An interlaboratory capillary zone electrophoresis-UV study of various monoclonal antibodies, instruments, and ε-aminocaproic acid lots

Capillary zone electrophoresis ultraviolet (CZE-UV) has become increasingly popular for the charge heterogeneity determination of mAbs and vaccines. The ε-aminocaproic acid (eACA) CZE-UV method has been used as a rapid platform method. However, in the last years, several issues have been observed, for example, loss in electrophoretic resolution or baseline drifts. Evaluating the role of eACA on the reported issues, various laboratories were requested to provide their routinely used eACA CZE-UV methods, and background electrolyte compositions. Although every laboratory claimed to use the He et al. eACA CZE-UV method, most methods actually deviate from He's. Subsequently, a detailed interlaboratory study was designed wherein two commercially available mAbs (Waters' Mass Check Standard mAb [pI 7] and NISTmAb [pI 9]) were provided to each laboratory, along with two detailed eACA CZE-UV protocols for a short-end, high-speed, and a long-end, high-resolution method. Ten laboratories participated each using their own instruments, and commodities, showing excellence method performance (relative standard deviations [RSDs] of percent time-corrected main peak areas from 0.2% to 1.9%, and RSDs of migration times from 0.7% to 1.8% [n = 50 per laboratory], analysis times in some cases as short as 2.5 min). This study clarified that eACA is not the main reason for the abovementioned variations.

Flow Cytometry Method Validation Protocols

Analytical method validation provides a means to ensure that data are credible and reproducible. This article will provide a brief introduction to analytical method validation as applied to cellular analysis by flow cytometry, along with practical procedures for four different types of validation. The first, Basic Protocol 1 (the limited validation protocol), is recommended for research and non-regulated laboratories. Next, Basic Protocol 2) presents a reasonable, fit-for-purpose validation approach appropriate for biopharma and research settings. Basic Protocol 3 addresses the type of validation performed in clinical laboratories for moderate-risk tests developed in house. Finally, Basic Protocol 4 describes the process that should be applied whenever a method is being transferred from one facility to another. All four validation plans follow the fit-for-purpose validation approach, in which the validation parameters are selected based on the intended use of the assay. These validation protocols represent the minimal requirement and may not be applicable for every intended use such as high-risk clinical assays or data to be used as a primary endpoint in a clinical trial. The recommendations presented here are consistent with the white papers published by the American Association of Pharmaceutical Scientists and the International Clinical Cytometry Society, as well as with Clinical Laboratory Standards Institute Guideline H62: Validation of Assays Performed by Flow Cytometry (CLSI, 2021). © 2023 Wiley Periodicals LLC. Basic Protocol 1: Limited validation Basic Protocol 2: Fit-for-purpose validation for biopharma and research settings Basic Protocol 3: Validation for moderate clinical risk laboratory developed tests Basic Protocol 4: Transfer validation.

Discordance of HER2 Expression and/or Amplification on Repeat Testing

We sought to assess discordance of HER2 status in patients with HER2-amplified/expressing solid tumors who underwent reevaluation of HER2 status. Patients with metastatic solid tumors and HER2 expression by IHC or amplification by FISH/next-generation sequencing on local testing underwent central HER2 IHC/FISH testing with either archival or fresh biopsies and were evaluated for discordance in HER2 status. 70 patients (12 cancer types) underwent central HER2 reevaluation, including 57 (81.4%) with a new biopsy. In 30 patients with HER2 3+ on local IHC, 21 (70.0%) were 3+, 5 (16.7%) were 2+, 2 (6.7%) were 1+, and 2 (6.7%) had 0 HER2 expression on central IHC. In 15 patients whose cancers were 2+ on local IHC, 2 (13.3%) were 3+, 5 (33.3%) were 2+, 7 (46.7%) were 1+, and 1 (6.7%) had 0 HER2 expression on central IHC. HER2 discordance was seen in 16 of 52 (30.8%) of patients with HER2 overexpression/amplification who underwent a new image-guided biopsy. Discordance was observed in 10 (33.3%) of 30 patients who received intervening HER2-targeted therapy and in 6 (23.8%) of 22 patients who did not. In the 8 patients who had central HER2 assessment from the same archival block used for local testing, none were discordant. Discordance of HER2 status is common in patients with tumors previously identified as HER2-expressing, especially in patients with HER2 2+ tumors. Repeat biomarker evaluation may have value when considering HER2-targeted therapies.

