Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 615
Filtrar
1.
Alzheimers Res Ther ; 16(1): 91, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664832

RESUMEN

BACKGROUND: Given the rising awareness of health-related lifestyle modifications, the impact of changes in body weight (BW) on cognitive function and dementia generates significant concern. This study aimed to investigate the association between BW changes and dementia in a middle-aged Korean population. METHODS: A retrospective, population-based longitudinal study was conducted utilizing data from the National Health Insurance Service (NHIS) database. Participants aged 40 years or older in 2011 who underwent at least five health checkups between 2002 and 2011 were followed-up for dementia until 2020. A total of 3,635,988 dementia-free Korean aged < 65 at baseline were examined. We analyzed the association between BW variability independent of the mean (VIM) with BW cycle, defined as either an upward or a downward direction of BW, and the risk of incident dementia. RESULTS: The results showed an increased risk of dementia in the highest quartile of VIM quartile (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.47-1.58) compared to the lowest quartile of VIM. Additionally, the results showed an even higher increased risk of dementia in the highest BW cycle (≥ 2 cycles of 10% BW = HR 2.00, 95% CI 1.74-1.29). Notably, the combined concept of VIM with BW cycle showed an even higher dementia risk (highest quartile of VIM with ≥ 2 cycles of 10% BW = HR 2.37, 95% CI 2.05-2.74) compared to the baseline group (lowest quartile of VIM with < 3% BW cycle). CONCLUSIONS: The present study highlights the importance of considering BW changes with BW variability along with the BW cycle to assess dementia risk in detail, providing valuable insights for preventive strategies.


Asunto(s)
Peso Corporal , Demencia , Humanos , Masculino , Femenino , Demencia/epidemiología , Persona de Mediana Edad , Estudios Longitudinales , Peso Corporal/fisiología , República de Corea/epidemiología , Estudios Retrospectivos , Adulto , Factores de Riesgo , Estudios de Cohortes , Anciano , Edad de Inicio
2.
Artículo en Inglés | MEDLINE | ID: mdl-38623949

RESUMEN

Cost-effective and environmentally friendly Fe-based active materials offer exceptionally high energy capacity in lithium-ion batteries (LIBs) due to their multiple electron redox reactions. However, challenges, such as morphology degradation during cycling, cell pulverization, and electrochemical stability, have hindered their widespread use. Herein, we demonstrated a simple salt-assisted freeze-drying method to design a double-shelled Fe/Fe3C core tightly anchored on a porous carbon framework (FEC). The shell consists of a thin Fe3O4 layer (≈2 nm) and a carbon layer (≈10 nm) on the outermost part. Benefiting from the complex nanostructuring (porous carbon support, core-shell nanoparticles, and Fe3C incorporation), the FEC anode delivered a high discharge capacity of 947 mAh g-1 at 50 mA g-1 and a fast-rate capability of 305 mAh g-1 at 10 A g-1. Notably, the FEC cell still showed 86% reversible capacity retention (794 mAh g-1 at 50 mA g-1) at a high cycling temperature of 80 °C, indicating superior structural integrity during cycling at extreme temperatures. Furthermore, we conducted a simple solid-state fluorination technique using the as-prepared FEC sample and excess NH4F to prepare iron fluoride-carbon composites (FeF2/C) as the positive electrode. The full cell configuration, consisting of the FEC anode and FeF2/C cathode, reached a remarkable capacity of 200 mAh g-1 at a 20 mA g-1 rate or an energy density of approximately 530 Wh kg-1. Thus, the straightforward and simple experimental design holds great potential as a revolutionary Fe-based cathodic-anodic pair candidate for high-energy LIBs.

3.
J Dent ; 144: 104941, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38490323

RESUMEN

OBJECTIVES: To evaluate how restoration thickness (0.5 mm and 0.7 mm) affects the fabrication trueness of additively manufactured definitive resin-based laminate veneers, and to analyze the effect of restoration thickness and margin location on margin quality. METHODS: Two maxillary central incisors were prepared either for a 0.5 mm- or 0.7 mm-thick laminate veneer. After acquiring the partial-arch scans of each preparation, laminate veneers were designed and stored as reference data. By using these reference data, a total of 30 resin-based laminate veneers were additively manufactured (n = 15 per thickness). All veneers were digitized and stored as test data. The reference and test data were superimposed to calculate the root mean square values at overall, external, intaglio, and marginal surfaces. The margin quality at labial, incisal, mesial, and distal surfaces was evaluated. Fabrication trueness at each surface was analyzed with independent t-tests, while 2-way analysis of variance was used to analyze the effect of thickness and margin location on margin quality (α = 0.05). RESULTS: Regardless of the evaluated surface, 0.7 mm-thick veneers had lower deviations (P < 0.001). Only the margin location (P < 0.001) affected the margin quality as labial margins had the lowest quality (P < 0.001). CONCLUSION: Restoration thickness affected the fabrication trueness of resin-based laminate veneers as 0.7 mm-thick veneers had significantly higher trueness. However, restoration thickness did not affect the margin quality and labial margins had the lowest quality. CLINICAL SIGNIFICANCE: Laminate veneers fabricated by using tested urethane-based acrylic resin may require less adjustment when fabricated in 0.7 mm thickness. However, marginal integrity issues may be encountered at the labial surface.


