Programmed Death-Ligand 1 as a Regulator of Tumor Progression and Metastasis

Programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint has long been implicated in modeling antitumor immunity; PD-1/PD-L1 axis inhibitors exert their antitumor effects by relieving PD-L1-mediated suppression on tumor-infiltrating T lymphocytes. However, recent studies have unveiled a distinct, tumor-intrinsic, potential role for PD-L1. In this review, we focus on tumor-intrinsic PD-L1 signaling and delve into preclinical evidence linking PD-L1 protein expression with features of epithelial-to-mesenchymal transition program, cancer stemness and known oncogenic pathways. We further summarize data from studies supporting the prognostic significance of PD-L1 in different tumor types. We show that PD-L1 may indeed have oncogenic potential and act as a regulator of tumor progression and metastasis.     

Aryl diazonium functionalization of carbon nanohorns

Carbon nanohorns (CNHs) are a relatively new material within the family of elongated carbon nanostructures. A strategy for their solubilization is presented here. Aryl diazonium functionalization of CNHs has been achieved giving rise to soluble materials in common organic solvents as well as water. The modified CNHs have been characterized by complementary spectroscopic and microscopic means as well as thermal gravimetric analysis and dynamic light scattering measurements.     

Healthcare provider cultural competency: Development and initial validation of a patient report measure.

Objective: Health researchers have proposed that provider cultural competency may contribute to health disparities. Yet, this belief continues to lack empirical support, and this is due in part to measurement issues that have plagued the cultural competency construct. In the present research, we report on the development of a theoretically grounded, generally applicable, and patient report measure of provider cultural competency. Design: Samples of predominantly African American patients (N = 310) were recruited from three urban medical clinics to complete a survey about their relationship with their physician. Main Outcome Measures: We examined the factor structure, validity and other psychometric characteristics of a newly proposed patient report measure of provider cultural competency. Results: Psychometric analyses supported a tripartite model of cultural competency that was comprised of patient judgments of their physician's cultural knowledge, awareness, and skill. In addition, this result was replicated across multiple clinical contexts, while also demonstrating convergent and incremental validity when correlated with measures of trust, satisfaction and discrimination. Conclusion: This newly proposed measure addresses prior limitations in cultural competency measurement and may enhance future research by providing a standardized tool for use in multiple clinical and cultural contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimizing Radio Network Planning Evolution Towards Microcellular Systems

Wireless Personal Communications - Service demand in cellular radio networks is generally heterogeneous and non uniform, leading to asymmetrical topologies. This complexity along with the multiple...     

Fe(III)-humate complexes from Megalopolis peaty lignite: A novel eco-friendly fertilizer

Fe(III)-humate complexes were synthesized from Greek peaty lignite of the Megalopolis Basin. The preparation was carried out under mild and low-energy conditions producing a biodegradable, eco-friendly and effective material to substitute the synthetic chelates Fe-EDDHA, Fe-EDTA and Fe-DTPA. Due to both the existing expanded configuration of the humic substances (that make binding sites accessible to the metal ions) and the ionization of functional groups, alkaline environment facilitates the association between Fe(III) ions and the lignite-derived humic substances. UV-vis and IR spectra revealed coordination of the metal ions with the carboxylic and phenolic groups of the oxygen-rich humic substances. Fe(III)-humate complexes were proved stable in a wide pH range similar to Fe-EDDHA synthetic chelates. Furthermore, the presence of K⁺ and humic matter increases the agronomic value of this material establishing alternative applications for Megalopolis peaty lignite.     

