Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 111
Filtrar
1.
Polymers (Basel) ; 16(5)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38475283

RESUMO

This manuscript presents a comprehensive study on the sustainable optimization of asphalt mixtures tailored for regions prone to flooding. The research addresses the challenges associated with water damage to asphalt pavements by incorporating innovative additives. The study centers on incorporating recycled Low-Density Polyethylene (LDPE) and a tailored Carnauba-Soybean Oil Additive, advancing asphalt mixtures with a Control mix, LDPE (5%) + Control, and LDPE (5%) + 3% Oil + Control. A critical aspect of the research involves subjecting these mixtures to 30 wetting and drying cycles, simulating the conditions prevalent in tropical flood-prone areas. The incorporation of innovative additives in asphalt mixtures has demonstrated significant improvements across various performance parameters. Tensile Strength Ratio (TSR) tests revealed enhanced tensile strength, with the LDPE (5%) + 3% Oil-modified mixture exhibiting an impressive TSR of 85.7%. Dynamic Modulus tests highlighted improved rutting resistance, showcasing a remarkable increase to 214 MPa in the LDPE (5%) with a 3% Oil-modified mixture. The Semi-Circular Bending (SCB) test demonstrated increased fracture resistance and energy absorption, particularly in the LDPE (5%) with 3% Oil-modified mixture. Hamburg Wheel-Tracking (HWT) tests indicated enhanced moisture resistance and superior rutting resistance at 20,000 cycles for the same mixture. Cantabro tests underscored improved aggregate shatter resistance, with the LDPE (5%) + 3% Oil-modified mixture exhibiting the lowest weight loss rate at 9.820%. Field tests provided real-world insights, with the LDPE (5%) + 3% Oil mixture displaying superior stability, a 61% reduction in deflection, and a 256% improvement in surface modulus over the control mixture. This research lays the groundwork for advancing the development of sustainable, high-performance road pavement materials, marking a significant stride towards resilient infrastructure in flood-prone areas.

2.
Ann Hepatobiliary Pancreat Surg ; 28(2): 144-154, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38356257

RESUMO

Backgrounds/Aims: Socioeconomic determinants of health are incompletely characterized in cholangiocarcinoma (CCA). We assessed how socioeconomic status influences initial treatment decisions and survival outcomes in patients with CCA, additionally performing multiple sub-analyses based on anatomic location of the primary tumor. Methods: Observational study using the 2018 submission of the Surveillance, Epidemiology, and End Results (SEER)-18 Database. In total, 5,476 patients from 2004-2015 with a CCA were separated based on median household income (MHI) into low income (< 25th percentile of MHI) and high income (> 25th percentile of MHI) groups. Seventy-three percent of patients had complete follow up data, and were included in survival analyses. Survival and treatment outcomes were calculated using R-studio. Results: When all cases of CCA were included, the high-income group was more likely than the low-income to receive surgery, chemotherapy, and local tumor destruction modalities. Initial treatment modality based on income differed significantly between tumor locations. Patients of lower income had higher overall and cancer-specific mortality at 2 and 5 years. Non-cancer mortality was similar between the groups. Survival differences identified in the overall cohort were maintained in the intrahepatic CCA subgroup. No differences between income groups were noted in cancer-specific or overall mortality for perihilar tumors, with variable differences in the distal cohort. Conclusions: Lower income was associated with higher rates of cancer-specific mortality and lower rates of surgical resection in CCA. There were significant differences in treatment selection and outcomes between intrahepatic, perihilar, and distal tumors. Population-based strategies aimed at identifying possible etiologies for these disparities are paramount to improving patient outcomes.

