Three-dimensional reconstruction of Y-IrNi rhombic dodecahedron nanoframe by STEM/EDS tomography.

The structural analysis of nanocrystals via transmission electron microscopy (TEM) is a valuable technique for the material science field. Recently, two-dimensional images by scanning TEM (STEM) and energy-dispersive X-ray spectroscopy (EDS) have successfully extended to three-dimensional (3D) imaging by tomography. However, despite improving TEM instruments and measurement techniques, detector shadowing, the missing-wedge problem, X-ray absorption effects, etc., significant challenges still remain; therefore, the various required corrections should be considered and applied when performing quantitative tomography. Nonetheless, this 3D reconstruction technique can facilitate active site analysis and the development of nanocatalyst systems, such as water electrolysis and fuel cell. Herein, we present a 3D reconstruction technique to obtain tomograms of IrNi rhombic dodecahedral nanoframes (IrNi-RFs) from STEM and EDS images by applying simultaneous iterative reconstruction technique and total variation minimization algorithms. From characterizing the morphology and spatial chemical composition of the Ir and Ni atoms in the nanoframes, we were able to infer the origin of the physical and catalytic durability of IrNi-RFs. Also, by calculating the surface area and volume of the 3D reconstructed model, we were able to quantify the Ir-to-Ni composition ratio and compare it to the EDS measurement result.

Clinicopathological and Genetic Characteristics of Patients of Different Ages with Diffuse Sclerosing Variant Papillary Thyroid Carcinoma.

Diffuse sclerosing variant papillary thyroid carcinoma (DSVPTC) is commonly observed in young patients, with a median age at diagnosis in the third decade of life. Further, the risk of recurrence is higher for DSVPTC than for classical PTC. Therefore, this study aimed to describe the clinicopathological and genetic characteristics of patients of different ages with DSVPTC. We retrospectively reviewed 397 patients who underwent thyroidectomy for DSVPTC at Gangnam Severance Hospital, Yonsei University, from January 2005 to December 2017. The mean age at diagnosis was 36.7 ± 11.6 years, with most patients (163, 41.1%) aged 31-40 years. DSVPTC was predominant in women (276, 69.5%). We observed recurrence in 46 (11.6%) patients, with regional nodal recurrence being the most common type of recurrence (32 patients, 69.6%). The mean tumour size was larger in younger patients than in older patients. DSVPTC was more aggressive in paediatric patients with a larger-sized tumour, more common multiplicity, and lateral neck metastasis. Through random sampling, we selected 41 patients by age group and examined the mutations in 119 genes using next-generation sequencing. BRAF, KRAS, and TERT displayed relatively higher mutation rates than other genes. DSVPTC displays different clinical, pathological, and molecular profiles than classical PTC. The BRAF, KRAS, and TERT mutations are the most important, with age-specific differences.

Management of endocrine surgical disorders during COVID-19 pandemic: expert opinion for non-surgical options.

PURPOSE: The COVID-19 pandemic brought unprecedented conditions for overall health care systems by restricting resources for non-COVID-19 patients. As the burden of the disease escalates, routine elective surgeries are being cancelled. The aim of this paper was to provide a guideline for management of endocrine surgical disorders during a pandemic. METHODS: We used Delphi method with a nine-scale Likert scale on two rounds of voting involving 64 experienced eminent surgeons and endocrinologists who had the necessary experience to provide insight on endocrine disorder management. All voting was done by email using a standard questionnaire. RESULTS: Overall, 37 recommendations were voted on. In two rounds, all recommendations reached an agreement and were either endorsed or rejected. Endorsed statements include dietary change in primary hyperparathyroidism, Cinacalcet treatment in secondary hyperparathyroidism, alpha-blocker administration for pheochromocytoma, methimazole ± ß-blocker combination for Graves' disease, and follow-up for fine-needle aspiration results of thyroid nodules indicated as Bethesda 3-4 cytological results and papillary microcarcinoma. CONCLUSION: This survey summarizes expert opinion for the management of endocrine surgical conditions during unprecedented times when access to surgical treatment is severely disrupted. The statements are not applicable in circumstances in which surgical treatment is possible.

A Comparative Study of the Accuracy of Dental CAD Programs in Designing a Fixed Partial Denture.