Evaluation of custom posts and cores fabricated by two digital technologies in core and post space dimensions

PURPOSE

To evaluate the adaptability between posts and post spaces and the rationality of cores fabricated by two digital custom post-and-core processes.

MATERIALS AND METHODS

Titanium post-and-cores were fabricated by digital scanning impression technology or digital scanning wax-pattern technology on tooth defect molds of incisors, premolars, and molars, with traditional lost-wax casts of these teeth as the controls. Micro-CT and a laboratory scanner were used to determine intervals between post wall and root canal wall of the root apex, middle, and cervix of each sample in cross-, sagittal, and coronal sections; intervals between the end of post and tooth; diameters of cervical, middle, and incisal part at cross-, sagittal, and coronal sections of each sample, as well as shoulder widths.

RESULTS

The three fabrication processes showed significant differences in intervals between post-and-core prostheses and root canal walls, diameters of all parts of cores, and shoulder widths. Scanning impressions showed significant advantages in the main part of post-and-cores in incisors and premolars, while the scanning wax-pattern process showed obvious inferiorities in premolars and molars. As to core spatial size, values of measured sites in the scanning impression process were closer to the standard than those of the traditional process, while differences between the measured value of the scanning wax-pattern process were much more obvious than in the traditional process.

CONCLUSIONS

The use of digital custom post-and-core scanning impressions improved the rationality and precision of post-and-core dimensions compared with two other processes.

Comparison of Analytical Procedures in Method Transfer and Bridging Experiments

Comparison of two analytical procedures is the primary objective of a method transfer or when replacing an old procedure with a new one in a single lab. Guidance for comparing two analytical procedures is provided in USP <1010> based on separate tests for accuracy and precision. Determination of criteria is somewhat problematic for these comparisons because of the interdependence of accuracy and precision. In this paper, a total error approach is proposed that requires a single criterion based on an allowable out-of-specification (OOS) rate at the receiving lab. This approach overcomes the difficulty of allocating acceptance criteria between precision and bias. Computations can be performed with any simulation software. Numerical examples are provided for four experimental designs that are typical in a method transfer study. Finally, recommendations are provided to help the user set criteria that provide an acceptable probability of passing for practical sample sizes.

An Evaluation of the Accuracy and Precision of Ceramic Orthodontic Bracket Slot Dimensions Utilizing Micro-Computed Tomography (Micro-CT)

This study's aim is to determine the accuracy and precision of the bracket slot height in MBT 0.022″ ceramic brackets. Five brackets from 11 different systems (n = 55) were scanned using micro-computed tomography (micro-CT). The slot height was measured at the face (external) and base (internal) of the slot. Data were analyzed using a One-Sample t-Test, and a Paired t-Test. The lowest external height was seen in OrthoCare Purity^® at 0.02264″ (2.9%), and the greatest in TOC Ghost Advanced^® at 0.02736″ (24.4%). The lowest internal height was seen in Forestadent Glam^® at 0.02020″ (-8.2%), and the greatest in TOC Ghost Advanced^® at 0.2547″ (15.8%). OrthoCare Purity^® measurements corresponded most closely with the expected measurements. TP InVu^® was found to be the most precise bracket for external height (range = 0.00043″) and American Orthodontics 20/40^® for internal height (range = 0.00028″). In assessing slot geometry, all brackets demonstrated a higher mean external slot height compared to the internal measurements at the base of the bracket. Orthodontic bracket slots are larger than expected and slot parallelism was not observed in any bracket brand tested. Similarly, slot dimensions are imprecise where two 'identical' brackets have different slot sizes. The clinician should, therefore, assume that play is most likely higher than expected.

Comparative analysis on efficiency and accuracy of parallel confocal microscopy and three-dimensional in motion video with triangulation technology-based intraoral scanner under influence of moisture and mouth opening - A crossover clinical trial

Aim

The intraoral scanners are digital devices used to digitise the oral tissues. The accuracy of the intraoral scanners has been studied under different environmental conditions, but there might be differences that occur in the actual oral environment, which is still in question. The aim of the study was to evaluate the accuracy and efficiency of Parallel Confocal Microscopy and 3D in motion video with triangulation technology-based intraoral scanners under the influence of moisture and mouth opening.

