Perfluoroaryl Bicyclic Cell‐Penetrating Peptides for Delivery of Antisense Oligonucleotides

Exon‐skipping antisense oligonucleotides are effective treatments for genetic diseases, yet exon‐skipping activity requires that these macromolecules reach the nucleus. While cell‐penetrating peptides can improve delivery, proteolytic instability often limits efficacy. It is hypothesized that the bicyclization of arginine‐rich peptides would improve their stability and their ability to deliver oligonucleotides into the nucleus. Two methods were introduced for the synthesis of arginine‐rich bicyclic peptides using cysteine perfluoroarylation chemistry. Then, the bicyclic peptides were covalently linked to a phosphorodiamidate morpholino oligonucleotide (PMO) and assayed for exon skipping activity. The perfluoroaryl cyclic and bicyclic peptides improved PMO activity roughly 14‐fold over the unconjugated PMO. The bicyclic peptides exhibited increased proteolytic stability relative to the monocycle, demonstrating that perfluoroaryl bicyclic peptides are potent and stable delivery agents.     

Styrene copolymers as pollutant adsorbents : Safe sampling volume determination

The determination of safe sampling volumes of benzene and acetone on air samplers filled with Porapak Q, Chromosorb 101, 102 and 103 is described. Two direct methods are employed; one method is based on frontal chromatography, while the second one is a concentration method followed by thermal desorption. The results are compared to those determined by the indirect pulse chromatographic method. The safe sampling volumes determined by the direct methods were in accordance. The indirect method gives slightly different values; however, this procedure is carried out at "infinite dilution". The effect of the pollutant concentration on the safe sampling volumes was also examined. The values decrease with increasing pollutant concentration.     

Brownmillerites CaFeO2.5 and SrFeO2.5 as Catalyst Support for CO Oxidation

The support material can play an important role in oxidation catalysis, notably for CO oxidation. Here, we study two materials of the Brownmillerite family, CaFeO_2.5 and SrFeO_2.5, as one example of a stoichiometric phase (CaFeO_2.5, CFO) and one existing in different modifications (SrFeO_2.75, SrFeO_2.875 and SrFeO₃, SFO). The two materials are synthesized using two synthesis methods, one bottom-up approach via a complexation route and one top-down method (electric arc fusion), allowing to study the impact of the specific surface area on the oxygen mobility and catalytic performance. CO oxidation on ¹⁸O-exchanged materials shows that oxygen from SFO participates in the reaction as soon as the reaction starts, while for CFO, this onset takes place 185 °C after reaction onset. This indicates that the structure of the support material has an impact on the catalytic performance. We report here on significant differences in the catalytic activity linked to long-term stability of CFO and SFO, which is an important parameter not only for possible applications, but equally to better understand the mechanism of the catalytic activity itself.     

Bounds for the Kirchhoff index via majorization techniques

Using a majorization technique that identifies the maximal and minimal vectors of a variety of subsets of ${\mathbb{R}^{n}}$ , we find upper and lower bounds for the Kirchhoff index K(G) of an arbitrary simple connected graph G that improve those existing in the literature. Specifically we show that $$K(G) \geq \frac{n}{d_{1}} \left[ \frac{1}{1+\frac{\sigma}{\sqrt{n-1}}} + \frac{(n-2)^{2}}{n-1-\frac{\sigma}{\sqrt{n-1}}}\right] ,$$ where d ₁ is the largest degree among all vertices in G, $$\sigma ^{2} = \frac{2}{n} \sum_{(i, j) \in E} \frac{1}{d_{i}d_{j}} = \left( \frac{2}{n}\right) R_{-1}(G),$$ and R _?1(G) is the general Randi? index of G for ${\alpha =-1}$ . Also we show that $$K(G) \leq \frac{n}{d_{n}}\left( \frac{n-k-2}{1-\lambda _{2}}+\frac{k}{2}+\frac{1}{\theta}\right) ,$$ where d _n is the smallest degree, ${\lambda _{2}}$ is the second eigenvalue of the transition probability of the random walk on G, $$k = \left \lfloor \frac{\lambda _{2} \left( n-1\right) +1}{\lambda _{2}+1}\right\rfloor {\rm and}\quad\theta = \lambda _{2} \left( n-k-2\right) -k+2.$$      

Multi-functional coating of cellulose nanocrystals for flexible packaging applications

In this paper, we systematically address the performance of cellulose nanocrystals (CNs) coated flexible food packaging films. Firstly, the morphology of CNs from cotton linters and homogeneity of its coating on different substrates were characterized by transmission electronic microscopy and atomic force microscopy. Then, the 1.5 μm thick CNs coating on polyethylene terephthalate (PET), oriented polypropylene, oriented polyamide (OPA), and cellophane films were characterized for their mechanical, optical, anti-fog, and barrier properties. CNs coating reduces the coefficient of friction while maintaining high transparency (~90 %) and low haze (3–4 %) values, and shows excellent anti-fog properties and remarkable oxygen barrier (oxygen permeability coefficient of CNs coating, P’O₂, 0.003 cm³ μm m^?2 24 h^?1 kPa^?1). In addition, the Gelbo flex test combined with oxygen permeance (PO₂) measurements and optical microscopy are firstly reported for evaluating the durability of coatings, revealing that the CNs coated PET and OPA provide the best performance among the investigated coated films. CNs are therefore considered to be a promising multi-functional coating for flexible food packaging.     

