Exsolution of Ru Nanoparticles on BaCe0.9 Y0.1 O3-δ Modifying Geometry and Electronic Structure of Ru for Ammonia Synthesis Reaction Under Mild Conditions.

Green ammonia is an efficient, carbon-free energy carrier and storage medium. The ammonia synthesis using green hydrogen requires an active catalyst that operates under mild conditions. The catalytic activity can be promoted by controlling the geometry and electronic structure of the active species. An exsolution process is implemented to improve catalytic activity by modulating the geometry and electronic structure of Ru. Ru nanoparticles exsolved on a BaCe0.9 Y0.1 O3-δ support exhibit uniform size distribution, 5.03 ± 0.91 nm, and exhibited one of the highest activities, 387.31 mmolNH3  gRu -1  h-1 (0.1 MPa and 450 °C). The role of the exsolution and BaCe0.9 Y0.1 O3-δ support is studied by comparing the catalyst with control samples and in-depth characterizations. The optimal nanoparticle size is maintained during the reaction, as the Ru nanoparticles prepared by exsolution are well-anchored to the support with in-plane epitaxy. The electronic structure of Ru is modified by unexpected in situ Ba promoter accumulation around the base of the Ru nanoparticles.

Clinical history of female-to-male transgender patients is needed to avoid misinterpretation of cervical Papanicolaou tests.

OBJECTIVE: Cervical cancer screening is as important in female-to-male transgender (FTMT) patients as it is in cisgender female patients. The aim of this study was to examine the impact of clinical information regarding gender identity and testosterone therapy on the cytological interpretations. METHODS: A list of FTMT patients and cisgender female patients who had received a cervical Papanicolaou (Pap) test for cancer screening was obtained. The cytological diagnoses, rendered at the time of collection, were recorded. A retrospective slide review with knowledge of the pertinent clinical information, including testosterone therapy status, was performed. The data sets were statistically compared. RESULTS: Of 122 cervical Pap tests in 111 FTMT individuals, 23 (19%) had surgical follow-ups; 73 (60%) had HPV testing, of which 12 (16%) were positive for high-risk strains; and 79 (65%) were known to be receiving testosterone. On the "original" review, 12 (9.8%) tests were diagnosed as unsatisfactory. Seventy-one (58%) Pap tests were initially diagnosed as negative for intraepithelial lesion or malignancy (NILM) without atrophy and 32 (26%) with atrophy. Seven (5.7%) of the tests were initially diagnosed as abnormal. On the "retrospective" review, the rate of unsatisfactory tests remained the same, and atrophy was observed in 76 (62%) tests. The number of abnormal tests was reduced to 4 (3.3%) after the retrospective review. Almost all comparative studies returned a P-value of ≤0.05. CONCLUSION: Our findings indicate that clinical information regarding whether a subject is transgender and/or is receiving testosterone therapy is crucial to avoiding Pap test overcalls.

A comprehensive investigation of direct ammonia-fueled thin-film solid-oxide fuel cells: Performance, limitation, and prospects.

Ammonia is a promising carbon-free hydrogen carrier. Owing to their nickel-rich anodes and high operating temperatures, solid oxide fuel cells (SOFCs) can directly utilize NH3 fuel-direct-ammonia SOFCs (DA-SOFCs). Lowering the operating temperature can diversify application areas of DA-SOFCs. We tested direct-ammonia operation using two types of thin-film SOFCs (TF-SOFCs) under 500 to 650°C and compared these with a conventional SOFC. The TF-SOFC with a nickel oxide gadolinium-doped ceria anode achieved a peak power density of 1330 mW cm-2 (NH3 fuel under 650°C), which is the best performance reported to date. However, the performance difference between the NH3 and H2 operations was significant. Electrochemical impedance analyses, ammonia conversion quantification, and two-dimensional multi-physics modeling suggested that reduced ammonia conversion at low temperatures is the main cause of the performance gap. A comparative study with previously reported DA-SOFCs clarified that incorporating a more active ammonia decomposition catalyst will further improve low-temperature DA-SOFCs.

Accelerating problem-solving capacities of sub-national public health professionals: an evaluation of a digital immunization training intervention.