Settings and Design

This was an Cross over clinical controlled study.

Materials and Methods

The controlled in vivo study included healthy subjects who were in need of CBCT for the purpose of locating the position of unerupted third molars before going abroad for a job. The subjects were exposed to scans in the upper and lower jaws with two intraoral scanners based on 3D motion video technology with triangulation (Medit) and parallel confocal microscopy (Trios) under the influence of two oral conditions, which were moisture (presence and absence of moisture) and mouth opening (30 mm and 50 mm, respectively). A total of 96 scans were obtained and superimposed individually over the reference CBCT scans to find the deviations in the Geomagic Rapidform (version 2020, USA) software. The efficiency of the scanners was calculated by recording the time taken and the number of images obtained after each scan.

Statistical Analysis Used

The significance was calculated by using the independent and paired sample t test in SPSS software (IBM, version 23).

Results

Based on the surface analysis, the trueness of the intra-oral scanners had statistically significant differences when compared between 3D in motion video technology with Triangulation and Parallel Confocal Microscopy (P < 0.05) whereas no statistical significance was observed in precision. There was a significant difference observed in the efficiency of the intra-oral scanners (P < 0.05).

Conclusion

There is a significant difference in the accuracy and efficiency of the intraoral scanners under the influence of oral conditions, such as different moisture levels and mouth opening conditions. 3D in motion video technology with Triangulation showed better results with the least deviation than Parallel Confocal Microscopy.

WITHDRAWN: Accuracy and reproducibility of tablet-based applications for three-dimensional facial scanning: an in-vitro study

This article has been withdrawn at the request of the author(s).

Short-Term Precision and Repeatability of Radiofrequency Echographic Multi Spectrometry (REMS) on Lumbar Spine and Proximal Femur: An In Vivo Study

To determine the short-term intra-operator precision and inter-operator repeatability of radiofrequency echographic multi-spectrometry (REMS) at the lumbar spine (LS) and proximal femur (FEM). All patients underwent an ultrasound scan of the LS and FEM. Both precision and repeatability, expressed as root-mean-square coefficient of variation (RMS-CV) and least significant change (LSC) were obtained using data from two consecutive REMS acquisitions by the same operator or two different operators, respectively. The precision was also assessed in the cohort stratified according to BMI classification. The mean (±SD) age of our subjects was 48.9 ± 6.8 for LS and 48.3 ± 6.1 for FEM. Precision was assessed on 42 subjects at LS and 37 subjects on FEM. Mean (±SD) BMI was 24.71 ± 4.2 for LS and 25.0 ± 4.84 for FEM. Respectively, the intra-operator precision error (RMS-CV) and LSC resulted in 0.47% and 1.29% at the spine and 0.32% and 0.89% at the proximal femur evaluation. The inter-operator variability investigated at the LS yielded an RMS-CV error of 0.55% and LSC of 1.52%, whereas for the FEM, the RMS-CV was 0.51% and the LSC was 1.40%. Similar values were found when subjects were divided into BMI subgroups. REMS technique provides a precise estimation of the US-BMD independent of subjects' BMI differences.

Quantifying the age structure of free-ranging delphinid populations: Testing the accuracy of Unoccupied Aerial System photogrammetry

