A corresponding states treatment of the liquid–vapor saturation line

In this work we analyze correlations for the maxima of products of some liquid–vapor saturation properties. These points define new characteristic properties of each fluid that are shown to exhibit linear correlations with the critical properties. We also demonstrate that some of these properties are well correlated with the acentric factor. An application is made to predict the properties of two new low global warming potential (GWP) refrigerants.     

Modeling the liquid filling in capillary well microplates for analyte preconcentration

An attractive advantage of the capillary well microplate approach is the ability to conduct evaporative analyte preconcentration. We advance the use of hydrophobic materials for the wells which apart from reducing material loss through wetting also affords self entry into the well when the droplet size reduces below a critical value. Using Surface Evolver simulation without gravity, we find the critical diameters D(c) fitting very well with theoretical results. When simulating the critical diameters D(c)(G) with gravity included, the gravitational effect could only be ignored when the liquid volumes were small (difference of 5.7% with 5 μL of liquid), but not when the liquid volumes were large (differences of more than 22% with 50 μL of liquid). From this, we developed a modifying equation from a series of simulation results made to describe the gravitational effect. This modifying equation fitted the simulation results well in our simulation range (100°≤θ≤135° and 1 μL≤V≤200 μL). In simulating the condition of multiple wells underneath each droplet, we found that having more holes did not alter the critical diameters significantly. Consequently, the modifying relation should also generally express the critical diameter for multiple wells under a droplet.     

Butylated hydroxytoluene analogs: synthesis and evaluation of their multipotent antioxidant activities

A computer-aided predictions of antioxidant activities were performed with the Prediction Activity Spectra of Substances (PASS) program. Antioxidant activity of compounds 1, 3, 4 and 5 were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation assays to verify the predictions obtained by the PASS program. Compounds 3 and 5 showed more inhibition of DPPH stable free radical at 10?? M than the well-known standard antioxidant, butylated hydroxytoluene (BHT). Compound 5 exhibited promising in vitro inhibition of Fe2?-induced lipid peroxidation of the essential egg yolk as a lipid-rich medium (83.99%, IC?? 16.07 ± 3.51 μM/mL) compared to α-tocopherol (α-TOH, 84.6%, IC?? 5.6 ± 1.09 μM/mL). The parameters for drug-likeness of these BHT analogues were also evaluated according to the Lipinski’s “rule-of-five” (RO5). All the BHT analogues were found to violate one of the Lipinski’s parameters (LogP > 5), even though they have been found to be soluble in protic solvents. The predictive polar surface area (PSA) and absorption percent (% ABS) data allow us to conclude that they could have a good capacity for penetrating cell membranes. Therefore, one can propose these new multipotent antioxidants (MPAOs) as potential antioxidants for tackling oxidative stress and lipid peroxidation processes.     

12(S)-Hydroxyheptadeca-5Z,8E,10E-trienoic acid suppresses UV-induced IL-6 synthesis in keratinocytes, exerting an anti-inflammatory activity

12(S)-Hydroxyheptadeca-5Z,8E,10E-trienoic acid (12- HHT) is an enzymatic product of prostaglandin H(2) (PGH(2)) derived from cyclooxygenase (COX)-mediated arachidonic acid metabolism. Despite the high level of 12-HHT present in tissues and bodily fluids, its precise function remains largely unknown. In this study, we found that 12-HHT treatment in HaCaT cells remarkably down-regulated the ultraviolet B (UVB) irradiation-induced synthesis of interleukin-6 (IL-6), a pro-inflammatory cytokine associated with cutaneous inflammation. In an approach to identify the down-stream signaling mechanism by which 12-HHT down-regulates UVB-induced IL-6 synthesis in keratinocytes, we observed that 12-HHT inhibits the UVB-stimulated activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB). In addition, we found that 12-HHT markedly up-regulates MAPK phosphatase-1 (MKP-1), a critical negative regulator of p38 MAPK. When MKP-1 was suppressed by siRNA knock-down, the 12-HHT-mediated inhibitory effects on the UVB-stimulated activation of p38 MAPK and NF-κB, as well as the production of IL-6, were attenuated in HaCaT cells. Taken together, our results suggest that 12-HHT exerts anti-inflammatory effect via up-regulation of MKP-1, which negatively regulates p38 MAPK and NF-κB, thus attenuating IL-6 production in UVB-irradiated HaCaT cells. Considering the critical role of IL-6 in cutaneous inflammation, our findings provide the basis for the application of 12-HHT as a potential anti-inflammatory therapeutic agent in UV-induced skin diseases.     