PURPOSE: Error testing at each stage of prosthetic manufacturing remains relatively underdeveloped for computer-aided design/computer-aided manufacturing methods, and no experimental studies have validated the computer-aided design programs. This study aimed to test the accuracy and trueness of the computer-aided design of a three-unit fixed prosthesis. MATERIALS AND METHODS: Three computer-aided design programs (Exocad, Dental System™, and inLab 16) were tested on the designs of a three-unit fixed partial denture, and a three-dimensional analysis program was used to calculate the internal clearance error for the computer-aided design prostheses. The Kruskal-Wallis and Dunn's post hoc tests were used to reveal significant differences in trueness between the three computer-aided design programs (α < 0.05). RESULTS: Dental System™ showed the lowest mean error values for #24 and #26 at the mesial margin (both 0 µm), mesial wall (0.10, 0.12 µm, respectively), occlusal surface (-0.05, 0.10 µm), distal wall (0.23, -0.02 µm), and distal margin (both 0 µm). In sum, except for the mesial margin and distal margin site of tooth #26, the mean error value of Dental System™ was statistically the lowest, followed by those of Exocad and inLab 16 (p < 0.003). CONCLUSIONS: The accuracy of computer-aided design differed according to the type of computer-aided design program. Dental System™ achieved the best trueness at the margins, axial walls, and occlusal surface, followed by Exocad and inLab 16.

Pantoea ananatis carotenoid production confers toxoflavin tolerance and is regulated by Hfq-controlled quorum sensing.

Carotenoids are widely used in functional foods, cosmetics, and health supplements, and their importance and scope of use are continuously expanding. Here, we characterized carotenoid biosynthetic genes of the plant-pathogenic bacterium Pantoea ananatis, which carries a carotenoid biosynthetic gene cluster (including crtE, X, Y, I, B, and Z) on a plasmid. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the crtEXYIB gene cluster is transcribed as a single transcript and crtZ is independently transcribed in the opposite direction. Using splicing by overlap extension with polymerase chain reaction (SOE by PCR) based on asymmetric amplification, we reassembled crtE-B, crtE-B-I, and crtE-B-I-Y. High-performance liquid chromatography confirmed that Escherichia coli expressing the reassembled crtE-B, crtE-B-I, and crtE-B-I-Y operons produced phytoene, lycopene, and ß-carotene, respectively. We found that the carotenoids conferred tolerance to UV radiation and toxoflavin. Pantoea ananatis shares rice environments with the toxoflavin producer Burkholderia glumae and is considered to be the first reported example of producing and using carotenoids to withstand toxoflavin. We confirmed that carotenoid production by P. ananatis depends on RpoS, which is positively regulated by Hfq/ArcZ and negatively regulated by ClpP, similar to an important regulatory network of E. coli (HfqArcZ →RpoS Í° ClpXP). We also demonstrated that Hfq-controlled quorum signaling de-represses EanR to activate RpoS, thereby initiating carotenoid production. Survival genes such as those responsible for the production of carotenoids of the plant-pathogenic P. ananatis must be expressed promptly to overcome stressful environments and compete with other microorganisms. This mechanism is likely maintained by a brake with excellent performance, such as EanR.

Selection and functional identification of a synthetic partial ABA agonist, S7.

The stress hormone abscisic acid (ABA) helps plants to survive under abiotic stresses; however, its use as an agrochemical is limited by its chemical instability and expense. Here, we report the development of an in vivo screening system to isolate chemicals able to induce ABA signalling responses in rice (Oryza sativa) protoplasts. This system consists of an ABA-hypersensitive synthetic promoter containing ABRE and DRE motifs driving a luciferase reporter gene. After efficiently transfecting rice protoplasts with this construct, we screened chemicals library with a similar molecular weight and chemical structure to ABA and identified one chemical, S7, that induced ABA signalling by mediating interactions between the group I and II OsPYL receptors and certain OsPP2CAs in a yeast two-hybrid assay. In an in vitro pulldown assay, S7 was found to mediate a weak interaction between OsPYL5/8 and various OsPP2CAs. S7 treatments did not affect seedling growth or seed germination, but could reduce water loss. Rice seedlings treated with S7 exhibited transcriptome profiles that partially overlapped those treated with ABA. Taken together, we concluded that S7 is a new partial ABA agonist, which has potential use in future dissections of ABA signalling and as an agrochemical.