3.
Eur J Psychotraumatol ; 15(1): 2306102, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38334695

RESUMO

Introduction: Healthcare workers (HCWs) often experience morally challenging situations in their workplaces that may contribute to job turnover and compromised well-being. This study aimed to characterize the nature and frequency of moral stressors experienced by HCWs during the COVID-19 pandemic, examine their influence on psychosocial-spiritual factors, and capture the impact of such factors and related moral stressors on HCWs' self-reported job attrition intentions.Methods: A sample of 1204 Canadian HCWs were included in the analysis through a web-based survey platform whereby work-related factors (e.g. years spent working as HCW, providing care to COVID-19 patients), moral distress (captured by MMD-HP), moral injury (captured by MIOS), mental health symptomatology, and job turnover due to moral distress were assessed.Results: Moral stressors with the highest reported frequency and distress ratings included patient care requirements that exceeded the capacity HCWs felt safe/comfortable managing, reported lack of resource availability, and belief that administration was not addressing issues that compromised patient care. Participants who considered leaving their jobs (44%; N = 517) demonstrated greater moral distress and injury scores. Logistic regression highlighted burnout (AOR = 1.59; p < .001), moral distress (AOR = 1.83; p < .001), and moral injury due to trust violation (AOR = 1.30; p = .022) as significant predictors of the intention to leave one's job.Conclusion: While it is impossible to fully eliminate moral stressors from healthcare, especially during exceptional and critical scenarios like a global pandemic, it is crucial to recognize the detrimental impacts on HCWs. This underscores the urgent need for additional research to identify protective factors that can mitigate the impact of these stressors.


This study explored the nature of moral stressors encountered by health care workers, along with impacts on moral injury and intentions to leave their jobs.Morally distressing encounters were common, with the most prevalent and distressing experiences being organizational or team-based in nature.Findings revealed that severity of moral injury, particularly related to trust violation or betrayal, was a key factor influencing healthcare workers' intentions to leave their jobs.


Assuntos
COVID-19 , Pandemias , Humanos , Prevalência , Canadá/epidemiologia , Princípios Morais , COVID-19/epidemiologia , Pessoal de Saúde
4.
J Neurooncol ; 166(2): 321-330, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38263486

RESUMO

PURPOSE: The purpose of this study was to determine the safety, feasibility, and immunologic responses of treating grade 4 astrocytomas with multiple infusions of anti-CD3 x anti-EGFR bispecific antibody (EGFRBi) armed T cells (EGFR BATs) in combination with radiation and chemotherapy. METHODS: This phase I study used a 3 + 3 dose escalation design to test the safety and feasibility of intravenously infused EGFR BATs in combination with radiation and temozolomide (TMZ) in patients with newly diagnosed grade 4 astrocytomas (AG4). After finding the feasible dose, an expansion cohort with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) tumors received weekly EGFR BATs without TMZ. RESULTS: The highest feasible dose was 80 × 109 EGFR BATs without dose-limiting toxicities (DLTs) in seven patients. We could not escalate the dose because of the limited T-cell expansion. There were no DLTs in the additional cohort of three patients with unmethylated MGMT tumors who received eight weekly infusions of EGFR BATs without TMZ. EGFR BATs infusions induced increases in glioma specific anti-tumor cytotoxicity by peripheral blood mononuclear cells (p < 0.03) and NK cell activity (p < 0.002) ex vivo, and increased serum concentrations of IFN-γ (p < 0.03), IL-2 (p < 0.007), and GM-CSF (p < 0.009). CONCLUSION: Targeting AG4 with EGFR BATs at the maximum feasible dose of 80 × 109, with or without TMZ was safe and induced significant anti-tumor-specific immune responses. These results support further clinical trials to examine the efficacy of this adoptive cell therapy in patients with MGMT-unmethylated GBM. CLINICALTRIALS: gov Identifier: NCT03344250.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Temozolomida/uso terapêutico , Leucócitos Mononucleares/patologia , Neoplasias Encefálicas/genética , Linfócitos T/patologia , Glioblastoma/tratamento farmacológico , Receptores ErbB , Antineoplásicos Alquilantes/uso terapêutico , Antineoplásicos Alquilantes/farmacologia
5.
Internet Interv ; 34: 100644, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38099095