Asunto(s)
Resinas Compuestas , Adaptación Marginal Dental , Materiales Dentales , Coronas con Frente Estético , Incisivo , Propiedades de Superficie , Humanos , Materiales Dentales/química , Resinas Compuestas/química , Ensayo de Materiales , Diseño de Prótesis Dental , Porcelana Dental/química , Diseño Asistido por Computadora , Cerámica/química , Poliuretanos/química , Metacrilatos/química
4.
BMC Med Inform Decis Mak ; 24(1): 67, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448921

RESUMEN

Deep learning has been increasingly utilized in the medical field and achieved many goals. Since the size of data dominates the performance of deep learning, several medical institutions are conducting joint research to obtain as much data as possible. However, sharing data is usually prohibited owing to the risk of privacy invasion. Federated learning is a reasonable idea to train distributed multicenter data without direct access; however, a central server to merge and distribute models is needed, which is expensive and hardly approved due to various legal regulations. This paper proposes a continual learning framework for a multicenter study, which does not require a central server and can prevent catastrophic forgetting of previously trained knowledge. The proposed framework contains the continual learning method selection process, assuming that a single method is not omnipotent for all involved datasets in a real-world setting and that there could be a proper method to be selected for specific data. We utilized the fake data based on a generative adversarial network to evaluate methods prospectively, not ex post facto. We used four independent electrocardiogram datasets for a multicenter study and trained the arrhythmia detection model. Our proposed framework was evaluated against supervised and federated learning methods, as well as finetuning approaches that do not include any regulation to preserve previous knowledge. Even without a central server and access to the past data, our framework achieved stable performance (AUROC 0.897) across all involved datasets, achieving comparable performance to federated learning (AUROC 0.901).


Asunto(s)
Electrocardiografía , Estudios Multicéntricos como Asunto , Humanos , Conocimiento , Privacidad
5.
J Nutr Health Aging ; 28(5): 100212, 2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38489995

RESUMEN

Iron plays a crucial role in many physiological processes, including oxygen transport, bioenergetics, and immune function. Iron is assimilated from food and also recycled from senescent red blood cells. Iron exists in two dietary forms: heme (animal based) and non-heme (mostly plant based). The body uses iron for metabolic purposes, and stores the excess mainly in splenic and hepatic macrophages. Physiologically, iron excretion in humans is inefficient and not highly regulated, so regulation of intestinal absorption maintains iron homeostasis. Iron losses occur at a steady rate via turnover of the intestinal epithelium, blood loss, and exfoliation of dead skin cells, but overall iron homeostasis is tightly controlled at cellular and systemic levels. Aging can have a profound impact on iron homeostasis and induce a dyshomeostasis where iron deficiency or overload (sometimes both simultaneously) can occur, potentially leading to several disorders and pathologies. To maintain physiologically balanced iron levels, reduce risk of disease, and promote healthy aging, it is advisable for older adults to follow recommended daily intake guidelines and periodically assess iron levels. Clinicians can evaluate body iron status using different techniques but selecting an assessment method primarily depends on the condition being examined. This review provides a comprehensive overview of the forms, sources, and metabolism of dietary iron, associated disorders of iron dyshomeostasis, assessment of iron levels in older adults, and nutritional guidelines and strategies to maintain iron balance in older adults.

6.
Artículo en Inglés | MEDLINE | ID: mdl-38520565

RESUMEN

PURPOSE: Disparities in oral cavity and pharyngeal cancer based on race/ethnicity and socioeconomic status have been reported, but the impact of living within areas that are persistently poor at the time of diagnosis and outcome is unknown. This study aimed to investigate whether the incidence, 5-year relative survival, stage at diagnosis, and mortality among patients with oral cavity and pharyngeal cancers varied by persistent poverty. METHODS: Data were drawn from the SEER database (2006-2017) and included individuals diagnosed with oral cavity and pharyngeal cancers. Persistent poverty (at census tract) is defined as areas where ≥ 20% of the population has lived below the poverty level for ~ 30 years. Age-adjusted incidence and 5-year survival rates were calculated. Multivariable logistic regression was used to estimate the association between persistent poverty and advanced stage cancer. Cumulative incidence and multivariable subdistribution hazard models were used to evaluate mortality risk. In addition, results were stratified by cancer primary site, sex, race/ethnicity, and rurality. RESULTS: Of the 90,631 patients included in the analysis (61.7% < 65 years old, 71.6% males), 8.8% lived in persistent poverty. Compared to non-persistent poverty, patients in persistent poverty had higher incidence and lower 5-year survival rates. Throughout 10 years, the cumulative incidence of cancer death was greater in patients from persistent poverty and were more likely to present with advanced-stage cancer and higher mortality risk. In the stratified analysis by primary site, patients in persistent poverty with oropharyngeal, oral cavity, and nasopharyngeal cancers had an increased risk of mortality compared to the patients in non-persistent poverty. CONCLUSION: This study found an association between oral cavity and pharyngeal cancer outcomes among patients in persistent poverty indicating a multidimensional strategy to improve survival.

