Carboxylmethyl chitosan-graft-poly(γ-benzyl-l-glutamate) glycopeptides: Synthesis and particle formation as encapsulants

Amphiphilic glycopeptides, carboxylmethyl chitosan-graft-poly(γ-benzyl-l-glutamate) (m-Chi-g-PBLG), were synthesized through ring-opening polymerization of γ-benzyl-l-glutamate N-carboxyanhydride (NCA) using short chained m-Chi as the macroinitiator and employed to form vesicles in aqueous solution. The elemental and NMR analyses revealed that the polymerization degree (DP) of grafted PBLG could be tuned by varying the feed ratio of NCA to m-Chi. The conformation of the grafted PBLG chains transformed from β-sheet to α-helix was correlated with the PBLG chain length. The m-Chi-g-PBLG vesicles can be prepared using double emulsion method and their sizes can be adjusted between 140 and 250 nm. The encapsulation of a model compound, FITC-dextran, in the vesicles revealed their potential applications as encapsulants or carriers. The in vitro release data revealed that a sustained release of FITC-dextran for a time period over two weeks can be achieved.     

Mesoporous drug carrier systems for enhanced delivery rate of poorly water-soluble drug: nimodipine

Journal of Porous Materials - Two mesoporous silica materials: MCM-41 and SBA-15 were applied as potential nanocarriers for poorly soluble drug—nimodipine. Drug incorporation was performed...     

New Insights to Clathrin and Adaptor Protein 2 for the Design and Development of Therapeutic Strategies

The Amyloid Precursor Protein (APP) has been extensively studied for its role as the precursor of the β-amyloid protein (Aβ) in Alzheimer’s disease (AD). However, our understanding of the normal function of APP is still patchy. Emerging evidence indicates that a dysfunction in APP trafficking and degradation can be responsible for neuronal deficits and progressive degeneration in humans. We recently reported that the Y₆₈₂ mutation in the ₆₈₂YENPTY₆₈₇ domain of APP affects its binding to specific adaptor proteins and leads to its anomalous trafficking, to defects in the autophagy machinery and to neuronal degeneration. In order to identify adaptors that influence APP function, we performed pull-down experiments followed by quantitative mass spectrometry (MS) on hippocampal tissue extracts of three month-old mice incubated with either the ₆₈₂YENPTY₆₈₇ peptide, its mutated form, ₆₈₂GENPTY₆₈₇ or its phosphorylated form, ₆₈₂pYENPTY₆₈₇. Our experiments resulted in the identification of two proteins involved in APP internalization and trafficking: Clathrin heavy chain (hc) and its Adaptor Protein 2 (AP-2). Overall our results consolidate and refine the importance of Y₆₈₂ in APP normal functions from an animal model of premature aging and dementia. Additionally, they open the perspective to consider Clathrin hc and AP-2 as potential targets for the design and development of new therapeutic strategies.     

Sequence annotation of nuclear receptor ligand-binding domains by automated homology modeling

The quality of three-dimensional homology models derived fromprotein sequences provides an independent measure of the suitabilityof a protein sequence for a certain fold. We have used automatedhomology modeling and model assessment tools to identify putativenuclear hormone receptor ligand-binding domains in the genomeof Caenorhabditis elegans. Our results indicate that the availabilityof multiple crystal structures is crucial to obtaining usefulmodels in this receptor family. The majority of annotated mammaliannuclear hormone receptors could be assigned to a ligand-bindingdomain fold by using the best model derived from any of fourtemplate structures. This strategy also assigned the ligand-bindingdomain fold to a number of C.elegans sequences without priorannotation. Interestingly, the retinoic acid receptor crystalstructure contributed most to the number of sequences that couldbe assigned to a ligand-binding domain fold. Several causesfor this can be suggested, including the high quality of thisprotein structure in terms of our assessment tools, similaritybetween the biological function or ligand of this receptor andthe modeled genes and gene duplication in C.elegans.     

A non-symmetric discretization formula for the numerical solution of elasto-hydrodynamic lubrication circular contact problem

The control volume method has been employed to obtain an appropriate discretization scheme for the numerical solution of the two-dimensional Reynolds equation. A non-symmetric discretization formula has been developed and incorporated into the author's computer program. The lubricant film thickness distribution for a typical configuration of the EHL circular contact has been solved as a benchmark. Results are presented. Convergence behavior is investigated using different density of grids for computations. A comparison with the finite difference-based formula is presented. Dependence of results on the grid density is reduced in comparison with results obtained using the finite difference formula. On conclusion, an additional discussion on the discretization of the Reynolds equation is presented and further recommendations are given.     

Anomalous weak values via a single photon detection

Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre-and...     

Lambda: A Cold War Polish line encryptor and the networks it served

The article elaborates the Lambda V.24/V.28 line encryptor and secure digital communications lines used by the Cold War Polish intelligence agencies.     

InGaAs-InP P-I (MQW)-N surface-normal electroabsorption modulatorsexhibiting better than 8:1 contrast ratio for 1.55-μm applicationsgrown by gas-source MBE

We report growth of In_0.53Ga_0.47 As-InP multiple quantum well (MQW) modulators operating at 1.55 μm for fiber-to-the-home applications. By employing a 200-period InGaAs-InP MQW stack in the intrinsic region of a p-i-n structure and working in reflection, we have been able to realize surface-normal modulator devices that exhibit better than an 8:1 contrast ratio. This is the highest contrast ratio reported to date for this type of device working at this wavelength     

LiF enhanced nucleation of the low temperature microcrystalline silicon prepared by plasma enhanced chemical vapour deposition

A 15-nm lithium fluoride (LiF) thin film evaporated on glass substrate is shown to enhance the nucleation of microcrystalline Si grown by plasma enhanced chemical vapour deposition at the amorphous/microcrystalline boundary conditions. The effect is more pronounced at low substrate temperatures, nucleation density being 10 times higher at ∼ 80 °C. The effect is ascribed to the ionic chemical nature of LiF, the low work function material used in organic electronic devices, and we propose its use for micro patterning crystalline Si regions in otherwise amorphous Si film.