Understanding the population health status of long-lived and slow-reproducing species is critical for their management. However, it can take decades with traditional monitoring techniques to detect population-level changes in demographic parameters. Early detection of the effects of environmental and anthropogenic stressors on vital rates would aid in forecasting changes in population dynamics and therefore inform management efforts. Changes in vital rates strongly correlate with deviations in population growth, highlighting the need for novel approaches that can provide early warning signs of population decline (e.g., changes in age structure). We tested a novel and frequentist approach, using Unoccupied Aerial System (UAS) photogrammetry, to assess the population age structure of small delphinids. First, we measured the precision and accuracy of UAS photogrammetry in estimating total body length (TL) of trained bottlenose dolphins (Tursiops truncatus). Using a log-transformed linear model, we estimated TL using the blowhole to dorsal fin distance (BHDF) for surfacing animals. To test the performance of UAS photogrammetry to age-classify individuals, we then used length measurements from a 35-year dataset from a free-ranging bottlenose dolphin community to simulate UAS estimates of BHDF and TL. We tested five age classifiers and determined where young individuals (<10 years) were assigned when misclassified. Finally, we tested whether UAS-simulated BHDF only or the associated TL estimates provided better classifications. TL of surfacing dolphins was overestimated by 3.3% ±3.1% based on UAS-estimated BHDF. Our age classifiers performed best in predicting age-class when using broader and fewer (two and three) age-class bins with ~80% and ~72% assignment performance, respectively. Overall, 72.5%-93% of the individuals were correctly classified within 2 years of their actual age-class bin. Similar classification performances were obtained using both proxies. UAS photogrammetry is a non-invasive, inexpensive, and effective method to estimate TL and age-class of free-swimming dolphins. UAS photogrammetry can facilitate the detection of early signs of population changes, which can provide important insights for timely management decisions.

Study of Liquid-Based Cytology Using Next-Generation Sequencing as a Liquid Biopsy Application in Patients with Advanced Oncological Disease

In patients with advanced cancer, it is necessary to detect driver mutations and genetic arrangements. If a mutation is found, targeted therapy may become an option. However, in most patients with advanced cancer, obtaining material can be challenging, and these determinations must be made based on small biopsies or cytologic samples. We analyzed the ability of liquid-based cytology to determine the mutational status in patients with advanced cancer by next-generation sequencing. We studied cytologic samples from 28 patients between 1 January 2018 and 31 December 2022. All samples were processed by next-generation sequencing using the Oncomine^® Precision and Comprehensive Assay Panels for Solid Tumors. Eleven male and 17 female patients with a median age of 63.75 years were included. Clinical stage IV was predominant in 21 patients. Eleven patients died, and 17 survived. The DNA and RNA concentrations were 10.53 ng/µL and 13 ng/µL, respectively. Eleven patients showed actionable mutations, and 17 showed other genomic alterations. Liquid-based cytology can be used as a component of liquid biopsy, as it allows the identification of actionable mutations in patients with advanced oncological disease. Our findings expand the utility of liquid biopsy from different body fluids or cell aspirates.

Reproducibility of the digital palate in forensic investigations, a two-year retrospective cohort study of twins

OBJECTIVES

The palatal scans of the same individuals were compared after two years to assess forensic reproducibility. The effect of orthodontic treatment, the comparison area and the digitization approach were investigated.

METHODS

The palate was scanned in 20 pairs of monozygotic twins by an intraoral scanner (IOS) three times to assess repeatability. They were rescanned two years later by two different IOSs. An elastic impression and a plaster model were also made and scanned by a laboratory scanner (indirect digitization). Mean absolute distance between scans was compared after best-fit alignment. Scans from the two sessions were compared to evaluate the combined effect of aging, orthodontic treatment and different digitization methods (forensic reproducibility). Additionally, the scans of different digitization methods from the second session were compared (technical reproducibility). The between-siblings difference was compared in the two sessions to evaluate the effect of aging on palatal morphology.

RESULTS

The anterior palatal area showed significantly better repeatability and forensic reproducibility than the whole palate (p<0.001), but orthodontic treatment had no effect. Indirect digitization produced lower forensic and technical reproducibility than IOSs. For IOSs, repeatability (22 µm) was significantly (p<0.001) better than either forensic (75-77 µm) or technical reproducibility (37 µm). No significant changes were observed from the first to the second session in the between-sibling comparison. The closest between-sibling value (239 µm) considerably exceeded the highest forensic reproducibility value (141 µm).

CONCLUSIONS

Reproducibility is acceptable between the different IOSs, even two years apart, but is poor between IOS and indirect digitization. The anterior palate is relatively stable in young adults.

CLINICAL SIGNIFICANCE

Intraoral scanning of the anterior palatal area has superior reproducibility, regardless of the IOS brand. Therefore, the IOS method could be suitable for identifying humans through anterior palatal morphology. However, the digitization of elastic impressions or plaster models had low reproducibility, preventing their application for forensic purposes.

