactivity co-localized with neuronal beta-nicotinamide adenine dinucleotide phosphate diaphorase staining, a marker for nitric oxide synthase. The functional significance of argininosuccinate synthetase-like immunoreactivity and argininosuccinate lyase-like immunoreactivity was shown by testing the effects of exogenous citrulline on responses to enteric inhibitory nerve stimulation, which were assessed by measuring contractions, inhibitory junction potentials and electrical slow waves. As shown previously, arginine analogues (L-nitroarginine methyl ester or L-nitroarginine; 100 microM) inhibited nitric oxide-dependent responses, and excess L-arginine restored inhibitory responses. Citrulline alone (0.1-2 mM) had no effect on nitrergic transmission under control conditions, but in the presence of L-nitroarginine methyl ester or L-nitroarginine, citrulline (0.1-2 mM) restored nitrergic transmission in a concentration-dependent manner. Other neutral amino acids (L-serine, L-leucine) did not mimic the effects of citrulline. Taken together, these data suggest that enteric nitrergic neurons have the enzymatic apparatus and functional capability of recycling citrulline to arginine.     

An effect of Ca2+ on the Intrinsic Cl(-)-conductance of rat kidney cortex brush border membrane vesicles

Monoclonal murine anti-pesticide antibodies were produced by in vitro immunisation (IVI) of cultured splenocytes with the pesticides sulcofuron and flucofuron. The majority of both anti-flucofuron and anti-sulcofuron antibodies obtained were of the IgM isotype, rather than IgG. When used in an indirect enzyme-linked immunosorbent assay (ELISA), the antibodies bound to plate coating antigens which incorporated haptens that mimicked moieties present within the immunising pesticide. The antibodies exhibited a high degree of specificity, with the degree of cross-reactivity related to the structural similarity between the hapten present in the plate coating antigen and the moieties present within the immunising pesticide. These results indicated that antibodies specific to both sulcofuron and flucofuron had been produced by IVI. Synthesis of both hapten analogues and immunogens as required for methods based on in vivo immunisation was avoided, whilst antibody production was also comparatively more rapid than traditional methods and minimised animal discomfort.     

Contractile responses and structure of small bronchi isolated from rats after 20 months' exposure to ozone

Short-term exposure to high concentrations of ozone has been shown to increase airway responsiveness in normal humans and in all laboratory animal species studied to date. While our knowledge concerning the pulmonary effects of single exposures to ozone has increased rapidly over recent years, the effects of repeated exposures are less understood. The goal of the present study was to determine whether airway responsiveness is increased after near-lifetime exposure to ozone. Airway segments representing approximately eighth generation airways were isolated from Fischer 344 rats of both genders that had been exposed for 6 hr per day, 5 days per week for 20 months to 0, 0.12, 0.5, or 1.0 parts per million (ppm) ozone. Circumferential tension development was measured in isolated airways in response to bethanechol, acetylcholine, and electrical field stimulation. Responsiveness of the airways to the contractile stimuli was described by the effective dose or frequency that elicited half-maximum contraction (ED50) and the maximum response. Since ozone exposure is associated with remodeling of peripheral airways, smooth muscle area was determined and tension responses were normalized to the area measurements. Before normalization of tension data to smooth muscle area, neither the ED50 nor maximum response of small bronchi to the contractile stimuli was altered after chronic ozone exposure. Smooth muscle area was greater in airways isolated from animals that had been exposed to 0.5 ppm ozone. After accounting for smooth muscle area, maximum responses of the small bronchi isolated from male rats were significantly reduced after 0.12 and 0.5 ppm ozone. Although not significant statistically, a similar trend was observed in airways isolated from female rats. These results suggest that the increase in airway responsiveness associated with acute ozone exposure does not persist during near-lifetime exposure. Although the mechanism responsible for the adaptation to the effects of O3 on airway responsiveness is unknown, the results indicate that smooth muscle cell function was compromised by the chronic exposure. The mechanism(s) responsible for mediating this effect and the relevance of these results to humans remains to be determined.     

Solution structure of the donor site of a trans-splicing RNA

The CYP51 gene encoding eburicol 14 alpha-demethylase (P450(14DM)) was cloned from a genomic library of the filamentous fungal plant pathogen Penicillium italicum, by heterologous hybridisation with the corresponding gene encoding lanosterol 14 alpha-demethylase from the yeast Candida tropicalis. The nucleotide sequence of a 1739-bp genomic fragment and the corresponding cDNA clone comprises an open reading frame (ORF) of 1545 bp, encoding a protein of 515 amino acids with a predicted molecular mass of 57.3 kDa. The ORF is interrupted by three introns of 60, 72 and 62 bp. The C-terminal part of the protein includes a characteristic haem-binding domain, HR2, common to all P450 genes. The deduced P. italicum P450(14DM) protein and the P450(14DM) proteins from Candida albicans, C. tropicalis and Saccharomyces cerevisiae share 47.2, 47.0 and 45.8% amino acid sequence identity. Therefore, the cloned gene is classified as a member of the CYP51 family. Multiple copies of a genomic DNA fragment of Pl italicum containing the cloned P450 gene were introduced into Aspergillus niger by transformation. Transformants were significantly less sensitive to fungicides which inhibit P450(14DM) activity, indicating that the cloned gene encodes a functional eburicol 14 alpha-demethylase.     

Arousal of negative emotions and symptom-specific reactivity in chronic low back pain patients.

Anger may have greater effects on chronic pain severity than other negative emotions and may do so by increasing muscle tension near the site of injury (symptom-specific reactivity). For patients with chronic low back pain (CLBP), relevant muscles are lower paraspinals (LP). Ninety-four CLBP patients and 79 controls underwent anger and sadness recall interviews. EMG and cardiovascular activity were recorded. Patients exhibited greater LP tension increases during anger and slower recovery than controls. Only patients showed greater LP reactivity during anger than sadness. For both groups, trapezius reactivity during anger and sadness did not differ. LP reactivity to anger correlated with everyday pain severity for patients. Anger-induced symptom-specific LP reactivity may be linked to chronic pain aggravation among CLBP patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)