RESUMO

As mobile and wearable devices continue to grow in popularity, there is strong yet unrealized potential to harness people's mobile sensing data to improve our understanding of their cellular and biologically-based diseases. Breakthrough technical innovations in tumor modeling, such as the three dimensional tumor microenvironment system (TMES), allow researchers to study the behavior of tumor cells in a controlled environment that closely mimics the human body. Although patients' health behaviors are known to impact their tumor growth through circulating hormones (cortisol, melatonin), capturing this process is a challenge to rendering realistic tumor models in the TMES or similar tumor modeling systems. The goal of this paper is to propose a conceptual framework that unifies researchers from digital health, data science, oncology, and cellular signaling, in a common cause to improve cancer patients' treatment outcomes through mobile sensing. In support of our framework, existing studies indicate that it is feasible to use people's mobile sensing data to approximate their underlying hormone levels. Further, it was found that when cortisol is cycled through the TMES based on actual patients' cortisol levels, there is a significant increase in pancreatic tumor cell growth compared to when cortisol levels are at normal healthy levels. Taken together, findings from these studies indicate that continuous monitoring of people's hormone levels through mobile sensing may improve experimentation in the TMES, by informing how hormones should be introduced. We hope our framework inspires digital health researchers in the psychosocial sciences to consider how their expertise can be applied to advancing outcomes across levels of inquiry, from behavioral to cellular.

6.
BMC Psychiatry ; 23(1): 836, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37964206

RESUMO

OBJECTIVE: Canadian Armed Forces (CAF) members and Veterans are more likely to experience mental health (MH) conditions, such as posttraumatic stress disorder (PTSD), than the general Canadian population. Previous research suggests that an increasing number of individuals are employing cannabis for MH symptom relief, despite a lack of robust evidence for its effectiveness in treating PTSD. This research aimed to: (1) describe the prevalence of current cannabis use among MH treatment-seeking CAF members and Veterans; and (2) estimate the association between current cannabis use and a number of sociodemographic, military, and MH-related characteristics. METHOD: Using cross-sectional intake data from 415 CAF members and Veterans attending a specialized outpatient MH clinic in Ontario, Canada, between January 2018 and December 2020, we estimated the proportion of CAF members and Veterans who reported current cannabis use for either medical or recreational purposes. We used multivariable logistic regression to estimate adjusted odds ratios for a number of sociodemographic, military, and MH-related variables and current cannabis use. RESULTS: Almost half of the study participants (n = 187; 45.1%) reported current cannabis use. Respondents who reported current cannabis use for medical purposes had a higher median daily dose than those who reported current cannabis use for recreational purposes. The multivariable logistic regression identified younger age, lower income, potentially hazardous alcohol use, and increased bodily pain as statistically significant correlates of current cannabis use among our MH treatment-seeking sample. PTSD severity, depressive severity, sleep quality, and suicide ideation were not statistically associated with current cannabis use. CONCLUSIONS: Almost half of our treatment-seeking sample reported current cannabis use for medical or recreational purposes, emphasizing the importance of screening MH treatment-seeking military members and Veterans for cannabis use prior to commencing treatment. Future research building upon this study could explore the potential impact of cannabis use on MH outcomes.


Assuntos
Cannabis , Militares , Transtornos de Estresse Pós-Traumáticos , Veteranos , Humanos , Veteranos/psicologia , Saúde Mental , Estudos Transversais , Militares/psicologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Ontário/epidemiologia
7.
Polymers (Basel) ; 15(21)2023 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-37959936

