["Sequential Chimeric Osteocutaneous DCIA-Perforator-SIEA Flap to Reconstruct an Osteocutaneous Defect in the Lower Extremity and the Importance of Preserving the Ascending Branch - A Case Report"]. / "Sequenzieller chimärer Beckenkamm-SIEA-Lappen zur Rekonstruktion eines osteokutanen Defektes des Unterschenkels und die Wichtigkeit zur Schonung des Ramus Ascendens ­ ein Fallbericht".

BACKGROUND: The deep circumflex iliac artery (DCIA) perforator flap is an established method to reconstruct osteocutaneous defects. However, the cutaneous perforators come with a great anatomic variability. To deal with this problem, we used a sequential chimeric osteocutaneous free flap for reconstruction. PATIENTS AND METHODS: A 58-year-old man presented with an open tibial fracture after an avalanche accident resulting in an extended osteocutaneous defect in the lower extremity. The injury required osteocutaneous free flap coverage. We reconstructed the defect with a sequential chimeric osteocutaneous DCIA-perforator-SIEA flap. RESULTS: The preservation of the ascending branch of the deep circumflex iliac vessels offered us the possibility to effectively cover an extended osteocutaneous defect in the lower extremity with a sequential chimeric osteocutaneous DCIA-perforator-SIEA flap. In our patient, the sequential chimeric osteocutaneous DCIA-perforator-SIEA flap healed without complications. A small hernia developed at the inguinal donor site area, but it healed without further complications after surgical treatment. The patient regained an adequate function and returned to daily life and physical exercise. CONCLUSION: While preparing the DCIA-perforator free flap, it is important to preserve the ascending branch of the deep circumflex iliac vessels and the vessels needed to harvest either a SIEA or SCIP flap.

Solvent-dependent stabilization of metastable monolayer polymorphs at the liquid-solid interface.

Self-assembly of 1,3,5-tris(4'-biphenyl-4"-carbonitrile)benzene monolayers was studied at the liquid-solid interface by scanning tunneling microscopy. Application of different fatty acid homologues as solvents revealed a solvent-induced polymorphism. Yet, tempering triggered irreversible phase transitions of the initially self-assembled monolayers, thereby indicating their metastability. Interestingly, in either case, the same thermodynamically more stable and more densely packed monolayer polymorph was obtained after thermal treatment, irrespective of the initial structure. Again, the same densely packed structure was obtained in complementary solvent-free experiments conducted under ultrahigh vacuum conditions. Thus, self-assembly of metastable polymorphs at room temperature is explained by adsorption of partially solvated species under kinetic control. The irreversible phase transitions are induced by thermal desolvation, that is, desorption of coadsorbed solvent molecules.

Solution preparation of two-dimensional covalently linked networks by polymerization of 1,3,5-Tri(4-iodophenyl)benzene on Au(111).

The polymerization of 1,3,5-tri(4-iodophenyl)benzene (TIPB) on Au(111) through covalent aryl-aryl coupling is accomplished using a solution-based approach and investigated by scanning tunneling microscopy. Drop-casting of the TIPB monomer onto Au(111) at room temperature results in poorly ordered noncovalent arrangements of molecules and partial dehalogenation. However, drop-casting on a preheated Au(111) substrate yields various topologically distinct covalent aggregates and networks. Interestingly, some of these covalent nanostructures do not adsorb directly on the Au(111) surface, but are loosely bound to a disordered layer of a mixture of chemisorbed iodine and molecules, a conclusion that is drawn from STM data and supported by X-ray photoelectron spectroscopy. We argue that the gold surface becomes covered by a strongly chemisorbed iodine monolayer which eventually inhibits further polymerization.

Effect of ZrO2 addition on the mechanical properties of porous TiO2 bone scaffolds.

This study aimed at the investigation of the effect of zirconium dioxide (ZrO2) addition on the mechanical properties of titanium dioxide (TiO2) bone scaffolds. The highly biocompatible TiO2 has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO2 is known for its excellent mechanical properties. Ultra-porous TiO2 scaffolds (>89% porosity) were produced using polymer sponge replication with 0-40 wt.% of the TiO2 raw material substituted with ZrO2. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO2 led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO2 scaffolds. Further ZrO2 additions resulted in reduction of compressive strength in comparison to containing no ZrO2. The appearance of zirconium titanate (ZrTiO4) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds.

Incorporation dynamics of molecular guests into two-dimensional supramolecular host networks at the liquid-solid interface.

The objective of this work is to study both the dynamics and mechanisms of guest incorporation into the pores of 2D supramolecular host networks at the liquid-solid interface. This was accomplished by adding molecular guests to prefabricated self-assembled porous monolayers and the simultaneous acquisition of scanning tunneling microscopy (STM) topographs. The incorporation of the same guest molecule (coronene) into two different host networks was compared, where the pores of the networks either featured a perfect geometric match with the guest (for trimesic acid host networks) or were substantially larger than the guest species (for benzenetribenzoic acid host networks). Even the moderate temporal resolution of standard STM experiments in combination with a novel injection system was sufficient to reveal clear differences in the incorporation dynamics in the two different host networks. Further experiments were aimed at identifying a possible solvent influence. The interpretation of the results is aided by molecular mechanics (MM) and molecular dynamics (MD) simulations.

Extended two-dimensional metal-organic frameworks based on thiolate-copper coordination bonds.

Self-assembly and surface-mediated reactions of 1,3,5-tris(4-mercaptophenyl)benzene--a three-fold symmetric aromatic trithiol--are studied on Cu(111) by means of scanning tunneling microscopy (STM) under ultrahigh-vacuum (UHV) conditions. In order to reveal the nature of intermolecular bonds and to understand the specific role of the substrate for their formation, these studies were extended to Ag(111). Room-temperature deposition onto either substrate yields densely packed trigonal structures with similar appearance and lattice parameters. Yet, thermal annealing reveals distinct differences between both substrates: on Cu(111) moderate annealing temperatures (~150 °C) already drive the emergence of two different porous networks, whereas on Ag(111) higher annealing temperatures (up to ~300 °C) were required to induce structural changes. In the latter case only disordered structures with characteristic dimers were observed. These differences are rationalized by the contribution of the adatom gas on Cu(111) to the formation of metal-coordination bonds. Density functional theory (DFT) methods were applied to identify intermolecular bonds in both cases by means of their bond distances and geometries.

A combined ion-sputtering and electron-beam annealing device for the in vacuo postpreparation of scanning probes.

We describe the setup, characteristics, and application of an in vacuo ion-sputtering and electron-beam annealing device for the postpreparation of scanning probes (e.g., scanning tunneling microscopy (STM) tips) under ultrahigh vacuum (UHV) conditions. The proposed device facilitates the straightforward implementation of a common two-step cleaning procedure, where the first step consists of ion-sputtering, while the second step heals out sputtering-induced defects by thermal annealing. In contrast to the standard way, no dedicated external ion-sputtering gun is required with the proposed device. The performance of the described device is demonstrated by SEM micrographs and energy dispersive x-ray characterization of electrochemically etched tungsten tips prior and after postprocessing.

Surface mediated synthesis of 2D covalent organic frameworks: 1,3,5-tris(4-bromophenyl)benzene on graphite(001), Cu(111), and Ag(110).

The on surface synthesis of a two-dimensional (2D) covalent organic framework from a halogenated aromatic monomer under ultra-high vacuum conditions is shown to be dependent on the choice of substrate.