Clinical behavior and outcome of papillary T1 thyroid cancers: South Korea vs. Turkey vs. Colombia in a cohort study analyzing oncological outcomes.

BACKGROUND/PURPOSE: There has not been an international multicentric study to examine the relationship between thyroid cancer clinical outcomes and geographic location for South Korea, Colombia, and Turkey, whereas thyroid cancer is amongst the highest three cancer types seen in South Korea and Turkey. The aim of the study was to assess regional differences of T1 papillary thyroid cancer outcomes in Korea, Turkey and Colombia. METHODS: This is an observational non-randomized study. A total of 2720 patients who have been operated for T1 papillary thyroid cancer between 2011 and 2014 and are on routine follow-up have been recruited. The mean follow-up was 46.4 ± 10.7 months. Data were collected in a commonly used database and analyses were conducted. RESULTS: Patients participated in South Korea (88.2%), Turkey (9.1%) and Colombia (2.6%). Eighty percent were female. Female dominance tended to be higher in Colombia (p = 0.01). Mean age at diagnosis was 45.2 years. There was no mortality. Recurrence tended to be higher in Colombia (p < 0.001). Moreover, statistical analysis revealed differences among patients regarding symptoms (p < 0.001), family history (p < 0.001), euthyroidism (p < 0.001), anti-Tg and/or anti-TPO positivity (p < 0.001), FNAB results (p < 0.001), type of resection (p < 0.001), prophylactic central node dissection (p < 0.001), tumor size (p < 0.001), multifocality (p < 0.001), bilaterality (p < 0.001), tumor subtype (p < 0.001) and radioactive iodine treatment (p < 0.01). CONCLUSION: Thyroid cancer is becoming more commonly diagnosed worldwide. This international multicentric study has identified differences in disease presentation, treatment approaches and outcome, which need to be investigated, especially by increasing the number of participating countries. Future comparisons will facilitate developments in treatment for the benefit of patient outcomes.

Evaluation of Zirconia Surfaces after Strong-Acid Etching and Its Effects on the Shear Bond Strength of Dental Resin Cement.

The present study was intended to investigate changes in the microstructure and phase transformation of zirconia surfaces using etching and airborne-particle abrasion (AB) and the effects of these processes on the shear bond strength of dental resin cements to zirconia. Four groups were classified according to the surface treatment as follows: etching for 15 min (ET15), etching for 30 min (ET30), AB, and etching for 15 min following AB (ABET). These groups were then classified into two subgroups (a total of 8 groups with 11 specimens/group) according to the resin cement used for bonding, namely, Rely-X U200 (3M ESPE, St. Paul, MN, USA) or Panavia F 2.0 (Kuraray, Kurashiki, Okayama, Japan). Shear bond strength testing was performed using a universal testing device. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were also performed. When using Rely-X U200, ET15 exhibited the highest mean shear bond strength; the strengths of ET15, ABET, and ET30 were significantly higher than that of AB. When using Panavia F 2.0, ABET demonstrated the highest mean shear bond strength; the strengths of ABET and ET15 were significantly higher than those of ET30 and AB. The etched surface of zirconia could be observed using SEM, and the phase transformations resulting from each surface treatment were detected by XRD. Strong-acid etching of zirconia induced significant surface changes that increased the shear bond strength of resin cement, and the resin adhesive strength was higher when zirconia was etched with strong acid vs. AB alone.

Structural determinants for pyrabactin recognition in ABA receptors in Oryza sativa.

