Measurements of single chain form factors by small-angle neutron scattering from polystyrene blends containing high concentrations of labelled molecules

A series of small angle neutron scattering measurements on blends of normal polystyrene (PSH) and labelled (deuterated) polystyrene (PSD) have been made with concentrations of PSD from 5 to 50 mol %. It is shown that the single chain form factor of the polymer in bulk can be obtained from a single concentration measurement for any concentration of labelled molecules, providing the molecular weights of the parent and labelled molecules are the same and the molecular weight distributions are narrow.     

Fluorescene in situ hybridization establishes homology between human and silvered leaf monkey chromosomes, reveals reciprocal translocations between chromosomes homologous to human Y/5, 1/9, and 6/16, and delineates an X1X2Y1Y2/X1X1X2X2 sex-chromosome system

The adhesive core of the desmosome is composed of cadherin-like glycoproteins of 2 families, desmocollins and desmogleins. The desmosomal cadherins show distinct patterns of expression in adult epidermis, and we have suggested that the desmocollins have a functional role in regulating the differentiation and/or morphogenesis of that epithelium (North et al. [1996] Proc. Natl. Acad. Sci. USA 93:7701-7705.). To examine this hypothesis, we cloned murine desmocollins and examined the induction patterns of desmocollins 1 and 3 during skin and skin appendage development. Desmocollins 3 and 1 were first expressed in epidermis in highly regional patterns at embryonic days 13.0 and 13.5, respectively, and both were up-regulated in general body epidermis at day 14.5. At this stage, epidermis is undifferentiated and the desmocollins showed an unexpected expression pattern. However, by day 18.5 when skin had undergone terminal differentiation, desmocollin 1 and 3 expression resembled that found in the adult. Thus, the establishment of the adult pattern of desmocollin expression corresponds to the adult pattern of epidermal stratification. We suggest that it is the ratio of desmocollin 1 to desmocollin 3 expression at different levels in the epidermis that is fundamental in establishing this pattern of differentiation.     

Developing independence in a life transition: Investing the self in the concerns of the day.

Developing independence involves mastering the tasks of each life transition. Those more anxious about developing independence will become more invested in the normative tasks of each transition, and this anxiety will spread to the domain represented by these tasks. In Study 1, Honors College students expressed their anxiety about developing independence in academic performance at the beginning of college when this was the normative task and in social relationships after college when this was the normative task. This anxiety could be distinguished from other (e.g., academic) anxiety. In Study 2, sorority women expressed anxiety about developing independence in family and sorority relationships. Data demonstrate the social construction of anxiety and the dynamics of personality change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

X-ray Fluorescence Uptake Measurement of Functionalized Gold Nanoparticles in Tumor Cell Microsamples

Quantitative cellular in vitro nanoparticle uptake measurements are possible with a large number of different techniques, however, all have their respective restrictions. Here, we demonstrate the application of synchrotron-based X-ray fluorescence imaging (XFI) on prostate tumor cells, which have internalized differently functionalized gold nanoparticles. Total nanoparticle uptake on the order of a few hundred picograms could be conveniently observed with microsamples consisting of only a few hundreds of cells. A comparison with mass spectroscopy quantification is provided, experimental results are both supported and sensitivity limits of this XFI approach extrapolated by Monte-Carlo simulations, yielding a minimum detectable nanoparticle mass of just 5 pg. This study demonstrates the high sensitivity level of XFI, allowing non-destructive uptake measurements with very small microsamples within just seconds of irradiation time.     

Structural Investigation and Molecular Modeling Studies of Strobilurin-Based Fungicides Active against the Rice Blast Pathogen Pyricularia oryzae

The increasing emergence of fungicide-resistant pathogens requires urgent solutions for crop disease management. Here, we describe a structural investigation of new fungicides obtained by combining strobilurin and succinate dehydrogenase inhibitor pharmacophores. We identified compounds endowed with very good activity against wild-type Pyricularia oryzae, combined in some cases with promising activity against strobilurin-resistant strains. The first three-dimensional model of P. oryzae cytochrome bc1 complex containing azoxystrobin as a ligand was developed. The model was validated with a set of commercially available strobilurins, and it well explains both the resistance mechanism to strobilurins mediated by the mutation G143A and the activity of metyltetraprole against strobilurin-resistant strains. The obtained results shed light on the key recognition determinants of strobilurin-like derivatives in the cytochrome bc1 active site and will guide the further rational design of new fungicides able to overcome resistance caused by G143A mutation in the rice blast pathogen.     

