Deok-Won Lee is an oral and maxillofacial surgery specialist and associate professor of Kyung Hee University Schoole of Dentistry. His expertise is in treating and improving the oral and maxillofacial health and wellbeing of people. His research on dental implant materials creates new pathways for improving healthcare. He is continually building and investigating on adequate material for implantation through invivo and invitro models based on years of experience in research, evaluation, teaching and administration both in hospital and education institutions.

Introduction: The timing of cranioplasty and method of bone flap storage are known risk factors of non-union and resorption of bone flaps. In this ani¬mal experimental study, we evaluated the efficacy of cranioplasty using frozen autologous bone flap, and examined whether the timing of cranio¬plasty after craniectomy affects bone fusion and new bone formation.
Method and materials: Total 8 rabbits (male, older than 16 weeks) were divided into two groups of early cranioplasty group (EG, 4 rabbits) and delayed cranioplasty group (DG, 4 rabbits). The rabbits of each group were performed cranioplasty via frozen autologous bone flaps 4 weeks (EG) and 8 weeks (DG) after craniectomy. In order to obtain control data, the cranioplasty immediate after craniectomy were made on the contralateral cranial bone of the rabbits (control group, CG).The bone fusion and new bone formation were evaluated by micro-CT scan and histological examination 8 weeks after cranioplasty on both groups.
Results: In the micro-CT scans, the mean values of the volume and the surface of new bone were 50.13±7.18 mm3 and 706.23±77.26 mm2 in EG, 53.78±10.86 mm3 and 726.60±170.99 mm2 in DG, and 31.51±12.84 mm3 and 436.65±132.24 mm2 in CG. In the statistical results, significant differences were shown between EG and CG and between DG and CG (volume: p=0.028 and surface: p=0.008). The histological results confirmed new bone formation in all rabbits.
Conclusion: We observed new bone formation on all the frozen autologous bone flaps that was stored within 8 weeks. The timing of cranioplasty showed no difference of degree of new bone formation. Not only the healing period after cranioplasty but the time interval from craniectomy to cranioplasty could affect the new bone formation.

This study was supported by a grant from the National Research Foundation of Korea (NRF-2014R1A1A1002630 and NRF-2016R1A2B4014600)

Nada E.Omer is an associate professor of physics at Uninersity of Dammam,KSA. Regarding her work; teaching and supervision of research for undergraduate and graduates students in the field of physics and doing researches using available computer software in material sciences as well as doing experimental tresearch on nanoparticle synthesis and its medical applications as well as energy applications.

Green nanoparticle synthesized need to be incorporated into nanotechnologies at the source along with medical applications. This work scopes in the context of potential health effects of nanoparticles. Gold nanoparticles were synthesized using biomaterial mix of Olea europaea fruit and Acacia nilotica extracts, Sivler and Titania nanoparticles were synthesized using Lupin bean extract. The formation of the particles was characterized by x-ray Diffraction followed by Zitasizer for measured particles average size 10-100 nm. Energy-dispersive spectrometer (EDS) equipped with scanning electron microscopy illustrated the morphology and elemental analysis for the nanoparticles. Different shapes for the nanoparticles were examined by Transmission electron microscopy (TEM). The three ecofriendly green synthesized Au, Ag, and Tio2 nanoparticles have shown efficient antibacterial effect towards both Gram-positive and Gram-negative strain which can be very promising for wide variety of applications in nanomedicine.

Jae-Hun Jeong has expertise in the properties of two-dimensional materials such as MoS2 and MoSe2. His large-area growth technology and in-depth research have laid the foundation for 2D materials to be used in next-generation applications. His research approach, which focuses on deep physics, and his large-area growth techniques, are expected to make a valuable contribution to the development of new-level devices.

Two-dimensional transition metal dichalcogenides (TMDs) have attracted great interest for applications in optoelectronic device. We studied the optical properties of the large area MoSe₂ thin film on c-axis sapphire (0001) substrate grown by molecular beam epitaxy (MBE). Photoluminescence (PL), Raman, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were measured to evaluate the film quality. We obtained the optical absorption spectra of mono-, bi- and tri-layer MoSe₂ and observed optical critical point which is correspond to the direct transition at Г-point of the Brillouin zone (BZ) at ~3 eV. Increasing the number of layer, the intensity of the absorption peak at Г-point was increased and its position was shifted. The changes in peak at Г-point are caused by the band structure depending on the number of layer, resulting in the modulation of the joint density of state (JDOS). Since the geometrical band shape of conduction band and valance band are similar around Г-point for few layer MoSe₂, both van Hove singularities (VHS) and band nesting contribute to strong absorption peak. Using 3eV optical pump, we can selectively excite the MoSe₂ by choosing suitable number of layer. The modulation of band structure and strong photon-electron interaction of 2D material would be widely applied to photonic and optoelectronic devices.

