RESUMO
BACKGROUND AND AIMS: Patients with left-sided breast cancer receive a higher mean heart dose (MHD) after radiotherapy, with subsequent risk of ischaemic heart disease. However, the optimum dosimetric predictor among cardiac substructures has not yet been determined. METHODS AND RESULTS: This study retrospectively reviewed 2158 women with breast cancer receiving adjuvant radiotherapy. The primary endpoint was a major ischaemic event. The dose-volume parameters of each delineated cardiac substructure were calculated. The risk factors for major ischaemic events and the association between MHD and major ischaemic events were analysed by Cox regression. The optimum dose-volume predictors among cardiac substructures were explored in multivariable models by comparing performance metrics of each model. At a median follow-up of 7.9 years (interquartile range 5.6-10.8 years), 89 patients developed major ischaemic events. The cumulative incidence rate of major ischaemic events was significantly higher in left-sided disease (P = 0.044). Overall, MHD increased the risk of major ischaemic events by 6.2% per Gy (hazard ratio 1.062, 95% confidence interval 1.01-1.12; P = 0.012). The model containing the volume of the left ventricle receiving 25 Gy (LV V25) with the cut-point of 4% presented with the best goodness of fit and discrimination performance in left-sided breast cancer. Age, chronic kidney disease, and hyperlipidaemia were also significant risk factors. CONCLUSION: Risk of major ischaemic events exist in the era of modern radiotherapy. LV V25 ≥ 4% appeared to be the optimum parameter and was superior to MHD in predicting major ischaemic events. This dose constraint could aid in achieving better heart protection in breast cancer radiotherapy, though a further validation study is warranted.
Assuntos
Neoplasias da Mama , Neoplasias Unilaterais da Mama , Feminino , Humanos , Neoplasias Unilaterais da Mama/radioterapia , Estudos Retrospectivos , Neoplasias da Mama/radioterapia , Dosagem Radioterapêutica , Coração , Doses de RadiaçãoRESUMO
The phase behavior of 12-hydroxystearic acid (12-HSA) in even-numbered alkanes ranging from octane (C8) to hexatriacontane (C36) was measured by visual observation of liquid + solid to liquid and liquid-liquid to liquid cloud points and liquid + solid to liquid + liquid transitions. In general solid phases were stabilized to low concentration and higher temperature with increasing alkane length. Liquid-liquid immiscibility was observed in larger alkanes starting with octadecane. The liquidus lines of shorter alkanes (octane to hexadecane) showing only liquid to liquid + solid transitions were fit with an attenuated associated solution model based on the Flory-Huggins lattice model assuming that 12-HSA forms a carboxylic acid dimer over all concentrations investigated. The fit results show that 12-HSA forms associated structures with degrees of association ranging from 3.7-4.5 dimers in the neat 12-HSA. At low concentrations, the 12-HSA is dissociated into dimers, however the free energy cost of dissociation stabilizes the solid phase giving a sharp knee at low concentrations. The role of 12-HSA association in its phase behavior and gelation behavior are discussed. More broadly, the importance of solute association in small molecule organogelators and its potential as a molecular design parameter similar to other component thermodynamic parameters, such as melting temperature and heat of fusion, is discussed.
RESUMO
A semi-crystalline, shape memory polymer (SMP) is fabricated by free radical cross-linking, polymerization, and grafting in a blend of n-octadecyl acrylate and polybutadiene (PB). Poly(n-octadecyl acrylate) (PODA) is a side-chain crystalline polymer, which serves as the structure-fixing network counterbalancing the elastically deformed, cross-linked polymer network. At a constant 50/50 ratio of monomer and polymer the amount of free radical initiator, dicumyl peroxide (DCP) is varied from 1% to 5% w/w PB. From swelling measurements and calculation of the cross-link density it is determined that DCP produces greater than one cross-link per DCP molecule. It is found that lower cross-linking efficiency is favorable for higher shape fixity. This lower efficiency is found to produce a higher degree of crystallinity of the PODA in the 2-5% DCP samples, which is determined to be the main driver of higher shape fixity of the polymer. A SMP with >90% fixity and 100% recovery at uniaxial strains from 34-79% is achieved. This material should be useful for mold processing of shape memory articles. This approach provides a method to decouple the elastomeric and thermoplastic portions of a SMP to convert commodity elastomers into SMPs and tailor the shape memory response.
