Category: Statistics

J Funct Biomater. 2023 Jan 28;14(2):68. doi: 10.3390/jfb14020068.

ABSTRACT

(1) Background: Considering that the appearance of a dental material is an important factor that contributes to the success of prosthetic restorations. The purpose of this study is to investigate the optical properties and color changes among the layers of three commercial zirconias, to compare the aspect of the polished and glazed surfaces before and after aging and to evaluate the effects of hydrothermal degradation on their aesthetics. (2) Methods: Forty-eight plate-shaped samples were sectioned from presintered blocks of each multilayer translucent zirconia with different Yttrium content: Ceramill Zolid fx ML (5 mol%) = CeZ, STML (4 mol%) = STM, IPS e.maxZirCAD CEREC/in Lab MT Multi (4 mol% + 5 mol%) = IPZ. The samples were sintered according to the recommendation of each manufacturer, and half (24) of them were polished and the other half (24) glazed on one of the surfaces. Each type was equally divided into one control and one aging group, and, for each material, this resulted in four groups (n = 12): polished-control, polished-autoclaved glazed-control, and glazed-autoclaved. The artificial aging was carried out with an autoclave and distilled water at 134 °C, 0.2 MPa for 1 h, and for optical parameters (TP, CR, OP) and color change (ΔE*) measurements on a black and white background in a CIE L*a*b* color system, a spectrophotometer was used. The specimens were evaluated in incisal, cervical, and medium areas on polished and glazed samples before and after the aging stage. Statistical analysis was achieved with a two-way ANOVA test, the unpaired t-test, and the paired t-test. (3) Results: Before and after aging, the mean TP values for polished samples were higher than the glazed ones. After aging, the mean TP values increased for all groups (except polished CeZ), and significant differences were reported for polished STM, IPZ. After LTD, the opalescence registered an increase for almost all groups (except polished CeZ, polished and glazed IPZ-medium area), and significant differences were reported for almost all groups (except STM-incisal, IPZ-cervical, medium areas). The levels of color change were between extremely slight to perceivable. (4) Conclusions: Optical properties of the selected multilayer zirconia were influenced by polishing and glazing as surface treatment and affected by artificial aging (CeZ the least); perceivable color changes for polished STM, IPZ were detected.

PMID:36826868 | DOI:10.3390/jfb14020068

J Funct Biomater. 2023 Jan 26;14(2):67. doi: 10.3390/jfb14020067.

ABSTRACT

Digital dentistry and new techniques for the dental protheses’ suprastructure fabrication have undergone a great evolution in recent years, revolutionizing the quality of dental prostheses. The aim of this work is to determine whether the best horizontal marginal fit is provided by the CAD-CAM technique or by laser sintering. These values have been compared with the traditional casting technique. A total of 30 CAD-CAM models, 30 laser sintering models, and 10 casting models (as control) were fabricated. The structures realized with chromium-cobalt (CrCo) have been made by six different companies, always with the same model. Scanning electron microscopy with a high-precision image analysis system was used, and 10,000 measurements were taken for each model on the gingival (external) and palatal (internal) side. Thus, a total of 1,400,000 images were measured. It was determined that the CAD-CAM technique is the one that allows the best adjustments in the manufacturing methods studied. The laser sintering technique presents less adjustment, showing the presence of porosities and volume contraction defects due to solidification processes and heterogeneities in the chemical composition (coring). The technique with the worst adjustments is the casting technique, containing numerous defects in the suprastructure. The statistical analysis of results reflected the presence of statistically significant gap differences between the three manufacturing methods analyzed (p < 0.05), with the samples manufactured by CAD-CAM and by traditional casting processes being the ones that showed lower and higher values, respectively. No statistically significant differences in fit were observed between the palatal and gingival fit values, regardless of the manufacturing method used. No statistically significant differences in adjustment between the different manufacturing centers were found, regardless of the process used.

PMID:36826866 | DOI:10.3390/jfb14020067

J Funct Biomater. 2023 Jan 23;14(2):63. doi: 10.3390/jfb14020063.