Jianmei Chen received her B.Eng. in chemical engineering and materials science from Shandong Normal University, Shandong, China, in 2011. She received Ph.D. degrees in material science and engineering from institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Jiangsu, China, in 2017. Mainly focus on the AFM lithography technique and application of Kelvin probe microscope in charge storage in dielectric material, plasmonic nanostructures fabrication and application in optoelectronics

Precisely positioning of plasmonic nanoparticles into multiplexed nanostructures with high controllability and reproducibility plays an important role for emerging advanced device applications. Many techniques employed to produce multiplexed nanostructures are limited by complicate fabrication process and difficulties with scalability. Here the work reports a scalable strategy to fabricate multiplexed plasmonic nanoparticle structures by mechanical scratching with AFM lithography. Under the assistance of polymer resist, gold nanoparticles assembled on the silicon substrate can be directly scratched by AFM tip to form well defined nanostructures, and different size or shape of gold nanoparticles can be controllable scratched at a high speed of 1000µm/s and remain the integrity of particle arrays after removing the polymer. By precisely controlling the scratching loading force, multiplexed nanostructures of plasmonic nanoparticles can be further achieved which demonstrate multiplex plasmonic properties and surface-enhanced Raman scattering (SERS) responses. When the multiplexed nanostructure is further integrated into organic light-emitting diodes device, it intuitionisticly expresses multiplexed plasmonic effects on the device performance. It gives a new aspect for multilevel assembly to the application of multiplexed SERS response or exploration for the plasmon enhanced devices.

Samia A. Kosa completed her Ph.D. in Chemical Engineering and Advanced Materials, 2004, from University of Newcastle upon Tyne, United Kingdom. Presently, she is working as Associate Professor at the chemistry department, King Abdulaziz University in Jeddah Saudi Arabia. Her research is focused on materials chemistry, nanochemistry and nanotechnology, synthesis of catalyst and designed Photocatalytic and photoelectrocatalytic systems for the destruction of aqueous pollutants and water disinfection; measurement of photo-degradation of organic dyes, paints and polymers.

In this study LTA, zeolite was prepared from Saudi white silica as a main source of silica. The effect of ultrasonic irradiation on the crystal structure and ability to ion exchange of some heavy metals were studied. Many techniques was used to characterize the prepared zeolite includes XRD with crystal lattice analysis, EPR and finally ion exchange isotherm of some heavy metal ions. The results showed that the ultra-sonicated zeolite exhibits different behavior towards ion exchange with increasing its capacity. The ultra-sonicated zeolite showed little increase in the lattice parameters with increasing in the crystal size. Fitting adsorption isotherms on the metal adsorbed showed an observable change in the behavior of ultra-sonicated zeolite towards the metals exchanged.

Deok-Won Lee is an Oral and Maxillofacial Surgery Specialist and Associate Professor of Kyung Hee University College of Dentistry. His expertise is in treating and improving the oral and maxillofacial health and wellbeing of people. His research on dental implant materials creates new pathways for improving healthcare. He is continually building and investigating on adequate material for implantation through in-vivo and in-vitro models based on years of experience in research, evaluation, teaching and administration both in hospital and education institutions

Introduction: Gold nanoparticles (GNPs) are widely used in diagnostics, drug delivery, biomedical imaging and photothermal therapy due to their surface plasmon resonance, fluorescence, and easy-surface functionalization. According to recent studies, GNPs display a positive effect on the osteogenic differentiation of mesenchymal stem cells (MSCs) and MC3T3-E1 osteoblast-like cells. The aim of this study was to develop a new approach for bone tissue regeneration based on the utilization of a biodegradable hydrogel loaded with GNPs.

Methods & Materials: We used photo-curable gelatin hydrogels (Gel) to provide a proof of principle of GNPs in regeneration strategies for bone tissue repair. We investigated the effects of these Gel–GNP composite hydrogels both in-vitro and in- vivo. The hybrid hydrogel was formed by irradiating a mixture of a photo-initiator, methacrylated gelatin (GelMA) and GNPs with ultraviolet (UV) light. The content and distribution of GNPs in the GelMA solution and hydrogel were determined by UV-Vis spectroscopy, differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). The GNPs embedded in a gelatin hydrogel were evaluated for their capacity to induce osteogenic differentiation of human adipose-derived stem cells (ADSCs).

Results: The in-vitro results showed that the hydrogels loaded with GNPs promote proliferation, differentiation and alkaline phosphate (ALP) activities of human adipose-derived stem cells (ADSCs) as they differentiate towards osteoblast cells in a dose-dependent manner. Moreover, the in-vivo results showed that these hydrogels loaded with high concentrations of GNPs had a significant influence on new bone formation.

Conclusion: The Gel–GNP displayed significantly higher new bone formation in animal tests. Through these in-vitro and in-vivo tests, we found that the Gel–GNP can be a useful material for bone tissue engineering.

Mustafa Can is an Assistant Professor of Chemistry at Sakarya University. He has received his BS degree in Chemistry (1999), MS degree in Chemistry (2002), and PhD degree in Physical Chemistry from Sakarya University, Sakarya, Turkey. He has his expertise in development of polymers with functional groups that provide specific chemical reactivity on precious metals. His research interests also include core-shell nanoparticles production and usage of Li-air battery electrode for adsorption.

A facile, eco-friendly, room-temperature method for rapid one-pot synthesis of Au metallic nanoparticles has been developed based on the successive reduction of Au(III) precursors with gallic acid (GA) in an aqueous environment. The morphology and surface analysis of the resulting Au nanoparticles were confirmed by transmission electron microscopy followed by X-ray photoelectron spectroscopy. In order to tune particle size optimum GA amount is determined with TEM and particle size distribution was measured. The average particle size of gold nanoparticles was calculated as 40 nm. This study effectively demonstrates for the Au NPs synthesis which can be effectively achieved by acting GA as reducer and stabilizator.