7.
Asia Pac J Public Health ; : 10105395241240949, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38553968

RESUMEN

This study aimed to investigate the factors affecting smoking relapse and to develop predictive models among Korean national 5-day smoking cessation program participants. The subjects were 518 smokers and follow-up was continued for 6 months after discharge. A predictive logistic model and risk score were developed from the multivariate logistic models and compared using the area under the receiver operating characteristic curve (area under the curve [AUC]). The smoking relapse rate within 6 months after program participation was 38.4%. The AUCs of the logistic regression model and risk score model were similar (odds ratio [OR] = 0.69, 95% confidence interval [CI] [0.64, 0.75]; 0.69, 95% CI [0.63, 0.74], respectively) in the development data set, and those of the risk score model were similar between the development and validation data sets (OR = 0.68, 95% CI [0.59, 0.77]). The risk score used by the six risk factors could predict smoking relapse among participants who attended a 5-day inpatient smoking cessation program.

8.
JAMA Netw Open ; 7(3): e243802, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38530308

RESUMEN

IMPORTANCE: Epidemiologic evidence regarding the outcomes of dietary sodium intake on mortality remains limited for low-income individuals, particularly Black people. OBJECTIVE: To investigate the associations of excessive dietary sodium with all-cause and cause-specific mortality among predominantly low-income Black and White Americans. DESIGN, SETTING, AND PARTICIPANTS: This cohort study included participants aged 40 to 79 years from the Southern Community Cohort Study who were recruited at Community Health Centers in 12 southeastern states from 2002 to 2009. Analyses were conducted between March 2022 and June 2023. EXPOSURES: Dietary sodium intake was assessed using a validated food frequency questionnaire at baseline. MAIN OUTCOMES AND MEASURES: Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) and 95% CIs for mortality outcomes (all-cause, cardiovascular disease [CVD], coronary heart disease [CHD], stroke, heart failure, cancer, and other) associated with sodium intake. Nonlinear associations and population-attributable risk (PAR) of the mortality burden associated with excess sodium were further assessed. RESULTS: Among the 64 329 participants, 46 185 (71.8%) were Black, 18 144 (28.2%) were White, and 39 155 (60.9%) were female. The mean (SD) age at study enrollment was 51.3 (8.6) years for Black participants and 53.3 (9.3) years for White counterparts. Mean (SD) dietary sodium intake was 4512 (2632) mg/d in Black individuals and 4041 (2227) mg/d in White individuals; 37 482 Black individuals (81.2%) and 14 431 White individuals (79.5%) exceeded the current dietary recommendations of 2300 mg/d. During a median (IQR) follow-up of 13.8 (11.3-15.8) years, 17 811 deaths were documented, including 5701 from CVD. After adjustment for potential confounders, in Black individuals, HRs per 1000-mg increase in daily sodium intake were 1.07 (95% CI, 1.03-1.10) and 1.08 (95% CI, 1.02-1.14) for deaths from total CVD and CHD, respectively; while in White individuals, the corresponding HRs were 1.08 (95% CI, 1.02-1.14) and 1.13 (95% CI, 1.03-1.23). No significant associations were found for cancer mortality. PAR estimates suggest that sodium intake above the recommended threshold may account for 10% of total CVD, 13% of CHD, and 30% of heart failure deaths in this low-income southern population. CONCLUSIONS AND RELEVANCE: In this cohort study of 64 329 low-income Americans, nearly 80% of study participants consumed sodium exceeding the current recommended daily amount, which was associated with 10% to 30% of CVD mortality. Public health programs targeted to reduce sodium intake among this underserved population may be beneficial.


