Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 114
Filter
1.
Phys Chem Chem Phys ; 26(14): 10769-10783, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38516907

ABSTRACT

To effectively utilize MXenes, a family of two-dimensional materials, in various applications that include thermoelectric devices, semiconductors, and transistors, their thermodynamic and mechanical properties, which are closely related to their stability, must be understood. However, exploring the large chemical space of MXenes and verifying their stability using first-principles calculations are computationally expensive and inefficient. Therefore, this study proposes a machine learning (ML)-based high-throughput MXene screening framework to identify thermodynamically stable MXenes and determine their mechanical properties. A dataset of 23 857 MXenes with various compositions was used to validate this framework, and 48 MXenes were predicted to be stable by ML models in terms of heat of formation and energy above the convex hull. Among them, 45 MXenes were validated using density functional theory calculations, of which 23 MXenes, including Ti2CClBr and Zr2NCl2, have not been previously known for their stability, confirming the effectiveness of this framework. The in-plane stiffness, shear moduli, and Poisson's ratio of the 45 MXenes were observed to vary widely according to their constituent elements, ranging from 90.11 to 198.02 N m-1, 64.00 to 163.40 N m-1, and 0.19 to 0.58, respectively. MXenes with Group-4 transition metals and halogen surface terminations were shown to be both thermodynamically stable and mechanically robust, highlighting the importance of electronegativity difference between constituent elements. Structurally, a smaller volume per atom and minimum bond length were determined to be preferable for obtaining mechanically robust MXenes. The proposed framework, along with an analysis of these two properties of MXenes, demonstrates immense potential for expediting the discovery of stable and robust MXenes.

2.
Arch Orthop Trauma Surg ; 143(1): 107-114, 2023 Jan.
Article in English | MEDLINE | ID: mdl-34180004

ABSTRACT

INTRODUCTION: Routine orthopedic implant removal surgery (OIRS) in patients with no implant-related symptoms after union is controversial. Various factors, such as various fracture sites, fracture types, and accompanying fractures at other sites, act as error variables in the evaluation of routine OIRS. The purpose of this study is to evaluate the benefits of orthopedic implant removal surgery (OIRS) in patients with no implant-related symptoms such as infection and soft tissue irritation after union of isolated lower extremity shaft fractures from a patient-centered evaluation MATERIALS AND METHODS: Eighty-four patients who achieved fracture union after internal fixation of femoral shaft or tibial shaft fractures (March 2004 to December 2018) and who showed no implant-related symptoms were evaluated retrospectively. Minimum post-OIRS follow-up period was 1 year. Thirty-eight patients were treated with intramedullary nail and 13 were treated with plate and screws for femoral shaft fracture. Twenty patients were treated with intramedullary nail and 13 were treated with plate and screws for tibial shaft fracture. All patients subsequently underwent OIRS. Quality of life (QoL) and lower extremity pain using visual analogue scale (VAS) were evaluated 1 day before OIRS. Patient satisfaction with the OIRS, VAS, and QoL were assessed at least 1 year after OIRS using the SF-36 questionnaire. RESULTS: The physical component score, mental component score, and scores of all eight domains showed significant improvement after OIRS (p < 0.01). Patients with femoral shaft fractures tended to have lower pre- and post-OIRS SF-36 scores than those with tibial shaft fracture. Among patients with femoral shaft fracture, SF-36 scores were comparable in the nail and plate groups. Among patients with tibial shaft fracture, nail group showed relatively better QoL than the plate group, before and after OIRS in spite of several complications such as formation of scar tissue, nerve damage, and refracture. CONCLUSIONS: Patients with no implant-related symptoms showed significant improvement in QoL and satisfaction after OIRS. This suggests that OIRS is beneficial from the patients' evaluation. LEVEL OF EVIDENCE: Therapeutic Level II.