Liver Lipids of Patients with Hepatitis B and C and Associated Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) still remains a difficult to cure malignancy. In recent years, the focus has shifted to lipid metabolism for the treatment of HCC. Very little is known about hepatitis B virus (HBV) and C virus (HCV)-related hepatic lipid disturbances in non-malignant and cancer tissues. The present study showed that triacylglycerol and cholesterol concentrations were similar in tumor adjacent HBV and HCV liver, and were not induced in the HCC tissues. Higher levels of free cholesterol, polyunsaturated phospholipids and diacylglycerol species were noted in non-tumorous HBV compared to HCV liver. Moreover, polyunsaturated phospholipids and diacylglycerols, and ceramides declined in tumors of HBV infected patients. All of these lipids remained unchanged in HCV-related HCC. In HCV tumors, polyunsaturated phosphatidylinositol levels were even induced. There were no associations of these lipid classes in non-tumor tissues with hepatic inflammation and fibrosis scores. Moreover, these lipids did not correlate with tumor grade or T-stage in HCC tissues. Lipid reprogramming of the three analysed HBV/HCV related tumors mostly resembled HBV-HCC. Indeed, lipid composition of non-tumorous HCV tissue, HCV tumors, HBV tumors and HBV/HCV tumors was highly similar. The tumor suppressor protein p53 regulates lipid metabolism. The p53 and p53S392 protein levels were induced in the tumors of HBV, HCV and double infected patients, and this was significant in HBV infection. Negative correlation of tumor p53 protein with free cholesterol indicates a role of p53 in cholesterol metabolism. In summary, the current study suggests that therapeutic strategies to target lipid metabolism in chronic viral hepatitis and associated cancers have to consider disease etiology.     

Thermal evaluation of the use of porous ceramic plates on ventilated façades—part II: Thermal behavior

The effects of porous ceramic plates on the thermal behavior of ventilated façades were evaluated, and the results are presented herein. Thermal behavior in a ventilated façade of specimens containing 40 wt% of lime mud and a firing temperature of 1100°C was evaluated and compared with a commercial porcelain ceramic tile, which was the reference material. An experimental apparatus was designed to evaluate the thermal performance of the studied ventilated façades. The results revealed that the ventilated façade composed of the studied porous ceramic tiles produced a greater reduction in temperature between the external environmental and the interior of a box representing a building (ΔT5) of 65.7°C, compared with the façade composed of the commercial porcelain ceramic tiles (ΔT5 = 56.0°C) and even the traditional façade (ΔT5 = 49.1°C). Thus, porous ceramic tiles based on byproducts are promising candidates for ventilated façade systems.     

Fabrication of hybrid proton-exchange membranes using a brandnew high temperature ionic liquid as charge transporting and clay modifier

The search for more compatibility between ionic liquids (ILs) and polymer matrices in proton-exchange membrane fuel cells (PEMFCs) is one of the ways in which IL leaking from proton-exchange membranes could be minimized. In this work, it is presented the synthesis of an aromatic high temperature ionic liquid (HTIL), which, incorporated into an aromatic matrix such as sulfonated polyether ether ketone (sPEEK), is expected to diminish the IL leaking that normally affects PEMFC. Phenylethylammonium trifluoromethane sulfonate (PhetaTfO) was successfully synthesized and characterized. Its melting point of 88°C makes it to classify as a HTIL and it was employed as modifier of natural Montmorillonite, forming the phenylethylammonium intercalated montmorillonite (MmtPheta) and thus, ternary membranes containing PhetaTfO, MmtPheta, and sPEEK were prepared and characterized. Immersion tests demonstrated a higher compatibility of PhetaTfO with matrix when compared to the reference DemaTfO, which was reflected in up to 30% lower IL loss by the synthesized IL than the DemaTfO; X-rays diffraction (XRD) patterns demonstrated that the modified clay was properly dispersed inside the membranes, while dynamic mechanical analyses (DMA) results indicated a strong plasticizer effect along the increase of PhetaTfO content inside the membrane, while at the same time, the conductivity increased in an exponential manner, which permitted to identify an empiric exponential equation to evaluate the effect of concentration on ionic conductivity. The maximum conductivity obtained at IL concentrations of around 38 wt% was 0.2 mS/cm. It could expect high ionic conductivities of 10 mS/cm when the concentration of this IL is 60%; nevertheless, in order to achieve that, crosslinking treatments should be done to give the membranes enough mechanical resistance.