BACKGROUND: This article reports an evaluation of the Immunization Training Challenge Hackathons (ITCH), invented by The Geneva Learning Foundation (TGLF) for national and sub-national immunization staff who strive to develop the knowledge and capacity of others to improve immunization program performance. ITCH, a fully-digital program focused on networked collaborative problem-solving between peers, provided an "opt-in" activity for learners in the Teach to Reach (T2R) Accelerator Program designed to improve training effectiveness in the immunization sphere. METHODS: Conducted by a team from the University of Georgia, this mixed method evaluation consisted of thematic analysis of recorded sessions and open-ended comments; and statistical analyses of application and follow-up survey data. The evaluation focused on what was learned and how ITCH participants implemented what they learned. Key stakeholder interviews provided supplemental data about program intent and results. ITCH consisted of 17 30-min sessions held in 2020, in English and French, with 581 participating at least once out of 1,454 enrolled in the overall program. Challenge owners and respondents came from 15 African and Asian countries and spanned different roles with differing scope. RESULTS: Over 85% [n = 154] of survey respondents [n = 181, a 31% response rate] indicated they were able to implement what they learned from the ITCH sessions. A majority [n = 139, 76.7%] reported finding the sessions useful. Issues with poor connectivity and the timing of the live meetings impeded some in their ability to participate, a problem compounded by consequences of the pandemic. The ITCH process constituted of learning or coming to consciousness simultaneously of four types of learning - participants realizing how much they could learn from each other (peer learning), experiencing the power of defying distance to solve problems together (remote learning), and feeling a growing sense of belonging to a community (social learning), emergent across country borders and health system levels (networked learning). CONCLUSIONS: Based on evaluation findings, it was concluded that ITCH demonstrated an effective scalable, informal, non-didactic, experience-led, fast-paced, peer learning design. A focus on community engagement and developing brokering skills was recommended.

The Retrievability of Calcium Silicate-Based Sealer during Retreatment and the Effectiveness of Additional Passive Ultrasonic Irrigation: A Microcomputed Tomographic Study.

This study investigated the retreatability of EndoSeal MTA (Maruch, Wonju, Korea) according to the presence or absence of a canal isthmus and the additional use of passive ultrasonic irrigation (PUI) through microcomputed tomography (micro-CT) imaging. An epoxy resin sealer (AH Plus (Dentsply DeTrey, Konstanz, Germany)) was used as a reference for comparison. Forty-five artificial mandibular molars (TRUETOOTH #19, DELABS, Santa Barbara, CA) with a mesial canal with an isthmus and a distal canal without an isthmus were obturated using gutta-percha and one of the following sealers (n = 15 each): AH Plus, EndoSeal MTA, and EndoSeal MTA + PUI. Micro-CT scanning was performed to assess the void volume (as a percentage) at three root levels. After the root fillings were removed, second micro-CT scanning was conducted to evaluate the amount of remaining root filling material. The Kruskal-Wallis H test and post hoc analysis were used for between-group comparisons. The Mann-Whitney U test was used for comparisons between canals with and without an isthmus (p < 0.05). In the EndoSeal MTA group, the void volume and remaining filling materials were higher irrespective of the presence or absence of an isthmus. In apical lesions in the EndoSeal MTA group, the void ratio was significantly lower, and there was a significantly higher amount of remaining filling material. Regardless of the presence of an isthmus, the amount of remaining filling material of the EndoSeal + PUI group was reduced to a similar degree as the AH plus group. When performing retreatment for root canals filled with EndoSeal MTA, removal of the filling material can be more difficult in the apical region. The additional use of PUI can improve the efficacy of removal.

Comparison of Dentinal Tubule Penetration between a Calcium Silicate-Based Sealer with Ultrasonic Activation and an Epoxy Resin-Based Sealer: A Study Using Confocal Laser Scanning Microscopy.

OBJECTIVE: The aim of this study was to compare the degree of dentinal penetration between an epoxy resin-based sealer applied by using two different filling methods and an ultrasonically activated calcium silicate-based sealer via confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: Forty-five extracted permanent maxillary premolars with type II canals (Vertucci's classification) were subjected to the experiment. The root canals were instrumented and distributed randomly into the following three groups: AH Plus + continuous wave technique (AHC group); AH Plus + single cone technique (AHS group); and Endoseal MTA + single cone technique with ultrasonic activation (EMS) group. Each sealer was labeled with rhodamine B dye to allow visualization under CLSM. The sealer penetration depth in each sample was observed at 2 mm and 5 mm from the apex by using CLSM. The data were statistically analyzed by using analysis of variance or Kruskal-Wallis H test according to normality of variable (α = 0.05). RESULTS: In all groups, the maximum sealer penetration depth, mean fluorescence intensity, and sum fluorescence intensity values were higher at the 5-mm level than at the 2-mm level. At the 5-mm level, the EMS group showed the lowest value (p = 0.02). At the 2-mm level, there were no statistically significant differences among any of the groups. The AHC group showed higher values than the other groups, but there was no statistically significant difference in the apical area where access of instruments was difficult. CONCLUSION: The AHC group showed the highest dentinal tubule penetration, but had questionable filing efficacy in the apical area, which is of particular importance for the success of root canal treatment. Therefore, in areas such as the apical 2 mm of premolars with type II canals, which are difficult to access by using instruments such as heat carriers, other appropriate approaches may be required accordingly.