Subject(s)
Femoral Fractures , Fracture Fixation, Intramedullary , Tibial Fractures , Humans , Quality of Life , Retrospective Studies , Fracture Fixation, Intramedullary/adverse effects , Bone Nails , Femoral Fractures/surgery , Tibial Fractures/complications , Tibial Fractures/surgery , Lower Extremity/surgery , Patient-Centered Care , Fracture Healing , Treatment Outcome
3.
Medicina (Kaunas) ; 59(5)2023 May 21.
Article in English | MEDLINE | ID: mdl-37241228

ABSTRACT

Background and Objectives: Receptor tyrosine kinase-like orphan receptor type 1 (ROR1) plays a critical role in embryogenesis and is overexpressed in many malignant cells. These characteristics allow ROR1 to be a potential new target for cancer treatment. The aim of this study was to investigate the role of ROR1 through in vitro experiments in endometrial cancer cell lines. Materials and Methods: ROR1 expression was identified in endometrial cancer cell lines using Western blot and RT-qPCR. The effects of ROR1 on cell proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) markers were analyzed in two endometrial cancer cell lines (HEC-1 and SNU-539) using either ROR1 silencing or overexpression. Additionally, chemoresistance was examined by identifying MDR1 expression and IC50 level of paclitaxel. Results: The ROR1 protein and mRNA were highly expressed in SNU-539 and HEC-1 cells. High ROR1 expression resulted in a significant increase in cell proliferation, migration, and invasion. It also resulted in a change of EMT markers expression, a decrease in E-cadherin expression, and an increase in Snail expression. Moreover, cells with ROR1 overexpression had a higher IC50 of paclitaxel and significantly increased MDR1 expression. Conclusions: These in vitro experiments showed that ROR1 is responsible for EMT and chemoresistance in endometrial cancer cell lines. Targeting ROR1 can inhibit cancer metastasis and may be a potential treatment method for patients with endometrial cancer who exhibit chemoresistance.


Subject(s)
Endometrial Neoplasms , Epithelial-Mesenchymal Transition , Female , Humans , Epithelial-Mesenchymal Transition/genetics , Cell Line, Tumor , Drug Resistance, Neoplasm , Endometrial Neoplasms/drug therapy , Endometrial Neoplasms/genetics , Cell Proliferation , Cell Movement , Paclitaxel/pharmacology , Paclitaxel/therapeutic use , Gene Expression Regulation, Neoplastic , Receptor Tyrosine Kinase-like Orphan Receptors/genetics , Receptor Tyrosine Kinase-like Orphan Receptors/metabolism
4.
BMC Endocr Disord ; 22(1): 89, 2022 Apr 04.
Article in English | MEDLINE | ID: mdl-35379219

ABSTRACT

BACKGROUND: Immune checkpoint inhibitors (ICIs) cause thyroid immune-related adverse effects (irAEs). However, associations between each type of thyroid immune-related adverse effect (irAE) and the anti-tumor effect of ICI remains unknown. This study aimed to determine the effects of each type of thyroid dysfunction on patient survival. METHODS: Patients who initiated ICI treatment from January 2015 to December 2019 in Seoul St. Mary's Hospital were retrospectively analyzed. Thyroid dysfunction was classified into four types: newly developed overt or subclinical hypothyroidism, thyrotoxicosis, worsened hypothyroidism, and subclinical hyperthyroidism. Patients were divided into two groups according to the presence or absence of thyroid dysfunction. RESULTS: Among the 191 patients, 64 (33.5%) developed thyroid irAEs. There was no significant difference in age, sex, or cancer type between the two groups. The overall survival in patients with thyroid irAEs was significantly higher than that in patients without thyroid irAEs (25 months vs. 18 months, respectively, p = 0.005). After adjusting for confounding factors, the hazard ratio for mortality in the thyroid irAE group compared to the no thyroid irAE group was 0.480 (p = 0.006). Newly developed overt or subclinical hypothyroidism patients showed a significantly lower hazard ratio for mortality of 0.324 (p = 0.002). Patients with thyrotoxicosis showed a worse hazard ratio for mortality than those without thyroid irAE, although the difference was not statistically significant. CONCLUSIONS: It was verified that ICI treatment-induced thyroid dysfunction was associated with better survival, even in the real-world practice. Thus, endocrinologists should cooperate with oncologists to monitor patients treated with ICIs.