Assuntos
Materiais Inteligentes , Acrilatos , Butadienos , Elastômeros , Radicais Livres , PolimerizaçãoRESUMO
Colorectal cancer (CRC) patients who receive cancer surgeries from higher-volume providers may have better outcomes. However, the definitions of surgical volume may affect the results. We aim to analyze the effects of different definitions of surgical volume on patient outcomes. We conducted a nationwide population-based study in Taiwan that enrolled all patients who underwent definitive surgery for newly diagnosed CRC. We used three common definitions of surgical volume: total volume means the total surgical number conducted by the same provider during the study period; cumulative volume was calculated as the number of operations the surgeon performed before the index procedure; annual volume was calculated as the number of times the surgeon had been responsible for surgery during the index year. In this study, we included 100,009 newly diagnosed CRC patients, including 55.8% males, of median age 66 years at diagnosis (range 20-105 years). After adjustment for the patient and provider characteristics, we found that CRC patients receiving definitive surgery by higher-volume providers had better outcomes, especially where surgeon volume may play a more important role than hospital volume. The cumulative volume could predict the 5-year mortality of the study cohort better than the total and annual volume.
Assuntos
Neoplasias Colorretais , Hospitais , Masculino , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/cirurgia , Taiwan/epidemiologiaRESUMO
BACKGROUND: Breast cancer is one of the most common cancers in women, and treatment options include surgery, systemic therapies, and radiotherapy (RT). While postoperative RT plays an important role in reducing local recurrence rates and improving survival outcomes, its exact impact on patients with pathological stage IIB breast cancers remains unidentified. METHODS: In this retrospective cohort study, patients with newly diagnosed pathological stage IIB breast cancer who underwent surgery and postoperative RT were included. The data were collected from medical records, and survival outcomes were assessed using the Kaplan-Meier method, log-rank tests, and Cox regression models. RESULTS: In total, 350 patients participated in this study. Overall survival, locoregional recurrence-free survival, event-free survival, and distant metastasis-free survival rates did not significantly differ between those who received RT and those who did not. Multivariate analyses revealed that patients who received anthracycline or taxane chemotherapy had better survival outcomes. CONCLUSION: Our findings demonstrated that postoperative RT had no significant effect on overall survival, locoregional recurrence, event-free survival, or distant metastasis rates in patients with pathological stage IIB breast cancer. However, anthracycline- and taxane-based chemotherapies were associated with improved outcomes. These findings demonstrated the complexities of treating such patient populations with multimodal therapies. Further research is needed to ensure optimal postoperative RT in patients with pathological stage IIB breast cancer. Clinicians must consider individual patient characteristics and incorporate comprehensive treatment approaches to ensure successful outcomes in this population.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Mastectomia/métodos , Mastectomia Segmentar/efeitos adversos , Estudos de Coortes , Estudos Retrospectivos , Recidiva Local de Neoplasia/epidemiologia , Taxoides , Antraciclinas , Estadiamento de NeoplasiasRESUMO
BACKGROUND: Stereotactic ablative radiotherapy (SABR) is now the standard of care for patients with inoperable early-stage lung cancer. Many of these patients are elderly. EGFR (epidermal growth factor receptor) mutation is also common in the Asian population. METHODS: To evaluate the effects of old age and EGFR mutation on treatment outcomes and toxicity, we reviewed the medical records of 71 consecutive patients with inoperable early-stage non-small cell lung cancer (NSCLC) who received SABR at Taipei Veterans General Hospital between 2015 and 2021. RESULTS: The study revealed that median age, follow-up, Charlson comorbidity index, and ECOG score were 80 years, 2.48 years, 3, and 1, respectively. Of these patients, 37 (52.1%) were 80 years or older, and 50 (70.4%) and 21 (29.6%) had T1 and T2 diseases, respectively. EGFR mutation status was available for 33 (46.5%) patients, of whom 16 (51.5%) had a mutation. The overall survival rates at 1, 3, and 5 years were 97.2, 74.9, and 58.3%, respectively. The local control rate at 1, 3, and 5 years was 97.1, 92.5, and 92.5%, respectively. Using Cox proportional hazards regression we found that male sex was a risk factor for overall survival (p = 0.036, 95% CI: 1.118-26.188). Two patients had grade 2 pneumonitis, but no other grade 2 or higher toxicity was observed. We did not find any significant differences in treatment outcomes or toxicity between patients aged 80 or older and those with EGFR mutations in this cohort. CONCLUSION: These findings indicate that age and EGFR mutation status do not significantly affect the effectiveness or toxicity of SABR for patients with inoperable early-stage NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Radiocirurgia , Carcinoma de Pequenas Células do Pulmão , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Estadiamento de Neoplasias , Radiocirurgia/efeitos adversos , Carcinoma de Pequenas Células do Pulmão/etiologia , Taiwan , Resultado do TratamentoRESUMO
