Tag: pubmed

Eur Oral Res. 2024 Sep 5;58(3):133-138. doi: 10.26650/eor.20231302012.

ABSTRACT

PURPOSE: The objective of this study was to assess the impact of preheating on the microhardness and flexural strength of bulk-fill resin composites.

MATERIALS AND METHODS: In this in vitro study, forty-two specimens were prepared of each composite, X-tra fil and Opus Bulk Fill, resulting in 84 disk-shaped specimens for microhardness testing and 84 bar-shaped specimens for flexural strength analysis. The specimens were divided into four groups as follows: Group 1: X-tra fil composite with preheating (at 68°C for 15 minutes), group 2: X-tra fil composite without preheating (at room temperature), group 3: Opus Bulk Fill composite with the same preheating method, group 4: Opus Bulk Fill composite without preheating. Microhardness was assessed using the Vickers test with a diamond indenter, and flexural strength was measured using a 3-point flexural test. Statistical comparisons were performed on the calculated results.

RESULTS: In the preheated groups, both X-tra fil and Opus Bulk Fill composites exhibited significantly higher mean flexural strength compared to the non-preheated groups (p<0.001). However, there was no significant difference in the mean microhardness between the two groups for either type of composite (p=0.719). Additionally, the mean flexural strength and microhardness of X-tra fil composite, in both preheated and non-preheated conditions, were higher than those of the Opus Bulk Fill composite (p<0.001).

CONCLUSION: Preheating bulk-fill composites to 68°C has no detrimental effect on their microhardness and increases the flexural strength of these materials. Furthermore, the degree of microhardness and flexural strength in bulk-fill composites varies between brands and is influenced by their chemical compositions.

PMID:39588475 | PMC:PMC11586042 | DOI:10.26650/eor.20231302012

Eur Oral Res. 2024 Sep 5;58(3):108-119. doi: 10.26650/eor.20241312721.

ABSTRACT

PURPOSE: Valid and reliable scales which have been developed for assessing individuals’ attitudes toward oral health and are based on multiple theoretical views are limited in number in the literature. Hence, there is a need for more scale development studies for further evaluation of the psychometric properties of the oral and dental health attitudes of students. The aim of this study was to develop a scale for measuring college undergraduates’ attitudes toward oral and dental health.

MATERIALS AND METHODS: A sample of 770 college undergraduates (241 male, 529 female) enrolled in various academic programs of three universities in Turkey participated in this study. We collected data from two separate samples. The data obtained from sample 1 (n = 470) were used for Exploratory Factor Analysis (EFA) and the data from sample 2 (n = 300) were utilized for undertaking Confirmatory Factor Analysis (CFA). To test the construct validity, EFA, CFA, convergent validity, and measurement invariance were used, respectively.

RESULTS: In the first stage, EFA was conducted on a 48-item scale. EFA results showed that the final version of the Oral Health Attitude Scale (OHA-S) had a six-factor structure: sensitivity, importance, avoidance of harmful elements, tendency towards products and activities, awareness, and social impact. To confirm this structure, CFA was used. CFA results showed good model fit indexes. The final version of the scale consisted of 41 items with six factors. Moreover, Cronbach’s alpha and Spearman-Brown Split-Half coefficients showed a good level of reliability. Moreover, t-scores were statistically significant for 27% of the lower and upper groups.

CONCLUSION: The developed scale was found to be a potential tool for measuring and evaluating university students’ attitudes toward oral and dental health.

PMID:39588474 | PMC:PMC11586041 | DOI:10.26650/eor.20241312721

Eur Oral Res. 2024 Sep 5;58(3):127-132. doi: 10.26650/eor.2024200224.

ABSTRACT

PURPOSE: The aim of this study is to evaluate and compare the color stability of nanoparticles reinforced maxillofacial silicone after disinfection with neutral soap, 4% chlorhexidine, and ozone water.

MATERIALS AND METHODS: According to ISO 4823, a metal die was fabricated, and 96 samples were created using Room Temperature Vulcanizing silicone (RTV), Heat Temperature Vulcanizing silicone (HTV), and 3% silicone dioxide nanoparticle-reinforced RTV and HTV silicones. The samples were disinfected using neutral soap, 4% chlorhexidine, and ozone water for 10 minutes, three times a day, for 60 days. The samples were divided into four groups: Group 1 (RTV), Group 2 (3% SiO2 nanoparticle-reinforced RTV), Group 3 (HTV), and Group 4 (3% SiO2 nanoparticle-reinforced HTV). The color stability of the maxillofacial silicones was evaluated before and after disinfection using a UV spectrophotometer. The obtained color stability values were statistically analyzed using two-way ANOVA and Tukey’s HSD test. Values were considered significant when p<0.05.