Asunto(s)
Enfermedades Cardiovasculares , Insuficiencia Cardíaca , Neoplasias , Sodio en la Dieta , Humanos , Femenino , Masculino , Causas de Muerte , Estudios de Cohortes , Blanco , Población Negra , Sodio , Sodio en la Dieta/efectos adversos
9.
Int J Prosthodont ; 37(7): 133-141, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38498865

RESUMEN

PURPOSE: To evaluate the flexural strength (FS) and microhardness of various CAD/CAM restorative materials intended for definitive use. The effect of hydrothermal aging on the mechanical properties of these materials was also investigated. MATERIALS AND METHODS: A total of 210 bar-shaped specimens (17 × 4 × 1.5 mm ± 0.02 mm) were fabricated via either subtractive manufacturing (SM) methods-reinforced composite resin (SM-CR), polymer-infiltrated ceramic network (SM-PICN), fine-structured feldspathic ceramic (SMFC), nanographene-reinforced polymethyl methacrylate (PMMA; SM-GPMMA), PMMAbased resin (SM-PMMA)-or additive manufacturing (AM) methods with urethane acrylate-based resins (AM-UA1 and AM-UA2). Specimens were then divided into two subgroups (nonaged or hydrothermal aging; n = 15). A three-point flexural strength test was performed, and five specimens from the nonaged group were submitted to microhardness testing. Specimens were subjected to 10,000 thermal cycles, and the measurements were repeated. RESULTS: Regardless of aging, SM-CR had the highest FS (P < .001), followed by SM-GPMMA (P ≤ .042). In nonaged groups, AM-UA2 had a lower FS than all other materials except SM-FC (P = 1.000). In hydrothermal aging groups, AM specimens had lower FS values than other materials, except SM-PMMA. With regard to microhardness, there was no significant difference found between any of the tested materials (P ≥ .945) in the nonaged and hydrothermal aging groups. CONCLUSIONS: The effect of hydrothermal aging on FS varied depending on the type of restorative material. Regardless of aging condition, SM-CR showed the highest FS values, whereas SM-FC had the highest microhardness. Hydrothermal aging had no significant influence on the microhardness of the tested materials.


Asunto(s)
Resistencia Flexional , Polimetil Metacrilato , Materiales Dentales , Resinas Compuestas , Polímeros , Ensayo de Materiales , Propiedades de Superficie , Diseño Asistido por Computadora
10.
Int J Prosthodont ; 37(7): 151-158, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38498866

RESUMEN

PURPOSE: This study investigated the impact of reducing the oxygen concentration via nitrogen injection during the postcuring process of 3D-printed dental materials. MATERIALS AND METHODS: Resin specimens for dental crown and bridge (15-mm diameter, both 1-mm and 2-mm heights) were 3D-printed and rinsed. Subsequently, the postcuring process was conducted on nine groups categorized according to atmospheric conditions within the curing device (20% [control], 10%, and 5% oxygen) and curing times (10, 15, and 20 minutes). Surface roughness was measured using a gloss meter. Surface polymerization was confirmed through Fourier-transform infrared spectroscopy (FT-IR) analysis, and the flexural strength and elastic modulus of the specimens were measured using a universal testing machine. Water absorption and solubility were determined according to Inernational Organization for Standardization (ISO) standards. All evaluation criteria were statistically analyzed using one-way ANOVA and Tukey's post hoc test based on oxygen concentration. RESULTS: The elastic modulus did not show statistically significant differences in all groups. However, compared to the control group, the flexural strength, degree of conversion, and gloss significantly increased in the groups with decreased oxygen concentrations. Conversely, water solubility and water absorption significantly decreased in a few groups with reduced oxygen concentration. CONCLUSIONS: Reducing oxygen concentration through nitrogen injection during the postcuring process of 3D printing enhances the suitability of the dental prosthetic materials. The significant increase in flexural strength can particularly enhance the utility of these materials in dental prosthetics.


Asunto(s)
Impresión Tridimensional , Agua , Espectroscopía Infrarroja por Transformada de Fourier , Ensayo de Materiales , Docilidad , Agua/química , Nitrógeno , Resinas Sintéticas , Propiedades de Superficie
11.
Int J Prosthodont ; 37(7): 19-29, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38489217

RESUMEN

PURPOSE: To evaluate the effect of polymerization unit, polishing, and coffee thermocycling on the color and translucency of additively manufactured polyurethane-based resins with different viscosities. In addition, their color behavior was compared with the color of the shade tab throughout the fabrication steps and aging. MATERIALS AND METHODS: Disk-shaped specimens (Ø10 × 2 mm) were fabricated from polyurethane-based resins with different viscosities (Tera Harz TC-80DP and C&B permanent; n = 30 per material). Baseline color coordinates were measured after cleaning. The specimens in each resin group were divided into three subgroups (n = 10 per subgroup) to be polymerized with different polymerization units (Otoflash G171 [FLN], Wash and Cure 2.0 [CLED1], and P Cure [CLED2]), polished, and subjected to coffee thermocycling. Color coordinates were remeasured after each process. Color differences (ΔE00) and relative translucency parameter (RTP) values were calculated. Data were statistically analyzed (α = .05). RESULTS: Time points and polymerization units affected the ΔE00 for each material (P ≤ .049). ΔE00 of each polymerization unit pair had significant differences within and among different time points within each material (P ≤ .024). ΔE00 (when compared with the shade tab) and RTP were mostly affected by polymerization units and time points within both materials (P ≤ .042). CONCLUSIONS: Tested polymerization units, polishing, and coffee thermocycling affected the color difference and translucency of tested resins. Color differences ranged from moderately unacceptable to extremely unacceptable, and the differences in translucency values mostly ranged from perceptible to unacceptable, according to previous thresholds. In addition, tested resin-polymerization unit pairs had unacceptable color differences when compared to the shade tab. CLED1 may enable higher color stability for tested resins.