KEY MESSAGE: We determined the structure of OsPYL/RCAR3:OsPP2C50 complex with pyrabactin. Our results suggest that a less-conserved phenylalanine of OsPYL/RCAR subfamily I is one of considerations of ABA agonist development for Oryza sativa. Pyrabactin is a synthetic chemical mimicking abscisic acid (ABA), a naturally occurring phytohormone orchestrating abiotic stress responses. ABA and pyrabactin share the same pocket in the ABA receptors but pyrabactin modulates ABA signaling differently, exhibiting both agonistic and antagonistic effects. To explore structural determinants of differential functionality of pyrabactin, we determined the crystal structure of OsPYL/RCAR3:pyrabactin:OsPP2C50, the first rice ABA receptor:co-receptor complex structure with a synthetic ABA mimicry. The water-mediated interaction between the wedging Trp-259 of OsPP2C50 and pyrabactin is lost, undermining the structural integrity of the ABA receptor:co-receptor. The loss of the interaction of the wedging tryptophan of OsPP2C with pyrabactin appears to contribute to the weaker functionality of pyrabactin. Pyrabactin in the OsPYL/RCAR3:OsPP2C50 complex adopts a conformation different from that in ABA receptors from Arabidopsis. Phe125, specific to the subfamily I of OsPYL/RCARs in the ABA binding pocket, appears to be the culprit for the differential conformation of pyrabactin. Although the gate closure essential for the integrity of ABA receptor:co-receptor is preserved in the presence of pyrabactin, Phe125 apparently restricts accessibility of pyrabactin, leading to decreased affinity for OsPYL/RCAR3 evidenced by phosphatase assay. However, Phe125 does not affect conformation and accessibility of ABA. Yeast two-hybrid, germination and gene transcription analyses in rice also support that pyrabactin imposes a weak effect on the control of ABA signaling. Taken together, our results suggest that phenylalanine substitution of OsPYL/RCARs subfamily I may be one of considerations for ABA synthetic agonist development.

A Dominant Negative OsKAT2 Mutant Delays Light-Induced Stomatal Opening and Improves Drought Tolerance without Yield Penalty in Rice.

Stomata are the main gateways for water and air transport between leaves and the environment. Inward-rectifying potassium channels regulate photo-induced stomatal opening. Rice contains three inward rectifying shaker-like potassium channel proteins, OsKAT1, OsKAT2, and OsKAT3. Among these, only OsKAT2 is specifically expressed in guard cells. Here, we investigated the functions of OsKAT2 in stomatal regulation using three dominant negative mutant proteins, OsKAT2(T235R), OsKAT2(T285A) and OsKAT2(T285D), which are altered in amino acids in the channel pore and at a phosphorylation site. Yeast complementation and patch clamp assays showed that all three mutant proteins lost channel activity. However, among plants overexpressing these mutant proteins, only plants overexpressing OsKAT2(T235R) showed significantly less water loss than the control. Moreover, overexpression of this mutant protein led to delayed photo-induced stomatal opening and increased drought tolerance. Our results indicate that OsKAT2 is an inward- rectifying shaker-like potassium channel that mainly functions in stomatal opening. Interestingly, overexpression of OsKAT2(T235R) did not cause serious defects in growth or yield in rice, suggesting that OsKAT2 is a potential target for engineering plants with improved drought tolerance without yield penalty.

Random Item MIRID Modeling and Its Application.

The Model With Internal Restrictions on Item Difficulty (MIRID; Butter, 1994) has been useful for investigating cognitive behavior in terms of the processes that lead to that behavior. The main objective of the MIRID model is to enable one to test how component processes influence the complex cognitive behavior in terms of the item parameters. The original MIRID model is, indeed, a fairly restricted model for a number of reasons. One of these restrictions is that the model treats items as fixed and does not fit measurement contexts where the concept of the random items is needed. In this article, random item approaches to the MIRID model are proposed, and both simulation and empirical studies to test and illustrate the random item MIRID models are conducted. The simulation and empirical studies show that the random item MIRID models provide more accurate estimates when substantial random errors exist, and thus these models may be more beneficial.

Preparation of a Proton-Exchange Me mbrane with -SO3H Group Based on Polyethylene and Poly(vinylidene fluoride) Film by Radiation-Induced Graft Polymerization for Proton-Exchange Fuel Cell.

This paper reports the preparation of a proton-exchange membrane (PEM) with sulfonic acid (-SO3H) groups based on polyethylene (PE) films and poly(vinylidene fluoride) (PVdF) films by the radiation-induced graft polymerization (RIGP) of sodium styrene sulfonate (NaSS) in the presence of the polymerizable access agents, such as acrylic acid and pyrollidone in a methanol solution. A PEM with -SO3H based on PE and PVdF films were confirmed by ATR, XPS and contact angle measurements. The water uptake (%), graft yield (%), ion-exchange content (mmol/g), and proton conductivity (S/cm), as well as the current density (mA/cm2), and power density (mW/cm) for PEM with -SO3H groups prepared by RIGP were evaluated. The PEM prepared with the -SO3H groups based on PE and PVdF films can be used as a proton-exchange fuel cell membrane.