RESUMO

Rising traffic volume, heavy loads, and construction activities have raised concerns about expansion joint device damage. This study focuses on developing an innovative expansion joint using polymer-modified rubber asphalt as the filling material to enhance its service life. Styrene-butadiene-styrene (SBS) emerged as a suitable modifier for rubber-modified asphalt, significantly improving elasticity and adhesion. Through the strategic combination of 3- and 2-block linear SBS, the elasticity and adhesion properties were significantly improved, resulting in the formulation of a well-suited polymer-modified rubber asphalt binder. The developed asphalt binder exhibits impressive elastic recovery (61.1% to 66.1%), surpassing commercial products, with enhanced constructability and workability (15% to 21% viscosity reduction). The carefully engineered mastic asphalt mixture showcases self-leveling characteristics at a moderate 210 °C, addressing historical constructability challenges. Settlement is 40% less than traditional hot mix asphalt for surface layers, with improved moisture and stripping resistance, enhancing existing asphalt plug joint durability and workability. Collectively, this novel mixture, comprising polymer-modified rubber and mastic asphalt, showcases the potential to enhance the durability of existing asphalt plug joints while ensuring superior constructability and workability.

8.
Polymers (Basel) ; 15(22)2023 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-38006186

RESUMO

This research investigates the quantitative impact of incorporating epoxy resin and crumb rubber powder (CRP) into cement asphalt mortar (CAM) for railway track stabilization. The study reveals significant improvements in various key parameters compared to conventional CAM. The modified CAM exhibits a 12.7% reduction in flow time, indicative of enhanced flowability, and a substantial 62.4% decrease in the mixing stability gap, demonstrating superior mixing stability. Additionally, the modified CAM displays remarkable early-age compressive strength, with increases of up to 15.3% compared to traditional CAM formulations. Importantly, the modified CAM showcases robust resistance to challenging environmental conditions, with only a 6.7% strength reduction after exposure to sulfuric acid, highlighting its acid resistance, and exceptional freeze-thaw resistance, with a mere 1.5% strength reduction after undergoing six cycles. In a mock-up test simulating real-world conditions, the modified CAM effectively prevents ballast layer settlement, underscoring its potential to enhance the durability of railway track infrastructure. These quantitative findings not only endorse the practical feasibility of epoxy resin and CRP-enhanced CAM but also suggest its potential to contribute significantly to railway track longevity, reduce maintenance expenditures, and ensure operational reliability.

9.
BMJ Case Rep ; 16(10)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37816575

RESUMO

Colchicine myopathy typically presents acutely to subacutely with progressive limb weakness. The patients may not be on high doses of colchicine but almost always have acute kidney injury. Dehydration from colchicine-induced diarrhoea is often a precipitating factor. The concomitant neurotoxicity may produce mild sensory complaints. This combination of acute neurological symptoms preceded by diarrhoea prompts the diagnosis of Guillain-Barre syndrome (GBS). The absence of cranial nerve deficits, raised creatine kinase and myotonic discharges on electromyogram may help in differentiating this condition from GBS. We describe a clinical sign, myoedema - a mounding phenomenon of muscle that is elicited by percussion and resolves when the patient recovers. It aids in the bedside diagnosis of acute colchicine myopathy as well as distinguish it from other more common causes of acute flaccid paralysis. We also discuss the possible mechanism of colchicine toxicity and the mounding phenomenon.


Assuntos
Síndrome de Guillain-Barré , Doenças Musculares , Doenças Neuromusculares , Humanos , Colchicina/efeitos adversos , Doenças Musculares/induzido quimicamente , Doenças Musculares/diagnóstico , Doenças Musculares/complicações , Doenças Neuromusculares/induzido quimicamente , Síndrome de Guillain-Barré/diagnóstico , Diarreia/induzido quimicamente
10.
Front Psychol ; 14: 1235211, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37842704

RESUMO

Introduction: The COVID-19 pandemic has resulted in heightened moral distress among health care workers (HCWs) worldwide. Past research has shown that effective leadership may mitigate potential for the development of moral distress. However, no research to date has considered the mechanisms by which leadership might have an influence on moral distress. We sought to evaluate longitudinally whether Canadian HCWs' perceptions of workplace support and ethical work environment would mediate associations between leadership and moral distress. Methods: A total of 239 French- and English-speaking Canadian HCWs employed during the COVID-19 pandemic were recruited to participate in a longitudinal online survey. Participants completed measures of organizational and supervisory leadership at baseline and follow-up assessments of workplace support, perceptions of an ethical work environment, and moral distress. Results: Associations between both organizational and supervisory leadership and moral distress were fully mediated by workplace supports and perceptions of an ethical work environment. Discussion: To ensure HCW well-being and quality of care, it is important to ensure that HCWs are provided with adequate workplace supports, including manageable work hours, social support, and recognition for efforts, as well as an ethical workplace environment.