ABSTRACT

Cu addition to alloys for biomedical applications has been of great interest to reduce bacterial growth. In situ-alloyed Ti6Al4V(ELI)-3at.%Cu was successfully manufactured by laser powder bed fusion (L-PBF). Even so, post-heat treatments are required to avoid distortions and/or achieve required/desired mechanical and fatigue properties. The present study is focused on the investigation of microstructural changes in L-PBF Ti6Al4V(ELI)-3at.%Cu after stress relieving and annealing treatments, as well as their influence on osteoblast and bactericidal behavior. After the stress relieving treatment, a homogenously distributed β phase and CuTi₂ intermetallic precipitates were observed over the α’ matrix. The annealing treatment led to the increase in amount and size of both types of precipitates, but also to phase redistribution along α lamellas. Although microstructural changes were not statistically significant, such increase in β and CuTi₂ content resulted in an increase in osteoblast proliferation after 14 days of cell culture. A significant bactericidal behavior of L-PBF Ti6Al4V(ELI)-3at.%Cu by means of ion release was found after the annealing treatment, provably due to the easier release of Cu ions from β phase. Biofilm formation was inhibited in all on Cu-alloyed specimens with stress relieving but also annealing treatment.

PMID:36826862 | DOI:10.3390/jfb14020063

J Appl Clin Med Phys. 2023 Feb 24:e13939. doi: 10.1002/acm2.13939. Online ahead of print.

ABSTRACT

PURPOSE: There has been much research interest in automated head-and-neck (HN) planning with the goal of reducing planning time and inter-planner variability while improving plan quality. However, clinical uses are still limited and institution-dependent due to the plan complexity. This work aims to investigate whether the use of a novel semi-automated two-step optimization method (TSP) can improve the quality and efficiency of planning while providing a simple framework that other institutions can follow.

METHODS AND MATERIALS: Forty patients (two and three prescription isodose levels) were retrospectively studied. Plans were generated by TSP which incorporates a knowledge-based planning solution. Comparisons were performed for plan conformity and selected dose-volume indices between clinical plan (CP) and TSP. Blind reviews were carried out by 15 clinicians to determine preference between the CP and TSP, as well as clinical suitability.

RESULTS: For majority of patients studied, TSP had similar or slightly better conformity for the high-dose PTV, and better conformity for the low-dose PTV and 45 Gy isodose lines compared to CP. The only statistically significant difference observed for the serial organs was a reduction of the spinal cord maximum dose with TSP. Except for left parotid gland (D_mean and V₃₀ for both 2R× and 3R× groups) and oral cavity (D_mean for 3R× group), TSP had significant dose reductions for all parallel organs compared to CP. Blind reviewers either showed preference/no preference for 57.2%/21.7% (2R×) and 57.5%/27.8% (3R×) of TSP compared with CP. Excluding no preference votes, 60% of TSP were preferred. TSP was selected majority of the time when looking at the vote distribution for each patient individually.

CONCLUSION: Our TSP allows plans to be created within 90-min time frame while offering improvements in plan quality and less inter-planner variability as compared to traditional planning techniques.

PMID:36826845 | DOI:10.1002/acm2.13939

J Vis. 2023 Feb 1;23(2):12. doi: 10.1167/jov.23.2.12.

ABSTRACT

The external noise paradigm and perceptual template model (PTM) have successfully been applied to characterize observer properties and mechanisms of observer state changes (e.g. attention and perceptual learning) in several research domains, focusing on individual level analysis. In this study, we developed a new hierarchical Bayesian perceptual template model (HBPTM) to model the trial-by-trial data from all individuals and conditions in a published spatial cuing study within a single structure and compared its performance to that of a Bayesian Inference Procedure (BIP), which separately infers the posterior distributions of the model parameters for each individual subject without the hierarchical structure. The HBPTM allowed us to compute the joint posterior distribution of the hyperparameters and parameters at the population, observer, and experiment levels and make statistical inferences at all these levels. In addition, we ran a large simulation study that varied the number of observers and number of trials in each condition and demonstrated the advantage of the HBPTM over the BIP across all the simulated datasets. Although it is developed in the context of spatial attention, the HBPTM and its extensions can be used to model data from the external noise paradigm in other domains and enable predictions of human performance at both the population and individual levels.