In Vitro Metabolism of Flucetosulfuron by Human Liver Microsomes.

To investigate herbicide metabolism, human liver microsomes were incubated with threo- and erythro-isomers of flucetosulfuron. Each isomer produced one metabolite; the metabolites were unambiguously identified as enzymatic hydrolysis products by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). These metabolites were synthesized, producing white solids characterized using LC-MS/MS and nuclear magnetic resonance spectroscopy (1H and 13C). Using specific esterase inhibitors and activators, carboxylesterases and cholinesterases were demonstrated to be involved in flucetosulfuron metabolism. Under optimized metabolic conditions, the kinetic parameters for metabolite formation from threo-flucetosulfuron and erythro-flucetosulfuron were: Vmax, 151.41 and 134.38 nmol/min/mg protein, respectively; Km, 2957.37 and 2798.53 µM, respectively; and CLint, 51.20 and 48.02 µL/min/mg microsomes respectively. No significant kinetic differences were observed between the two isomers. These results indicated that the primary metabolic pathway for both flucetosulfuron isomers in human liver microsomes involves hydrolysis, catalyzed by carboxylesterase and cholinesterase.

A simple and sensitive biosensor strain for detecting toxoflavin using ß-galactosidase activity.

In this study, we developed a simple and sensitive biosensor for the determination of toxoflavin (which is toxic to various plants, fungi, animals, and bacteria) in natural samples based on ß-galactosidase activity. The proposed toxoflavin detection method for toxin-producing bacteria or toxin-contaminated foods is simple and cost effective. Burkholderia glumae, a species known to cause rice grain rot and wilt in various field crops, produces toxoflavin under the control of a LysR-type transcriptional regulator ToxR and its ligand toxoflavin. As the expression of toxoflavin biosynthetic genes requires toxoflavin as a co-activator of ToxR, a novel biosensor stain was constructed based on lacZ reporter gene integration into the first gene of the toxoflavin biosynthesis operon, toxABCDE of B. glumae. The biosensor was composed of a sensor strain (COK71), substrates (X-gal or ONPG), and culture medium, without any complex preparation process. We demonstrated that the biosensor strain is highly specific to toxoflavin, and can quantify relative amounts of toxoflavin compared with known concentrations of toxoflavin. The proposed method was reliable and simple; samples containing 50-500 nM of toxoflavin could be analyzed. More importantly, the proposed biosensor strain could identify toxoflavin-producing bacteria in real samples. The excellent performance of this biosensor is useful for diagnostic purposes, such as detecting toxoflavin-contaminated foods and environmental samples.

A retrospective study on related factors affecting the survival rate of dental implants.

PURPOSE: The aim of this retrospective study is to analyze the relationship between local factors and survival rate of dental implant which had been installed and restored in Seoul Veterans Hospital dental center for past 10 years. And when the relationship is found out, it could be helpful to predict the prognosis of dental implants. MATERIALS AND METHODS: A retrospective study of patients receiving root-shaped screw-type dental implants placed from January 2000 to December 2009 was conducted. 6385 implants were placed in 3755 patients. The following data were collected from the dental records and radiographs: patient's age, gender, implant type and surface, length, diameter, location of implant placement, bone quality, prosthesis type. The correlations between these data and survival rate were analyzed. Statistical analysis was performed with the use of Kaplan-Meier analysis, Chi-square test and odds ratio. RESULTS: In all, 6385 implants were placed in 3755 patients (3120 male, 635 female; mean age 65 ± 10.58 years). 108 implants failed and the cumulative survival rate was 96.33%. There were significant differences in age, implant type and surface, length, location and prosthesis type (P<.05). No significant differences were found in relation to the following factors: gender, diameter and bone quality (P>.05). CONCLUSION: Related factors such as age, implant type, length, location and prosthesis type had a significant effect on the implant survival.