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Background An increased risk of anemia during edoxaban thromboprophylaxis in orthopedic surgery has been reported. However, the risk factors for the exacerbation of anemia requiring transfusion with irradiated red blood cell concentrates during postoperative edoxaban thromboprophylaxis remain unknown. Therefore, this study investigated the factors that increase the possibility of transfusion during edoxaban thromboprophylaxis after orthopedic surgery by reanalyzing clinical data from a previous collection. Methods A total of 221 patients who underwent total hip or knee arthroplasty at a single center between July 2011 and June 2012 were included in this study. Among these, 167 patients who received 30 mg of postoperative edoxaban thromboprophylaxis were retrospectively analyzed to identify critical factors for transfusion during edoxaban thromboprophylaxis after orthopedic surgery. Results Lower preoperative hemoglobin levels and higher intraoperative blood loss per body weight were significantly associated with an increase in the frequency of transfusion during postoperative edoxaban thromboprophylaxis. These factors were also potentially related to increased coagulation parameters during edoxaban thromboprophylaxis. Conclusion Our study shows that lower preoperative hemoglobin levels and higher intraoperative blood loss are associated with increased coagulation parameters with edoxaban thromboprophylaxis after orthopedic surgery and may lead to worsening of anemia, thereby requiring blood transfusion.
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This study aimed to clarify the fracture resistance of resin abutments built on endodontically treated roots with the remaining coronal teeth via static and cyclic loading tests. Endodontically treated bovine roots, which had a remaining coronal tooth covered with an occupied area for a quarter and half of the circumference at the tensile side or covered the circumference at both the tensile and compressive sides, were fabricated to build up to the resin abutment. Fracture resistance was evaluated via static and cyclic loading tests by applying a load of 30° to the tooth axis. Half of the circumference of the remaining coronal tooth showed a significantly higher static fracture load and survival rate. The remaining coronal tooth on the compressive side improved the dynamic fracture resistance associated with severe fractures. The occupied area and location of the remaining coronal tooth affected the static and dynamic fracture resistances.
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Dente Suporte , Análise do Estresse Dentário , Teste de Materiais , Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente não Vital , Bovinos , Animais , Falha de Restauração Dentária , Resistência à Tração , Técnicas In Vitro , Propriedades de SuperfícieRESUMO
PURPOSE: Dynamic chest radiography using X-ray fluoroscopic video analysis has shown potential for the diagnosis of pulmonary embolism (PE), but its diagnostic performance remains uncertain. We aimed to evaluate the diagnostic performance of fluoroscopic video analysis for diagnosing PE. METHODS: A prospective single-center observational study was conducted between October 2020 and January 2022. Fifty consecutive adult patients, comprising definitive PE, pulmonary hypertension (PH), or suspected PH, were enrolled. The study population was classified into 23 PE and 27 non-PE cases by contrast-enhanced computed tomography, lung scintigraphy, right heart catheterization, and pulmonary angiography. Cineradiographic images of 10-second breath-holds were obtained and analyzed using a fluoroscopic video analysis workstation to generate pulmonary circulation images. Two blinded cardiologists qualitatively assessed the presence or absence of perfusion defects on the pulmonary circulation images. The diagnosis obtained from the fluoroscopic analysis was compared with the definitive diagnosis. The primary outcomes included sensitivity, specificity, positive and negative predictive values, and overall accuracy for diagnosing PE. RESULTS: Perfusion defects were observed in 21 of 23 PE patients and 13 of 27 non-PE patients. The diagnostic performance of fluoroscopic video analysis for diagnosing PE showed a sensitivity of 91%, specificity of 52%, positive predictive value of 62%, negative predictive value of 88%, and overall accuracy of 70%. CONCLUSIONS: The high sensitivity of the fluoroscopic video analysis suggests its potential usefulness in ruling out PE without the need for contrast media or radionuclide; however, its specificity and overall accuracy remain limited.