Subject(s)
Immune Checkpoint Inhibitors , Neoplasms , Humans , Immune Checkpoint Inhibitors/adverse effects , Neoplasms/drug therapy , Prognosis , Retrospective Studies , Thyroid Gland/pathology
5.
Nano Lett ; 21(14): 6343-6351, 2021 07 28.
Article in English | MEDLINE | ID: mdl-33998792

ABSTRACT

Extracellular electrical stimulation (ES) can provide electrical potential from outside the cell membrane, but it is often ineffective due to interference from external factors such as culture medium resistance and membrane capacitance. To address this, we developed a vertical nanowire electrode array (VNEA) to directly provide intracellular electrical potential and current to cells through nanoelectrodes. Using this approach, the cell membrane resistivity and capacitance could be excluded, allowing effective ES. Human fetal neural stem cells (hfNSCs) were cultured on the VNEA for intracellular ES. Combining the structural properties of VNEA and VNEA-mediated ES, transient nanoscale perforation of the electrode was induced, promoting cell penetration and delivering current to the cell. Intracellular ES using VNEA improved the neuronal differentiation of hfNSCs more effectively than extracellular ES and facilitated electrophysiological functional maturation of hfNSCs because of the enhanced voltage-dependent ion-channel activity. The results demonstrate that VNEA with advanced nanoelectrodes serves as a highly effective culture and stimulation platform for stem-cell neurogenesis.


Subject(s)
Nanowires , Neural Stem Cells , Cell Differentiation , Electric Stimulation , Electrodes , Humans , Neurogenesis
6.
Nano Lett ; 21(3): 1274-1281, 2021 Feb 10.
Article in English | MEDLINE | ID: mdl-33523666

ABSTRACT

Surface-textured polymer nanocomposite (PNC) films are utilized in many device applications, and therefore understanding the relaxation behavior of such films is important. By extending an in situ wrinkle relaxation method, we observed that the thermal stability of wrinkled PNC films, both above and below the glass transition temperature (Tg), is proportional to a film's nanoparticle (polymer grafted and bare) concentration, with a slope that changes sign at a compensation temperature (Tcomp) that is determined to be in the vicinity of the film's Tg. This provides unambiguous confirmation of entropy-enthalpy compensation (EEC) as a general feature of PNC films, implying that the stability of PNC films changes from being enhanced to becoming diminished by simply passing through this characteristic temperature, a phenomenon having evident practical ramifications. We suggest EEC will also arise in films where residual stresses are associated with the film fabrication process, which is relevant to nanotech device applications.

7.
Medicina (Kaunas) ; 58(2)2022 Feb 11.
Article in English | MEDLINE | ID: mdl-35208591

ABSTRACT

Background and Objectives: For preventing postoperative delirium (POD), identifying the risk factors is important. However, the relationship between blood transfusion and POD is still controversial. The aim of this study was to identify the risk factors of POD, to evaluate the impact of blood transfusion in developing POD among people undergoing spinal fusion surgery, and to show the effectiveness of big data analytics using a clinical data warehouse (CDW). Materials and Methods: The medical data of patients who underwent spinal fusion surgery were obtained from the CDW of the five hospitals of Hallym University Medical Center. Clinical features, laboratory findings, perioperative variables, and medication history were compared between patients without POD and with POD. Results: 234 of 3967 patients (5.9%) developed POD. In multivariate logistic regression analysis, the risk factors of POD were as follows: Parkinson's disease (OR 5.54, 95% CI 2.15-14.27; p < 0.001), intensive care unit (OR 3.45 95% CI 2.42-4.91; p < 0.001), anti-psychotics drug (OR 3.35 95% CI 1.91-5.89; p < 0.001), old age (≥70 years) (OR 3.08, 95% CI 2.14-4.43; p < 0.001), depression (OR 2.8 95% CI 1.27-6.2; p < 0.001). The intraoperative transfusion (OR 1.1, 95% CI 0.91-1.34; p = 0.582), and the postoperative transfusion (OR 0.91, 95% CI 0.74-1.12; p = 0.379) had no statistically significant effect on the incidence of POD. Conclusions: There was no relationship between perioperative blood transfusion and the incidence of POD in spinal fusion surgery. Big data analytics using a CDW could be helpful for the comprehensive understanding of the risk factors of POD, and for preventing POD in spinal fusion surgery.


