Low‐Level Laser Therapy Restores the Oxidative Stress Balance in Acute Lung Injury Induced by Gut Ischemia and Reperfusion

It remains unknown if the oxidative stress can be regulated by low‐level laser therapy (LLLT) in lung inflammation induced by intestinal reperfusion (i‐I/R). A study was developed in which rats were irradiated (660 nm, 30 mW, 5.4 J) on the skin over the bronchus and euthanized 2 h after the initial of intestinal reperfusion. Lung edema and bronchoalveolar lavage fluid neutrophils were measured by the Evans blue extravasation and myeloperoxidase (MPO) activity respectively. Lung histology was used for analyzing the injury score. Reactive oxygen species (ROS) was measured by fluorescence. Both expression intercellular adhesion molecule 1 (ICAM‐1) and peroxisome proliferator‐activated receptor‐y (PPARy) were measured by RT‐PCR. The lung immunohistochemical localization of ICAM‐1 was visualized as a brown stain. Both lung HSP70 and glutathione protein were evaluated by ELISA. LLLT reduced neatly the edema, neutrophils influx, MPO activity and ICAM‐1 mRNA expression. LLLT also reduced the ROS formation and oppositely increased GSH concentration in lung from i‐I/R groups. Both HSP70 and PPARy expression also were elevated after laser irradiation. Results indicate that laser effect in attenuating the acute lung inflammation is driven to restore the balance between the pro‐ and antioxidants mediators rising of PPARy expression and consequently the HSP70 production.     

Pd–NHC Catalyzed Biaryl Coupling by Direct C–H Activation—A Novel Strategy for the Synthesis of Dibenzocyclooctane Lignans

Cross-coupling reactions, such as Buchwald-Hartwig arylamination and direct intramolecular biaryl coupling by C–H activation, were carried out using various Palladium-N-heterocyclic carbenes (Pd–NHC) as catalysts. The yields were good to excellent. The latter strategy was adopted to transform two dibenzylbutane lignans, isolated from the leaves of Ocotea macrophylla (Lauraceae), into the corresponding dibenzocyclooctane lignans in good overall yields.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Study of the degradation of a new PLA braided biomaterial in buffer phosphate saline,basic and acid media,intended for the regeneration of tendons and ligaments

The purpose of this study was to evaluate the effects of hydrolytic degradation on the properties of a PLA hollow braid designed as a new concept of biodegradable prosthesis for the regeneration of tendons and ligaments. The main function of the braided material is to bear mechanical loads while it is being replaced by the newly-generated tissue. The kinetics of braided material degradation is thus an important factor in determining the success of the product. In order to study this mechanism, PLA braid was subjected to a 12-month degradation process at 37 °C in PBS at pH 7.4 (to simulate the human physiological medium) and to accelerated degradation for one month in pH 12 and pH 3 solutions. Degradation of the braid subjected to hydrolysis was evaluated by weight loss, molecular weight distribution, mechanical properties, and calorimetric and morphologic analyses. The weight loss in a basic medium reached 21%, versus no significant change in the other media. Average molecular weight was reduced by approximately 50% in the three media, with loss of mechanical properties in all cases. The morphological changes were more evident in the PLA degraded in the basic medium. The crystallinity of the material increased at the first stages of degradation, regardless of the medium used.     

Performance of density functional theory in computing nonresonant vibrational (hyper)polarizabilities

A set of exchange‐correlation functionals, including BLYP, PBE0, B3LYP, BHandHLYP, CAM‐B3LYP, LC‐BLYP, and HSE, has been used to determine static and dynamic nonresonant (nuclear relaxation) vibrational (hyper)polarizabilities for a series of all‐trans polymethineimine (PMI) oligomers containing up to eight monomer units. These functionals are assessed against reference values obtained using the Møller–Plesset second‐order perturbation theory (MP2) and CCSD methods. For the smallest oligomer, CCSD(T) calculations confirm the choice of MP2 and CCSD as appropriate for assessing the density functionals. By and large, CAM‐B3LYP is the most successful, because it is best for the nuclear relaxation contribution to the static linear polarizability, intensity‐dependent refractive index second hyperpolarizability, static second hyperpolarizability, and is close to the best for the electro‐optical Pockels effect first hyperpolarizability. However, none of the functionals perform satisfactorily for all the vibrational (hyper)polarizabilities studied. In fact, in the case of electric field‐induced second harmonic generation all of them, as well as the Hartree–Fock approximation, yield the wrong sign. We have also found that the Pople 6–31+G(d) basis set is unreliable for computing nuclear relaxation (hyper)polarizabilities of PMI oligomers due to the spurious prediction of a nonplanar equilibrium geometry. © 2013 Wiley Periodicals, Inc.     

