Can Endoscopic Tympanoplasty Be a Good Alternative to Microscopic Tympanoplasty? A Systematic Review and Meta-Analysis

Although efficacies and proportions of tympanoplasty performed via endoscopic ear surgery (EES) have gradually introduced, it remains unclear whether total EES is a good alternative to microscopic ear surgery (MES). Herein, we aimed to compare therapeutic effects of EES and MES in patients receiving tympanoplasty or myringoplasty. A search of MEDLINE, PubMed, and Embase databases was conducted to compare the efficacies of EES and MES. Two investigators independently reviewed all studies and extracted data with a standardized form. We assessed risk of bias and calculated pooled odds ratio (OR) estimates with a 95% confidence interval (CI). Thirteen studies (607 EES patients and 678 MES patients) met inclusion criteria for quantitative meta-analysis. In pooled analysis, those who undergo EES have 0.99 times the OR of graft success compared to those with MES (95% CI, 0.84 to 1.16; P=0.894). In qualitative analysis, comparable hearing improvement was observed between the two groups, despite inconsistent audiometric evaluation. The air-bone gaps (ABGs) improved 2.02 dB less in EES than in MES (mean difference of improvements of ABGs, 2.02; 95% CI, –3.84 to –0.20; P=0.029); however, substantial heterogeneity and publication bias limited the integrity of this analysis. Further, EES significantly decreased canalplasty rate, wound complications, and operation time, compared to MES. Moreover, patients receiving EES reported higher cosmetic satisfaction than patients receiving MES. EES can be a good alternative to MES in terms of comparable graft success rate and hearing outcomes in patients receiving tympanoplasty or myringoplasty. Moreover, EES was less invasive, resulting in higher cosmetic satisfaction, reduced morbidity, and shorter operation time. Our results may affect decision-making and outcome prediction in cases of EES; however, confirmation is needed to clarify potential bias

Porous SiOC beads by freeze-drying polycarbosilane emulsions

Porous silicon oxycarbide (SiOC) beads were prepared by freeze-drying of water-in-oil (w/o) emulsion, containing water and polycarbosilane (PCS) dissolved p-xylene in the presence of sodium xylenesulfonate (SXS) as an emulsifier. The emulsion was frozen by being dropped onto a liquid N₂ bath, which resulted in 1~2 mm sized beads. After curing at 200°C for 1 h in air and subsequent pyrolysis at 800°C for 1 h in an Ar gas flow, porous SiOC beads were obtained. Freeze-dried beads showed lamellae-shaped macro-pore structures at a moderate freezing rate due to a phase separation behavior of PCS during freezing, while no lamellae pores were formed at a very high freezing rate. Lamellae-shaped pores developed along the freezing direction. Water droplets that were formed in w/o emulsion converted to spherical pores after drying. The combined processes of producing PCS emulsion and freeze-drying of emulsion resulted in two types of macro-pores: lamellae-shaped and spherical pores. Meso-pores, of which specific surface area and average pore size were 71.5 m² g⁻¹ and 4.85 nm, respectively, were formed inside the SiOC strut.Keywords: Polycarbosilane, Polymer emulsion, Freeze-drying, Porous SiOC bea

Polarity engineering in polycrystalline ZnO by inversion boundaries

Two distinctive polarity-engineered microstructures were obtained in polycrystalline ZnO ceramics by inducing two different types of inversion boundaries (IBs) inside individual grains to examine the effect of the different polarities on the varistor performances. The presence of head-to-head IBs induced by the addition of Sb and tail-to-tail IBs by doping Ti was directly confirmed by the characteristic geometry of the chemical etch pits. It was proposed that a consequent polarity on the grain boundary planes, which are affected by the presence of head-to-head IBs is crucial in exhibiting the superior performance of ZnO varistors.open2

Expansion of cytotoxic natural killer cells in multiple myeloma patients using K562 cells expressing OX40 ligand and membrane-bound IL-18 and IL-21.

