Biobased thermosets from the free‐radical copolymerization of conjugated linseed oil

New polymeric thermosets were prepared through the bulk free‐radical copolymerization of 100% conjugated linseed oil, acrylonitrile, and divinylbenzene. Under the appropriate reaction conditions and with the appropriate curing sequence, 61–96 wt % of the oil was incorporated into the crosslinked thermosets. The resulting yellow, transparent thermosets varied from being soft and flexible to being hard and brittle. Dynamic mechanical analysis and thermogravimetric analysis showed that these thermosets had good mechanical properties and thermal stability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 979–985, 2007     

Characteristic study of N07718 superalloy surface prepared by cold spray

For better performance in erosive–corrosive, wear and other extreme environmental conditions surface properties of metals and alloys are usually altered by different techniques. Amongst the various surface coating techniques cold spraying is a relatively new and less reported method. Coating formation at energy lower than the melting stage of materials brings novelty to this process. In this study surface of UNS No. - N07718 alloy is altered by cold spraying chromium-carbide (nickel-chromium) layer. The microstructure properties of this cold sprayed surface are observed by various characterization techniques and the results are used to study mechanism of coating layer formation by cold spray process. This newly developed cold sprayed surface is found to be eligible for further testing in wear and erosive-corrosive environmental conditions.     

Introducing Glycolinkers for the Functionalization of Cytotoxic Drugs and Applications in Antibody–Drug Conjugation Chemistry

Antibody–drug conjugates (ADCs) are promising alternatives to naked antibodies for selective drug‐delivery applications and treatment of diseases such as cancer. Construction of ADCs relies upon site‐selective, efficient and mild conjugation technologies. The choice of a chemical linker is especially important, as it affects the overall properties of the ADC. We envisioned that hydrophilic bifunctional chemical linkers based on carbohydrates would be a useful class of derivatization agents for the construction of linker–drug conjugates and ADCs. Herein we describe the synthesis of carbohydrate‐based derivatization agents, glycolinker–drug conjugates featuring the tubulin inhibitor monomethyl auristatin E and an ADC based on an anti‐EGFR antibody. In addition, an initial in vitro cytotoxicity evaluation of the individual components and the ADC is provided against EGFR‐positive cancer cells.     

Stable SOI micromachined electrostatic AC voltage reference

We have designed and manufactured a micromachined moving plate capacitor to be used as an AC voltage reference in electrical metrology. The reference is based on the characteristic AC current–voltage curve of the component having a maximum, the value of which ideally depends only on the geometry of the component and material properties of single crystalline silicon. The electrode surface stability is essential in this application and hence a new fabrication process has been developed to metallize both surfaces of an electrostatically actuated micromachined structure. The stability of the AC reference voltage at a frequency of 100 kHz and an RMS voltage value 6.4 V was measured to be ±60 ppm over 14 h.     

Fixation of distal femoral osteotomies with self-reinforced poly(L/DL)lactide 70 : 30/bioactive glass composite rods. An experimental study on rats

Self-reinforced poly(L/DL)lactide 70:30/bioactive glass [SR-P(L/DL)LA/bioactive glass] composite rods, 2 mm in diameter and 36 mm in length, were implanted into the dorsal subcutaneous tissue of 16 rats. Osteotomies of the distal femur were fixed with these rods (2 x 15 mm) in 64 other rats. The follow-up times varied from one week to one year. After sacrifice, three-point bending and shear tests, and molecular weight measurements were performed for subcutaneously placed rods. Radiological, histological, histomorphometrical, microradiographic, and oxytetracycline-fluorescence studies of the osteotomized and intact control femora were performed. At 24 weeks the mechanical properties had decreased significantly. Thirty-nine osteotomies healed uneventfully. One of the 64 evaluated osteotomies showed signs of infection at six weeks, and there were 19 non-unions and six delayed unions. In 20 operations the fixation was loose and out of these 14 non-unions were observed. No gross signs of inflammatory or foreign-body reactions were observed. The present investigation showed that the mechanical strength and fixation properties of SR-P(L/DL)LA/bioactive glass composite rods are suitable for fixation of cancellous bone osteotomies in rats as long as the operative technique is correct. The present article is the first report on the application of SR-P(L/DL)LA/bioactive glass composite rods for fixation of cancellous bone osteotomies.     

Compressional Behaviour of an Agglomerated Cellulose Powder

The ability of an agglomerated cellulose powder to total and plastic deformation was evaluated and compared with those of Avicel PH 101, Emcocel and an experimental depolymerized cellulose powder. The elastic recovery of compressed cellulose tablets was also measured. The effects of deformation of the material during the tableting process and recovery of tablet after maximum compression on the mechanical strength of tablets were also discussed.

The apparent net work done into tablets during compression as well as the yield pressures to total and plastic deformation, determined from the Heckel treatment, showed no great differences between the agglomerated cellulose powder and the other cellulose powders. Thus all the cellulose materials studied had rather similar ability to total, i.e. elastic and plastic, deformation and to permanent, i.e. pure plastic, deformation. The obvious fragmentation of the agglomerated cellulose powder already at low compressional pressure, however, seemed to be advantageous for the formation of strong compacts.

Both rapid and total elastic recovery of compressed cellulose tablets showed clear differences between the cellulose materials and these differences correlated with the previously measured strength of cellulose tablets. The agglomerated cellulose powder had the smallest tendency to both kind of elastic recoveries of tablets. Obviously, due to the large interparticle contact areas, the ability of this material to establish more bonds between adjacent particles during compression was greater than those of other celluloses. The elastic recovery was greatest for depolymerized cellulose tablets indicating the poorest binding ability of the particles of this material.     

BET Inhibition Upregulates SIRT1 and Alleviates Inflammatory Responses

Control of histone acetylation is a part of the epigenetic mechanism that regulates gene expression and chromatin architecture. The members of the bromodomain and extra terminal domain (BET) protein family are a group of epigenetic readers that recognize histone acetylation, whereas histone deacetyl‐ ases such as sirtuin 1 (SIRT1) function as epigenetic erasers. We observed that BET inhibition by the specific inhibitor JQ1 upregulated SIRT1 expression and activated SIRT1. Moreover, we observed that BET inhibition functionally reversed the pro‐inflammatory effect of SIRT1 inhibition in a cellular lung disease model. SIRT1 activation is desirable in many age‐related, metabolic and inflammatory diseases; our results suggest that BET protein inhibition would be beneficial in treatment of those conditions. Most importantly, our findings demonstrate a novel mechanism of SIRT1 activation by inhibition of the BET proteins.     

Comparison of two methods for extraction of volatiles from marine PL emulsions

The dynamic headspace (DHS) thermal desorption principle using Tenax GR tube, as well as the solid phase micro‐extraction (SPME) tool with carboxen/polydimethylsiloxane 50/30 µm CAR/PDMS SPME fiber, both coupled to GC/MS were implemented for the isolation and identification of both lipid and Strecker derived volatiles in marine phospholipids (PL) emulsions. Comparison of volatile extraction efficiency was made between the methods. For marine PL emulsions with a highly complex composition of volatiles headspace, a fiber saturation problem was encountered when using CAR/PDMS‐SPME for volatiles analysis. However, the CAR/PDMS‐SPME technique was efficient for lipid oxidation analysis in emulsions of less complex headspace. The SPME method extracted volatiles of lower molecular weights more efficient than the DHS method. On the other hand, DHS Tenax GR appeared to be more efficient in extracting volatiles of higher molecular weights and it provided a broader volatile spectrum for marine PL emulsion than the CAR/PDMS‐SPME method.