Asunto(s)
Café , Implantes Dentales , Polimerizacion , Poliuretanos , Color , Ensayo de Materiales , Propiedades de Superficie , Resinas Compuestas
12.
Medicine (Baltimore) ; 103(10): e37426, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38457577

RESUMEN

The aim of this study was to compare survival outcomes of 3 different radical hysterectomy (RH) types, namely total abdominal radical hysterectomy (TARH), total laparoscopic radical hysterectomy (TLRH), and laparoscopy-assisted radical vaginal hysterectomy (LARVH), in patients with FIGO stage IB2 cervical cancer. We retrospectively identified a cohort of patients who underwent RH for cervical cancer between 2010 and 2017. Patients with stage IB2 cervical cancer were included and were classified into TARH, TLRH, and LARVH treatment groups. Survival outcomes were estimated by the Kaplan-Meier method and compared with the log-rank test. Cox proportional hazards models were fit to estimate the independent association of RH technique with outcome. 194 patients were included in this study: 79 patients in the TARH group, 55 in the TLRH group, and 60 in the LARVH group. No significant differences were found in clinicopathological characteristics between the 3 RH groups. On comparing survival outcomes with TARH, both TLRH and LARVH showed no significant difference in terms of 5-year overall survival (TARH vs TLRH, P = .121 and TARH vs LARVH, P = .436). Conversely, compared to the TARH group, 5-year progression-free survival (PFS) was significantly worse in the TLRH group (P = .034) but not in the LARVH group (P = .288). Multivariate analysis showed that TLRH surgical approach (hazard ratio, 3.232; 95% confidence interval, 1.238-8.438; P = .017) was an independent prognostic factor for PFS in patients with IB2 cervical cancer. Our study suggests that in patients with FIGO stage IB2 cervical cancer, among the minimally invasive RH approaches, TLRH and LARVH, only TLRH approach was associated with worse PFS when compared with the TARH approach.


Asunto(s)
Laparoscopía , Neoplasias del Cuello Uterino , Femenino , Humanos , Histerectomía Vaginal/métodos , Neoplasias del Cuello Uterino/patología , Estudios Retrospectivos , Estadificación de Neoplasias , Histerectomía/métodos , Laparoscopía/métodos , Supervivencia sin Enfermedad
13.
EClinicalMedicine ; 68: 102445, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38333540

RESUMEN

Background: Diabetes is a major public health concern. We aimed to evaluate the long-term risk of incident type 2 diabetes in a non-diabetic population using a deep learning model (DLM) detecting prevalent type 2 diabetes using electrocardiogram (ECG). Methods: In this retrospective study, participants who underwent health checkups at two tertiary hospitals in Seoul, South Korea, between Jan 1, 2001 and Dec 31, 2022 were included. Type 2 diabetes was defined as glucose ≥126 mg/dL or glycated haemoglobin (HbA1c) ≥ 6.5%. For survival analysis on incident type 2 diabetes, we introduced an additional variable, diabetic ECG, which is determined by the DLM trained on ECG and corresponding prevalent diabetes. It was assumed that non-diabetic individuals with diabetic ECG had a higher risk of incident type 2 diabetes than those with non-diabetic ECG. The one-dimensional ResNet-based model was adopted for the DLM, and the Guided Grad-CAM was used to localise important regions of ECG. We divided the non-diabetic group into the diabetic ECG group (false positive) and the non-diabetic ECG (true negative) group according to the DLM decision, and performed a Cox proportional hazard model, considering the occurrence of type 2 diabetes more than six months after the visit. Findings: 190,581 individuals were included in the study with a median follow-up period of 11.84 years. The areas under the receiver operating characteristic curve for prevalent type 2 diabetes detection were 0.816 (0.807-0.825) and 0.762 (0.754-0.770) for the internal and external validations, respectively. The model primarily focused on the QRS duration and, occasionally, P or T waves. The diabetic ECG group exhibited an increased risk of incident type 2 diabetes compared with the non-diabetic ECG group, with hazard ratios of 2.15 (1.82-2.53) and 1.92 (1.74-2.11) for internal and external validation, respectively. Interpretation: In the non-diabetic group, those whose ECG was classified as diabetes by the DLM were at a higher risk of incident type 2 diabetes than those whose ECG was not. Additional clinical research on the relationship between the phenotype of ECG and diabetes to support the results and further investigation with tracked data and various ECG recording systems are suggested for future works. Funding: National Research Foundation of Korea.