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Valor Preditivo dos Testes , Embolia Pulmonar , Humanos , Embolia Pulmonar/diagnóstico por imagem , Estudos Prospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Fluoroscopia , Reprodutibilidade dos Testes , Circulação Pulmonar , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/fisiopatologia , Cinerradiografia , Gravação em Vídeo , Adulto , Imagem de Perfusão/métodos , Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/fisiopatologia , Interpretação de Imagem Radiográfica Assistida por ComputadorRESUMO
OBJECTIVE: Treponema denticola has been strongly implicated in the pathogenesis of chronic periodontitis. Previously, we reported that the potential transcriptional regulator TDE_0259 (oxtR1) is upregulated in the bacteriocin ABC transporter gene-deficient mutant. OxtR1 may regulate genes to adapt to environmental conditions during colonization; however, the exact role of the gene in T. denticola has not been reported. Therefore, we investigated its function using an oxtR1-deficient mutant. METHODS: The growth rates of the wild-type and oxtR1 mutant were monitored under anaerobic conditions; their antibacterial agent susceptibility and gene expression were assessed using a liquid dilution assay and DNA microarray, respectively. An electrophoretic mobility shift assay was performed to investigate the binding of OxtR1 to promoter regions. RESULTS: The growth rate of the bacterium was accelerated by the inactivation of oxtR1, and the mutant exhibited an increased minimum inhibitory concentration against ofloxacin. We observed a relative increase in the expression of genes associated with potential ferrodoxin (TDE_0260), flavodoxin, ABC transporters, heat-shock proteins, DNA helicase, iron compounds, and lipoproteins in the mutant. OxtR1 expression increased upon oxygen exposure, and oxtR1 complementation suppressed the expression of potential ferrodoxin. Our findings also suggested that OxtR1 binds to a potential promoter region of the TDE_0259-260 operon. Moreover, the mutant showed a marginal yet significantly faster growth rate than the wild-type strain under H2O2 exposure. CONCLUSION: The oxygen-sensing regulator OxtR1 plays a role in regulating the expression of a potential ferrodoxin, which may contribute to the response of T. denticola to oxygen-induced stress.
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Regulação Bacteriana da Expressão Gênica , Treponema denticola , Treponema denticola/genética , Treponema denticola/efeitos dos fármacos , Treponema denticola/crescimento & desenvolvimento , Treponema denticola/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regiões Promotoras Genéticas , Estresse Oxidativo , Anaerobiose , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Oxigênio/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Perfilação da Expressão Gênica , Estresse FisiológicoRESUMO
The study presents a novel setup for measuring the flow regime of hydrate particles in a gas-dominated flow, which is of interest for applications such as natural gas transportation. A closed-flow loop, driven by a novel internal fan, enables continuous observation of hydrate particle behavior in a gas flow. The experimental setup allows the production and insertion of HFC134a gas hydrate particles with diameters of 10-50 µm into the gas flow loop via a bypass loop. The performance curve of the internal fan is validated, and its suitability for achieving the required flow speed (5 m/s) is demonstrated. Through an observation window using camera systems, the flow regime of glass beads is successfully visualized and analyzed. To validate the experimental data, a coupled computational fluid dynamics-discrete element method model is used to simulate the particle flow density distribution. The study findings demonstrate the effectiveness of the experimental setup in characterizing the flow regime of hydrate particles in a gas-dominated flow.