RESULTS: The 3% SiO2 nanoparticle-reinforced HTV silicone showed better color stability compared to HTV and RTV silicones, with the least difference observed in the 3% SiO2 nanoparticle-reinforced RTV.

CONCLUSION: Ozone water caused the least change in the color of maxillofacial silicone compared to other disinfectant solutions.

PMID:39588472 | PMC:PMC11586037 | DOI:10.26650/eor.2024200224

Endosc Int Open. 2024 Sep 9;12(9):E1006-E1014. doi: 10.1055/a-2370-5812. eCollection 2024 Sep.

ABSTRACT

Background and study aims Variation between trainers in providing traditional gastrointestinal endoscopy training, in which residents learn endoscopy by doing under the supervision of endoscopy trainers, may cause differences in endoscopy competence between residents. In this study, we explored endoscopy trainers’ views on the current status and desired future best practices regarding endoscopy training. Methods This mixed-methods study comprised quantitative survey data collected from 158 endoscopy trainers working in 26 gastroenterology teaching hospitals in the Netherlands and semi-structured interviews with 15 gastroenterology residency (associate) program directors (PDs). Survey data were analyzed using descriptive statistics and interview results with thematic analysis. Results There was considerable variability in endoscopy training practices between teaching hospitals in the structure of endoscopy supervision, criteria used to determine the level of supervision, and participation of trainers in endoscopy teaching courses. Interview participants agreed that an endoscopy training supervisor requires several teaching strategies, highlighting the importance of formal education in endoscopy teaching. Interview participants perceived self-regulated learning strategies as essential for residents to learn endoscopy effectively. The perceived main barriers to effective supervision were a lack of time and heavy workload. Participants expressed the desire for more standardization in endoscopy training programs between teaching hospitals. Conclusions Considerable variability in endoscopy training practices between gastroenterology teaching hospitals was identified. Formal education on endoscopy teaching, promotion of self-regulated learning, and standardization of endoscopy training programs and supervision practices have the potential to improve future endoscopy training.

PMID:39588471 | PMC:PMC11586648 | DOI:10.1055/a-2370-5812

Vet Res Forum. 2024;15(10):545-550. doi: 10.30466/vrf.2024.2025342.4218. Epub 2024 Oct 15.

ABSTRACT

Cryopreservation and re-transplantation of ovarian tissue is a relatively new technique to preserve fertility. This study evaluated the preservation of ovarian follicles after the vitrification-thawing procedure by implanting ovarian fragments into the gluteus muscle of rabbit. Bilateral ovariectomy was performed on each rabbit. The cortices were separated from the medullae of ovaries and divided into four fragments. One fresh cortical fragment was used as a control, fixed in 10.00% formalin. Three fragments underwent vitrification-thawing for two weeks. Two of these vitrified-thawed fragments were auto-transplanted into separate locations within the opened gluteus muscle, while the final fragment was fixed in 10.00% formalin. Eight weeks after re-implantation, biopsies were collected from the ovarian fragments and fixed in 10.00% formalin. The numbers and areas (µm²) of morphologically normal follicles were evaluated on sections stained with Hematoxylin and Eosin through light microscopy. The follicular morphology in the ovarian fragments immediately after vitrification-thawing remained similar to that of the fresh ovary. The number of morphologically intact follicles was significantly lower in the ovarian fragments eight weeks after re-implantation than fresh ovary and ovarian tissue fragments after vitrification-thawing procedure. However, follicular development to the antral stage was observed in all samples eight weeks after re-implantation. There was no statistical difference in the areas (µm²) of primordial, primary, pre-antral, and antral follicles in the ovarian fragments before cryopreservation, immediately after vitrification-thawing, and following re-implantation procedures. Auto-transplantation of ovarian tissue into the gluteus muscle of rabbits could be a viable approach for preserving ovarian follicles after vitrification-thawing procedure.

