Investigations into the utility of high-surface area silica pellets as potential solid-phase synthesis supports

Grace-Davidson silica pellets (SMR-057-015) are found to be optimal for surface grafting of (RO)₃Si(CH₂)₃FG reagents. While loadings of up to 2.1 mmol g⁻¹ can be attained (ca. 0.05 mmol per pellet) access of further reagents to the graft sites is problematic above loadings of 0.8 mmol g⁻¹. ¹³C CPMAS NMR studies may be carried out on individual pellets (using natural abundance substrates) and the resulting spectra are diagnostic in identifying successful subsequent coupling reactions.     

Separation of post-translational modifications in monoclonal antibodies by exploiting subtle conformational changes under mildly acidic conditions

Chromatographic separation plays a key role in the identification, quantification, and characterization of protein variants. Here we describe separation of species containing two post-translational modifications (glycosylation and methionine oxidation) in the Fc fragment of a monoclonal antibody. The method is based on cation-exchange chromatography under mildly acidic conditions that destabilize mainly the CH2 domain. Our data suggest that the separation is not mediated by the chemical modification itself, but rather by subtle structural changes induced by the chemical modification in the domain-decoupled conformation that monoclonal antibodies adopt around pH 4. Compared to other procedures already described in the literature, this method demonstrates an improved separation and allows purification of species in the native fold for additional functional characterization. This approach of separation under conditions where the protein assumes an alternative conformation could find a more general utility for the separation of chemical modifications in proteins.     

The effectiveness of the organosolv process in wheat straw delignification optimizing temperature and time reaction

Cellulose - The present study investigates the organosolv treatment of wheat straw, for the optimization of cellulose delignification, which will serve as raw material for the paper industry. The...     

Correlation of Phosphorus Adsorption with Chemical Properties of Aluminum-Based Drinking Water Treatment Residuals Collected from Various Parts of the United States

Over the past several decades, the value of drinking water treatment residuals (WTRs), a byproduct of the coagulation process during water purification, has been recognized in various environmental applications, including sustainable remediation of phosphorus (P)-enriched soils. Aluminum-based WTRs (Al-WTRs) are suitable adsorbent materials for P, which can be obtained and processed inexpensively. However, given their heterogeneous nature, it is essential to identify an easily analyzable chemical property that can predict the capability of Al-WTRs to bind P before soil amendment. To address this issue, thirteen Al-WTRs were collected from various geographical locations around the United States. The non-hazardous nature of the Al-WTRs was ascertained first. Then, their P adsorption capacities were determined, and the chemical properties likely to influence their adsorption capacities were examined. Statistical models were built to identify a single property to best predict the P adsorption capacity of the Al-WTRs. Results show that all investigated Al-WTRs are safe for environmental applications, and oxalate-extractable aluminum is a significant indicator of the P adsorption capacity of Al-WTRs (p-value = 0.0002, R² = 0.7). This study is the first to report a simple chemical test that can be easily applied to predict the efficacy of Al-WTRs in binding P before their broadscale land application.     

Metallo-Drugs in Cancer Therapy: Past,Present and Future

Cancer treatments which include conventional chemotherapy have not proven very successful in curing human malignancies. The failures of these treatment modalities include inherent resistance, systemic toxicity and severe side effects. Out of 50% patients administrated to chemotherapy, only 5% survive. For these reasons, the identification of new drug designs and therapeutic strategies that could target cancer cells while leaving normal cells unaffected still continues to be a challenge. Despite advances that have led to the development of new therapies, treatment options are still limited for many types of cancers. This review provides an overview of platinum, copper and ruthenium metal based anticancer drugs in clinical trials and in vitro/in vivo studies. Presumably, copper and ruthenium complexes have greater potential than Pt(II) complexes, showing reduced toxicity, a new mechanism of action, a different spectrum of activity and the possibility of non-cross-resistance. We focus the discussion towards past, present and future aspects.     

Enantioselective synthesis of tetrafluorinated glucose and galactose

Polyfluorinated carbohydrates have emerged as interesting probes to investigate "polar hydrophobicity" effect(s) in protein-carbohydrate interactions. A convenient enantioselective synthesis of tetrafluorinated analogues of two of the most important monosaccharides, D-glucose and D-galactose, is reported, as well as our first results regarding the glycosylation of these sugar analogues.     

Characterization of the inhibition of enveloped virus infectivity by the cationic acrylate polymer eudragit E100

The antiviral effects of the cationic acrylate polymer E100 on a panel of lipid-enveloped viruses and the interactions involved are studied. The treatment of several common viruses with E100 induced a dose-dependent inhibition of the infectivity of viruses below the detection limit of the assays employed. Similarly, the treatment of human sera infected with HIV or HCV reduced virus RNA plasma levels to undetectable values. This implies that Eudragit E100 can interact with enveloped viruses, even in the presence of proteins, through a mechanism that is not reversed by titration of the positively charged groups of the polymer, opening the possibility to remove viral particles with the polymer as it is eliminated.     

Generating complex ontology instances from documents

This paper presents a novel Information Extraction system able to generate complex instances from free text available on the Web. The approach is based on a non-monotonical processing over ontologies, and makes use of entity recognizers and disambiguators in order to adequately extract and combine instances and their relations. Experiments conducted over the archaeology research domain provide encouraging results in both efficiency and efficacy and suggest that the tool is suitable for its application on other similar Semantic Web resources.     

Gallic esters of 4,5-dinitrocatechol as potential building blocks for thermotropic liquid crystals

A series of unsubstituted and 1,4-disubstituted gallic catecholates 1, 6 and 7 as possible candidates for wedge-shaped mesogens were prepared starting from the respective benzene derivatives 2a-c and gallic esters 5a-h. The mesomorphic properties were investigated by DSC. However, only the 4,5-dinitro derivatives 1d,f-h with C₈H₁₇ and C₁₀H₂₁ to C₁₂H₂₅ alkyl side chains displayed mesophases, as evaluated by fluidity and optical anisotropy.