Cu(II) complexes with heterocyclic substituted thiosemicarbazones: the case of 5-formyluracil. Synthesis,characterization, x-ray structures,DNA interaction studies,and biological activity

Two new 5-formyluracil thiosemicarbazone (H(3)ut) derivatives, Me-H(3)ut (1) and Me(2)-H(3)ut (2), were synthesized by reacting thiosemicarbazides, mono- and dimethylated on the aminic nitrogen, with 5-formyluracil and were subsequently characterized. These ligands, treated with copper chloride and nitrate, afforded three complexes: [Cu(Me-H(3)ut)Cl(2)].H(2)O (3), [Cu(Me(2)-H(3)ut)Cl(2)].H(2)O (4), and [Cu(Me-H(3)ut)(NO(3))(OH(2))(2)]NO(3) (5). The crystal structures of these complexes have been determined by single-crystal X-ray diffraction. In 3 and 4, a similar pentacoordination is present; the copper atom is surrounded by the ligand SNO donor atoms and by two chloride ions. The structure of 5 consists of [Cu(Me-H(3)ut)(NO(3))(OH(2))(2)](+) cations and nitrate anions. The copper coordination (4 + 2) involves the SNO ligand atoms and a water oxygen in the basal plane; the apical positions are occupied by a second water oxygen and by an oxygen of a monodentate nitrate group. Two biochemical techniques, namely DNA titration in the UV-vis region and thermal denaturation, have been employed to probe the details of DNA binding of these compounds. Analysis of the results suggests that our compounds are able to interact with DNA by electrostatic and groove binding but not by intercalation. The compounds have been also tested in vitro on human leukemic cell line U937, but they are not able to inhibit significantly cell proliferation.     

Cell protection from Ca2+-overloading by bioactive molecules extracted from olive pomace

We are reporting in the present study that molecules extracted from olive pomace prevent cell death induced by Ca²⁺-overloading in different cell types. Exposure of cells to these molecules counteracts the Ca²⁺-induced cell damages by reducing the activation of the Ca²⁺-dependent protease calpain, acting possibly through the modification of the permeability to Ca²⁺ of the plasma membrane. The purification step by RP-HPLC suggests that effective compound(s), differing from the main biophenols known to be present in the olive pomace extract, could be responsible for this effect. Our observations suggest that bioactive molecules present in the olive pomace could be potential candidates for therapeutic applications in pathologies characterised by alterations of intracellular Ca²⁺ homeostasis.     

A one-pot direct regioselective iodination of Fischer-Borsche product using periodic acid in PEG-400

A metal-free and greener approach for the one-pot direct iodination and dehydrogenation of dihydrobenzo[a]carbazoles has been developed using periodic acid in polyethylene glycol-400 (PEG-400) under mild condition. This method has been proven to be tolerate to a broad range of functional groups, with good to excellent yields include metal-free inexpensive catalyst, easy work-up, benign reaction condition and high regioselectivity. The solvent has been successfully recycled up to 5 times without any loss of activity in an aqueous medium.     

A liquid chromatography–atmospheric pressure photoionization tandem mass spectrometric method for the determination of azaarenes in atmospheric particulate matter

The development, optimization and validation of a liquid chromatography–atmospheric pressure photoionization tandem mass spectrometric (LC–APPI/MS/MS) method for the determination of 15 azaarenes (4-azafluorene, benzo[h] and -[f]quinoline, phenanthridine, acridine, 1-azafluoranthene, 4-azapyrene, benz[a]- and -[c]acridine, -10-azabenzo[a]pyrene, 7,9- and 7,10-dimethylbenz[c]acridine, dibenz[a,j]-, -[c,h] and [a,i]acridine) in airborne particulate matter is described. Each compound was detected and quantified operating in multiple reaction monitoring mode. Extraction of azaarenes was achieved using accelerated solvent extraction (ASE) with dichlormethane/methanol (50/50, v/v). After extraction, no additional clean-up procedure like solid phase or liquid/liquid extraction was necessary. Limits of quantification (S/N × 10) ranged from 0.2 pg/μl to 1.4 pg/μl, matrix dependent recoveries were between 57% and 94%, with relative standard deviations from 8% to 17%. Applicability of the method was demonstrated analyzing 10 samples of particulate matter (PM_2.5) collected in winter 2008. In all samples dimethylbenz[c]acridines as well as dibenzacridines were below the limit of quantification, concentration of the remaining analytes were in the range from 0.002 ng/m³ to 0.356 ng/m³.     

Chlorella minutissima—A Promising Fuel Alga for Cultivation in Municipal Wastewaters

It is imperative to slash the cost of algal oil to less than $50 bbl^?1 for successful algal biofuel production. Use of municipal wastewater for algal cultivation could obviate the need for freshwater and the nutrients—N and P. It would also add CO₂ through bacterial activity. Chlorella minutissima Fott et Nova dominated the entire phycoflora year around and through each stage of the wastewater treatment at the oxidation pond system of Wazirabad (Delhi) in India. The ability to grow so profusely in such varied and contrasting situations made this alga unique. Besides pollution tolerance, it grew heterotrophically in dark under acidic conditions and as a mixotroph in presence of light over a range of organic C substrates. It could utilize both ammoniacal and nitrate nitrogen, survived anaerobicity, 5% NaCl and ?10 bar of osmotic stress. C. minutissima grew at pH 4–11 and raised the pH set initially by 1 to 3 units in 7.5 h. It showed gigantism and largely kept afloat in presence of utilizable organic carbon, while flocculated in mineral medium and on aging. The alga also possessed potential for biofuel production. The studied parameters indicate why C. minutissima was a potential biomass builder in municipal sewage and could be used to determine which other alga(e) may serve the purpose.