Subject(s)
Delirium , Spinal Fusion , Aged , Blood Transfusion , Data Warehousing , Delirium/epidemiology , Delirium/etiology , Humans , Postoperative Complications/etiology , Risk Factors , Spinal Fusion/adverse effects
8.
Medicina (Kaunas) ; 58(12)2022 Dec 17.
Article in English | MEDLINE | ID: mdl-36557069

ABSTRACT

Background and Objectives: Identification and targeting of membrane proteins in tumor cells is one of the key steps in the development of cancer drugs. The receptor tyrosine kinase-like orphan receptor (ROR) type 1 is a type-I transmembrane protein expressed in various cancer tissues, which is in contrast to its limited expression in normal tissues. These characteristics make ROR1 a candidate target for cancer treatment. This study aimed to identify the prognostic value of ROR1 expression in cancers. Materials and Methods: We conducted a comprehensive systematic search of electronic databases (PubMed) from their inception to September 2021. The included studies assessed the effect of ROR1 on overall survival (OS) and progression-free survival (PFS). Hazard ratios (HR) from collected data were pooled in a meta-analysis using Revman version 5.4 with generic inverse-variance and random effects modeling. Results: A total of fourteen studies were included in the final analysis. ROR1 was associated with worse OS (HR 1.95, 95% confidence interval (CI) 1.50−2.54; p < 0.001) with heterogeneity. The association between poor OS and ROR1 expression was high in endometrial cancer, followed by ovarian cancer, and diffuse large B cell lymphoma. In addition, ROR1 was associated with poor PFS (HR 1.84, 95% CI 1.60−2.10; p < 0.001), but heterogeneity was not statistically significant. In subgroup analysis, high ROR1 expression showed a significantly higher rate of advanced stage or lymph node metastasis. Conclusions: This meta-analysis provides evidence that ROR1 expression is associated with adverse outcome in cancer survival. This result highlights ROR1 as a target for developmental therapeutics in cancers.


Subject(s)
Endometrial Neoplasms , Ovarian Neoplasms , Female , Humans , Receptor Tyrosine Kinase-like Orphan Receptors/metabolism , Prognosis , Endometrial Neoplasms/pathology
9.
Cancer Control ; 28: 10732748211039758, 2021.
Article in English | MEDLINE | ID: mdl-34569320

ABSTRACT

BACKGROUND AND AIMS: This retrospective study aimed to investigate the impact of positive hepatitis B core antibody (anti-HBc) and metabolic disorders on clinical characteristics of hepatocellular carcinoma (HCC) patients in an HBV-endemic area. METHODS: A total of 1950 consecutive patients newly diagnosed with HCC between 2002 and 2015 were included. Patient records were reviewed. We compared non-viral and non-alcoholic HCC patients with other etiological groups for HCC. In addition, we compared HCC patients with negative hepatitis B surface antigen (HBsAg) and positive anti-HBc to those with negative HBsAg and negative anti-HBc, and to those with HBV. RESULTS: The prevalence of non-viral and non-alcoholic HCC increased from 7% in 2002-2011 to 12% in 2012-2015. The proportion of non-viral and non-alcoholic HCC gradually increased with age. Patients with non-viral and non-alcoholic HCC exhibited higher rates of metabolic disorders and preserved liver function. The rate of anti-HBc positivity was similarly high in all HCC etiological groups. The clinical features of HCC patients with negative HBsAg and positive anti-HBc were similar to those with negative HBsAg and negative anti-HBc, but significantly different from those with HBV HCC. Regarding tumor characteristics, patients in the non-viral and non-alcoholic HCC group had more advanced stages of tumors (mUICC stage III-V and BCLC stage C/D). There was no significant difference in overall survival among the patient groups. The presence of anti-HBc did not affect patient survival. CONCLUSION: Patients with non-viral and non-alcoholic HCC had a relatively high prevalence of metabolic disorders and preserved liver function. However, they had advanced tumor stage compared to patients from other etiological groups. Anti-HBc positivity did not affect the clinical characteristics or prognosis of non-HBV HCC patients in this study.