Naturally diffused sintering aid for highly conductive bilayer electrolytes in solid oxide cells.

Solid oxide cells (SOCs) are promising sustainable and efficient electrochemical energy conversion devices. The application of a bilayer electrolyte comprising wide electrolytic oxide and highly conductive oxide is essential to lower the operating temperatures while maintaining high performance. However, a structurally and chemically ideal bilayer has been unattainable through cost-effective conventional ceramic processes. Here, we describe a strategy of naturally diffused sintering aid allowing the fabrication of defect-free doped-zirconia/doped-ceria bilayer electrolyte with full density and reduced interdiffusion layer at lower sintering temperature owing to the supply of small but appropriate amount of sintering aid from doped zirconia to doped ceria that makes the thermal shrinkages of both layers perfectly congruent. The resulting SOCs exhibit a minimal ohmic loss of 0.09 ohm cm2 and remarkable performances in both fuel cell (power density exceeding 1.3 W cm−2) and electrolysis (current density of −1.27 A cm−2 at 1.3 V) operations at 700°C.

Comparison of Anti-Bacterial Efficacy between Passive Ultrasonic Irrigation and 980 nm-GaAlAs Laser Application in Two Root Types.

Background and Objectives: The purpose of the present study was to investigate the anti-bacterial efficacy of passive ultrasonic irrigation (PUI) and a 980-nm-gallium-aluminum-arsenide (GaAlAs) laser using a real-time DNA-based quantitative polymerase chain reaction (qPCR) assay and scanning electron microscopy (SEM). Materials and Methods: Eighty-six extracted single- and double-rooted human teeth were used in the experiment. The following four experimental groups were evaluated, as well as a control group: group 1: single root + PUI (n = 20); group 2: single root + laser application (n = 20); group 3: double roots + PUI (n = 20); group 4: double roots + laser application (n =20); control group (n = 6): 3 single roots, 3 double roots. The qPCR assay was performed in three stages to evaluate the efficacy of the adjunctive method against Enterococcus faecalis. SEM analysis was also used to examine the microstructure of root canal surfaces. The data were statistically analyzed using the Friedman test and the Kruskal-Wallis test with Bonferroni adjustment. Results: The decrease in the DNA levels from S1 (before preparation) to S2 (just after preparation) was highly significant in all groups, and decreases in DNA levels from S2 to S3 (after incubation for 1 week) were found in all experimental groups except group 1. An inter-group analysis showed that PUI was significantly more effective in terms of antibacterial efficacy than GaAlAs laser irradiation in single root (p < 0.05). However, in double roots, experimental groups did not show significantly lower DNA levels than the control group (p > 0.05). SEM images showed that cleaning of the root canal surface and reduction of dentin debris were achieved only in single-rooted teeth when using PUI application. Conclusions: Two adjunctive methods were effective in reducing E. faecalis in single rooted tooth.

Atypical de Quervain's thyroiditis diagnosed as atypia of undetermined significance by cytology and suspicious for cancer by Afirma Genomic Sequencing Classifier.

We report a case of atypical de Quervain's thyroiditis diagnosed as atypia of undetermined significance by cytology and suspicious for cancer by Afirma Genomic Sequencing Classifier. A 71-year-old male underwent thyroid ultrasound for goiter and was found to have two American Thyroid Association (ATA) 2015 high-suspicion nodules. The larger, 2.2-cm nodule was biopsied and the cytology showed atypical follicular cells and histiocytes. The Afirma Genomic Sequencing Classifier (detecting mRNA expression profile) result was ''suspicious'' (risk of malignancy ~50%) but Afirma Xpression Atlas (detecting specific mutations) did not find mutations in BRAF V600E, RET/PTC1, or RET/PTC3. The patient saw two endocrine surgeons and two endocrinologists who each recommended hemithyroidectomy. The patient chose to monitor the nodules. A new diagnostic ultrasound performed 3 months after the first one showed that the thyroid was significantly smaller and the previously seen nodules were no longer found. Re-examination of the cellular smears confirmed that the cytological findings were also compatible with de Quervain's thyroiditis. This case illustrates that atypical de Quervain's thyroiditis should be in the differential diagnosis of thyroid nodules for cytologists, radiologists, and clinicians. Furthermore, this case demonstrates that atypical de Quervain's thyroiditis can generate false positive results of molecular tests for indeterminate thyroid nodules.

