Management of frontal sinus trauma: a retrospective study of surgical interventions and complications.

BACKGROUND: Frontal sinus injuries are relatively rare among facial bone traumas. Without proper treatment, they can lead to fatal intracranial complications, including meningitis or brain abscesses, as well as aesthetic and functional sequelae. The management of frontal sinus injuries remains controversial, with various treatment methods and outcomes being reported. This article describes the clinical characteristics, surgical methods, and outcomes among 17 patients who underwent surgery for frontal sinus injury and related complications. CASE PRESENTATION: We retrospectively included 17 patients who underwent surgery for frontal sinus injury and its related complications at the Kangwon National University Hospital between July 2010 and September 2021. Among them, six underwent simple open reduction and fixation of the anterior wall, eight underwent sinus obliteration, and three underwent cranialization. Two patients who underwent sinus obliteration died due to infection-related complications. The patient who underwent cranialization reported experiencing chronic headache and expressed dissatisfaction regarding the esthetic outcomes of the forehead. Except for these three patients, the other patients achieved satisfactory esthetic and functional recovery. CONCLUSION: Active surgical management of frontal sinus injuries is often required owing to the various complications caused by these injuries; however, several factors, including the fracture type, clinical presentation, related craniomaxillofacial injury, and medical history, should be considered while formulating the treatment plan. Surgical treatment through the opening of the frontal sinus should be actively considered in patients with severely damaged posterior wall fractures and those at risk of developing infection.

Charge-driven liquid-crystalline behavior of ligand-functionalized nanorods in apolar solvent.

Concentrated colloidal suspensions of nanorods often exhibit liquid-crystalline (LC) behavior. The transition to a nematic LC phase, with long-range orientational order of the particles, is usually well-captured by Onsager's theory for hard rods, at least qualitatively. The theory shows how the volume fraction at the transition decreases with increasing aspect ratio of the rods. It also explains that the long-range electrostatic repulsive interaction occurring between rods stabilized by their surface charge can significantly increase their effective diameter, resulting in a decrease in the volume fraction at the transition, as compared to sterically stabilized rods. Here, we report on a system of ligand-stabilized LaPO4 nanorods, of aspect ratio ≈ 11, dispersed in apolar medium exhibiting the counter-intuitive observation that the onset of nematic self-assembly occurs at an extremely low volume fraction of ≈ 0.25%, which is lower than observed (≈ 3%) with the same particles when charged-stabilized in polar solvent. Furthermore, the nanorod volume fraction at the transition increases with increasing concentration of ligands, in a similar way as in polar media where increasing the ionic strength leads to surface charge screening. This peculiar system was investigated by dynamic light scattering, Fourier-transform infrared spectroscopy, zetametry, electron microscopy, polarized light microscopy, photoluminescence measurements, and X-ray scattering. Based on these experimental data, we formulate several tentative scenarios that might explain this unexpected phase behavior. However, at this stage, its full understanding remains a pending theoretical challenge. Nevertheless, this study shows that dispersing anisotropic nanoparticles in an apolar solvent may sometimes lead to spontaneous ordering events that defy our intuitive ideas about colloidal systems.

Vectorial probing of electric and magnetic transitions in variable optical environments and vice-versa.

We use europium doped single crystalline NaYF4nanorods for probing the electric and magnetic contributions to the local density of optical states (LDOS). Reciprocically, we determine intrinsic properties of the emitters (oscillator strength, quantum yield) by comparing their measured and simulated optical responses in front of a mirror. We first experimentally determine the specifications of the nanoprobe (orientation and oscillator strength of the electric and magnetic dipoles moments) and show significant orientation sensitivity of the branching ratios associated with electric and magnetic transitions. In a second part, we measure the modification of the LDOS in front of a gold mirror in a Drexhage's experiment. We discuss the role of the electric and magnetic LDOS on the basis of numerical simulations, taking into account the orientation of the dipolar emitters. We demonstrate that they behave like degenerated dipoles sensitive to polarized partial LDOS.

Monazite LaPO4:Eu3+ nanorods as strongly polarized nano-emitters.

Orientation analyses of macromolecules or artificial particles are vital for both fundamental research and practical bio-applications. An accurate approach is monitoring the polarization spectroscopy of lanthanide-doped nanocrystalline materials. However, nanomaterials are often far from ideal for the colloidal and polarization luminescence properties. In the present study, we synthesize well-dispersed LaPO4:Eu3+ nanomaterials in an anisotropic rod shape. Microwave heating with excess addition of phosphate precursor invokes a rapid phase transition of rhabdophane into monazite. The colloidal stability of the nanorod suspension is outstanding, demonstrated by showing liquid crystalline behaviors. The monazite nanorods are also superior in luminescence efficiency with limited defects. The emission spectrum of Eu3+ consists of well-defined lines with prominent polarization dependencies for both the forced electric dipole transitions and the magnetic dipole transitions. All the results demonstrate that the synthesized monazite nanorods can serve as an accurate probe in orientation analyses and potential applications, such as in microfluidics and biological detections.

