Some necessary and sufficient conditions for the convergence of sequences of unilateral convex sets

We establish some necessary and sufficient conditions for the convergence in $\text{W}{}_0{}^{\mathrm{1,p}}\text{(Ω)}$ of sequences of convex sets determined by obstacles. These conditions are expressed in terms of properties of the p-capacities of the level sets of the obstacles.     

Studies on the synthesis of heterocyclic compounds. XV. Preparation of a new series of macrocycles with the diglycolyl moiety

A new series of macrocycles containing the diglycolyl moiety have been prepared. The compounds prepared were: 7,9,18,20-tetrahydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclooctadecin-6,10,17,21-tetraone ( 1 ), 1,4,7,10,13,16-hexaoxacyclooctadecane-2,6,11,15-tetraone ( 2 ), 8,7,17,18-tetramethyl-1,4,7,10,13,16-hexaoxa-cyclooctadecane-2,6,11,15-tetraone ( 3 ) and 2,5,8,15,18,21 -hexaoxatricyclo[20,4,0,0^9.14]hexacosan-3,7,16,20-tetraone ( 4 ). The compound 4 has been isolated in the four diastereoisomers: trans-syn-trans 4a , trans-anti-trans 4b , cis-syn-cis 4c and cis-anti-cis 4d .     

Electron impact mass spectrometry of some cyclic tetraesters containing a tartaric moiety

The mass spectrometric behaviour of some cyclic tetraesters containing tartaric moiety is described and discussed in detail with the aid of linked scans and exact mass measurements. The peculiar fragmentation patterns are emphasized.     

Reconstruction of cosmic and beam-halo muons with the CMS detector

The powerful muon and tracker systems of the CMS detector together with dedicated reconstruction software allow precise and efficient measurement of muon tracks originating from proton-proton collisions. The standard muon reconstruction algorithms, however, are inadequate to deal with muons that do not originate from collisions. This note discusses the design, implementation, and performance results of a dedicated cosmic muon track reconstruction algorithm, which features pattern recognition optimized for muons that are not coming from the interaction point, i.e., cosmic muons and beam-halo muons. To evaluate the performance of the new algorithm, data taken during Cosmic Challenge phases I and II were studied and compared with simulated cosmic data. In addition, a variety of more general topologies of cosmic muons and beam-halo muons were studied using simulated data to demonstrate some key features of the new algorithm.     

Analysis of carbamate and phenylurea pesticide residues in fruit juices by solid-phase microextraction and liquid chromatography-mass spectrometry

A new analysis method to detect carbamates and phenylurea pesticide residues in fruit juices was developed using solid-phase microextraction (SPME) coupled with liquid chromatography-single quadrupole mass spectrometry (LC/MS) and liquid chromatography-quadrupole ion trap mass spectrometry (LC/QIT-MS). The pesticide residues present in watery matrices as fruit juices were extracted using three types of fibers: 50-microm Carbowax/templated resin (CW/TPR), 60-mum poly(dimethylsiloxane)/divinylbenzene (PDMS/DVB) and 85-microm polyacrylate. The different extraction conditions were evaluated choosing as the best parameters 90 min (time), 20 degrees C (temperature) and 1 ml (volume). After extraction, the desorption (in a static mode) was performed in the specific interface chamber SPME/HPLC, previously filled with 70% methanol and 30% water. The best recoveries, evaluated at two fortification levels (0.2 and 0.5 mg kg(-1)) in fruit juices, were obtained using PDMS/DVB and CW/TPR fibers, and ranged from 25 to 82% (monolinuron, diuron and diethofencarb), with relative standard deviations (RSDs) from 1 to 17%. All the limits of quantification (LOQs) were in the range of 0.005-0.05 microg ml(-1) and, in any case, equal to, or lower than, maximum residue limits (MRLs) established by Italian and Spanish legislations. The mass spectrometry analyses were carried out using an electrospray ionization (ESI) source operating in the positive mode both for single quadrupole and for QIT mass analysers, operating in selected ion monitoring (SIM) and in multiple reaction monitoring (MRM) modes, respectively. The proposed new method can be applied to the determination of selected pesticides in real samples of fruit juices.     

An ESPI experimental study on the phenomenon of fracture in glass. Is it brittle or plastic?

The crack opening displacement (COD) in annealed soda-lime (float) glass has been measured with an electronic speckle pattern interferometry (ESPI) apparatus using coherent laser light. Specimens, naturally pre-cracked with a particular technique, were loaded under strain-driven bending until crack propagated; at regular intervals loading was paused to let the crack reach subcritical equilibrium and the COD measured. By using a post-processing algorithm comparing four images lighted with phase-shifted laser beams, surface displacements could be measured at a resolution of .Glass transparency has allowed to see through that the propagating crack front is not sharp but curved, jagged and merged in an opaque neighborhood. Numerical simulations show that the measured CODs cannot be reproduced if cohesive surface forces à la Barenblatt-Dugdale bridge the crack lips; instead a plastic-like region must form in a bulk neighborhood of the tip, where inelastic strains are associated with volume increase rather than deviatoric distortion. For this, a Gurson-Tvergaard model of porous plasticity, accounting for the formation of microvoids/microcracks, has been found more efficient than classical von Mises plasticity. This study confirms the formation at the crack tip of a process zone, whose occurrence in brittle materials like glass is still a subject of controversy.     

On the Motive Power of Chemical Transformations in?Open Systems

The classical basic concepts of cyclic processes and the efficiency of heat engines are used here to conjecture about the laws of thermodynamics for open systems that can exchange matter with a surrounding environment. An ideal chemomechanical elastic bar is envisioned that changes its stiffness while undergoing a chemical transformation which is, in turn, influenced by the axial strain of the bar. Stable equilibrium states are identified as minimizers of the total energy, which is assumed to be nonconvex in type. If the bar is loaded and then alternatively placed in environments at chemical potentials either ?? _i or ?? _s >?? _i , a reversible cycle analogous to the classical Carnot cycle may be traced. In this case, the environmental ??chemical potential?? plays the role of the temperature and the ??chemical work?? the role of heat. For the system, the main form of interaction with the exterior, other than mechanical work, is the exchange of mass of a component at different environmental chemical potentials. It is then possible to obtain an elementary theory of chemical engines in which efficiency estimates (in terms of environmental chemical potentials) and related pertinent issues can be discussed. This model may serve as a basis for analyzing coupled chemo-mechanical processes occurring in materials such as ionized gels for possible applications as actuators, and to interpret complex phenomena in biological systems, such as the chemical kinetics of smooth muscles.     

Ruthenium anticancer compounds: myths and realities of the emerging metal-based drugs

Ruthenium anticancer drugs have attracted an increasing interest in the last 20 years and two of them have entered clinical trials. Compared to platinum drugs, the complexes based on ruthenium are often identified as less toxic and capable of overcoming the resistance induced by platinum drugs in cancer cells. These activities were attributed to the transportation to tumour cells by transferrin and to the selective activation to more reactive species by the reducing environment of solid tumours as compared to healthy tissues. Ruthenium anticancer drugs have been almost always designed to mimic platinum drugs, particularly for targeting DNA. Indeed, none of the above properties has never been clearly demonstrated even for the ruthenium drugs that entered clinical trials. The suggestion for the future is to change the perspective when designing new chemical entities, abandoning the philosophy that guided the actual panel of ruthenium drugs and to look further into the fine mechanism by which the most relevant ruthenium complexes available kill the target tumour cells, then focusing on targets selective of tumour cells and responsible for cell growth and malignancy.