PMID:39588459 | PMC:PMC11585844 | DOI:10.30466/vrf.2024.2025342.4218

Bone Marrow Transplant. 2024 Nov 25. doi: 10.1038/s41409-024-02480-3. Online ahead of print.

ABSTRACT

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell malignancy and the only curable therapy is allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, allo-HSCT is not appropriate for all CMML patients, and relapse is the leading cause of treatment failure. This project conducted a nationwide multicenter real-world study to develop a novel prediction scoring system for early relapse. A total of 238 CMML patients from twenty-seven medical centers treated with allo-HSCT, and 307 adult patients with CMML who underwent allo-HSCT in a publicly available research dataset from the Center for International Blood and Marrow Transplantation Registry (CIBMTR) database were included. Independent prognostic factors for the early relapse of CMML posttransplantation were identified according to competing risk regression methods. Four prognostic factors were identified: bone marrow blasts >10% (hazard ratio [HR], 4.262; P = 0.014), age >60 years (HR, 6.221; P = 0.007), hemoglobin level <100 g/L (HR, 3.695; P = 0.004), and non TET2 gene mutation (HR, 3.425; P = 0.017). A risk-grading scoring system was developed based on the regression coefficients and patients were stratified into low-risk (0-1 point), intermediate-risk (1.5-2 points) and high-risk ( > 2 points) groups. The validated internal c-statistic was 0.767 (95% confidence interval [CI], 0.674-0.860), and the external c-statistic was 0.769 (95% CI, 0.703-0.836). In the derivation cohort, the cumulative incidence rates of early relapse in the low-risk, intermediate-risk, and high-risk groups were 1.35% (95% CI: 1-4%), 10.40% (95% CI: 4-16%), and 29.54% (95% CI: 16-39%) (P < 0.001), respectively. This scoring system can be utilized to early identification of patients at a high risk of relapse and contributing to the implementation of urgent medical support.

PMID:39587323 | DOI:10.1038/s41409-024-02480-3

Ecol Appl. 2024 Nov 25:e3066. doi: 10.1002/eap.3066. Online ahead of print.

ABSTRACT

Earthworms are a key faunal group in agricultural soils, but little is known on how farming systems affect their communities across wide climatic gradients and how farming system choice might mediate earthworms’ exposure to climate conditions. Here, we studied arable soil earthworm communities on wheat fields across a European climatic gradient, covering nine pedo-climatic zones, from Mediterranean to Boreal (S to N) and from Lusitanian to Pannonian (W to E). In each zone, 20-25 wheat fields under conventional or organic farming were sampled. Community metrics (total abundance, fresh mass, and species richness and composition) were combined with data on climate conditions, soil properties, and field management and analyzed with mixed models. There were no statistically discernible differences between organic and conventional farming for any of the community metrics. The effects of refined arable management factors were also not detected, except for an elevated proportion of subsurface-feeding earthworms when crop residues were incorporated. Soil properties were not significantly associated with earthworm community variations, which in the case of soil texture was likely due to low variation in the data. Pedo-climatic zone was an overridingly important factor in explaining the variation in community metrics. The Boreal zone had the highest mean total abundance (179 individuals m^-2) and fresh mass (86 g m^-2) of earthworms while the southernmost Mediterranean zones had the lowest metrics (<1 individual m^-2 and <1 g m^-2). Within each field, species richness was low across the zones, with the highest values being recorded at the Nemoral and North Atlantic zones (mean of 2-3 species per field) and declining from there toward north and south. No litter-dwelling species were found in the southernmost, Mediterranean zones. These regional trends were discernibly related to climate, with the community metrics declining with the increasing mean annual temperature. The current continent-wide warming of Europe and related increase of severe and rapid onsetting droughts will likely deteriorate the living conditions of earthworms, particularly in southern Europe. The lack of interaction between the pedo-climatic zone and the farming system in our data for any of the earthworm community metrics may indicate limited opportunities for alleviating the negative effects of a warming climate in cereal field soils of Europe.

PMID:39587320 | DOI:10.1002/eap.3066

Sci Rep. 2024 Nov 26;14(1):29258. doi: 10.1038/s41598-024-80610-z.