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INTRODUCTION: There is limited data on the safety of direct oral anticoagulants (DOACs) in fragile patients with venous thromboembolism (VTE). MATERIALS AND METHODS: We used the COMMAND VTE Registry-2 enrolling patients with acute symptomatic VTE. The study population consisted of 3928 patients receiving DOACs, who were divided into fragile (2136 patients) and non-fragile groups (1792 patients). Fragility was defined as patients of age ≥ 75 years, creatinine clearance level ≤ 50 ml/min, and/or body weight ≤ 50 kg. RESULTS: The fragile group significantly more often received reduced doses of DOACs compared to the non-fragile group (51 % and 19 %, P < 0.001). The cumulative 5-year incidence of major bleeding was numerically higher in the fragile group than the non-fragile group (15.0 % and 11.1 %, P = 0.052), even with no significant excess risk after adjusting for confounders (HR 1.03, 95%CI 0.81-1.31, P = 0.78). The cumulative 5-year incidence of clinically relevant bleeding was significantly higher in the fragile group than the non-fragile group (28.6 % and 19.6 %, P < 0.001), even after adjusting for confounders (HR 1.28, 95%CI 1.08-1.53, P = 0.005). There was no significant difference in cumulative 5-year incidence of recurrent VTE between the groups (9.6 % and 8.9 %, P = 0.68), which was consistent after adjusting for confounders (HR 1.13, 95%CI 0.84-1.51, P = 0.41). CONCLUSIONS: Among VTE patients receiving DOACs, fragile patients were associated with a numerically higher rate of major bleeding and a significantly increased risk of clinically relevant bleeding, but not an increased risk of recurrent VTE.
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Tromboembolia Venosa , Humanos , Idoso , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/induzido quimicamente , Anticoagulantes/efeitos adversos , Administração Oral , Recidiva , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Sistema de RegistrosRESUMO
Prompt termination of pregnancy in patients with decompensated pulmonary arterial hypertension (PAH) is imperative for improvement of maternal hemodynamics, but such termination may also result in maternal death due to further deterioration of PAH immediately after delivery. However, there have been limited reports on whether implementation of PAH therapy with continuation of pregnancy improves the maternal outcome, especially in treatment-naïve patients with PAH. A 24-year-old woman was admitted to our hospital with a chief complaint of dyspnea (WHO functional class IV) at 22â¯weeks and 3â¯days of gestation. She was diagnosed with PAH accompanied by right heart failure and low cardiac output. Intensive treatment was initiated with inotropic agents, oxygen therapy, and PAH therapy, resulting in improvement of her hemodynamics. A caesarean section was performed at 23â¯weeks and 3â¯days. Although her pulmonary arterial pressure transiently increased with oxygenation deteriorating immediately after delivery, worsening PAH improved without mechanical circulatory support. She continued receiving pulmonary vasodilators without relapse of pulmonary hypertension for three years. The improvement of pulmonary hemodynamics prior to delivery with PAH therapy led to a favorable outcome after delivery. Learning objective: Pulmonary hemodynamics in pregnant patients with pulmonary arterial hypertension (PAH) can deteriorate with the continuation of pregnancy, while termination can also cause PAH surge immediately after delivery. In treatment-naïve patients with PAH, who are most likely to benefit from PAH therapy, implementation of PAH therapy with continuation, even with a decompensated status, may improve the hemodynamics prior to delivery, resulting in a favorable outcome after delivery.
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BACKGROUND: In acetabular fracture surgery, an infra-acetabular screw (IAS) is inserted from the anterior to the posterior column through the infra-acetabular corridor to stabilize both columns. Although the IAS is useful for increasing fixation strength, proper placement requires proficiency and often results in extraosseous screw penetration. The complex anatomy of the infra-acetabular corridor and difficult intraoperative detection of the ideal insertion point and angle make proper placement of the IAS challenging. This study aimed to detect the ideal insertion point and angle of the IAS based on anatomical landmarks that can be directly identified intraoperatively. METHODS: We retrospectively reviewed the pelvic CT of 50 adults who underwent serial slice CT imaging. The pelvic inlet plane (PIP), which contains the anterior border of both the sacroiliac joint and posterior superior edge of the pubic symphysis, was used as the reference plane for the pelvic coordinate system to simulate the ideal insertion of IAS. The distance from the posterior superior edge of the pubic symphysis to the ideal insertion point of the IAS (IAS distance) and the angle and length of the IAS that could be inserted from the ideal insertion point were measured. RESULTS: The mean IAS distance was 61.0 ± 5.7 mm (57.6 ± 4.3 mm in men and 64.4 ± 4.9 mm in women). The mean angle between ideal IAS and yz-plane on the outlet view (α-angle) was 8.4 ± 6.6 ° (6.4 ± 5.6° in men and 10.5 ± 7.0° in women). The mean angle between ideal IAS and y-axis on the yz-plane (ß-angle) was 86.5 ± 10.6 ° (86.0 ± 10.3° in men and 87.0 ± 10.9° in women). The length of IAS was 97.1 ± 4.7 mm in men and 89.2 ± 3.6 mm in women. CONCLUSION: The IAS ideal insertion point detected as a distance from the pubic symphysis may aid in the proper insertion of the IAS during surgery. The insertion angle was parallel or tilted 10 ° laterally to the longitudinal axis in the pelvic outlet plane and almost perpendicular to the PIP in the sagittal plane when inserted from the ideal insertion point.