11.
JCO Precis Oncol ; 7: e2200594, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37561981

RESUMO

PURPOSE: Increased awareness of the distinct tumor biology for adolescents and young adults (AYAs) with cancer has led to improvement in outcomes for this population. However, in cholangiocarcinoma (CCA), a paucity of data exist on the AYA population. To our knowledge, we present the largest study to date on AYA disease biology, treatment patterns, and survival outcomes in CCA. METHODS: A multi-institutional cohort of patients with CCA diagnosed with intrahepatic cholangiocarcinoma (ICC) or extrahepatic cholangiocarcinoma (ECC) was used for analysis. Retrospective chart review was conducted on patients who were 50 years old and younger (young; n = 124) and older than 50 years (older; n = 723). RESULTS: Among 1,039 patients screened, 847 patients met eligibility (72% ICC, 28% ECC). Young patients had a larger median tumor size at resection compared with older patients (4.2 v 3.6 cm; P = .048), more commonly had N1 disease (65% v 43%; P = .040), and were more likely to receive adjuvant therapy (odds ratio, 4.0; 95% CI, 1.64 to 9.74). Tumors of young patients were more likely to harbor an FGFR2 fusion, BRAF mutation, or ATM mutation (P < .05 for each). Young patients were more likely to receive palliative systemic therapy (96% v 69%; P < .001), targeted therapy (23% v 8%; P < .001), and treatment on a clinical trial (31% v 19%; P = .004). Among patients who presented with advanced disease, young patients had a higher median overall survival compared with their older counterparts (17.7 v 13.5 months; 95% CI, 12.6 to 22.6 v 11.4 to 14.8; P = .049). CONCLUSION: Young patients with CCA had more advanced disease at resection, more commonly received both adjuvant and palliative therapies, and demonstrated improved survival compared with older patients. Given the low clinical trial enrollment and poor outcomes among some AYA cancer populations, data to the contrary in CCA are highly encouraging.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Humanos , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , Estudos Retrospectivos , Colangiocarcinoma/genética , Ductos Biliares Intra-Hepáticos/patologia , Neoplasias dos Ductos Biliares/patologia , Biologia
12.
Polymers (Basel) ; 15(15)2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37571187

RESUMO

This research addresses the urgent need for sustainable and durable asphalt mixtures by quantitatively investigating the effects of incorporating waste plastic aggregate (WPA) and magnesium-based additives. This study explores WPA content levels of 3%, 5%, and 7% wt of aggregate in combination with a fixed 3% wt epoxy resin content to the asphalt binder, supplemented with the 1.5% wt magnesium-based additive. The novelty of this research lies in its comprehensive analysis of various performance parameters, including deformation strength, indirect tensile strength (ITS), rut depth, and dynamic stability, to assess the impact of WPA, epoxy resin, and the magnesium-based additive on asphalt mixture properties. The results demonstrate significant improvements in key performance aspects with increasing WPA content. The WPA mixtures exhibit enhanced deformation strength, with values of 4.01, 3.7, and 3.32 MPa for 3, 5, and 7% wt WPA content, respectively, compared to the control mixture. Furthermore, the inclusion of WPA and epoxy resin, along with the magnesium-based additive, contributes to improved adhesion, cohesion, and resistance to stripping damage. Notably, the 7% wt WPA mixture showcases exceptional performance, characterized by a final rut depth of 2.66 mm and a dynamic stability of 7519 passes per millimeter, highlighting its superior rutting resistance and load-bearing capacity. This study also reveals the influence of WPA content on ITS and stiffness properties, with the 5% wt WPA mixture achieving an optimal balance between strength and stiffness. Overall, this research highlights the potential of incorporating WPA, epoxy resin, and magnesium-based additives in asphalt mixtures to enhance their performance and durability. By utilizing plastic waste materials and optimizing their combination with epoxy reinforcement, along with the innovative use of magnesium-based additive, the findings contribute to the development of sustainable infrastructure materials and pave the way for further advancements in the field.