OBJECTIVE: The stigma and prejudice of the public regarding psychiatric disorders are a long-standing social problem. However, health professionals are more likely to have negative attitudes and label people with mental health conditions. This study aimed to investigate how self-rated familiarity and literacy about schizophrenia are related to social distancing towards schizophrenia patients among health professionals in Taiwan. METHOD: This study used a cross-sectional questionnaire survey and invited respondents to complete the survey either electronically or in a pencil/paper format. Respondents included health professionals in different disciplines and students under medical placements. The survey instrument consists of three parts: sociodemographic information, the 18-item Social Distance Scale for schizophrenia, and the 19-item Schizophrenia Experience and Knowledge Questionnaires. Data were analyzed using linear regression models to explore sociodemographic factors, self-rated familiarity, and literacy total scores about social distance, attitude, and opinions towards schizophrenia. RESULT: In total, 420 health professionals completed the questionnaire, of which 24.5% were physicians, 36.0% nurses, 6.7% pharmacists, and 28.6% interns. The majority of respondents (n = 360, 85.7%) had contact experience with schizophrenia patients, and approximately 60% rated their experience as a positive impression. Although 62.9% of respondents had received psychiatric education or training, 86% believed that such education/training was insufficient. Moreover, over half of the respondents did not have confidence in their knowledge of schizophrenia. Older age, being married, and having more working experience were associated with high social distance, a negative attitude, and high prejudice. More familiarity with schizophrenia was associated with low social distance, a positive attitude, and less prejudice. A high literacy score was associated with a positive attitude and less prejudice, but no significant correlation was observed with social distance (ß ± SE = -0.26 ± 0.14, p = .057). Among respondents who rated their past contact experiences as negative, neither familiarity nor literacy was associated with social distance. CONCLUSION: High levels of self-rated familiarity and high literacy about schizophrenia were associated with low social distance, a positive attitude, and less prejudice towards schizophrenia among health professionals. Therefore, sufficient education and training are imperative to increase familiarity and knowledge of schizophrenia. Appropriate education could be implemented from different perspectives, including communication skills, resources of social support, and topics to reduce stigma and prejudice.
Assuntos
Esquizofrenia , Estudos Transversais , Humanos , Distanciamento Físico , Distância Psicológica , Estigma Social , Estereotipagem , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Cancer patients treated at higher-volume hospitals or by more experienced physicians have better outcomes. However, little is known about the effect of these provider volumes on the prognosis of patients receiving definitive radiotherapy (RT). This study aims to examine the independent association between hospital volume and physician volume in relation to the overall survival (OS) of nasopharyngeal cancer (NPC) patients after RT. METHODS: Patients with newly diagnosed NPC receiving definitive RT between 2001 and 2017 were identified from Taiwan's National Health Insurance Research Database. We collected demographic characteristics of patients, physicians and hospitals, as well as cancer treatment and comorbidities. Patients were categorized into quartiles according to cumulative hospital and physician volumes of their treatment providers. The effects of hospital and physician volumes on OS was examined by the frailty Cox regression model. RESULTS: A total of 16,315 NPC patients treated by 258 physicians in 92 hospitals were identified. When the effects of hospital volume and physician volume on survival were separately examined, both of them were positively associated with OS. In a fully adjusted model considering patient and provider characteristics, hospital volume, physician volume, and clustering effects, it showed that hospital volume significantly predicted OS, while physician volume did not. In patients treated with advanced technique RT, hospital volume was significantly associated with OS. However, volume effect was not observed in 2-D RT subgroup. CONCLUSIONS: NPC patients receiving RT at higher-volume hospitals saw better survival. Treatment for NPC should be centralized to high-volume hospitals rather than high-volume physicians.