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Acetábulo , Parafusos Ósseos , Fixação Interna de Fraturas , Fraturas Ósseas , Tomografia Computadorizada por Raios X , Humanos , Acetábulo/cirurgia , Acetábulo/lesões , Acetábulo/diagnóstico por imagem , Masculino , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/instrumentação , Feminino , Estudos Retrospectivos , Fraturas Ósseas/cirurgia , Fraturas Ósseas/diagnóstico por imagem , Adulto , Pessoa de Meia-Idade , Idoso , Articulação Sacroilíaca/cirurgia , Articulação Sacroilíaca/diagnóstico por imagem , Articulação Sacroilíaca/lesõesRESUMO
In mouse dentate gyrus, radial glia-like cells (RGLs) persist throughout life and play a critical role in the generation of granule neurons. A large body of evidence has shown that the combinatorial expression of transcription factors (TFs) defines cell types in the developing central nervous system (CNS). As yet, the identification of specific TFs that exclusively define RGLs in the developing mouse dentate gyrus (DG) remains elusive. Here we show that phospho-Smad3 (PSmad3) is expressed in a subpopulation of neural progenitors in the DG. During embryonic stage (E14-15), PSmad3 was predominantly expressed in gfap-GFP-positive (GFP+)/Sox2+ progenitors located at the lower dentate notch (LDN). As the development proceeds (E16-17), the vast majority of PSmad3+ cells were GFP+/Sox2+/Prox1low+/Ki67+ proliferative progenitors that eventually differentiated into granule neurons. During postnatal stage (P1-P6) PSmad3 expression was observed in GFP+ progenitors and astrocytes. Subsequently, at P14-P60, PSmad3 expression was found both in GFP+ RGLs in the subgranular zone (SGZ) and astrocytes in the molecular layer (ML) and hilus. Notably, PSmad3+ SGZ cells did not express proliferation markers such as PCNA and phospho-vimentin, suggesting that they are predominantly quiescent from P14 onwards. Significantly PSmad3+/GFP+ astrocytes, but not SGZ cells, co-expressed Olig2 and S100ß. Together, PSmad3+/Olig2- expression serves as an exclusive marker for a specific subpopulation of GFP+ neural progenitors and RGLs in the mouse DG during both embryonic and postnatal period.
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BACKGROUND: In this study, we investigated the effects of differences in scanning pathways during optical impression on the trueness and precision of full-arch impressions. METHODS: Reference data were obtained using a laboratory scanner. All optical impressions were measured across the dental arch using TRIOS® 3 in four different pathways. The reference and optical impression data were superimposed using the best-fit method. The criteria for superimposition were based on the starting side of the dental arch (partial arch best-fit method, PB) and based on the full arch (full arch best-fit method, FB). The data were compared between the left and right molars (starting and ending sides). The scan deviations for trueness (n = 5) and precision (n = 10) were obtained for each group by calculating the root mean square (RMS) of the deviation at each measurement point. Visual observations using superimposed color map images revealed variations in trueness. RESULTS: There were no significant differences in scanning time or amount of scan data between the four scanning pathways. Trueness did not differ significantly among the four pathways with respect to the starting and ending sides, regardless of the superimposition criteria. Precision with PB was significantly different between scanning pathways A and B, and pathways B and C for the starting sides, and between scanning pathways A and B, and pathways A and D for the ending sides. In contrast, there was no significant difference between the starting and ending side in pathways for FB. Regarding PB, color map images showed a large error range in the direction toward the molar radius for the occlusal surface and cervical regions on the ending sides. CONCLUSION: Differences in the scanning pathways did not affect trueness, regardless of the superimposition criteria. On the other hand, differences in the scanning pathways affected the precision of the starting and ending sides with PB. Scanning pathways B and D were more precise on the starting and ending sides, respectively.
