Control of the water adhesion on hydrophobic micropillars by spray coating technique

We present an alternative approach for controlling the water adhesion on solid superhydrophobic surfaces by varying their coverage with a spray coating technique. In particular, micro-, submicro-, and nanorough surfaces were developed starting from photolithographically tailored SU-8 micropillars that were used as substrates for spraying first poly(tetrafluoroethylene) submicrometer particles and subsequently iron oxide nanoparticles. The sprayed particles serve to induce surface submicrometer and nanoscale roughness, rendering the SU-8 patterns superhydrophobic (apparent contact angle values of more than 150°), and also to tune the water adhesion between extreme states, turning the surfaces from “non-sticky” to “sticky” while preserving their superhydrophobicity. The influence of the chemical properties and of the geometrical characteristics of the functionalized surfaces on the wetting properties is discussed within the frame of the theory. This simple method can find various applications in the fabrication of microfluidic devices, smart surfaces, and biotechnological and antifouling materials.     

Hamiltonian nilpotent centers of linear plus cubic homogeneous polynomial vector fields

We provide normal forms and the global phase portraits in the Poincaré disk for all Hamiltonian nilpotent centers of linear plus cubic homogeneous planar polynomial vector fields.     

Photocatalytic Hydrogen Evolution by Oleic Acid‐Capped CdS,CdSe, and CdS0.75Se0.25 Alloy Nanocrystals

Photocatalytic generation of hydrogen by using oleic acid‐capped CdS, CdSe, and CdS_0.75Se_0.25 alloy nanocrystals (quantum dots) has been investigated under visible‐light irradiation by employing Na₂S and Na₂SO₃ as hole scavengers. Highly photostable CdS_0.75Se_0.25 alloy nanocrystals gave the highest hydrogen evolution rate (1466 μmol h^?1 g^?1), which was about three times higher than that of CdS and seven times higher than that of CdSe.     

A multi-methodological approach for shipping registry selection in maritime transportation industry

Selecting the most suitable registry alternative for shipping fleets has become a highly complex strategic activity for ship owners in the maritime transportation industry, and necessitates consideration of both internal and external environmental factors, which can be both qualitative and quantitative. The aim of this paper is to propose an originally structured multi-methodological approach based on the systematic application of the SWOT analysis, the AHP and the TOPSIS methods to support the critical decision process on shipping registry selection under multiple criteria. In the proposed approach, the SWOT analysis is utilized to determine the key assessment factors on the shipping registry decision and to structure the decision hierarchy. While the AHP is used to measure the relative importance of evaluation criteria in this decision hierarchy, the TOPSIS is applied to rank the shipping registry alternatives. As a case study, major open registries are analyzed to select the most suitable of them for the fleet that is operated by a worldwide ship owner. The results show that the proposed multi-methodological approach takes the advantages of the SWOT analysis, the AHP and the TOPSIS to select the most suitable shipping registry. The proposed approach also provides a relatively simple and very well suited decision-making tool for this type of strategic decision making problem.     

Some Aspects of LrW1 (G) n L(p, q, W2dμ)(G)

Let G be a locally compact Abelian group with Haar measure. The authors discuss some basic properties of LrW1 (G) n L(p, q, W2dμ)(G) spaces. Then the necessary conditions for compact embeddings of the spaces LrW1 ( Rd) N L(p, q, W2dμ)( Rd) are showed.     

Some Aspects of Lw1^r （G）∩ L（p,q, w2dμ）（G）

Let G be a locally compact Abelian group with Haar measure. The authors discuss some basic properties of Lw1^r （G）∩ L（p, q, w2dμ）（G） spaces. Then the necessary conditions for compact embeddings of the spaces Lw1^r （R^d）∩ L（p, q, w2dμ）（R^d） are showed.     

Advances in Fibrin-Based Materials in Wound Repair: A Review

The first bioprocess that occurs in response to wounding is the deterrence of local hemorrhage. This is accomplished by platelet aggregation and initiation of the hemostasis cascade. The resulting blood clot immediately enables the cessation of bleeding and then functions as a provisional matrix for wound healing, which begins a few days after injury. Here, fibrinogen and fibrin fibers are the key players, because they literally serve as scaffolds for tissue regeneration and promote the migration of cells, as well as the ingrowth of tissues. Fibrin is also an important modulator of healing and a host defense system against microbes that effectively maintains incoming leukocytes and acts as reservoir for growth factors. This review presents recent advances in the understanding and applications of fibrin and fibrin-fiber-incorporated biomedical materials applied to wound healing and subsequent tissue repair. It also discusses how fibrin-based materials function through several wound healing stages including physical barrier formation, the entrapment of bacteria, drug and cell delivery, and eventual degradation. Pure fibrin is not mechanically strong and stable enough to act as a singular wound repair material. To alleviate this problem, this paper will demonstrate recent advances in the modification of fibrin with next-generation materials exhibiting enhanced stability and medical efficacy, along with a detailed look at the mechanical properties of fibrin and fibrin-laden materials. Specifically, fibrin-based nanocomposites and their role in wound repair, sustained drug release, cell delivery to wound sites, skin reconstruction, and biomedical applications of drug-loaded fibrin-based materials will be demonstrated and discussed.