Subject(s)
Carcinoma, Hepatocellular/epidemiology , Carcinoma, Hepatocellular/pathology , Hepatitis B Antibodies/immunology , Liver Neoplasms/epidemiology , Liver Neoplasms/pathology , Metabolic Diseases/epidemiology , Adult , Age Factors , Aged , Aged, 80 and over , Carcinoma, Hepatocellular/immunology , Female , Hepatitis B Antigens , Hepatitis B virus , Humans , Liver Neoplasms/immunology , Male , Middle Aged , Prognosis , Retrospective Studies , Risk Factors
10.
Nanotechnology ; 32(12): 125702, 2021 Mar 19.
Article in English | MEDLINE | ID: mdl-33264761

ABSTRACT

Gallium nitride nanowires (GaN NWs) with triangular cross-section exhibit universal conductance fluctuations (UCF) originating from the quantum interference of electron wave functions in the NWs. The amplitude of UCF is inversely proportional to the applied bias current. The bias dependence of UCF, combined with temperature dependence of the resistance suggests that phase coherent transport dominates over normal transport in GaN NWs. A unique temperature dependence of phase-coherent length and fluctuation amplitude is associated with inelastic electron-electron scattering in NWs. The phase-coherence length extracted from the UCF is as large as 400 nm at 1.8 K, and gradually decreases as temperature increases up to 60 K.

11.
Int J Mol Sci ; 22(16)2021 Aug 18.
Article in English | MEDLINE | ID: mdl-34445608

ABSTRACT

Antimicrobial peptides (AMPs) are short cationic amphipathic peptides with a wide range of antimicrobial properties and play an important role in the maintenance of immune homeostasis by modulating immune responses in the reproductive tract. As intra-amniotic infection and microbial dysbiosis emerge as common causes of preterm births (PTBs), a better understanding of the AMPs involved in the development of PTB is essential. The altered expression of AMPs has been reported in PTB-related clinical presentations, such as preterm labor, intra-amniotic infection/inflammation, premature rupture of membranes, and cervical insufficiency. Moreover, it was previously reported that dysregulation of AMPs may affect the pregnancy prognosis. This review aims to describe the expression of AMPs associated with PTBs and to provide new perspectives on the role of AMPs in PTB.


Subject(s)
Pore Forming Cytotoxic Proteins/adverse effects , Premature Birth/pathology , Female , Humans , Infant, Newborn , Pregnancy , Premature Birth/chemically induced
12.
Transfusion ; 59(7): 2324-2333, 2019 07.
Article in English | MEDLINE | ID: mdl-31022315

ABSTRACT

BACKGROUND: Hip arthroplasties are strongly associated with blood transfusion to compensate for perioperative bleeding. The purpose of this study was to evaluate the trends in transfusion associated with hip arthroplasties, using nationwide data supplied by the National Health Insurance Service. STUDY DESIGN AND METHODS: We used data from nationwide claims database of the Health Insurance Review Assessment Service. The data managed by the National Health Insurance Service were used to identify 161,934 hip arthroplasties under three categories, including bipolar hemiarthroplasty, total hip arthroplasty, and revision arthroplasty, from 2007 to 2015. The transfusion rates, transfusion amounts, the proportion of transfusion, and cost associated with each type of operation were investigated and stratified according to age, sex, hospital type, and region. RESULTS: The proportion of patients receiving any allogeneic transfusion was 81.1% in 9 years. The overall proportion of transfusion was 7% fresh frozen plasma, 12% platelets, and 77% RBCs. The average count of transfusions was 4.1 in bipolar hemiarthroplasty (343,815/83,729), 4.3 in total hip arthroplasty (196,869/46,097), and 8.7 in revision arthroplasty (35,044/4,024) from 2007 to 2015. CONCLUSION: In this nationally representative study of trends in transfusion associated with hip arthroplasty, we observed significantly high rates of blood transfusion among patients undergoing hip arthroplasties. Although the overall amount of transfusion declined, the allogeneic transfusion rate was still high from 2007 to 2015 in Korea, and higher than other countries are reporting.