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Dente Molar , Humanos , Dente Molar/diagnóstico por imagem , CintilografiaRESUMO
Knee arthroplasty, both total knee and unicompartmental, has had a significant impact on millions of patients globally. Although satisfaction is usually high, complications such as periprosthetic fracture are increasingly common. Distal femur periprosthetic fractures are relatively well researched and understood in comparison with periprosthetic proximal tibia fractures (PTFs). The management of PTFs is essentially an evidence-free area. This review explores the literature (or lack thereof) and integrates cases from Australia and Japan. As it stands, there is scant literature relating to all facets of PTFs, including, most concerningly, the management of them. Larger studies are required to help further investigate this important interface between arthroplasty and orthopaedic trauma. As a guide, those with loose prostheses will likely benefit most from revision total knee arthroplasty, while those with well-fixed prostheses can be managad according to the fracture with homage paid to the presence of the prosthesis. The use of periarticular locked plates is likely a better option over conventional large or small fragment plates. Nonoperative management is a viable option for selected individuals and can be associated with favorable outcomes.
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The Msp protein complex and the serine protease dentilisin are the best-characterized virulence factors in Treponema denticola, the major etiological agent of chronic periodontitis. In addition to these outer sheath factors, the cysteine protease dentipain contributes to pathogenicity, but its secretion, processing, cellular localization, and role in T. denticola virulence are not fully understood. In this study, we found that full-sized dentipain (74-kDa) and the 52-kDa truncated form of the enzyme are located, respectively, in the outer sheath derived from T. denticola dentilisin- and the Msp-deficient mutants. Furthermore, dentipain was barely detected in the wild-type strain. These results suggest that dentilisin and Msp, the major outer sheath proteins, are involved in the secretion and maturation of dentipain. Inactivation of the dentipain gene slowed the growth of T. denticola, and the effect was more profound in serum-free medium than in serum-containing medium. Several genes, including those encoding transporters and methyl-accepting chemotaxis proteins, were differentially expressed in the dentipain-deficient mutant. Furthermore, the mutant strain was more hydrophobic than the wild-type strain. Finally, the mutant showed less autoaggregation activity and adhesion to IgG in a serum-free medium than the wild-type strain. These findings suggest that dentipain contributes to the virulence of T. denticola by facilitating adhesion and acquisition of nutrients essential for colonization and proliferation in the gingival crevice under serum-rich conditions.
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Cisteína Proteases , Treponema denticola , Treponema denticola/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Quimotripsina/genética , Quimotripsina/metabolismo , Cisteína Proteases/genética , Peptídeo Hidrolases , Treponema/genéticaRESUMO
Edoxaban (Edx) has been approved to prevent venous thromboembolism after total knee and/or hip arthroplasty in Japan. However, the risk of anemia with Edx treatment remains elusive. No risk factors for Edx-associated anemia after orthopedic surgery have been reported. This study aimed to clarify the risk of anemia associated with Edx treatment and determine the risk factors for Edx-associated anemia after orthopedic surgery with a high risk for bleeding. First, the association between Edx treatment and the incidence of anemia-related events was retrospectively investigated by pharmacovigilance analyses using data from 5769,866 reports between the first quarters of 2016 and 2020 in the Food and Drug Administration Adverse Event Reporting System and 2752,050 reports between the fourth quarters of 2011 and 2019 in the Japanese Adverse Drug Event Report. Second, 221 patients who underwent Edx treatment after total knee and/or hip arthroplasty between July 2011 and June 2012 at a single center were included in a case-control study to clarify the risk factors for anemia. Edx treatment was associated with an increased risk of anemia-related events in orthopedic patients. Reduced renal function was identified as a critical risk factor for Edx-associated anemia after orthopedic surgery. The present study indicates that renal function should be considered in the risk management of increased Edx-associated anemia after orthopedic surgery.
