Fabrication of Octadecyl and Octadecanethiolate Self-Assembled Monolayers on Oxide-Free Si(111) with a One-Cell Process

Self-assembled monolayers (SAM) of 1-octadecene (ODE) and 1-octadecanethiol (ODT) were deposited on an oxide-free Si(111) surface with a one-cell method. The etching and SAM deposition of Si(111) were performed in one cell containing immiscible solutions in two layers: an aqueous solution of NH₄F and a toluene solution of organic SAM precursors (ODE and ODT). To remove surface Si oxides, the Si(111) surface was initially etched in the lower layer of NH₄F solution. The Si as etched was subsequently moved directly to the upper solution of the precursors for deposition of the SAM under illumination of white light. This one-cell approach avoids the Si surface, as etched, coming in contact with the atmosphere, so eliminating oxidation and contamination. The ODE and ODT SAM were characterized with measurements with an atomic force microscope (AFM) and X-ray photoelectron spectra (XPS). The resulting ODE SAM was more stable than the ODT SAM and exhibited satisfactory resistance to oxidation under the ambient atmosphere. The ODT SAM prepared with this one-cell method exhibited a resistance to atmospheric oxidation better than with a two-cell method

Modulation of Bone-Specific Tissue Regeneration by Incorporating Bone Morphogenetic Protein and Controlling the Shell Thickness of Silk Fibroin/Chitosan/Nanohydroxyapatite Core–Shell Nanofibrous Membranes

The presence of both osteoconductive and osteoinductive factors is important in promoting stem cell differentiation toward the osteogenic lineage. In this study, we prepared silk fibroin/chitosan/nanohydroxyapatite/bone morphogenetic protein-2 (SF/CS/nHAP/BMP-2, SCHB2) nanofibrous membranes (NFMs) by incorporating BMP-2 in the core and SF/CS/nHAP as the shell layer of a nanofiber with two different shell thicknesses (SCHB2-thick and SCHB-thin). The physicochemical properties of SCHB2 membranes were characterized and compared with those of SF/CS and SF/CS/nHAP NFMs. When tested in release studies, the release rate of BMP-2 and the concentration of BMP-2 in the release medium were higher for SCHB2-thin NFMs because of reduced shell thickness. The BMP-2 released from the nanofiber retained its osteoinductive activity toward human-bone-marrow-derived mesenchymal stem cells (hMSCs). Compared with SF/CS and SF/CS/nHAP NFMs, the incorporation of BMP-2-promoted osteogenic differentiation of hMSCs and the SCHB-thin NFM is the best scaffold during in vitro cell culture. Gene expression analysis by real-time quantitative polymerase chain reaction detected the evolution of both early and late marker genes of bone formation. The relative mRNA expression is in accordance with the effect of BMP-2 incorporation and shell thickness, while the same was reconfirmed through the quantification of bone marker protein osteocalcin. In vivo experiments were carried out by subcutaneously implanting hMSC-seeded SCHB2-thin NFMs and acellular controls on the back sides of nude mice. Immunohistochemical and histological staining confirmed ectopic bone formation and osteogenesis of hMSCs in SCHB2-thin NFMs. In conclusion, the SCHB2-thin NFM could be suggested as a promising scaffold for bone tissue engineering

Controlled Regiodivergent C–H Bond Activation of Imidazo[1,5‑<i>a</i>]pyridine via Synergistic Cooperation between Aluminum and Nickel

The catalytic method features a cooperative interaction between Ni and Al imparting remote C–H alkenylation at the C5 position of imidazo­[1,5-<i>a</i>]­pyridine with alkynes at mild conditions. Exclusion of AlMe₃ switches the selectivity to the C3 position. Reactions with styrene and other olefinic substrates affording C5-adducts by Ni/Al catalysis are also included

Operative data.

a<p>anterolateral thigh;</p>b<p>vastus lateralis;</p>c<p>superior thyroid artery;</p>d<p>transverse cervical artery;</p>e<p>split thickness skin graft;</p>f<p>intensive care unit.</p

Pharyngoesophageal reconstruction with the anterolateral thigh flap after total laryngopharyngectomy.

<p>(A) Preoperative marking. (B) After salvage pharyngolaryngectomy with neck dissection, an “empty” neck was noted. (C) A chimeric flap was composed of a skin paddle and a piece of vastus lateralis (VL) muscle. The skin paddle was tubularized to form a neoesophagus and the VL muscle was used to increase tissue bulk and to obliterate the dead space. (D) Immediate photograph after reconstruction.</p

Kaplan-Meier plot analyses of the overall survival (OS) and disease-free survival (DFS) of patient subgroups stratified by pathological nodal status (pN), BMI values, and surgical margins (mm).

<p>The inlets indicate statistically significant differences measured by log-rank test.</p

Postoperative complications.

<p>Postoperative complications.</p

Postoperative diet.

a<p>29 patients achieve oral intake.</p>b<p>tube feeding.</p

Kaplan-Meier survival analysis in patients with recurrent hypopharyngeal cancers after concurrent chemoradiotherapy receiving ablating salvage surgery and anterolateral thigh flap reconstruction.

<p>(A) & (B), Kaplan-Meier plots indicated that 5-year overall survival (OS) and disease-free survival (DFS) were 51.8% and 53.7%, respectively.</p

Patients’ details.

a<p>body mass index.</p