Measuring the order parameter of vertically aligned nanorod assemblies.

Vertically aligned nanorod assemblies are of great interest both for fundamental studies of anisotropic physical properties arising from the structures and for the development of functional devices utilizing such anisotropic characteristics. Simultaneous measurement of the homeotropic order parameter (Shomeo) of assemblies in dynamic states can allow further optimization of the assembly process and the device performance. Although many techniques (e.g. birefringence measurement, SAXS analysis, and high-resolution microscopy) have been proposed to characterise Shomeo, these do not yet meet the essential criteria such as for rapid, in situ and non-destructive analyses. Here, we propose a novel approach employing a unique photoluminescence behaviour of lanthanide-doped crystalline nanorods, of which the emission spectrum contains the detailed information on the structure of the assembly. We demonstrate a rapid in situ determination of Shomeo of Eu3+-doped NaYF4 nanorods of which the orientation is controlled under an external electric field. The method does not require the consideration of polarization and can be performed using a conventional fluorescence microscopy setup. This new methodology would provide a more in-depth examination of various assembled nanostructures and the collective dynamics of their building blocks.

Measuring 3D orientation of nanocrystals via polarized luminescence of rare-earth dopants.

Orientation of nanoscale objects can be measured by examining the polarized emission of optical probes. To retrieve a three-dimensional (3D) orientation, it has been essential to observe the probe (a dipole) along multiple viewing angles and scan with a rotating analyzer. However, this method requires a sophisticated optical setup and is subject to various external sources of error. Here, we present a fundamentally different approach employing coupled multiple emission dipoles that are inherent in lanthanide-doped phosphors. Simultaneous observation of different dipoles and comparison of their relative intensities allow to determine the 3D orientation from a single viewing angle. Moreover, the distinct natures of electric and magnetic dipoles originating in lanthanide luminescence enable an instant orientation analysis with a single-shot emission spectrum. We demonstrate a straightforward orientation analysis of Eu3+-doped NaYF4 nanocrystals using a conventional fluorescence microscope. Direct imaging of the rod-shaped nanocrystals proved the high accuracy of the measurement. This methodology would provide insights into the mechanical behaviors of various nano- and biomolecular systems.

Retrobulbar hematoma following the repair of an orbital wall fracture: a case series.

BACKGROUND: Retrobulbar hematoma is a rare complication after the repair of an orbital wall fracture, but the caution is required because the condition can cause blindness. CASE PRESENTATION: In this article, 3 cases of retrobulbar hematoma after the surgical repair of an orbital wall fracture are reported. In the first patient, the permanent loss of vision was involved, while in the second patient, the author was able to prevent loss of vision by performing immediate decompression after definite diagnosis and consulting with an ophthalmologist. In the third patient, there was no surgical treatment involved; he recovered on his own without major sequelae. CONCLUSIONS: Retrobulbar hematoma is a very serious condition that can result in blindness. Thus, when it is recognized, every effort should be made to preserve the patient's vision and prevent blindness.

Ambipolar Triple Cation Perovskite Field Effect Transistors and Inverters.

Ambipolar perovskite field-effect transistors and inverters with balanced mobilities are demonstrated. Thin-film field-effect-transistor-like inverters are developed, and a maximum gain of 23 in the first quadrant for VDD = 80 V is obtained.

Submental Intubation in Patients with Complex Maxillofacial Injuries.

Airway management in patients with complex maxillofacial injuries is a challenge to anesthesiologists. Submental intubation is a useful technique that is less invasive than tracheostomy in securing the airways where orotracheal and nasotracheal intubation cannot be performed. This procedure avoids the use of tracheostomy and bypasses its associated morbidities. A flexible and kink-resistant reinforced endotracheal tube with detachable universal connector is commonly used for submental intubation. Herein, we report cases involving submental intubation using a reinforced endotracheal tube with a non-detachable universal connector in patients with complex maxillofacial injuries.

Bandgap tuning of mixed organic cation utilizing chemical vapor deposition process.

Bandgap tuning of a mixed organic cation perovskite is demonstrated via chemical vapor deposition process. The optical and electrical properties of the mixed organic cation perovskite can be manipulated by varying the growth time. A slight shift of the absorption band to shorter wavelengths is demonstrated with increasing growth time, which results in the increment of the current density. Hence, based on the optimized growth time, our device exhibits an efficiency of 15.86% with negligible current hysteresis.