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Anemia , Artroplastia de Substituição , Estados Unidos , Humanos , Estudos Retrospectivos , Estudos de Casos e Controles , Anemia/epidemiologia , Rim/fisiologiaRESUMO
We explore the analytic structure of the three-channel S matrix by generalizing uniformization and making a single-valued map for the three-channel S matrix. First, by means of the inverse Jacobi's elliptic function we construct a transformation from eight Riemann sheets of the center-of-mass energy complex plane onto a torus, on which the three-channel S matrix is represented single-valued. Second, we show that the Mittag-Leffler expansion, a pole expansion, of the three-channel scattering amplitude includes not only topologically trivial but also nontrivial contributions and is given by the Weierstrass zeta function. Finally, taking a simple nonrelativistic effective field theory with contact interaction for the S=-2, I=0, J^{P}=0^{+}, ΛΛ-NΞ-ΣΣ coupled-channel scattering, we demonstrate that as a function of the uniformization variable the scattering amplitude is, in fact, given by the Mittag-Leffler expansion and is dominated by contributions from neighboring poles.
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Movement of marine debris is transboundary and complex, travelling vast distances and accumulating on shorelines. These marine debris wash ashore as stranded beach litter. The objective of this work is to identify release sources of marine debris accumulated along the Singapore coastlines collected by applying a time-backward adjoint marginal sensitivity method and citizen science data of stranded beach litter by a voluntary beach clean-up group. A popular tourist hotspot on the opposite shore was estimated as a possible release source contributing to the marine debris accumulation. This analytical result was validated by population density, industry types, rainfall, and inference from product packaging labels. The use of the citizen science data also illustrated potential as a data source for baseline monitoring and long-term cross-border research that influence policymaking. Future research can be conducted in an expanded domain, considering monsoon effects and instantaneous release events.
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Praias , Plásticos , Monitoramento Ambiental , Singapura , Resíduos/análiseRESUMO
BACKGROUND: Aortic valve stenosis (AS) leads to increased cardiovascular mortality and morbidity, and recent studies reported that even mild-to-moderate AS was associated with poor prognosis in the general population. This study investigated the prognostic impact of mild or moderate AS, defined as 2.0 m/s ≤ peak aortic jet velocity (Vmax) ≤3.9 m/s using echocardiography in acute myocardial infarction (AMI) patients.MethodsâandâResults: This study enrolled 3,049 AMI patients using data from the Mie ACS registry. Patients were divided into 2 groups according to Vmax: Group 1: Vmax <2.0 m/s and/or visually intact aortic valve in which all 3 leaflets are fully and evenly open; Group 2: 2.0 m/s ≤ Vmax ≤ 3.9 m/s. There were 2,976 patients in Group 1and 73 patients in Group 2. The Group 2 patients were older, had a higher percentage of males and had lower body mass index and Killip ≥2 than the Group 1 patients. Angiographic data, door-to-balloon time, and mechanical support were not different between the 2 groups. The Group 2 patients demonstrated a significantly higher all-cause mortality rate (P<0.01) and composite of cardiovascular death and heart failure hospitalization (P<0.01), and Kaplan-Meier analysis showed the same tendency in propensity score-matched patients. CONCLUSIONS: The present study revealed that mild or moderate AS based on Vmax is associated with poor prognosis following AMI.