Assuntos
Neoplasias Nasofaríngeas , Médicos , Hospitais , Humanos , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Modelos de Riscos ProporcionaisAssuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Neoplasias Pulmonares , Terapia com Prótons , Radioterapia de Intensidade Modulada , Humanos , Carcinoma de Células Escamosas do Esôfago/radioterapia , Neoplasias Esofágicas/radioterapia , Quimiorradioterapia , Dosagem RadioterapêuticaRESUMO
Broad-band dielectric spectroscopy (BDS) provides a powerful method of characterizing relaxation dynamics in diverse materials. Here we describe and employ a novel instrument for high-throughput broad-band dielectric spectroscopy (HTBDS) that accelerates this capability, enabling simultaneous measurements of 48 samples. This capability is based around a coaxial switching system for rapid scanning between multiple samples on the same sample stage, coordinated with shared environmental control. We validate the instrument by measuring dielectric response in three polymers, distributed across 48 sample sites, and comparing results to measurements via a standard BDS instrument. Results are found to be reproducible and are in agreement with relaxation times from traditional BDS. We then employ HTBDS to establish mixing rules for glass transition temperatures, kinetic fragility indices, and segmental stretching exponents in a series of acrylate copolymers, a matter of considerable technological interest in a variety of technological applications. Results are consistent with the empirical Fox rule for the glass transition temperature Tg averaging in polymer blends, while they reveal a linear mixing rule for kinetic fragility indices. Finally, we test several proposed correlations between these distinct dynamical properties. These results demonstrate that HTBDS enables measurements of polymer relaxation at a throughput approximately 10 times higher than that of standard BDS approaches, opening the door to high-throughput materials design of dynamic response across a broad range of frequencies.
Assuntos
Resinas Acrílicas/química , Espectroscopia Dielétrica/métodos , Simulação por Computador , Cinética , Modelos Moleculares , Estrutura Molecular , Transição de Fase , Software , Temperatura de TransiçãoRESUMO
BACKGROUND AND PURPOSE: To identify the risk factors for osteonecrosis of the jaw (ONJ) in oral cancer patients after surgery with and without adjuvant therapy in a nationwide, population-based study. MATERIAL AND METHODS: Using the Taiwan National Health Insurance Research Dataset, we recruited patients with newly diagnosed oral cancer between 1997 and 2011. All of them underwent primary surgery. Data regarding demographic characteristics; tooth extractions; medications; and cancer treatments, including types of mandibular surgery, radiotherapy and platinum-based chemotherapy, were collected for analysis. RESULTS: We identified 25,858 patients who suffered 2802 ONJ events. The ONJ incidence rate was 3.45 per 100 person-years. Lip cancer was associated with the highest risk of ONJ, followed by buccal mucosa, gum, mouth floor and tongue cancer. Using a time-dependent Cox regression model, multivariable analysis demonstrated that mandibulotomy (hazard ratio (HR), 1.25; 95% confidence interval (CI), 1.01-1.55; p<0.001), radiotherapy (HR, 1.39; 95% CI, 1.26-1.54; p<0.001) and platinum-based chemotherapy (HR, 1.94; 95% CI, 1.56-2.41; p<0.001) were significant risk factors for ONJ. In the subgroup analysis of patients receiving radiotherapy and patients not receiving radiotherapy, platinum-based chemotherapy remained a risk factor for ONJ. CONCLUSIONS: Mandibulotomy, radiotherapy and platinum-based chemotherapy were associated with an increased ONJ risk. Chemotherapy was a risk factor regardless of whether radiotherapy was administered.
Assuntos
Antineoplásicos/efeitos adversos , Doenças Maxilomandibulares/etiologia , Neoplasias Bucais/terapia , Osteonecrose/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de RiscoRESUMO
BACKGROUND: To evaluate the failure pattern and identify predictors of locoregional control in lateralized buccogingival cancer after postoperative radiotherapy (RT) at a single institution. METHODS: We retrospectively reviewed the clinical data of 150 patients with lateralized oral squamous cell carcinoma, including carcinoma of the buccal mucosa, gingiva and retromolar trigone. All patients underwent radical surgery followed by postoperative RT with or without concurrent chemotherapy. We registered planning computer tomography images with images obtained at recurrence and categorized the failure pattern as in-field, marginal, or out-field recurrence. RESULTS: The median follow-up duration was 47 months (range, 2-131 months). Twenty-eight patients (19%) experienced locoregional failure, including 20 local failure, 5 regional failure and 3 with both. Among the 24 patients who had image studies at recurrence, 15 patients had in-field recurrence, 5 were marginal recurrence and 4 were out-field recurrence. Seven patients (5%) had contralateral neck failure. Four of 5 patients with marginal failure had recurrent tumors in the infratemporal fossa. In multivariate analysis, extracapsular spread and positive or close surgical margin were associated with poor locoregional control. CONCLUSION: Local in-field recurrence is the most common failure pattern in lateralized buccogingival cancer after postoperative RT. The infratemporal fossa is a risk area for marginal failure and should be encompassed adequately in the postoperative RT field. Extracapsular spread and positive or close margin are predictors of locoregional control for lateralized oral cancer. Patients exhibiting such adverse features require more aggressive treatment.
Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias Gengivais/radioterapia , Mucosa Bucal/patologia , Neoplasias Bucais/radioterapia , Recidiva Local de Neoplasia/etiologia , Adulto , Idoso , Carcinoma de Células Escamosas/mortalidade , Terapia Combinada , Feminino , Seguimentos , Neoplasias Gengivais/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/mortalidade , Estudos RetrospectivosRESUMO
Whether age predicts treatment outcome of prostate cancer remains controversial. With the aging of the world population, properly understanding the effect of age may facilitate both treatment decision-making and defining the natural history of prostate cancer. Consecutive 581 patients with locally-confined adenocarcinoma of the prostate who received radical definitive radiotherapy(RT) (76-78 Gy) between 2004 and 2015 at a medical center in Taiwan were reviewed retrospectively. Median age was 78 years. The median follow-up was 66 months. The 5-year biochemical failure-free survival(BFFS), distant metastasis-free survival(DMFS), disease-specific survival(DSS), and overall survival(OS) rates were 84.9%, 93.8%, 97.8%, and 86.6%, respectively, for all patients. Comparing those above and below the age of 80, no difference in 5-year BFFS, DMFS, or DSS was found. Multivariate Cox regression analysis showed that tumor stage, Gleason score, initial PSA, and latency before RT were significant risk factors of BFFS. The latency before RT was significantly longer in the older group than in the under 80 group. Delay to start RT might explain the previous finding of inferior disease control in older patients in other studies. With the exception of OS, no other differences in outcomes or toxicities were observed in older patients.
Assuntos
Centros Médicos Acadêmicos/estatística & dados numéricos , Neoplasias da Próstata/radioterapia , Idoso , Idoso de 80 Anos ou mais , Determinação de Ponto Final , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Próstata/patologia , Lesões por Radiação/etiologia , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos , Risco , Análise de Sobrevida , Taiwan , Resultado do TratamentoRESUMO
Fundamental insight into excimer formation has been gained by using 9,10-bis[4-(9-carbazolyl)phenyl]anthracene] (Cz9PhAn) as a probe. Cz9PhAn exhibits a highly emissive blue fluorescence in solution and is found to emit a panchromatic white light spectrum (400-750 nm) in film, powder and single crystal, in which an additional excimer band appears at â¼550 nm. Detailed structural analyses, emission relaxation dynamics and a theoretical approach conclude the formation of an anthracene*/phenyl ring excimer through an overlap between π* (anthracene) and π (phenyl ring) orbitals in a face-to-edge stacking orientation. The rate of excimer formation is determined to be 2.2 × 109 s-1 at room temperature, which requires coupling with lattice motion with an activation energy of 0.44 kcal mol-1. Exploiting Cz9PhAn as a single emitter, a fluorescent white organic light emitting diode (WOLED) is fabricated with a maximum external quantum efficiency (ηext) of 3.6% at 1000 cd m-2 (4.2 V) and Commission Internationale de L'Eclairage (CIE) coordinates of (0.30, 0.33). The white-light Cz9PhAn reveals a preferred orientation of the transition dipole moment in the emitting layer to enhance light outcoupling. This non-doped, single component (Cz9PhAn) WOLED greatly reduces the complexity of the fabrication process, rendering a green and cost-effective alternative among the contemporary display/lighting technologies.
RESUMO
Compounds interaction on the biodegradation of acetone and methyl ethyl ketone (MEK) mixture in a composite bead biofilter was investigated. The biodegradation rate of two compounds in the exponential growth phase and stationary phase for the single compound and two compounds mixing systems was determined. The microbial growth rate and biochemical reaction rate of biodegraded two compounds was inhibited at higher compound inlet concentration for the single compound system. The microbial metabolic activity of biodegraded acetone in the microbial growth process and biochemical reaction process was inhibited by introducing MEK and was more pronounced at higher MEK inlet concentration and lower acetone inlet concentration for the two compounds mixing system. The maximum elimination capacity of acetone and MEK for the single compound system was smaller and greater than those for the two compounds mixing system, respectively.