Same but different: how agency modulates pain perception

Why is analgesic treatment more effective when it is self-administered? Strube et al. compare two possible accounts and show that the effect of agency on perception is linked to a shift in expectation (prior) rather than to reduced likelihood precision, highlighting that agency has a profound impact on the entire perceptual process.

Computational mechanisms of belief updating in relation to psychotic-like experiences

Introduction

Psychotic-like experiences (PLEs) may occur due to changes in weighting prior beliefs and new evidence in the belief updating process. It is still unclear whether the acquisition or integration of stable beliefs is altered, and whether such alteration depends on the level of environmental and belief precision, which reflects the associated uncertainty. This motivated us to investigate uncertainty-related dynamics of belief updating in relation to PLEs using an online study design.

Methods

We selected a sample (n = 300) of participants who performed a belief updating task with sudden change points and provided self-report questionnaires for PLEs. The task required participants to observe bags dropping from a hidden helicopter, infer its position, and dynamically update their belief about the helicopter's position. Participants could optimize performance by adjusting learning rates according to inferred belief uncertainty (inverse prior precision) and the probability of environmental change points. We used a normative learning model to examine the relationship between adherence to specific model parameters and PLEs.

Results

PLEs were linked to lower accuracy in tracking the outcome (helicopter location) (β = 0.26 ± 0.11, p = 0.018) and to a smaller increase of belief precision across observations after a change point (β = -0.003 ± 0.0007, p < 0.001). PLEs were related to slower belief updating when participants encountered large prediction errors (β = -0.03 ± 0.009, p = 0.001). Computational modeling suggested that PLEs were associated with reduced overall belief updating in response to prediction errors (βPE = -1.00 ± 0.45, p = 0.028) and reduced modulation of updating at inferred environmental change points (βCPP = -0.84 ± 0.38, p = 0.023).

Discussion

We conclude that PLEs are associated with altered dynamics of belief updating. These findings support the idea that the process of balancing prior belief and new evidence, as a function of environmental uncertainty, is altered in PLEs, which may contribute to the development of delusions. Specifically, slower learning after large prediction errors in people with high PLEs may result in rigid beliefs. Disregarding environmental change points may limit the flexibility to establish new beliefs in the face of contradictory evidence. The present study fosters a deeper understanding of inferential belief updating mechanisms underlying PLEs.

Accuracy (trueness and precision) of four tablet-based applications for three-dimensional facial scanning: an in-vitro study.: Tablet-based applications for 3D facial scanning

OBJECTIVES

This study aimed to investigate the overall and regional accuracy (trueness and precision) of digital three-dimensional (3D) facial scans obtained from four tablet-based applications, which were (Bellus) the Bellus Dental Pro® (Bellus3D, Inc. Campbell, CA, USA), (Capture) the Capture®: 3D Scan Anything (Standard Cyborg, Inc. San Francisco, CA, USA), (Heges) the Heges® (by Marek Simonik, Ostrava, North Moravia, Czech Republic), and (Scandy) the Scandy Pro 3D Scanner® (Scandy LLC, New Orleans, LA, USA).

METHODS

A mannequin's face was marked with 63 landmarks. Subsequently, it was scanned 5 times using each scan application on an iPad Pro® (Apple Inc., Cupertino, CA, USA). The digital measurements were obtained with MeshLab® (CNR-ISTI, Pisa, Tuscany, Italy) and compared to the manual measurements using a digital vernier caliper (Truper Herramientas S.A., Colonia Granada, Mexico City, Mexico). The absolute mean difference and the standard deviation of the dimensional discrepancies were calculated. Moreover, the data were analysed by using one-way ANOVA, Levene's test, and Bonferroni´s correction.

RESULTS

The absolute mean trueness values were Bellus 0.41 ± 0.35 mm, Capture 0.38 ± 0.37 mm, Heges 0.39 ± 0.38 mm, and Scandy 0.47 ± 0.44 mm. Moreover, precision values were Bellus 0.46 mm, Capture 0.46 mm, Heges 0.54 mm, and Scandy 0.64 mm. Comparing the regions, Capture and Scandy showed the highest absolute mean difference, which was 0.81 mm in the Frontal and Zygomaticofacial regions, respectively.