ABSTRACT

This study aimed to evaluate the predictive value of metabolic parameters in preoperative non-enhancing peritumoral regions (NEPTRs) for glioblastoma recurrence, using multivoxel hydrogen proton magnetic resonance spectroscopy (1H-MRS). Clinical and imaging data from patients with recurrent glioblastoma were analyzed. Through co-registration of preoperative and post-recurrence MRI, we identified future tumor recurrence regions (FTRRs) and future non-tumor recurrence regions (FNTRRs) within the NEPTRs. Metabolic parameters were recorded separately for each region. Cox regression analysis was applied to assess the association between metabolic parameters and glioblastoma recurrence. Compared to FNTRRs, FTRRs exhibited a higher Cho/Cr ratio, higher Cho/NAA ratio, and lower NAA/Cr ratio. Both Cho/NAA and Cho/Cr ratios were recognized as risk factors in univariate and multivariate analyses (P < 0.05). The Cox regression model indicated that Cho/NAA > 1.99 and Cho/Cr > 1.73 are independent risk factors for early glioblastoma recurrence. Based on these cut-off values, patients were stratified into low-risk and high-risk groups, with a statistically significant difference in recurrence rates between the two groups (P < 0.01). The Cho/NAA and Cho/Cr ratios in NEPTRs are independent predictors of future glioblastoma recurrence. Specifically, Cho/NAA > 1.99 and/or Cho/Cr > 1.73 in NEPTRs may indicate a higher risk of early postoperative recurrence at these regions.

PMID:39587278 | DOI:10.1038/s41598-024-80610-z

Sci Rep. 2024 Nov 26;14(1):29261. doi: 10.1038/s41598-024-80849-6.

ABSTRACT

The dynamic and multimodal nature of photovoltaic (PV) systems makes it challenging to examine all solar photovoltaic characteristics. Consequently, this study recommends a recently developed optimization method called the marine predator algorithm (MPA) for developing reliable PV models. In the traditional MPA, the two main search processes are Lévy flight (LF) and Brownian walk (BW), and the switch across them is unpredictable. This is while the transition between these two mechanisms is naturally continuous and dynamic. To rectify the limitation mentioned above, this research paper presents an innovative, dynamic shift function that effectively modulates the interplay that exists between the BW and LF procedures. By enhancing the changeover pattern between the primary phases of MPA, the suggested dynamic walk substantially boosts the performance of MPA. The dynamic Lévy-Brownian MPA (DLBMPA) is also made to be resilient in dealing with the parameterization limitations of PV Modeling approaches by using a constraint handling technique. The performance of DLBMPA is tested using ten popular optimization methods. Employing the DLBMPA achieved an average RMSE of 9.7 × 10^{– 4} in the parameter estimation across a number of multiple PV models, including the SDM, DDM, and TDM, where out of the ten optimization algorithms experimented, this was statistically significant (p < 0.05) better. In terms of averaged computation time, DLBMPA was 13 ms and still showed high accuracy in dealing with different irradiance and temperature levels. These improvements allow for MBPA to be credited as having a high efficiency when estimating the PV parameters since its speed of convergence and accuracy level surpass the previous techniques used.

PMID:39587262 | DOI:10.1038/s41598-024-80849-6

Nat Cancer. 2024 Nov 25. doi: 10.1038/s43018-024-00863-5. Online ahead of print.

ABSTRACT

Refractoriness to initial chemotherapy and relapse after remission are the main obstacles to curing T cell acute lymphoblastic leukemia (T-ALL). While tumor heterogeneity has been implicated in treatment failure, the cellular and genetic factors contributing to resistance and relapse remain unknown. Here we linked tumor subpopulations with clinical outcome, created an atlas of healthy pediatric hematopoiesis and applied single-cell multiomic analysis to a diverse cohort of 40 T-ALL cases. We identified a bone marrow progenitor (BMP)-like leukemia subpopulation associated with treatment failure and poor overall survival. The single-cell-derived molecular signature of BMP-like blasts predicted poor outcome across multiple subtypes of T-ALL and revealed that NOTCH1 mutations additively drive T-ALL blasts away from the BMP-like state. Through in silico and in vitro drug screenings, we identified a therapeutic vulnerability of BMP-like blasts to apoptosis-inducing agents including venetoclax. Collectively, our study establishes multiomic signatures for rapid risk stratification and targeted treatment of high-risk T-ALL.

PMID:39587259 | DOI:10.1038/s43018-024-00863-5