Stable and null current hysteresis perovskite solar cells based nitrogen doped graphene oxide nanoribbons hole transport layer.

UNLABELLED: Perovskite solar cells are becoming one of the leading technologies to reduce our dependency on traditional power sources. However, the frequently used component poly(3,4-ethylenedioxythiophene) polystyrene sulfonate ( PEDOT: PSS) has several shortcomings, such as an easily corroded indium-tin-oxide (ITO) interface at elevated temperatures and induced electrical inhomogeneity. Herein, we propose solution-processed nitrogen-doped graphene oxide nanoribbons (NGONRs) as a hole transport layer (HTL) in perovskite solar cells, replacing the conducting polymer PEDOT: PSS. The conversion efficiency of NGONR-based perovskite solar cells has outperformed a control device constructed using PEDOT: PSS. Moreover, our proposed NGONR-based devices also demonstrate a negligible current hysteresis along with improved stability. This work provides an effective route for substituting PEDOT: PSS as the effective HTL.

New Horizons for Perovskite Solar Cells Employing DNA-CTMA as the Hole-Transporting Material.

We investigate solution-processed low-temperature lead-halide perovskite solar cells employing deoxyribose nucleic acid (DNA)-hexadecyl trimethyl ammonium chloride (CTMA) as the hole-transport layer and (6,6)-phenyl C61 -butyric acid methyl ester (PCBM) as electron-acceptor layer in an inverted p-i-n device configuration. The perovskite solar cells utilizing a bio-based charge-transport layer demonstrate power conversion efficiency values of 15.86 %, with short-circuit current density of 20.85 mA cm(-2) , open circuit voltage of 1.04 V, and fill factor of 73.15 %, and improved lifetime. DNA-based devices maintained above 85 % of the initial efficiency after 50 days in air.

Effects of UV-ozone irradiation on copper doped nickel acetate and its applicability to perovskite solar cells.

The effects of UV-ozone (UVO) irradiation on copper-doped nickel acetate and its applicability to perovskite solar cells were investigated. UVO irradiation of copper-doped nickel acetate significantly increased the electrical conductivity (from 4.28 × 10(-4) S cm(-1) to 5.66 × 10(-2) S cm(-1)), which is due to the increased carrier concentration (from 3.53 × 10(13) cm(-3) to 2.41 × 10(16) cm(-3)), and the charge extraction efficiency was enhanced, leading to better compatibility with the hole transport layer. By UVO irradiation, the work function was increased from 4.95 eV to 5.33 eV by the surface dipole formation, which effectively reduced the interface barrier between the hole transport layer and the MAPbI3 light absorbing layer. UVO Irradiation of the underlying layer also allows the MAPbI3 precursors to form better morphology with highly arranged crystallinity. Compared to the cells using non-irradiated copper doped nickel acetate, UVO-irradiated copper-doped nickel acetate devices showed an enhanced open-circuit voltage (3% increase), short circuit current (16% increase), fill factor (5% increase), showing an enhanced power conversion efficiency of 12.2% (21% increase).

Organic devices based on nickel nanowires transparent electrode.

Herein, we demonstrate a facile approach to synthesize long nickel nanowires and discuss its suitability to replace our commonly used transparent electrode, indium-tin-oxide (ITO), by a hydrazine hydrate reduction method where nickel ions are reduced to nickel atoms in an alkaline solution. The highly purified nickel nanowires show high transparency within the visible region, although the sheet resistance is slightly larger compared to that of our frequently used transparent electrode, ITO. A comparison study on organic light emitting diodes and organic solar cells, using commercially available ITO, silver nanowires, and nickel nanowires, are also discussed.

Identification of novel allele on the locus 47z (DXYS5) in the Korean population.

Two homogenous sequences of 47z (DXYS5) are located on the X (DXYS5X) and Y (DXYS5Y) chromosomes, and these are known to be useful polymorphic markers for tracing male-specific gene flow such as the migration routes of human populations. Using the 47z/StuI PCR-RFLP system, we found a novel allele which showed two bands, in contrast to the previous two allele types, one band (Y1) and three bands (Y2). This means that copies of PCR products derived from both the DXYS5X and DXYS5Y loci were clearly cut by the StuI enzyme, implying that the DXYS5X locus of the X chromosome is polymorphic. Allelic frequencies examined in 267 male Korean individuals showed that 95.8% had Y1, 3.4% Y2, and 0.8% had the novel allele. Our findings should contribute to a better understanding of genetic polymorphism on X and Y chromosomes, the molecular evolution mechanism of sex chromosomes, and how the migration route of Koreans is related to those of other East Asian populations.