PMID:36826825 | DOI:10.1167/jov.23.2.12

Environ Sci Pollut Res Int. 2023 Feb 24. doi: 10.1007/s11356-023-25864-2. Online ahead of print.

ABSTRACT

China is experiencing a swift transformation from a rural to an urban society. This societal transition is the result of a country’s ambition toward economic development. Rapid urbanization impacts on human wellbeing, environment, and infrastructure. Unlike many cases of urban extension, China’s urbanization has led to increase in environmental issues, rather than to contain, and posed serious challenges to achieve sustainable development. To date, nevertheless, there is a little empirical enquiry on the spatiotemporal effects of multidimensional urbanization on green total factor productivity. Taking this into account, this article constructs a spatial panel data model based on 283 Chinese cities during 2006-2019. The results showed that the three types of urbanization (i.e., population, land, and economic) have positive effect on green total factor productivity (GTFP). Population urbanization has indirect positive effect on GTFP. Local land urbanization inhibits while surrounding land urbanization promotes GTFP. Economic urbanization has positive direct effect on GTFP. Considering regional heterogeneity, population and economic urbanization have positive effect on GTFP in eastern region. In central region, land urbanization significantly promotes GTFP, while economic urbanization has significant negative effect on GTFP. In the western region, the three types of urbanization are not conducive to GTFP. Considering sized heterogeneity, population and economic types of urbanization have significant negative effect on GTFP in small- and medium-sized cities. In large cities, the three types of urbanization have significant positive effects on GTFP. Considering temporal heterogeneity, the three types of urbanization significantly promote GTFP before 2014, but economic urbanization deteriorates GTFP after 2014. Our results recommend loosening Hukou system, improving land use efficiency, and developing technology and knowledge-intensive industries.

PMID:36826763 | DOI:10.1007/s11356-023-25864-2

Environ Sci Pollut Res Int. 2023 Feb 24. doi: 10.1007/s11356-023-25963-0. Online ahead of print.

ABSTRACT

This study explores the spatial and temporal evolution characteristics of transportation carbon emissions from multiple scales. Based on the integrated DMSP/OLS-NPP/VIIRS nighttime light data, a transportation carbon emission estimation model was constructed, and the spatial and temporal evolution characteristics of transportation carbon emissions in 30 provinces and some counties in China from 2000 to 2019 were analyzed. The main findings are as follows: (1) The goodness-of-fit of the estimation model improved from 51.2 to 87.15% by introducing the GDP variables. (2) At the provincial scale, the provinces with high carbon emissions from transportation were mainly distributed in the eastern region, with the highest value increasing from 19,171.6 million tons in 2000 to 71,545.98 million tons in 2019. The spatial distribution has a significant and positive spatial spillover effect, and the H-H aggregation was mainly distributed in the east-central region, showing a trend of expansion from the coast to the inland. Trend analysis showed that Shandong, Guangdong, Shanghai, and Jiangsu were areas with a rapid growth of high carbon emissions. (3) The county scale displayed a northeast-southwest evolutionary pattern, with the center of gravity in Henan. The spatial distribution showed a significant spatial agglomeration phenomenon. Trend analysis indicated that the transportation carbon emissions in 184 counties need to be controlled urgently, which was the focus of carbon emission reduction. This paper theoretically enriches the measurement method of transportation carbon emissions and overcomes the problem of insufficient spatial information of statistical data. In practice, it provides a scientific basis for accurate emission reduction and low-carbon development of transportation.

PMID:36826762 | DOI:10.1007/s11356-023-25963-0

Environ Sci Pollut Res Int. 2023 Feb 24. doi: 10.1007/s11356-023-25966-x. Online ahead of print.