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Estenose da Valva Aórtica , Infarto do Miocárdio , Humanos , Masculino , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico por imagem , Prognóstico , Índice de Gravidade de Doença , Volume SistólicoRESUMO
Detecting early-stage oral cancer and precancerous lesions are critical to improving patient prognosis and quality of life after treatment. Photodynamic diagnosis using 5-aminolevulinic acid enables the detection of malignant lesions. This study aimed to improve the diagnostic accuracy of photodynamic diagnosis using an objective chromaticity analysis of fluorescence emitted from oral lesions. Sixty-seven patients with clinically suspicious oral cavity lesions underwent photodynamic diagnosis after topical application of 5-aminolevulinic acid solution, followed by imaging and histological evaluation of the lesions. Chromaticity red and green values were measured from the fluorescence images on the lesion, and the red-to-green ratio was calculated. The photodynamic diagnosis allowed for the visualization of oral cancer and high-risk dysplasia as red fluorescence. Compared to low-risk dysplasia and benign lesions, oral cancer and high-risk dysplasia areas had a significantly higher red value and red-to-green ratio. After setting the cutoff value, sensitivity and specificity were 83.3-88.7% and 83.3-83.9%, respectively, when discriminating between oral cancer or high-risk dysplasia and low-risk dysplasia or benign lesions. Photodynamic diagnosis combined with chromaticity analysis may be a valuable diagnostic tool for detecting oral lesions, with a high likelihood of malignant transformation.
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The purpose of this study was to evaluate whether change in cuspal inclination influences the fracture load values of composite resin computer-aided design/computer-aided manufacturing (CAD/CAM) crowns. Abutment teeth and CAD/CAM crowns were prepared as they would be for treating a mandibular first premolar with two cusps. The CAD/CAM crowns were designed so that 1) the principal stress lines would be radially distributed from the two points of contact with the indenter to the occlusal area of the abutment (Type I), or 2) the principal stress lines would pass outside the occlusal area of the abutment (Types II and III). The CAD/CAM crowns were mounted on the abutments using one of two types of resin or polycarboxylate cement. Fracture load values were measured using a universal tester. The Type I CAD/CAM crowns exhibited the highest mean fracture load value, followed by the Type II crowns and then the Type III crowns, with significant differences seen between all types (p<0.05). The luting agent used (resin or polycarboxylate cement) showed no effect on the fracture load value. With the Type II and Type III crowns, significant differences in the fracture load value were observed between the Super-Bond and Hy-Bond polycarboxylate cement groups (p<0.05).
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Resinas Compostas , Cimentos Dentários , Cerâmica , Desenho Assistido por Computador , Coroas , Análise do Estresse Dentário , Teste de Materiais , Cimento de PolicarboxilatoRESUMO
Layered-type zirconia disks, which offer color gradation from enamel to cervical shade, have been employed in recent years to replicate the shades of natural teeth. The layered structure is effective at replicating colors and has helped popularize monolithic zirconia restorations. However, the sintering shrinkage of zirconia is very large; thus, controlling the sintering distortion is very important. Thus, the objective of this study was to determine the influence exerted by the layered structure of the zirconia disk and the vertical milling area on the sintering distortion. An experimental fixed partial denture (FPD) was designed based on a 4-unit monolithic zirconia FPD. A single-composition (SC)-type disk with no shade and a single-composition-layered (SCL)-type disk with shade gradation were selected for this study. In particular, three milling areas, the top end of the disk (area I), vertical center (area II), and bottom end of the disk (area III), were investigated. Moreover, the sintering distortions generated by the experimental FPDs were measured. Results showed that sintering distortion in 4-unit monolithic zirconia FPDs occurred in all SC and SCL areas. Additionally, the sintering distortions were affected by the layered structure of the zirconia disks, the degree of which depended on the milling area (area I > area II > area III). Thus, when fabricating dental prosthesis using SCL zirconia disks, the milling area must be selected considering both the color adjustment and sintering distortion.