Readily Constructed Glass Piston Pump for Gas Recirculation.

The recirculation of gases in a sealed reactor system is a broadly useful method in catalytic and electrocatalytic studies. It is especially relevant when a reactant gas reacts slowly with respect to residence time in a catalytic reaction zone and when mass transport control through the reaction zone is necessary. This need is well illustrated in the field of electrocatalytic N2 reduction, where the need for recirculation of 15N2 has recently become more apparent. Herein, we describe the design, fabrication, use, and specifications of a lubricant-free, readily constructed recirculating pump fabricated entirely from glass and inert polymer (poly(ether ether ketone) (PEEK), poly(tetrafluoroethylene) (PTFE)) components. Using these glass and polymer components ensures chemical compatibility between the piston pump and a wide range of chemical environments, including strongly acidic and organic electrolytes often employed in studies of electrocatalytic N2 reduction. The lubricant-free nature of the pump and the presence of components made exclusively of glass and PEEK/PTFE mitigate contamination concerns associated with recirculating gases saturated with corrosive or reactive vapors for extended periods. The gas recirculating glass pump achieved a flow rate of >500 mL min-1 N2 against atmospheric pressure at 15 W peak power input and >100 mL min-1 N2 against a differential pressure of +6 in. H2O (∼15 mbar) at 10 W peak power input.

Trends in the Surgical Management of Known or Suspected Differentiated Thyroid Cancer at a Single Institution, 2010-2018.

Background: The surgical management of nodular thyroid disease has been influenced by the advent of molecular diagnostics and recent guidelines recommending a more conservative approach to low-risk thyroid tumors. The purpose of this study was to assess practice changes arising from the early adoption of current literature within a single high-volume center. Methods: A retrospective cohort study of all patients evaluated or surgically treated for known or suspected thyroid cancer at a single institution was performed (2010-2018). We analyzed the yield of diagnostic thyroidectomy for indeterminate (Bethesda III and IV) nodules, the choice of initial operation for likely malignant (Bethesda V and VI) nodules, and the rate of completion thyroidectomy. The Cochran-Armitage test was used to assess the significance of any observed trends. Results: Of 2497 patients who underwent initial thyroidectomy from 2010 to 2018, 1791 patients had a tissue diagnosis of suspected or known thyroid cancer by cytopathology (Bethesda III-VI) or surgical pathology (differentiated thyroid cancer). In patients with likely malignant nodules but no clinical evidence of invasive or metastatic disease, the proportion managed with total thyroidectomy plus prophylactic neck dissection fell from 50% to 10% (p = 0.007). The proportion with likely malignant nodules managed definitively with thyroid lobectomy rose from 2% to 19% (p < 0.001). The rate of completion thyroidectomy for thyroid cancer found in the initial lobectomy specimen declined from 73% to 26% (p < 0.001). Among all patients with cytologically indeterminate nodules (n = 1036), we observed a decrease in the rate of diagnostic thyroidectomy from 67% to 35% over the study period (p = 0.015). Conclusions: The early adoption of new diagnostic technology and management guidelines has manifested in a less aggressive surgical approach to known or suspected thyroid cancer. Long-term follow-up will be required to assess oncologic and patient-centered outcomes arising from this modern strategy.

Association between overweight, obesity and incidence of advanced dental caries in South Korean adults: A 10-year nationwide population-based observational study.