CONCLUSIONS

The trueness and precision of all four tablet-based applications were clinically acceptable for diagnosis and treatment planning.

CLINICAL SIGNIFICANCE

The future of the three-dimensional facial scan is auspicious, and it has the potential to be affordable, accurate, and of great value for clinicians in their daily practice.

An Esthetic Approach for Rehabilitation of Long-Span Edentulous Arch Using Artificial Intelligence

Successful full-mouth rehabilitation requires contemporary and advanced treatment planning, especially in distal extension cases. Multiple treatment modalities are available in those cases. Treatment outcome in these patients remains challenging. Though implants are one of the treatment options in such scenarios, fixed removable partial dentures with precision attachments are the best treatment options for patients who cannot afford expensive treatment. We have made an attempt to describe a case report of a long-span edentulous arch by incorporating the ideas and information received from Chat Generative Pre-trained Transformer (GPT).

Cat alpha-1-acid glycoprotein enzyme-linked immunosorbent assay: performance characteristics and reference intervals

OBJECTIVES

The aim of this study was to evaluate performance of a feline-specific ELISA for the measurement of alpha-1-acid glycoprotein (AGP) and to establish a reference interval (RI).

METHODS

Surplus serum samples with low (~200 µg/ml), medium (~450 µg/ml) and high (~745 and 930 µg/ml) AGP concentrations were used to assess the intra- and inter-assay coefficients of variation (CVs). The quality goal for bioanalytical method validation was a CV of <20%. Linearity was assessed by serial dilution of a sample with a high AGP concentration. Spike recovery was evaluated by mixing samples with low, medium and high AGP concentrations at different ratios. To establish the RI, residual serum samples from 51 healthy adult cats that were presented for health examinations or blood donation between August 2020 and June 2021 were included.

RESULTS

The intra-assay CV was 8.5%, 4.3% and 4.0%, and the inter-assay CV was 18.8%, 15.5% and 11.5% for serum samples with low, medium and high AGP concentrations, respectively. Excellent linearity (R2 = 0.98) was demonstrated for AGP concentrations ranging between 251.6 and 954.4 µg/ml. Average recovery was 95.0-99.7%. The right-sided RI for AGP was 328 µg/ml (90% confidence interval 300-354). Age had a statistically significant impact (increasing values with older age, P = 0.0026), but sex did not (P = 0.44), on AGP concentrations.

CONCLUSIONS AND RELEVANCE

The ELISA was accurate and showed acceptable precision with the modification of dilution used in this study. AGP concentrations in this population appeared to increase with increasing age.

Efficient methods for multiple types of precise gene-editing in Chlamydomonas

Precise gene-editing using CRISPR/Cas9 technology remains a long-standing challenge, especially for genes with low expression and no selectable phenotypes in Chlamydomonas reinhardtii, a classic model for photosynthesis and cilia research. Here, we developed a multi-type and precise genetic manipulation method in which a DNA break was generated by Cas9 nuclease and the repair was mediated using a homologous DNA template. The efficacy of this method was demonstrated for several types of gene editing, including inactivation of two low-expression genes (CrTET1 and CrKU80), the introduction of a FLAG-HA epitope tag into VIPP1, IFT46, CrTET1 and CrKU80 genes, and placing a YFP tag into VIPP1 and IFT46 for live-cell imaging. We also successfully performed a single amino acid substitution for the FLA3, FLA10 and FTSY genes, and documented the attainment of the anticipated phenotypes. Lastly, we demonstrated that precise fragment deletion from the 3'-UTR of MAA7 and VIPP1 resulted in a stable knock-down effect. Overall, our study has established efficient methods for multiple types of precise gene editing in Chlamydomonas, enabling substitution, insertion and deletion at the base resolution, thus improving the potential of this alga in both basic research and industrial applications.

Patterning precision under non-linear morphogen decay and molecular noise

Morphogen gradients can instruct cells about their position in a patterned tissue. Non-linear morphogen decay has been suggested to increase gradient precision by reducing the sensitivity to variability in the morphogen source. Here, we use cell-based simulations to quantitatively compare the positional error of gradients for linear and non-linear morphogen decay. While we confirm that non-linear decay reduces the positional error close to the source, the reduction is very small for physiological noise levels. Far from the source, the positional error is much larger for non-linear decay in tissues that pose a flux barrier to the morphogen at the boundary. In light of this new data, a physiological role of morphogen decay dynamics in patterning precision appears unlikely.

