Thermally Managed, Injectable Optoelectronic Probe with Heat Dissipation Guide for Photodynamic Therapy.

The development of fabrication technologies and appearance of new materials has resulted in dramatic increase in the performance of electronic devices, while the overall size has decreased. Recent electronic devices made of micro/nano-size components show high efficiency and outstanding performance with compact size, but these devices have revealed several fatal problems. In particular, the isolated heat that is generated by numerous components concentrated in a limited small area at high density, such as bio-integrated devices, is an issue that needs to be urgently addressed, because it is closely related to the performance and lifetime of electronic devices. To solve these problems, the microscale light emitting diode (µLED)-based neural probe is introduced on an injectable heat dissipation guide. The heat dissipation guide is made of boron nitride (BN) nanomaterials with high thermal conductivity. The heat management noticeably improves the optical output performance of the µLEDs, in which BN effectively dissipates heat, and allows enhanced lighting from the LEDs to be transmitted through brain tissue without thermal damage. Moreover, it shows remarkable improvement in the therapeutic effect of photodynamic therapy of mouse cancer cells.

Development of deformable moving lung phantom to simulate respiratory motion in radiotherapy.

Radiation treatment requires high accuracy to protect healthy organs and destroy the tumor. However, tumors located near the diaphragm constantly move during treatment. Respiration-gated radiotherapy has significant potential for the improvement of the irradiation of tumor sites affected by respiratory motion, such as lung and liver tumors. To measure and minimize the effects of respiratory motion, a realistic deformable phantom is required for use as a gold standard. The purpose of this study was to develop and study the characteristics of a deformable moving lung (DML) phantom, such as simulation, tissue equivalence, and rate of deformation. The rate of change of the lung volume, target deformation, and respiratory signals were measured in this study; they were accurately measured using a realistic deformable phantom. The measured volume difference was 31%, which closely corresponds to the average difference in human respiration, and the target movement was - 30 to + 32mm. The measured signals accurately described human respiratory signals. This DML phantom would be useful for the estimation of deformable image registration and in respiration-gated radiotherapy. This study shows that the developed DML phantom can exactly simulate the patient׳s respiratory signal and it acts as a deformable 4-dimensional simulation of a patient׳s lung with sufficient volume change.

Plasmonic nanograting enhanced quantum dots excitation for cellular imaging on-chip.

We present the design and integration of a two-dimensional (2D) plasmonic nanogratings structure on the electrode of colloidal quantum dot-based light-emitting diodes (QDLEDs) as a compact light source towards arrayed on-chip imaging of tumor cells. Colloidal quantum dots (QDs) were used as the emission layer due to their unique capabilities, including multicolor emission, narrow bandwidth, tunable emission wavelengths, and compatibility with silicon fabrication. The nanograting, based on a metal-dielectric-metal plasmonic waveguide, aims to enhance the light intensity through the resonant reflection of surface plasmon (SP) waves. The key parameters of plasmonic nanogratings, including periodicity, slit width, and thicknesses of the metal and dielectric layers, were designed to tailor the frequency bandgap such that it matches the wavelength of operation. We fabricated QDLEDs with the integrated nanogratings and demonstrated an increase in electroluminescence intensity, measured along the direction perpendicular to the metal electrode. We found an increase of 34.72% in QDLED electroluminescence intensity from the area of the pattern and an increase of 32.63% from the photoluminescence of QDs deposited on a metal surface. We performed ex vivo transmission-mode microscopy to evaluate the nucleus-cytoplasm ratios of MDA-MB 231 cultured breast cancer cells using QDLEDs as the light source. We showed wavelength dependent imaging of different cell components and imaging of cells at higher magnification using enhanced emission from QDLEDs with integrated plasmonic nanogratings.

Tunable directive radiation of surface-plasmon diffraction gratings.

We experimentally demonstrate tunable radiation from a periodic array of plasmonic nanoscatterers, tailored to convert surface plasmon polaritons into directive leaky modes. Extending our previous studies on efficient directional beaming based on leaky-wave radiation from periodic gratings driven by a subwavelength slit, we experimentally show dynamic beam sweeping by tuning the directional leaky-wave mechanism in real-time. Two alternative tuning mechanisms, wavelength- and index-mediated beam sweeping, are employed to modify the relative phase of scattered light at each grating edge and provide the required modification of the radiation angle.

Surgical extraction of mandibular third molar in pterygomandibular space: a case report.

Impacted mandibular third molars are located between the second mandibular molar and mandibular ramus. However, ectopic mandibular third molars with heterotopic positions are reported in the subcondylar or pterygomandibular space. The usual cause of malposition is a cyst or tumor, and malposition without a pathology is rare. This case report described an impacted mandibular third molar in the pterygomandibular space without any associated pathology.

A 3-year longitudinal evaluation of subpedicle free connective tissue graft for gingival recession coverage.

BACKGROUND: The purpose of this study was to longitudinally evaluate, over a 3-year period, the reduction of gingival recession through use of a subepithelial free connective tissue graft placed under a coronally advanced partial-thickness pedicle flap. METHODS: Twenty-one buccal recession defects (mean 3.67 mm; range 3 to 4.5 mm; Miller Class I, II, and III) in 15 patients were treated using this technique. Amount of gingival recession (GR), clinical attachment loss (CAL), and width of keratinized gingiva (WKG) were followed for 3 years after surgery. The measurements were performed at presurgery, and 1, 3, 6, 12, 18, 24, and 36 months postsurgery. RESULTS: GR decreased from 3.67 +/- 0.58 mm at baseline to 0.33 +/- 0.43 mm at 36 months, representing a reduction of 3.33 mm, corresponding to 91.28% mean root coverage. CAL was significantly decreased at 36 months from 5.26 +/- 0.77 mm to 2.14 +/- 0.57 mm. At 36 months, 3.12 mm of attachment gain was obtained. WKG significantly increased after 36 months (1.95 mm). GR, CAL, and WKG had the most positive outcomes at 12 months and were maintained at stable levels throughout the 36-month observation period. CONCLUSIONS: These results indicate that the connective tissue graft with a partial thickness coronal advancement pedicle is a predictable method for root coverage and, provided that optimal maintenance care is provided, the clinical outcomes gained by this technique can be well maintained.