The objective of this study was to evaluate the association between overweight, obesity and the incidence of advanced dental caries in South Korean adults, using alternate measures. The participants included 376,077 people aged 20 years and older who had health examination at least one time between 2005 and 2008. This evaluation is based on a change of body mass index (BMI) category, for 10 years, using a nationally representative data resource available from the National Health Insurance System. Instead of using decayed, missing, and filled teeth (DMFT), the diagnostic codes which indicate dental caries, pulpal disease and visiting frequency at dental health professionals were used in this case. A multivariate adjusted Cox regression analysis was performed to examine the association between advanced dental caries and BMI. In addition to the BMI, a multivariate analysis of gender, age, lifestyle behaviors and systemic disease information was included. To this end, the hazard ratio (HR) and 95% confidence interval (CI) were calculated. Chiefly, it is noted that the overweight and obese people were more likely to develop advanced dental caries independent of the noted variables. The positive association between high BMI and incidence of advanced dental caries was more prominent in the population's characteristic of people who were in a classification of the elderly and women. Among the health and lifecycle behaviors, smoking or not was found to be one of the factors affecting the results. The alternate method used in this study showed that being overweight and obesity had a direct association with the incidence of advanced dental caries in Korean adults.

Author Correction: A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

A micro-computed tomographic study of remaining filling materials of two bioceramic sealers and epoxy resin sealer after retreatment.

OBJECTIVE: This study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Extracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction. RESULTS: The tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds. CONCLUSIONS: Within the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.

A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements.

The electrochemical synthesis of ammonia from nitrogen under mild conditions using renewable electricity is an attractive alternative1-4 to the energy-intensive Haber-Bosch process, which dominates industrial ammonia production. However, there are considerable scientific and technical challenges5,6 facing the electrochemical alternative, and most experimental studies reported so far have achieved only low selectivities and conversions. The amount of ammonia produced is usually so small that it cannot be firmly attributed to electrochemical nitrogen fixation7-9 rather than contamination from ammonia that is either present in air, human breath or ion-conducting membranes9, or generated from labile nitrogen-containing compounds (for example, nitrates, amines, nitrites and nitrogen oxides) that are typically present in the nitrogen gas stream10, in the atmosphere or even in the catalyst itself. Although these sources of experimental artefacts are beginning to be recognized and managed11,12, concerted efforts to develop effective electrochemical nitrogen reduction processes would benefit from benchmarking protocols for the reaction and from a standardized set of control experiments designed to identify and then eliminate or quantify the sources of contamination. Here we propose a rigorous procedure using 15N2 that enables us to reliably detect and quantify the electrochemical reduction of nitrogen to ammonia. We demonstrate experimentally the importance of various sources of contamination, and show how to remove labile nitrogen-containing compounds from the nitrogen gas as well as how to perform quantitative isotope measurements with cycling of 15N2 gas to reduce both contamination and the cost of isotope measurements. Following this protocol, we find that no ammonia is produced when using the most promising pure-metal catalysts for this reaction in aqueous media, and we successfully confirm and quantify ammonia synthesis using lithium electrodeposition in tetrahydrofuran13. The use of this rigorous protocol should help to prevent false positives from appearing in the literature, thus enabling the field to focus on viable pathways towards the practical electrochemical reduction of nitrogen to ammonia.

Influence of Luting Materials and Methods and the Restoration Surface on the Amount of Cement Remnants in Implant Restorations.

This study aimed to investigate the effects of the luting methods on the amount of cement remnants in implant restorations and to determine the restoration surface with the maximum amount of residual cement. Forty abutments and crowns were divided into 4 groups as follows: TB group, luting with zinc oxide-eugenol cement; TBV group, luting with zinc oxide-eugenol cement after application of a separating agent over the transmucosal area of the abutment; PI group, luting with methacrylate cement; and PIV group, luting with methacrylate cement after application of a separating agent. After cementation, all the quadrants of the specimens were photographed, and the amount and location of the cement remnants were statistically analyzed (P ≤ .05). The amount of cement remnants was significantly smaller in the groups with a separating agent. The type of luting material did not significantly affect the results. Cement remnants were more abundant on the mesial and distal sides than on the buccal and lingual sides of the restoration.

Promotion of Pt/CeO2 catalyst by hydrogen treatment for low-temperature CO oxidation.