Subject(s)
Arthroplasty, Replacement, Hip , Blood Component Transfusion/trends , National Health Programs , Adult , Aged , Female , Humans , Male , Middle Aged , Republic of Korea , Risk Factors
13.
J Am Chem Soc ; 139(37): 12931-12934, 2017 09 20.
Article in English | MEDLINE | ID: mdl-28885020

ABSTRACT

An aqueous-based approach for the scalable synthesis of nitrogen-doped porous carbons with high specific surface area (SSA) and high nitrogen content is presented. Low molecular weight polyacrylonitrile (PAN) is solubilized in water in the presence of ZnCl2 that also acts as a volatile porogen during PAN pyrolysis to form mesoporous structures with significantly increased SSA. By templating with commercial SiO2 nanoparticles, nanocellulose fillers or filter paper, nanocarbons with SSA = 1776, 1366, and 1501 m2/g, respectively and 10 wt % N content were prepared. The materials formed by this benign process showed excellent catalytic activity in oxygen reduction reaction via the four-electron mechanism.

14.
Nanotechnology ; 28(25): 255401, 2017 Jun 23.
Article in English | MEDLINE | ID: mdl-28548050

ABSTRACT

Silicon (Si) has a large theoretical capacity of 4200 mAhg-1 and has great potential as a high-performance anode material for Li ion batteries (LIBs). Meanwhile, nanostructures can exploit the potential of Si and, accordingly, many zero-dimensional (0D) and one-dimensional (1D) Si nanostructures have been studied. Herein, we report on two-dimensional (2D) Si nanostructures, Si nanosheets (SiNSs), as anodes for LIBs. These 2D Si nanostructures, with a thickness as low 5 nm and widths of several micrometers, show reversible crystalline-amorphous phase transformations with the lithi-/delithiation by the dimensionality of morphology and large surface area. The reversible crystalline-amorphous phase transformation provides a structural stability of Li+ insertions and makes SiNSs promising candidates for reliable high-performance LIBs anode materials.

15.
J Prosthet Dent ; 117(2): 253-259, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27666500

ABSTRACT

STATEMENT OF PROBLEM: Scanners are frequently used in the fabrication of dental prostheses. However, the accuracy of these scanners is variable, and little information is available. PURPOSE: The purpose of this in vitro study was to compare the accuracy of cast scanners with that of intraoral scanners by using different image impression techniques. MATERIAL AND METHODS: A poly(methyl methacrylate) master model was fabricated to replicate a maxillary first molar single-abutment tooth model. The master model was scanned with an accurate engineering scanner to obtain a true value (n=1) and with 2 intraoral scanners (CEREC Bluecam and CEREC Omnicam; n=6 each). The cast scanner scanned the master model and duplicated the dental stone cast from the master model (n=6). The trueness and precision of the data were measured using a 3-dimensional analysis program. The Kruskal-Wallis test was used to compare the different sets of scanning data, followed by a post hoc Mann-Whitney U test with a significance level modified by Bonferroni correction (α/6=.0083). The type 1 error level (α) was set at .05. RESULTS: The trueness value (root mean square: mean ±standard deviation) was 17.5 ±1.8 µm for the Bluecam, 13.8 ±1.4 µm for the Omnicam, 17.4 ±1.7 µm for cast scanner 1, and 12.3 ±0.1 µm for cast scanner 2. The differences between the Bluecam and the cast scanner 1 and between the Omnicam and the cast scanner 2 were not statistically significant (P>.0083), but a statistically significant difference was found between all the other pairs (P<.0083). The precision of the scanners was 12.7 ±2.6 µm for the Bluecam, 12.5 ±3.7 µm for the Omnicam, 9.2 ±1.2 µm for cast scanner 1, and 6.9 ±2.6 µm for cast scanner 2. The differences between Bluecam and Omnicam and between Omnicam and cast scanner 1 were not statistically significant (P>.0083), but there was a statistically significant difference between all the other pairs (P<.0083). CONCLUSIONS: An Omnicam in video image impression had better trueness than a cast scanner but with a similar level of precision.