14.
Dent Mater J ; 43(2): 216-226, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38417860

RESUMEN

This study aimed to investigate the effects of sandblasting on the physical properties and bond strength of two types of translucent zirconia: niobium-oxide-containing yttria-stabilized tetragonal zirconia polycrystals ((Y, Nb)-TZP) and 5 mol% yttria-partially stabilized zirconia (5Y-PSZ). Fully sintered disc specimens were either sandblasted with 125 µm alumina particles or left as-sintered. Surface roughness, crystal phase compositions, and surface morphology were explored. Biaxial flexural strength (n=10) and shear bond strength (SBS) (n=12) were evaluated, including thermocycling conditions. Results indicated a decrease in flexural strength of 5Y-PSZ from 601 to 303 MPa upon sandblasting, while (Y, Nb)-TZP improved from 458 to 544 MPa. Both materials significantly increased SBS after sandblasting (p<0.001). After thermocycling, (Y, Nb)-TZP maintained superior SBS (14.3 MPa) compared to 5Y-PSZ (11.3 MPa) (p<0.001). The study concludes that (Y, Nb)-TZP is preferable for sandblasting applications, particularly for achieving durable bonding without compromising flexural strength.


Asunto(s)
Materiales Dentales , Niobio , Óxidos , Materiales Dentales/química , Ensayo de Materiales , Propiedades de Superficie , Circonio/química , Itrio/química , Óxido de Aluminio , Resistencia al Corte
15.
J Glaucoma ; 33(5): 361-369, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38194280

RESUMEN

PRCIS: This nationwide analysis identified the prevalence and incidence of childhood glaucoma for an 18-year period. The prevalence and incidence of primary congenital glaucoma showed increasing trends. Juvenile open angle glaucoma, meanwhile, showed a decreasing tendency. PURPOSE: We aimed to determine the trends in the prevalence and incidence of childhood glaucoma in the entire population of South Korea. PATIENTS AND METHODS: A nationwide retrospective cohort study was performed with an age-specific and sex-specific population of South Korea. The Korean National Health Insurance Service claims database for 2002 to 2019 was accessed to identify cases of ophthalmologist-confirmed primary childhood glaucoma [ie, primary congenital glaucoma (PCG) and juvenile open angle glaucoma (JOAG)]. Incidence for PCG was estimated for a same-birth-year population, while that for JOAG was estimated using age-specific and sex-specific population figures. To verify the glaucoma cases, we also analyzed the diagnostic codes as well as any information on medication prescriptions and/or ocular-surgery history. RESULTS: During the 18-year observational period, totals of 505 and 7538 patients were diagnosed with PCG and JOAG, respectively. The mean prevalences of PCG and JOAG were 3.96±0.72 and 14.17±5.18, respectively. The prevalence of PCG showed an overall increasing trend during the study period, but the pattern was not significant ( ß =0.049, P =0.143); that of JOAG, meanwhile, showed a significant decreasing tendency ( ß =-0.713, P =0.001). PCG prevalence showed no difference between urban and rural areas, but JOAG showed a higher prevalence in rural areas ( P <0.001). As for mean incidence, the rates for PCG and JOAG were 1.54±0.49 and 5.02±1.95 (per 100,000 person-years), respectively, and were higher in males ( P <0.001 and P =0.013). CONCLUSION: This study identified childhood glaucoma prevalence and incidence in a general population of East Asian ethnicity. This data could help to promote a better understanding of the typical epidemiological features and clinical courses of childhood glaucoma patients.


Asunto(s)
Glaucoma de Ángulo Abierto , Humanos , República de Corea/epidemiología , Incidencia , Masculino , Femenino , Prevalencia , Estudios Retrospectivos , Niño , Preescolar , Adolescente , Lactante , Distribución por Edad , Distribución por Sexo , Glaucoma de Ángulo Abierto/epidemiología , Presión Intraocular/fisiología , Glaucoma/epidemiología , Recién Nacido , Bases de Datos Factuales
16.
Cancer Epidemiol Biomarkers Prev ; 33(4): 480-488, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38284815