Low temperature CO oxidation reaction is known to be facilitated over platinum supported on a reducible cerium oxide. Pt species act as binding sites for reactant CO molecules, and oxygen vacancies on surface of cerium oxide atomically activate the reactant O2 molecules. However, the impacts of size of Pt species and concentration of oxygen vacancy at the surface of cerium oxide on the CO oxidation reaction have not been clearly distinguished, thereby various diverse approaches have been suggested to date. Here using the co-precipitation method we have prepared pure ceria support and infiltrated it with Pt solution to obtain 0.5 atomic% Pt supported on cerium oxide catalyst, and then systematically varied the size of Pt from single atom to ∼1.7 nm sized nanoparticles and oxygen vacancy concentration at surface of cerium oxide by controlling the heat-treatment conditions, which are temperature and oxygen partial pressure. It is found that Pt nanoparticles in range of 1-1.7 nm achieve 100% of CO oxidation reaction at ∼100 °C lower temperature compared to Pt single atom owing to the facile adsorption of CO but weaker binding strength between Pt and CO molecules, and the oxygen vacancy in the vicinity of Pt accelerates CO oxidation below 150 °C. Based on this understanding, we show that a simple hydrogen reduction at 550 °C for the single atom Pt supported on CeO2 catalyst induces the formation of highly dispersed Pt nanoparticles with size of 1.7 ± 0.2 nm and the higher concentration of surface oxygen vacancies simultaneously, enabling 100% conversion from CO to CO2 at 200 °C as well as 16% conversion even at 150 °C owing to the synergistic effects of Pt nanoparticles and oxygen vacancies.

Accuracy of new implant impression technique using dual arch tray and bite impression coping.

PURPOSE: The purpose of this in vitro study was to evaluate the accuracy of a new implant impression technique using bite impression coping and a dual arch tray. MATERIALS AND METHODS: Two implant fixtures were placed on maxillary left second premolar and first molar area in dentoform model. The model with two fixtures was used as the reference. The impression was divided into 2 groups, n=10 each. In group 1, heavy/light body silicone impression was made with pick up impression copings and open tray. In group 2, putty/light body silicone impression was made with bite impression copings and dual arch tray. The reference model and the master casts with implant scan bodies were scanned by a laboratory scanner. Surface tessellation language (STL) datasets from test groups was superimposed with STL dataset of reference model using inspection software. The three-dimensional deviation between the reference model and impression models was calculated and illustrated as a color-map. Data was analyzed by independent samples T-test of variance at α=.05. RESULTS: The mean 3D implant deviations of pick up impression group (group 1) and dual arch impression group (group 2) were 0.029 mm and 0.034 mm, respectively. The difference in 3D deviations between groups 1 and 2 was not statistically significant (P=.075). CONCLUSION: Within limitations of this study, the accuracy of implant impression using a bite impression coping and dual arch tray is comparable to that of conventional pick-up impression.

Comparison of Cytopathologist-Performed Ultrasound-Guided Fine-Needle Aspiration With Cytopathologist-Performed Palpation-Guided Fine-Needle Aspiration: A Single Institutional Experience.

CONTEXT.­: Although fine-needle aspiration (FNA) practice by pathologists is now well established, it has been primarily performed by manual palpation. In recent years, pathologists have begun to venture into ultrasound-guided FNAs (UGFNAs). Reports on experiences with this relatively new technique for pathologists have shown promising results. However to date, there have been few studies in the literature comparing pathologist-performed UGFNA with the more traditional pathologist-performed palpation-guided FNA (PGFNA). OBJECTIVE.­: To compare UGFNA to PGFNA by cytopathologists at an academic medical center. DESIGN.­: A retrospective study of FNAs performed by cytopathologists within the University of California, Los Angeles (UCLA) pathology departmental FNA clinic was performed. Data collected included performance technique (UGFNA versus PGFNA), lesion site and size, adequacy status (nondiagnostic rate), and number of passes per procedure. Corresponding surgical pathology/flow cytometric/cytogenetic result follow-up was compared to FNA results. Findings between UGFNA and PGFNA cases were compared. RESULTS.­: Of 1029 FNA cases during the study period, there were 449 UGFNA cases (43.6%) and 580 PGFNA cases (56.4%). Nondiagnostic rates with UGFNA and PGFNA were 6.7% (30 of 449 cases) and 20.7% (120 of 580 cases), respectively. Nondiagnostic rate was also significantly lower with UGFNA than with PGFNA for lesions within the thyroid (6.0% versus 33.3%), head and neck (6.6% versus 21.2%), and salivary gland (6.2% versus 17.1%), and across all nodule sizes. A total of 495 of 1029 FNA cases (48.1%) had follow-up. Discordance rate was significantly lower with UGFNA than with PGFNA (5.4% versus 12.8%). CONCLUSIONS.­: This study shows improved performance characteristics of cytopathologist-performed UGFNA versus PGFNA.