Subject(s)
Dental Abutments , Dental Impression Technique , Computer-Aided Design , Dental Casting Technique , Dental Prosthesis Design , Humans , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , In Vitro Techniques
16.
J Prosthet Dent ; 116(4): 536-542, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27174406

ABSTRACT

STATEMENT OF PROBLEM: The fit of an interim implant restoration (IIR) is important for the effective treatment of patients with partial edentulism. However, no clinical trials have evaluated the marginal and internal fittings achieved with various fabrication methods. PURPOSE: The purpose of this in vitro study was to evaluate and compare the marginal and internal discrepancies in IIRs produced with 3 different methods. MATERIAL AND METHODS: Partially edentulous maxillary and mandibular casts from a transfer abutment were used. Prostheses were prepared by applying wax to the implant abutment. Shapes were copied using putty. IIRs were fabricated from poly(methyl methacrylate) for a conventional system with thermoplastic resin (CTR, n=40), a 4-axial milling machine with a crown-designed standard template library for a subtractive manufacturing system with Pekkton milling (SPM, n=40), and a 3-dimensional printer for an additive manufacturing system with digital light processing (ADL, n=40). The marginal and internal discrepancies were evaluated in each group using the silicone replica technique. The space between the abutment and the intaglio surface of the prosthesis was evaluated with a digital microscope (×160 magnification). Results were analyzed with nonparametric 2-way analysis of variance using rank-transformed values and Tukey post hoc test (α=.05). RESULTS: The fabricated IIRs were significantly different at all points (P<.001). Moreover, ADL was superior to CTR and SPM. IIRs were significantly different only at the intermarginal discrepancy (the vertical discrepancy between the crown and the point where the margin becomes round and changes to the axial wall), the axiogingival discrepancy (the vertical discrepancy between the internal surface and the axial wall adjacent to the gingival wall of the abutment), and the occlusal discrepancy (the vertical discrepancy between the occlusal wall of the abutment and the internal surface; this discrepancy comprises the internal discrepancy; P<.001). No significant differences were found among the IIRs at the marginal discrepancy (the vertical discrepancy between the abutment margin and the crown; P>.111) and the axio-occlusal discrepancy (the vertical discrepancy between the axial wall adjacent to the occlusal wall of the abutment and the internal surface; this discrepancy comprises the internal discrepancy; P>.257). CONCLUSIONS: ADL was superior to the other 2 fabrication methods. However, all 3 methods were suitable because they produced a marginal fit which was within the clinically acceptable range.


Subject(s)
Dental Marginal Adaptation , Dental Prosthesis Design/methods , Denture, Partial, Temporary , Dental Abutments , Dental Casting Technique , Dental Implant-Abutment Design , Humans , In Vitro Techniques
17.
J Prosthet Dent ; 115(6): 755-9, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26794703

ABSTRACT

STATEMENT OF PROBLEM: Information on the accuracy of intraoral video scanners for long-span areas is limited. PURPOSE: The purpose of this in vitro study was to evaluate and compare the trueness and precision of an intraoral video scanner, an intraoral still image scanner, and a blue-light scanner for the production of digital impressions. MATERIAL AND METHODS: Reference scan data were obtained by scanning a complete-arch model. An identical model was scanned 8 times using an intraoral video scanner (CEREC Omnicam; Sirona) and an intraoral still image scanner (CEREC Bluecam; Sirona), and stone casts made from conventional impressions of the same model were scanned 8 times with a blue-light scanner as a control (Identica Blue; Medit). Accuracy consists of trueness (the extent to which the scan data differ from the reference scan) and precision (the similarity of the data from multiple scans). To evaluate precision, 8 scans were superimposed using 3-dimensional analysis software; the reference scan data were then superimposed to determine the trueness. Differences were analyzed using 1-way ANOVA and post hoc Tukey HSD tests (α=.05). RESULTS: Trueness in the video scanner group was not significantly different from that in the control group. However, the video scanner group showed significantly lower values than those of the still image scanner group for all variables (P<.05), except in tolerance range. The root mean square, standard deviations, and mean negative precision values for the video scanner group were significantly higher than those for the other groups (P<.05). CONCLUSIONS: Digital impressions obtained by the intraoral video scanner showed better accuracy for long-span areas than those captured by the still image scanner. However, the video scanner was less accurate than the laboratory scanner.