RESUMEN

BACKGROUND: Despite the various anticancer activities of tocopherols, little is known about tocopherols associated with lung cancer risk among low-income African Americans (AA) and European Americans (EA) who are disproportionately affected by the disease. METHODS: We conducted a nested case-control study that included 209 incident lung cancer cases and 406 matched controls within the Southern Community Cohort Study. Using biospecimens collected at cohort enrollment, plasma levels of α-, ß/γ-, δ-, and total-tocopherols were measured by high-performance liquid chromatography with photodiode array detection. Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI) for lung cancer risk after adjusting for potential confounders. Stratified analyses were also conducted. RESULTS: Plasma levels of total-tocopherols were inversely associated with lung cancer risk overall [OR (95% CI) for the highest vs. lowest tertile = 0.51 (0.30-0.90)]. The inverse association remained significant among EAs [0.20 (0.06-0.65)], men [0.43 (0.21-0.90)], current smokers [0.49 (0.26-0.93)], and cases diagnosed within 2 years of blood draw [0.36 (0.15-0.86)], though we did not find a significant risk reduction among AAs [0.75 (0.39-1.45)]. Notably, we found significant interactions between α-tocopherol and race after controlling the FDR to correct for multiple comparisons (Pinteraction = 0.02). CONCLUSIONS: Our results indicate that plasma total-tocopherols are inversely associated with lung cancer risk, but the association may differ across specific isomeric forms of tocopherols, race, or other individuals' characteristics. Further large-scale studies are warranted to confirm our findings. IMPACT: Recommendations on tocopherols for lung cancer prevention should take isomers, race, and smoking behaviors into consideration.


Asunto(s)
Neoplasias Pulmonares , Tocoferoles , Masculino , Humanos , Estudios de Cohortes , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/etiología , Estudios de Casos y Controles , Modelos Logísticos , Factores de Riesgo
17.
JAMA Netw Open ; 7(1): e2351650, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38227312

RESUMEN

Importance: Light pollution's impact on human health is increasingly recognized, but its link to exudative age-related macular degeneration (EAMD) remains unclear. Objective: To investigate the association between exposure to outdoor artificial light at night (OALAN) and the risk of incident EAMD. Design, Setting, and Participants: In this nationwide population-based case-control study, all individuals 50 years or older with newly diagnosed EAMD between January 1, 2010, and December 31, 2011, were identified with reference to the Korean National Health Insurance Service registration program database for rare and intractable diseases. Birth year- and sex-matched controls (with no EAMD diagnosis until 2020) were selected at a 1:30 ratio. Data were acquired from May 1 to December 31, 2021, and analyzed from June 1 to November 30, 2022. Exposures: Mean levels of OALAN at participants' residential addresses during 2008 and 2009 were estimated using time-varying satellite data for a composite view of persistent nighttime illumination at an approximate scale of 1 km2. Main Outcomes and Measures: The hazard ratios (HRs) and 95% CIs of the association between residential OALAN and risk of incident EAMD were determined based on maximum likelihood estimation after adjusting for sociodemographic characteristics, comorbidities, and area-level risk factors (ie, nighttime traffic noise and particulate matter of aerodynamic diameter ≤10 µm in each participant's administrative district of residence). Results: A total of 126 418 participants were included in the analysis (mean [SD] age, 66.0 [7.9] years; 78 244 men [61.9%]). Of these, 4078 were patients with newly diagnosed EAMD and 122 340 were EAMD-free matched controls. In fully adjusted models, an IQR (55.8 nW/cm2/sr) increase in OALAN level was associated with an HR of 1.67 (95% CI, 1.56-1.78) for incident EAMD. The exposure-response curve demonstrated a nonlinear, concave upward slope becoming more pronounced at higher levels of light exposure (ie, at approximately 110 nW/cm2/sr). In a subgroup analysis, an IQR increase in OALAN was associated with increased risk of incident EAMD in urban areas (HR, 1.46 [95% CI, 1.33-1.61]) but not in rural areas (HR, 1.01 [95% CI, 0.84-1.22]). Conclusions and Relevance: In this nationwide population-based case-control study, higher levels of residential OALAN were associated with an increased risk of incident EAMD. Future studies with more detailed information on exposure, individual adaptive behaviors, and potential mediators are warranted.


Asunto(s)
Iluminación , Degeneración Macular , Anciano , Humanos , Masculino , Estudios de Casos y Controles , Bases de Datos Factuales , Degeneración Macular/epidemiología , Degeneración Macular/etiología , República de Corea , Iluminación/efectos adversos
18.
J Dent ; 141: 104830, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38163455