Poly(lactide-co-glycolide)-methoxy-poly(ethylene glycol) nanoparticles: drug loading and release properties

In this work, the drug loading and in vitro release properties of PLGA-mPEG nanoparticles were studied. Three methyl-xanthine derivatives differing significantly in aqueous solubility, i.e., caffeine, theophylline, and theobromine, were employed as model drugs. Two different PLGA-mPEG copolymer compositions, namely PLGA(40)mPEG(5) and PLGA(136)mPEG(5), were included in the study. The nanoparticles were prepared by a double emulsion technique. The drug release properties of the nanoparticles in phosphate buffered saline (PBS) and in human plasma were determined. An increase of the drug proportion in the feed led to increased drug loading. The composition of the PLGA-mPEG copolymer (PLGA/mPEG molar ratio) did not appear to affect drug loading and encapsulation. Caffeine exhibited higher loading in the nanoparticles than theobromine and this exhibited a little higher loading than theophylline. Solid-state solubility of the drug in PLGA-mPEG did not affect drug loading. Drug loading and encapsulation in the PLGA-mPEG nanoparticles appeared to be governed by the partition coefficient of the drug between the organic phase and the external aqueous phase employed in nanoparticle preparation. Relatively low loading and encapsulation values were obtained, suggesting that the physical entrapment of drugs in PLGA-mPEG nanoparticles could only be an option in the development of formulations of potent drugs. Only the release of the least water-soluble theobromine was efficiently sustained by its entrapment in the nanoparticles, indicating that the physical entrapment of drugs provides the means for the development of controlled-release PLGA-mPEG nanoparticulate formulations only in the case of drugs with low aqueous solubility.     

Fast and Precise Method for Pb Isotope Ratio Determination in Complex Matrices using GC-MC-ICPMS: Application to Crude Oil, Kerogen, and Asphaltene Samples

A new method to determine Pb isotope ratio without ion-exchange-matrix separation is proposed. After acid digestion, Pb was ethylated to Et(4)Pb, separated from the digested solution (black shale, asphaltene, crude oil and kerogen) by extraction in isooctane, and then injected into a gas chromatograph coupled to a multicollector inductively coupled plasma mass spectrometer. Seven isotopes ((202)Hg, (203)Tl, (204)Pb, (205)Tl, (206)Pb, (207)Pb, (208)Pb) were monitored simultaneously with peak duration of 23 s. GC elution was operated under wet plasma conditions where a thallium standard solution was introduced to the mass spectrometer for mass bias correction. The total time of the procedure (sample preparation and analysis, after acid digestion) was reduced by a factor of 15 compared to conventional-continuous sample introduction. Data treatment was carried out using the linear regression slope method. Mass bias was corrected using the double correction method (first thallium normalization followed by classical bracketing). For the (208/206)Pb and (207/206)Pb ratios, precision (2RSD(EXT), n = 21) was 49 and 69 ppm, and the bias between experimental results and reference values was better than 0.0033 and 0.0007 ‰, when injecting 1.2 ng of ethylated Pb SRM NIST 981 solution. Results obtained by this method were validated by comparison with those obtained via conventional-continuous sample introduction. The applicability of this approach was demonstrated with the analysis of black shale, asphaltene, crude oil and kerogen samples.     

Boron determination in a multi element national water monitoring program: the absence of legal limits

Directive 98/83/EC concerning the drinking water quality and Directive 80/777/EC for Natural Mineral Water demand strict control and monitoring for the presence of metals. The State General Laboratory as the official control laboratory (Accredited by ISO 17025:2005) implements a national monitoring program in order to ensure that the drinking and natural mineral water quality satisfy the requirements of the respective Directives. The National Monitoring program covers mainly metals such as Pb, Cd, Cr, Ni, As, Se, Sb, Hg, Mn, Cu, Fe, Al and B in water supplied for human consumption either by distribution networks, vending machines, mobile water containers, ground water intended for human consumption as well as bottled water. The determination of metals in water by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) is a technique that successfully meets the requirements of the above Directives as it is a very powerful tool for the measurement of metals at very low concentrations with high accuracy and precision. The results obtained indicate that metal concentrations in drinking and bottled water examined were by far, below the acceptable legal limits and even below the relevant detection limits. However, in samples of bottled natural mineral water, high boron concentration were determined and risk assessment was performed due to the absence of relevant legal limits. The present paper demonstrates the steps undertaken by the General Water Analysis Laboratory of the SGL for the validated method used by ICP-MS in the determination of trace metals including boron in drinking and bottled water.