Bounds for the Kirchhoff index via majorization techniques

Using a majorization technique that identifies the maximal and minimal vectors of a variety of subsets of ${\mathbb{R}^{n}}$ , we find upper and lower bounds for the Kirchhoff index K(G) of an arbitrary simple connected graph G that improve those existing in the literature. Specifically we show that $$K(G) \geq \frac{n}{d_{1}} \left[ \frac{1}{1+\frac{\sigma}{\sqrt{n-1}}} + \frac{(n-2)^{2}}{n-1-\frac{\sigma}{\sqrt{n-1}}}\right] ,$$ where d ₁ is the largest degree among all vertices in G, $$\sigma ^{2} = \frac{2}{n} \sum_{(i, j) \in E} \frac{1}{d_{i}d_{j}} = \left( \frac{2}{n}\right) R_{-1}(G),$$ and R _?1(G) is the general Randi? index of G for ${\alpha =-1}$ . Also we show that $$K(G) \leq \frac{n}{d_{n}}\left( \frac{n-k-2}{1-\lambda _{2}}+\frac{k}{2}+\frac{1}{\theta}\right) ,$$ where d _n is the smallest degree, ${\lambda _{2}}$ is the second eigenvalue of the transition probability of the random walk on G, $$k = \left \lfloor \frac{\lambda _{2} \left( n-1\right) +1}{\lambda _{2}+1}\right\rfloor {\rm and}\quad\theta = \lambda _{2} \left( n-k-2\right) -k+2.$$      

Achiral diacrylate with an anticlinic smectic phase

We present an achiral diacrylate that shows a phase transition from the synclinic smectic C phase (SmC) to the anticlinic smectic C (SmCalt). This last phase has been previously reported only for swallow-tailed or dimeric compounds. Our studies using differential scanning calorimetry, X-ray diffraction, polarizing optical microscopy and broad band dielectric spectroscopy suggest the existence of this mesophase in this bifunctional smectogen.     

Supramolecular Polymerization of C3‐Symmetric Organogelators: Cooperativity,Solvent, and Gelation Relationship

A systematic study of the influence of solvent and the size of C₃‐symmetric discotics on their supramolecular polymerization mechanism is presented. The cooperativity of the self‐assembly of the reported compounds is directly related to their gelation ability. The two series of C₃‐symmetric discotics investigated herein are based on benzene‐1,3,5‐tricarboxamides (BTAs) and oligo(phenylene ethynylene)‐based tricarboxamides (OPE? TAs) that are peripherally decorated with achiral ( 1 a and 2 a ) or chiral N‐(2‐aminoethyl)‐3,4,5‐trialkoxybenzamide units ( 1 b and 2 b ). The supramolecular polymerization of compounds 1 a , b and 2 a , b has been exhaustively investigated in a number of solvents and by using various techniques: variable‐temperature circular dichroism (VT‐CD) spectroscopy, concentration‐dependent ¹H NMR spectroscopy, and isothermal titration calorimetry (ITC). The supramolecular polymerization mechanism of compounds 2 is highly cooperative in solvents such as methylcyclohexane and toluene and is isodesmic in CHCl₃. Unexpectedly, chiral compound 1 b is practically CD‐silent, in contrast with previously reported BTAs. ITC measurements in CHCl₃ demonstrated that the supramolecular polymerization of BTA 1 a is isodesmic. These results confirm the strong influence of the π‐surface of the central aromatic core of the studied discotic and the branched nature of the peripheral side chains on the supramolecular polymerization. The gelation ability of these organogelators is negated in CHCl₃, in which the supramolecular polymerization mechanism is isodesmic.     

Structural Diversity from the Transannular Cyclizations of Natural Germacrone and Epoxy Derivatives: A Theoretical–Experimental Study

Treatment of germacrone ( 1 ) with different electrophiles, and of its epoxy derivatives germacrone‐4,5‐epoxide ( 2 ), germacrone‐1,10‐epoxide ( 3 ) and isogermacrone‐4,5‐epoxide ( 4 ) with Brönsted/Lewis acids and Ti^III, gives rise to a great structural diversity. Thus, by using a maximum of two steps, the production of more than 40 compounds corresponding to 14 skeletons is described. Computational calculations rationalizing the structural divergence produced are also described. Finally, since some of the compounds generated are bioactive natural sesquiterpenes, the mechanisms of formation of these substances will provide new insights in their biosynthesis.     

Ideological Complex Systems: Mathematical Theory

The goal of this article is to build an abstract mathematical theory rather than a computational one of the process of transmission of ideology. The basis of much of the argument is Patten's Environment Theory that characterizes a system with its double environment (input or stimulus and output or response) and the existing interactions among them. Ideological processes are semiotic processes, and if in Patten's theory, the two environments are physical, in this theory ideological processes are physical and semiotic, as are stimulus and response. © 2014 Wiley Periodicals, Inc. Complexity 21: 47–65, 2015