BACKGROUND: Natural killer (NK) cell-based immunotherapy is a promising treatment approach for multiple myeloma (MM), but obtaining a sufficient number of activated NK cells remains challenging. Here, we report an improved method to generate ex vivo expanded NK (eNK) cells from MM patients based on genetic engineering of K562 cells to express OX40 ligand and membrane-bound (mb) IL-18 and IL-21. METHODS: K562-OX40L-mbIL-18/-21 cells were generated by transducing K562-OX40L cells with a lentiviral vector encoding mbIL-18 and mbIL-21, and these were used as feeder cells to expand NK cells from peripheral blood mononuclear cells of healthy donors (HDs) and MM patients in the presence of IL-2/IL-15. Purity, expansion rate, receptor expression, and functions of eNK cells were determined over four weeks of culture. RESULTS: NK cell expansion was enhanced by short exposure of soluble IL-18 and IL-21 with K562-OX40L cells. Co-culture of NK cells with K562-OX40L-mbIL-18/-21 cells resulted in remarkable expansion of NK cells from HDs (9,860-fold) and MM patients (4,929-fold) over the 28-day culture period. Moreover, eNK cells showed increased expression of major activation markers and enhanced cytotoxicity towards target K562, U266, and RPMI8226 cells. CONCLUSIONS: Our data suggest that genetically engineered K562 cells expressing OX40L, mbIL-18, and mbIL-21 improve the expansion of NK cells, increase activation signals, and enhance their cytolytic activity towards MM cells

Characterization of pyramidal inversion boundaries in Sb2O 3-doped ZnO by using electron back-scattered diffraction (EBSD)

The composition planes of the inversion boundary induced by the addition of Sb2O3 to ZnO ceramics were analyzed crystallographically by the application of electron back-scattered diffraction (EBSD) analysis and stereographic projection techniques. The inversion boundary was determined to consist of three discrete composition planes, {0001}, {101̄1}, {101̄0}.open2

Ab-initio study of entropic stabilization of AgBi2I7

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Effect of Crystal Shape on the Grain Growth during Liquid Phase Sintering of Ceramics

he equilibrium or growth shape of ceramic materials is classified largely into two categories according to the thermodynamic conditions imposed. One is a polyhedral shape where the surface free energy is anisotropic, and the other a spherical shape where the surface free energy is isotropic. In the case of grains with a polyhedral shape of anisotropic surface free energy, so- called abnormal grain growth usually takes place due to a significant energy barrier for a growth unit to be attached to the crystal surface. In the case of grains with a spherical shape of isotropic surface free energy, however, normal grain growth with a uniform size distribution takes place. In this contribution, the state-of-the-art of our current understanding of the relationship between the crystal shape and the microstructure evolution during the sintering of ceramic materials in the presence of a liquid phase was discussed.close

Spontaneous generation of charged atoms or clusters during thermal evaporation of silver

Spontaneous generation of charged atoms or clusters was investigated during thermal evaporation of silver. For this, the effect of the applied electric bias on the film growth rate was examined during evaporation of silver at 1373 K in a tungsten basket. Film growth rates on three silicon substrates biased + 300, 0 and -300 V with respect to the chamber were 300, 420 and 960 nm per hour, respectively. The number density of generated positively-charged atoms or clusters could be measured by the electric current on the Faraday cup in the chamber. From the temperature dependence of the positive current, the activation energy for charging was determined to be similar to 2.2 eV. This value could be best explained by the surface ionization of clusters of a few atoms on the oxidized tungsten surface.N

First-Principles Investigation on Copper-Based Layered-Halide Perovskite(A2CuX4)

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Effects of grain size on the dielectric properties and tunabilities of sol-gel derived Ba(Zr0.2Ti0.8)O3 ceramics

The effects of the average grain size on the phase transformation and consequent changes in the dielectric properties of Pb(Mg1/3Nb2/3)O-3-30 mol % PbTiO3 were investigated. It was observed that the size refinement down to similar to 90 nm impeded the phase transformation of the cubic phase formed in the course of sintering either into rhombohedral or into tetragonal one, and a series of phase transformation from cubic to rhombohedral and then to tetragonal phase took place as the average grain size increased from similar to 90 nm to similar to 5.7 mu m. This dependence of the crystal structure on the grain size was qualitatively explained in terms of the capillarity effect and the free volume at the grain boundaries exerting a negative hydrostatic pressure on the grains. With the change in crystal structure the typical ferroelectric behavior in dielectric properties evolved into that of a relaxor and finally into a paraelectric one. The overall changes in the dielectric behavior were interpreted on the basis of the size-driven phase transformation. An anomalous dielectric behavior, i.e., a relatively high dielectric constant over a wide range of temperature (30-330 degrees C), was observed at the average grain size of similar to 330 nm possibly due to a state of a single domain in a single grain, while below similar to 90 nm all the phases in the system practically transformed into the paraelectric cubic phase.close7