RESUMEN

OBJECTIVES: This study compared the tooth morphology, internal fit, occlusion, and proximal contacts of dental crowns automatically generated via two deep learning (DL)-based dental software systems with those manually designed by an experienced dental technician using conventional software. METHODS: Thirty partial arch scans of prepared posterior teeth were used. The crowns were designed using two DL-based methods (AA and AD) and a technician-based method (NC). The crown design outcomes were three-dimensionally compared, focusing on tooth morphology, internal fit, occlusion, and proximal contacts, by calculating the geometric relationship. Statistical analysis utilized the independent t-test, Mann-Whitney test, one-way ANOVA, and Kruskal-Wallis test with post hoc pairwise comparisons (α = 0.05). RESULTS: The AA and AD groups, with the NC group as a reference, exhibited no significant tooth morphology discrepancies across entire external or occlusal surfaces. The AD group exhibited higher root mean square and positive average values on the axial surface (P < .05). The AD and NC groups exhibited a better internal fit than the AA group (P < .001). The cusp angles were similar across all groups (P = .065). The NC group yielded more occlusal contact points than the AD group (P = .006). Occlusal and proximal contact intensities varied among the groups (both P < .001). CONCLUSIONS: Crowns designed by using both DL-based software programs exhibited similar morphologies on the occlusal and axial surfaces; however, they differed in internal fit, occlusion, and proximal contacts. Their overall performance was clinically comparable to that of the technician-based method in terms of the internal fit and number of occlusal contact points. CLINICAL SIGNIFICANCE: DL-based dental software for crown design can streamline the digital workflow in restorative dentistry, ensuring clinically-acceptable outcomes on tooth morphology, internal fit, occlusion, and proximal contacts. It can minimize the necessity of additional design optimization by dental technician.


Asunto(s)
Aprendizaje Profundo , Porcelana Dental , Cerámica , Coronas , Diseño Asistido por Computadora , Diseño de Prótesis Dental/métodos , Adaptación Marginal Dental , Programas Informáticos
19.
Arch Gynecol Obstet ; 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38252305

RESUMEN

PURPOSE: To investigate the effect of intravenous MgSO4 on maternal cerebral hemodynamics as well as the association between altered Doppler indices of the ophthalmic arteries and ocular lesions in patients with preeclampsia. METHODS: After each of the 15 included patients was diagnosed with preeclampsia, MgSO4 was infused followed by transcranial Doppler tests of the indices of the ophthalmic, anterior, middle, posterior cerebral, vertebral, and basilar arteries, followed by a second MgSO4 infusion. The peak, mean, diastolic velocity, and pulsatile and resistance indices of each artery were automatically measured during testing. Based on the emergent data, the cerebral perfusion pressure, resistance-area product, and cerebral flow index were calculated. RESULTS: The cerebral perfusion pressure of the posterior cerebral arteries significantly decreased following the infusion of MgSO4 (p < 0.05). Before the infusion of MgSO4, cerebral perfusion pressure and cerebral flow index of the ophthalmic arteries were significantly increased (p < 0.05) in the preeclamptic pregnant patients with ocular lesions compared those without ocular lesions. After the infusion of MgSO4, the cerebral perfusion pressure and cerebral flow index of both ophthalmic arteries were slightly decreased, but the difference was not significant. CONCLUSIONS: Altered Doppler indices following the infusion of MgSO4 suggest significant changes in the hemodynamics of the posterior cerebral and ophthalmic arteries that are particularly related to the neurological signs and symptoms of women with preeclampsia. These findings may improve the understanding of the mechanism of the cerebral complications of preeclampsia. Advancing comprehension of these underlying mechanisms is postulated to play a pivotal role in the mitigation of hypertensive encephalopathy associated with preeclampsia.

20.
Psychiatry Investig ; 21(1): 100-108, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38200634

RESUMEN

OBJECTIVE: Recently, burnout and mental health issues regarding nurses are reported increasingly. This study aimed to investigate the prevalence of anxiety symptoms among hospital nurses and determine their association with psychological and job-related factors. METHODS: Data on demographics, job-related characteristics, burnout, Type A behavior patterns, self-esteem, and happiness were collected from 515 nurses working at a university hospital in Korea. Anxiety symptoms were assessed using the anxiety subscale of the Hospital Anxiety and Depression Scale, with scores of 8 or higher indicating the presence of anxiety symptoms. Demographic, job-related, and psychological factors were compared according to the presence of anxiety. Logistic regression was conducted to identify factors associated with anxiety symptoms. RESULTS: Two hundred and four (39.6%) participants had anxiety symptoms. Self-esteem and happiness were associated with a lower risk of anxiety symptoms, whereas burnout was associated with a higher risk of anxiety symptoms. Furthermore, being female, having a career of less than five years, and requiring counseling due to stress were associated with a higher risk of anxiety symptoms. Being younger, female, or a basic nurse; having a career of less than five years; partaking in shift work; experiencing job dissatisfaction; requiring counseling due to stress; being exposed to higher levels of burnout; and having lower levels of self-esteem and happiness were all found to be significantly correlated with anxiety symptoms. CONCLUSION: These findings suggest that promoting self-esteem and happiness while reducing burnout may be beneficial in preventing and managing anxiety symptoms among hospital nurses.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...