Forecast-driven model for prepositioning supplies in preparation for a foreseen hurricane

In this paper, we present a forecast-driven dynamic model for prepositioning relief items in preparation for a foreseen hurricane. Our model uses forecast advisories issued by the National Hurricane Center (NHC), which are issued every 6?h. Every time a new advisory is issued with updated information, our model determines the amount and location of units to be prepositioned and it also re-prepositions already prepositioned units. The model also determines the best time for starting the prepositioning activities. Our approach uses a combination of Decision Theory and stochastic programming. The outcomes of our model are presented in a way that could be easily understood by humanitarian practitioners who are ultimately the ones who would use and apply our model.     

New Cobalt (II) Complexes with Imidazole Derivatives: Antimicrobial Efficiency against Planktonic and Adherent Microbes and In Vitro Cytotoxicity Features

Three novel Co(II) complexes of the type [Co(C₄H₅O₂)₂L₂] (where C₄H₅O₂ is methacrylate anion; L = C₃H₄N₂ (imidazole; HIm) (1), C₄H₆N₂ (2-methylimidazole; 2-MeIm) (2), C₅H₈N₂ (2-ethylimidazole; 2-EtIm) (3)) have been synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopic techniques, thermal analysis and single crystal X-ray diffraction. X-ray crystallography revealed for complexes (1) and (2) distorted trigonal bipyramid stereochemistry for Co(II), meanwhile for complex (3) evidenced that the unit cell comprises three molecular units with interesting structural features. In each unit, both stereochemistry adopted by metallic ion and coordination modes of carboxylate anions are different. The screening of antimicrobial activity revealed that Candida albicans planktonic cells were the most susceptible, with minimal inhibitory concentration (MIC) values of 7.8 μg/mL for complexes (1) and (2) and 15.6 μg/mL for complex (3). Complexes (1) and (2) proved to be more active than complex (3) against the tested bacterial strains, both in planktonic and biofilm growth state, with MIC and minimal biofilm eradication concentration (MBEC) values ranging from 15.6 to 62.5 μg/mL, the best antibacterial effects being noticed against Staphylococcus aureus and Pseudomonas aeruginosa. Remarkably, the MBEC values obtained for the four tested bacterial strains were either identical or even lower than the MIC ones. The cytotoxicity assay indicated that the tested complexes affected the cellular cycle of HeLa, HCT-8, and MG63 cells, probably by inhibiting the expression of vimentin and transient receptor potential canonical 1 (TRPC1). The obtained biological results recommend these complexes as potential candidates for the development of novel anti-biofilm agents.     

Synthesis,physico-chemical characterization and thermal behavior of new complexes with N4O2 donor set

Three new coordinative compounds of the type [Co(en)₂CO₃]·0.75H₂O (1) and [M(en)₂(H₂O)₂]CO₃ ((2) M:Ni, (3) M:Cu; en: ethylenediamine) were synthesized and characterized. The IR and UV–Vis spectral data indicate that ethylenediamine acts as chelate, while carbonate ions act as bidentate chelate ligand for (1)/counter ion for (2) and (3) generating complexes with octahedral stereochemistry. The thermal behavior provided confirmation of the complexes composition, as well as the number and the nature of water molecules and the intervals of thermal stability. The biological assays revealed a good activity against Enterococcus faecium for copper complex.     

Highly Functionalized and Potent Antiviral Cyclopentane Derivatives Formed by a Tandem Process Consisting of Organometallic,Transition‐Metal‐Catalyzed,and Radical Reaction Steps

A simple modular tandem approach to multiply substituted cyclopentane derivatives is reported, which succeeds by joining organometallic addition, conjugate addition, radical cyclization, and oxygenation steps. The key steps enabling this tandem process are the thus far rarely used isomerization of allylic alkoxides to enolates and single‐electron transfer to merge the organometallic step with the radical and oxygenation chemistry. This controlled lineup of multiple electronically contrasting reactive intermediates provides versatile access to highly functionalized cyclopentane derivatives from very simple and readily available commodity precursors. The antiviral activity of the synthesized compounds was screened and a number of compounds showed potent activity against hepatitis C and dengue viruses.     