13.
Future Sci OA ; 9(8): FSO875, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37621847

RESUMO

Aim: Ovarian cancer is a serious malignancy with high prevalence and mortality. Methods: We isolated and characterized an ovarian high-grade serous cancer cell line (M4) from a tumor of a Vietnamese patient with ovarian carcinoma. Results: The M4 cancer cell line showed good proliferation and stability in culture. Morphologically, the M4 cells showed similar characteristics to tumor cells such as a polyhedral shape, large irregular nuclei, high nuclear/cytoplasmic ratio, high nuclear density and expressing cancer markers like CA125, p53 and Ki67 markers. Conclusion: We have successfully isolated and characterized the M4 cell line from a Vietnamese patient with ovarian carcinoma.

14.
Support Care Cancer ; 31(9): 542, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37646867

RESUMO

PURPOSE: This study used ecological momentary assessment (EMA) to test the association between activity, location, and social company contexts with cancer caregivers' in-the-moment affect to identify precisely when and where to deliver psychological interventions for caregivers. METHODS: Current cancer caregivers (N = 25) received 8 EMA prompts per day for 7 consecutive days. At each prompt, caregivers reported their current positive affect and negative affect, as well as what they were doing, where they were located, and who they were with. Multilevel logistic regressions tested the associations between caregivers' contexts with their own person-mean-centered state (concurrent momentary level) and trait (overall weekly average) positive or negative affect. RESULTS: Caregivers reported lower state negative affect, as well as higher state positive affect, when socializing (ps < .001), when at a public location (ps < .03), and when around their friends, family, spouse/partner, or care recipient (i.e., person with cancer, ps < .02), relative to when not endorsing the context. Caregivers also reported lower state negative affect when eating/drinking or engaging in leisure (ps < .01; but no parallel effects for state positive affect). Caregivers reported higher state negative affect while working, when at their workplace, or when around work colleagues (ps < .001) and lower state positive affect when at home or alone (ps < .03). CONCLUSIONS: Results suggest the pertinence of a behavioral activation framework to mitigate the emotional strain of caregiving. Interventions that facilitate caregivers' ability to socialize with a range of friends and family, including their loved one with cancer, outside of the home may have the strongest positive emotional impact.


Assuntos
Cuidadores , Neoplasias , Humanos , Neoplasias/terapia , Terapia Comportamental , Emoções , Amigos
15.
Polymers (Basel) ; 15(13)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37447475

RESUMO

This study addresses the challenges of overlaying old concrete pavement with asphalt by introducing a new trackless tack coat material containing polymer. The aim is to enhance the durability of asphalt concrete overlay pavement on old cement concrete pavement. It contributes to the development of improved construction techniques for pavement rehabilitation and highlights the need for reliable adhesion performance evaluation based on different spray amounts and surface conditions. Additionally, to evaluate the effect of the adhesion performance based on the spraying amount, a tensile adhesion test was conducted by applying spray amounts of 0.30, 0.45, and 0.60 l/m2 on different surface conditions. The basic and adhesion performances of the polymer-modified tack coat material are evaluated through direct tensile and shear bond strength tests. The test outcomes demonstrated that the newly developed polymer-modified tack coat material had considerably greater adhesion strength compared to the traditional rapid-setting products. Its adhesive strength was 1.68 times higher on concrete and 1.78 times higher on asphalt. The new trackless tack coat material exhibited an adhesion performance of 1.05 MPa in direct tensile strength at 0.45 l/m2, which was 1.21 times higher than the rapid-setting tack coat. Results also confirmed that the new tack coat material exhibits values 1.90 times greater than the conventional rapid-setting tack coat material in shear bond strength, respectively. By simulating the process of separation and re-adhesion of pavement layers caused, the new tack coat material shows a tensile adhesion strength of 63% of the original state, which is advantageous for securing the durability of the pavement. Overall, the newly developed polymer-modified trackless tack coat has been shown to effectively enhance the adhesion performance between pavement layers without process delay, highlighting the potential of the new tack coat material to enhance the durability of asphalt concrete overlay pavement on old cement concrete pavement.