Catalytic C–H arylation of unactivated heteroaromatics with aryl halides by cobalt porphyrin

Direct C–H arylation of unactivated heteroaromatics with aryl halides catalyzed by cobalt porphyrin is reported. The reaction is proposed to go through a homolytic aromatic substitution reaction. The aryl radical is electrophilic and a SOMO–HOMO interaction is predominant in the aryl radical addition process.     

Crystal Structure and Spectroscopic Properties of trans‐Dibromidobis(propane‐1, 3‐diamine)chromium(III) Perchlorate

The structure of trans‐[Cr(tn)₂Br₂]ClO₄ (tn = propane‐1, 3‐diamine) has been determined by a single‐crystal X‐ray diffraction study at 100 K. The complex crystallizes in the space group P$\bar{1}$ of the triclinic system with two mononuclear formula units in a cell of dimensions a = 6.8220(4), b = 8.86199(9), c = 12.6644(8) Å and α = 77.859(7)°, β = 81.765(6)°, and γ = 77.764(7)°. The chromium atom is in a slightly distorted octahedral environment coordinated by four nitrogen atoms of two tn ligands and two bromine atoms in trans positions. The two six‐membered chelate rings in the complex cations are oriented in an anti chair‐chair conformation with respect to each other. The mean Cr–N(tn) and Cr–Br bonds are 2.093(3) and 2.4681(4) Å, respectively. The crystal packing is stabilized by hydrogen bonds. The infrared and electronic absorption spectral properties are consistent with the result of X‐ray crystallography. It is confirmed that the nitrogen atoms of the tn ligand are strong σ‐donors, but the bromido ligands have weak σ‐ and π‐donor properties toward the chromium(III) ion.     

Simple near‐infrared photodetector based on charge transfer complexes formed in molybdenum oxide doped N,N′‐di(naphthalene‐1‐yl)‐N,N′‐diphenyl‐benzidine

We have demonstrated a simple near‐infrared (NIR) photodetector (PD) based on charge transfer complex (CTC) formed in molybdenum trioxide (MoO₃) doped N,N′‐di(naphthalene‐1‐yl)‐N,N′‐diphenyl‐benzidine (NPB), which shows a photocurrent of about 0.35 A/cm² at –3 V under 980 nm illumination. The existence of CTC formation promotes photocurrent generation which is investigated by comparison with MoO₃ doped 2‐methyl‐9,10‐di(2‐naphthyl)anthracene (MADN) film which has no CTC absorption. It can be evolved that this kind of simple‐structure photodetector has potential application in the near‐infrared (NIR) detection area. It is shown in this Letter that although both MoO₃ and NPB have larger energy gaps of about 3 eV and weak absorption in the NIR region, the charge transfer complexes formed by mixing the two materials show an extra absorption band and good photoelectric response in the NIR region.

     

Projection decomposition in multiplier algebras

In this paper we present new structural information about the multiplier algebra M (A ){\mathcal M (\mathcal A )} of a σ-unital purely infinite simple C*-algebra A{\mathcal {A}}, by characterizing the positive elements A ? M (A ){A\in \mathcal M (\mathcal A )} that are strict sums of projections belonging to A{\mathcal A } . If A ? A{A\not\in \mathcal {A}} and A itself is not a projection, then the necessary and sufficient condition for A to be a strict sum of projections belonging to A{\mathcal {A} } is that ${\|A\| >1 }${\|A\| >1 } and that the essential norm ||A||_ess 3 1{\|A\|_{ess} \geq 1}. Based on a generalization of the Perera–Rordam weak divisibility of separable simple C*-algebras of real rank zero to all σ-unital simple C*-algebras of real rank zero, we show that every positive element of A{\mathcal {A}} with norm >1 can be approximated by finite sums of projections. Based on block tri-diagonal approximations, we decompose any positive element A ? M (A ){A\in \mathcal M (\mathcal {A} )} with ${\| A\| >1 }${\| A\| >1 } and || A||_ess 3 1{\| A\|_{ess} \geq 1} into a strictly converging sum of positive elements in A{\mathcal A} with norm >1.     

Preemptive repayment policy for multiple loans

We study the multi-loan-repayment problem by formulating it as a single-machine scheduling problem with preemptive and time-dependent processing times to minimize the makespan. We transform the scheduling problem into a continuous non-linear optimization problem and obtain an approximate solution by solving a series of the corresponding linear programming problems. We also identify agreeable conditions for the problem and discuss the computational complexity of the problem.