Probing key coordination interactions: configurationally restricted metal activated CXCR4 antagonists

The syntheses of configurationally restricted mono- and bis-macrocyclic copper(II) perchlorate complexes (copper(II) 5-benzyl-1,5,8,12-tetraazabicyclo[10.2.2]hexadecane and dicopper(II) 5,5'-[1,4-phenylenebis(methylene)]-bis(1,5,8,12-tetraazabicyclo[10.2.2]hexadecane)) are reported and the X-ray structure of the copper(II) mono-macrocyclic complex has been determined. EXAFS studies on the bis-macrocyclic species in aqueous solution show that the copper coordination spheres are essentially identical to the solid state structure, and do not vary in the presence of 20 equivalents of sodium acetate per metal centre. DFT calculations were carried out at the BP86/TZP level to determine the nature of potential binding interactions with CXCR4 aspartate residues. The alkylated single macrocyclic compound was modelled with an acetate included to represent the aspartate residue, demonstrating that the predicted macrocycle configuration has the lowest energy and the acetate interaction is effectively monodentate giving a distorted trigonal bipyramidal geometry at the copper centre. In vitro anti-HIV infection assays show that the configurationally restricted dicopper(II) complex is more active (average EC(50) = 0.026 microM against HIV-1) than the non-constrained dicopper(II) 1,1'-[1,4-phenylenebis(methylene)]-bis(1,4,8,11-tetraazacyclotetradecane) (average EC(50) = 0.047 microM against HIV-1) although it is an order of magnitude less active than the configurationally restricted dizinc(II) complex.     

Stereocontrol in radical Mannich equivalents for aminosugar synthesis: haloacetal and 2-(phenylthio)vinyl tethered radical additions to α-hydroxyhydrazones

Studies of stereocontrol in two types of radical equivalents of Mannich addition reactions offer new insights for application to aminosugar synthesis. In the first method, haloacetal addition (Ueno-Stork reaction) is extended to dihydroxyhydrazones, leading to an adduct with the unexpected 3-epi-l-daunosamine configuration. A neighboring α-benzyloxy substituent causes a dramatic reversal of stereocontrol compared with hydrazones where this substituent is absent; vicinal dipole repulsion is proposed to account for the diastereoselectivity. In the second method, radical addition-cyclization with thiophenol and treatment with fluoride leads to diastereoselective group transfer from a silicon-tethered ethynyl group to the CN bond of hydrazones, affording anti-hydrazino alcohols with a trans-2-(phenylthio)vinyl substituent. The one-pot process occurs under neutral, tin-free radical conditions, and offers stereocontrol which is complementary to the haloacetal method. Synthetic utility of the radical Mannich concept is demonstrated in a brief asymmetric synthesis of N-trifluoroacetyl-l-daunosamine from achiral precursors.     

Solubilisation of triolein by microemulsions containing C12E4/hexadecane/water: equilibrium and dynamics

Increasing triolein content of oil-in-water microemulsions in the pure C(12)E(4)/water/n-hexadecane/triolein system while maintaining a fixed surfactant concentration and volume fraction of drops raises the temperature of the solubilisation boundary, where excess oil separates, but has only a slight effect on the (higher) cloud point temperature, where excess water appears. Thus, the temperature range of the single-phase microemulsion shrinks and ultimately disappears. When such microemulsions are in equilibrium with excess oil, the hexadecane/triolein ratio is greater in the microemulsion, probably because the larger triolein molecules are unable to penetrate the hydrocarbon chain region of the surfactant films of the microemulsion droplets. Indeed, monolayer studies and calculations based on microemulsion and excess oil compositions indicate that the films have minimal triolein and similar ratios of hexadecane to surfactant. Triolein drops brought into contact with hexadecane-in-water microemulsions first swell as they incorporate hexadecane, then shrink owing to solubilisation. Interfacial tension decreases during this process until it becomes almost constant near 0.01 mN m(-1), suggesting that the drops in the final stages of solubilisation have high hexadecane contents. A microemulsion containing 10 wt% C(12)E(4) and 15 wt% hexadecane was able to remove over 50% of triolein from polyester fabric at 25 degrees C, more than twice that removed by an oil-free solution with the same surfactant concentration in similar experiments.     

Fabrication improvements for thermoset polyester (TPE) microfluidic devices

Thermoset polyester (TPE) microfluidic devices were previously developed as an alternative to poly(dimethylsiloxane) (PDMS) devices, fabricated similarly by replica molding, yet offering stable surface properties and good chemical compatibility with some organics that are incompatible with PDMS. This paper describes a number of improvements in the fabrication of TPE chips. Specifically, we describe methods to form TPE devices with a thin bottom layer for use with high numerical aperture (NA) objectives for sensitive fluorescence detection and optical manipulation. We also describe plasma-bonding of TPE to glass to create hybrid TPE-glass devices. We further present a simple master-pretreatment method to replace our original technique that required the use of specialized equipment.