ABSTRACT

Implementation of industrial wastes such as bottom ash in ground improvement can be cost-effective and environment-friendly. Ground improvement is an effective method of mitigation to improve problematic soils including soft kaolin clay soils as the problematic soils always expose to the severe settlements, low shear strength, immoderate plasticity, greater compressibility, dispersivity, bulging, erodibility, and susceptibility to climatic variables. Several studies conducted on the granular column using the bottom ash column. However, only a few studies have reported findings coherent with the statistical analysis. In this study, the lateral load capacity of bottom ash column-kaolin clay has been conducted. Coherently, the reinforced kaolin clay samples were tested via particle size distribution, Atterberg limit test, relative density, compaction test, permeability test, unconfined compression test, and unconsolidated undrained triaxial test with the single and group of encapsulated bottom ash columns with the geotextile encasement and a prediction model was developed. The effect of a number of columns, column diameter, column height, area replacement ratio, height penetration ratio, height-diameter column ratio, volume replacement ratio, and confining pressures on the shear strength of the single and group of encapsulated bottom ash columns have been investigated. The findings showed the effectiveness of using the bottom ash columns at various number of column, column diameter, column height, area replacement ratio, height penetration ratio, height-diameter column ratio, volume replacement ratio, and confining pressures can enhance the shear strength of the soil up to 77.00% at the optimal utilization of single encapsulated bottom ash column of 10-mm diameter and 80-mm height. Therefore, the study proved that the utilization of bottom ash waste as a granular column can significantly enhance the lateral load capacity of soft kaolin clay soil.

PMID:36826761 | DOI:10.1007/s11356-023-25966-x

J Thromb Thrombolysis. 2023 Feb 24. doi: 10.1007/s11239-023-02785-y. Online ahead of print.

ABSTRACT

INTRODUCTION: Postpartum hemorrhage (PPH) was the second leading cause of maternal death, accounting for approximately 14% of all pregnancy-related deaths between 2017 and 2019 in the United States. Several large multi-center studies have demonstrated decreased PPH rates with the use of tranexamic acid (TXA). Little data exists regarding the prevalence of TXA use in obstetric patients.

METHODS: We identified over 1.2 million US pregnancies between January 1, 2015 and June 30, 2021, with and without PPH by International Statistical Classification of Disease and Related Health Problems, Tenth Revision codes using Cerner Real-World Database™. TXA use and patient characteristics were abstracted from the electronic medical record.

RESULTS: During delivery, TXA was used approximately 1% of the time (12,394 / 1,262,574). Pregnant patients who did and did not receive TXA during delivery had similar demographic characteristics. Pregnant patients who underwent cesarean delivery (4,356 / 12,394), had a term delivery (10,199 / 12,394), and had comorbid conditions were more likely to receive TXA during hospitalization for delivery. The majority of TXA was use was concentrated in Arizona, Colorado, Idaho, New Mexico, Nevada, Utah, and Wyoming. During the study period the use of TXA increased in both patients with PPH and those without.

CONCLUSION: The data illustrate a rapid increase in the use of TXA after 2017 while the total number of pregnancies remained relatively constant. The observed increase in TXA use may reflect changing practicing patterns as the support for use of TXA in the setting of PPH prophylaxis increases.

PMID:36826757 | DOI:10.1007/s11239-023-02785-y

Insights Imaging. 2023 Feb 24;14(1):37. doi: 10.1186/s13244-023-01388-8.

ABSTRACT

BACKGROUND: Education in radiology should be an integral aspect of undergraduate medical training given the essential role of imaging in patient management. Since the introduction of the European Society of Radiology undergraduate curriculum a decade ago, radiology education has evolved.

OBJECTIVES: This survey aimed to assess the current status of undergraduate radiology education in Europe.

METHODS: An electronic survey on undergraduate teaching was distributed by the European Society of Radiology to delegates of the European Society of Radiology education committee and presidents of national radiological societies from April 1 to May 31, 2022. Data from the twenty questions were summarized using descriptive statistics.

RESULTS: There were 72 respondents from 36 countries. Radiology was taught to undergraduates in 95% (68/72), with a national or local curriculum informing radiology education in 93% (67/72). Radiology teaching was delivered by radiologists in 98% (58/59), across all years of medical school but most commonly in the fourth year of medical training (63%, 44/70), through various means including lectures, workshops, radiology department placements, online resources and simulation. Teaching hours were variable, with a minimum of 10 h reported.

CONCLUSION: This survey’s findings suggest an improvement over the last decade in the engagement of radiologists in the delivery of undergraduate radiology education in European countries affiliated with the European Society of Radiology.

PMID:36826721 | DOI:10.1186/s13244-023-01388-8