Subject(s)
Dental Arch/diagnostic imaging , Models, Dental , Video Recording/methods , Dental Arch/anatomy & histology , Dental Impression Technique , Humans , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , In Vitro Techniques , Reproducibility of Results
18.
J Am Chem Soc ; 137(51): 16000-3, 2015 Dec 30.
Article in English | MEDLINE | ID: mdl-26651363

ABSTRACT

Understanding shockwave-induced physical and chemical changes of impact-absorbing materials is an important step toward the rational design of materials that mitigate the damage. In this work, we report a series of network-forming ionic liquids (NILs) that possess an intriguing shockwave absorption property upon laser-induced shockwave. Microstructure analysis by X-ray scattering suggests nano-segregation of alkyl side chains and charged head groups in NILs. Further post-shock observations indicate changes in the low-Q region, implying that the soft alkyl domain in NILs plays an important role in absorbing shockwaves. Interestingly, we observe a shock-induced ordering in the NIL with the longest (hexyl) side chain, indicating that both nano-segregated structure and shock-induced ordering contribute to NIL's shockwave absorption performance.

19.
Mil Med ; 189(7-8): e1621-e1628, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38330091

ABSTRACT

BACKGROUND: The prevalence of metabolic diseases is increasing worldwide and is influenced by multiple environmental, psychological, and dietary factors. As overseas deployment (OD) of Korean soldiers brings about changes in these factors, this study aimed to explore the impact of OD on metabolic diseases. MATERIALS AND METHODS: We collected paired health checkup data of Korean soldiers between January 2020 and December 2022, before and after their deployment. We analyzed changes in lipid profile, fasting glucose, and liver function biomarkers during OD and compared the prevalence of metabolic diseases before and after the OD. RESULTS: A total of 2,953 soldiers were enrolled. During OD, body weight, body mass index, total cholesterol, low-density lipoprotein, and fasting glucose levels decreased significantly. Furthermore, the prevalence of obesity, impaired fasting glucose, and nonalcoholic fatty liver disease decreased significantly from 45.78% to 33.49%, P < .001; 38.60% to 34.41%, P < .001; and 24.89% to 18.88%, P < .001, respectively. In a subgroup analysis of participants with long-term deployment (duration >365 days), only the prevalence of obesity decreased significantly during deployment, whereas the prevalence of hypertension and dyslipidemia increased. CONCLUSIONS: Metabolic biomarkers improved, and the prevalence of metabolic diseases decreased significantly during OD. However, personnel with long-term deployment did not experience significant improvements in these parameters. Further analysis is needed to identify the factors influencing these discrepancies.


Subject(s)
Metabolic Diseases , Military Personnel , Humans , Male , Republic of Korea/epidemiology , Adult , Military Personnel/statistics & numerical data , Metabolic Diseases/epidemiology , Female , Prevalence , Body Mass Index , Fatty Liver/epidemiology , Biomarkers/blood , Biomarkers/analysis , Middle Aged
20.
J Liver Cancer ; 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38852989

ABSTRACT

Background: Although cigarette smoking has been associated with an increased risk of hepatocellular carcinoma (HCC), its association with HCC mortality remains underexplored. We aimed to evaluate the effect of smoking on early mortality in HCC patients following curative treatment. Methods: Data from the Korean Primary Liver Cancer Registry were examined for HCC patients who underwent liver resection or radiofrequency ablation between 2015 and 2018. Smoking cumulative dose was assessed in pack-years. The primary outcome was the 3-year overall survival (OS). Results: Among 1924 patients, 161 were classified as heavy smokers (≥ 40 pack-years). Heavy smokers exhibited a lower 3-year survival rate (77.1 %) than nonsmokers (83.3%), with a significant difference observed in the 3-year OS (p = 0.016). The assessment of smoking packyears in relation to 3-year OS revealed a dose-dependent pattern, with the hazard ratio exceeding 1.0 at 20 pack-years and continuing to rise until 40 pack-years, reaching peak at 1.21 (95% confidence interval: 1.01, 1.45). Multivariate Cox-regression analysis revealed heavy smoking, age ≥ 60 y, underlying cirrhosis, tumor size > 3 cm, vascular invasion, and Child-Pugh class B/C as risk factors for 3-year OS. Subgroup analyses of patients with a tumor size < 3 cm, absence of vascular invasion, and meeting the Milan criteria also showed inferior outcomes for heavy smokers in all three subgroups. Conclusion: Heavy smoking, defined as a history of > 40 pack-years, was linked to poorer 3-year survival outcomes in HCC patients undergoing curative treatments, underscoring the importance of smoking cessation in this population.

SELECTION OF CITATIONS
SEARCH DETAIL