Clear guidance to select the most accurate technologies for 3D printing dental models - A network meta-analysis

OBJECTIVES

Thus far, the findings of numerous studies conducted on the accuracy of three-dimensional (3D) printed dental models are conflicting. Therefore, the aim of the network meta-analysis (NMA) is to determine the accuracy of 3D printed dental models compared with digital reference models.

DATA

Studies comparing the accuracy of 3D printed full-arch dental models manufactured using different printing techniques to initial STL files were included.

SOURCES

This study was registered in PROSPERO (CRD42021285863). An electronic search was performed across four databases in November 2021, and search was restricted to the English language.

STUDY SELECTION

A systematic search was conducted based on a prespecified search query. 16,303 articles were pooled after the removal of the duplicates. Following study selection and data extraction, 11 eligible studies were included in the NMA in 6 subgroups. The outcomes were specified as trueness and precision and expressed as root mean square (RMS) and absolute mean deviation values. Seven printing technologies were analyzed: stereolithography (SLA), digital light processing (DLP), fused deposition modeling/fused filament fabrication (FDM/FFF), MultiJet, PolyJet, continuous liquid interface production (CLIP), and LCD technology. The QUADAS-2 and GRADE were used to evaluate the risk of bias and certainty of evidence.

CONCLUSIONS

SLA, DLP, and PolyJet technologies were the most accurate in producing precise full-arch dental models.

CLINICAL SIGNIFICANCE

The findings of the NMA suggest that SLA, DLP, and PolyJet technologies are sufficiently accurate for full-arch dental model production for prosthodontic purposes. In contrast, FDM/FFF, CLIP, and LCD technologies are less suitable for manufacturing dental devices.

Accurate Sizing of Nanoparticles Using a High-Throughput Charge Detection Mass Spectrometer without Energy Selection

The sizes and shapes of nanoparticles play a critical role in their chemical and material properties. Common sizing methods based on light scattering or mobility lack individual particle specificity, and microscopy-based methods often require cumbersome sample preparation and image analysis. A promising alternative method for the rapid and accurate characterization of nanoparticle size is charge detection mass spectrometry (CDMS), an emerging technique that measures the masses of individual ions. A recently constructed CDMS instrument designed specifically for high acquisition speed, efficiency, and accuracy is described. This instrument does not rely on an ion energy filter or estimates of ion energy that have been previously required for mass determination, but instead uses direct, in situ measurements. A standardized sample of ∼100 nm diameter polystyrene nanoparticles and ∼50 nm polystyrene nanoparticles with amine-functionalized surfaces are characterized using CDMS and transmission electron microscopy (TEM). Individual nanoparticle masses measured by CDMS are transformed to diameters, and these size distributions are in close agreement with distributions measured by TEM. CDMS analysis also reveals dimerization of ∼100 nm nanoparticles in solution that cannot be determined by TEM due to the tendency of nanoparticles to agglomerate when dried onto a surface. Comparing the acquisition and analysis times of CDMS and TEM shows particle sizing rates up to ∼80× faster are possible using CDMS, even when samples ∼50× more dilute were used. The combination of both high-accuracy individual nanoparticle measurements and fast acquisition rates by CDMS represents an important advance in nanoparticle analysis capabilities.

What to Prefer in Patients with Multibracket Appliances? Digital vs. Conventional Full-Arch Impressions-A Reference Aid-Based In Vivo Study

This study aimed to investigate the transfer accuracy and required time for digital full-arch impressions obtained from intraoral scanners (IOSs) versus conventional alginate impressions (CAIs) in patients with multibracket appliances (MBA). Thirty patients with buccal MBAs (metal brackets, archwire removed) were examined using an established reference aid method. Impression-taking using four IOSs (Primescan, Trios 4, Medit i700, Emerald S) and one CAI with subsequent plaster casting were conducted. One-hundred-twenty (n = 30 × 4) scans were analyzed with 3D software (GOM Inspect) and 30 (n = 30 × 1) casts were assessed using a coordinate measurement machine. Six distances and six angles were measured and compared to the reference aid values (ANOVA; p < 0.05). Except for the intermolar distance, transfer accuracy was significantly higher with IOSs than with CAIs (p < 0.05). No such difference was found regarding the six angles. In patients with MBAs, digital impression-taking using IOSs can be recommended. For all measured variables except one, the transfer accuracy of IOSs was better than or at least equivalent to the data from CAIs. In addition, significantly (p < 0.001) less time was necessary for all IOSs in comparison to CAIs plus plaster casting.

A Risk Prediction Model for Physical Restraints Among Older Chinese Adults in Long-term Care Facilities: Machine Learning Study

BACKGROUND

Numerous studies have identified risk factors for physical restraint (PR) use in older adults in long-term care facilities. Nevertheless, there is a lack of predictive tools to identify high-risk individuals.

OBJECTIVE

We aimed to develop machine learning (ML)-based models to predict the risk of PR in older adults.

METHODS

This study conducted a cross-sectional secondary data analysis based on 1026 older adults from 6 long-term care facilities in Chongqing, China, from July 2019 to November 2019. The primary outcome was the use of PR (yes or no), identified by 2 collectors' direct observation. A total of 15 candidate predictors (older adults' demographic and clinical factors) that could be commonly and easily collected from clinical practice were used to build 9 independent ML models: Gaussian Naïve Bayesian (GNB), k-nearest neighbor (KNN), decision tree (DT), logistic regression (LR), support vector machine (SVM), random forest (RF), multilayer perceptron (MLP), extreme gradient boosting (XGBoost), and light gradient boosting machine (Lightgbm), as well as stacking ensemble ML. Performance was evaluated using accuracy, precision, recall, an F score, a comprehensive evaluation indicator (CEI) weighed by the above indicators, and the area under the receiver operating characteristic curve (AUC). A net benefit approach using the decision curve analysis (DCA) was performed to evaluate the clinical utility of the best model. Models were tested via 10-fold cross-validation. Feature importance was interpreted using Shapley Additive Explanations (SHAP).

RESULTS

A total of 1026 older adults (mean 83.5, SD 7.6 years; n=586, 57.1% male older adults) and 265 restrained older adults were included in the study. All ML models performed well, with an AUC above 0.905 and an F score above 0.900. The 2 best independent models are RF (AUC 0.938, 95% CI 0.914-0.947) and SVM (AUC 0.949, 95% CI 0.911-0.953). The DCA demonstrated that the RF model displayed better clinical utility than other models. The stacking model combined with SVM, RF, and MLP performed best with AUC (0.950) and CEI (0.943) values, as well as the DCA curve indicated the best clinical utility. The SHAP plots demonstrated that the significant contributors to model performance were related to cognitive impairment, care dependency, mobility decline, physical agitation, and an indwelling tube.

CONCLUSIONS

The RF and stacking models had high performance and clinical utility. ML prediction models for predicting the probability of PR in older adults could offer clinical screening and decision support, which could help medical staff in the early identification and PR management of older adults.

Negative emotion reduces visual working memory recall variability: A meta-analytical review

Negative emotion is often hypothesized to trigger a more deliberate processing mode. This effect can manifest as increased precision of information maintained in working memory (WM) captured by reduced WM recall variability under an induced negative emotional state. However, some recent evidence shows that WM representations are immune to any emotional influences. Here, we meta-analyze existing evidence based on data from 13 experiments across 491 participants who performed a delay-estimation WM task under negative and neutral emotional states. We find that induced negative emotional state modestly reduces WM recall variability and increases recall failures relative to the neutral condition. These effects are moderated by participants' self-report negative experiences during emotion induction. Collectively, these data suggest that negative emotion influences how much and how well one can remember in WM. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Roadmap for precision preclinical x-ray radiation studies

This Roadmap paper covers the field of precision preclinical x-ray radiation studies in animal models. It is mostly focused on models for cancer and normal tissue response to radiation, but also discusses other disease models. The recent technological evolution in imaging, irradiation, dosimetry and monitoring that have empowered these kinds of studies is discussed, and many developments in the near future are outlined. Finally, clinical translation and reverse translation are discussed.