16.
Polymers (Basel) ; 15(11)2023 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-37299303

RESUMO

The quality of pavements in tropical climates is negatively affected by the frequent wet and dry cycles during the rainy season, as well as by issues related to overloading from heavy trucks and traffic congestion. Contributing to this deterioration are factors such as acid rainwater, heavy traffic oils, and municipal debris. In light of these challenges, this study aims to assess the viability of a polymer-modified asphalt concrete mixture. This study investigates the feasibility of a polymer-modified asphalt concrete mixture with the addition of 6% crumb rubber powder from waste car tires and 3% epoxy resin to counter the harsh conditions of tropical climate weather. The study involved subjecting test specimens to five to 10 cycles of contaminated water (100% rainwater + 10% used oil from trucks), curing for 12 h, and air drying in a chamber of 50 °C for 12 h to simulate critical curing conditions. The specimens underwent fundamental laboratory performance tests such as the indirect tensile strength test, dynamic modulus test, four points bending test, and Cantabro test, as well as the double load condition in the Hamburg wheel tracking test to determine the effectiveness of the proposed polymer-modified material in actual conditions. The test results confirmed that the simulated curing cycles had a critical impact on the durability of the specimens, with the greater curing cycles leading to a significant drop in the strength of the material. For example, the TSR ratio of the control mixture dropped from 90% to 83% and 76% after five and 10 curing cycles, respectively. Meanwhile, the modified mixture showed a decrease from 93% to 88% and 85% under the same conditions. The test results revealed that the effectiveness of the modified mixture outperformed the conventional condition in all tests, with a more prominent impact observed under overload conditions. Under double conditions in the Hamburg wheel tracking test and a curing condition of 10 cycles, the maximum deformation of the control mixture sharply increased from 6.91 to 22.7 mm, whereas the modified mixture increased from 5.21 to 12.4 mm. Overall, the test results confirm the durability of the polymer-modified asphalt concrete mixture under harsh tropical climate conditions, promoting its application for sustainable pavements, especially in Southeast Asian countries.

17.
Materials (Basel) ; 16(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37049108

RESUMO

Conventional hot mix asphalt overlaying on trench infrastructure typically necessitates extended cooling times for further works and can have adverse effects on buried components, such as electricity cables and hot water pipes. Therefore, this research aims to investigate the use of warm guss mastic asphalt (at an installation temperature of 160 °C) as an overlaying material for mini-trenches, which can reduce the cooling time required for traffic opening and improve the efficiency of the construction process. This research involved two stages: first, lab testing and related research results were used to generate the thermal conductivity and specific heat necessary for simulation work. Second, a finite element model analysis was conducted to evaluate the thermal transmission of the overlaying surface and the buried conduit based on the summer pavement temperature distribution through the Korean Pavement Research Program. Afterward, the field test bed was constructed to verify the simulation. The results indicate that the optimal thickness of the overlaying material and the concrete covering should be designed to ensure thermal durability and meet traffic opening requirements. The overlaying depth of the mini trench using warm mix guss mastic asphalt should be less than 100 mm to meet with the traffic opening time, while the thickness of the concrete covering should be designed to be more than 100 mm to ensure thermal durability. Additionally, the findings suggest that the application of warm guss asphalt could reduce the opening time by 30 min to 1 h and 25 min compared to conventional hot guss asphalt materials. When the pavement surface temperature for the traffic opening is controlled at 50 °C, the asphalt mixture requires at least 2 h to 5 h to meet the cooling criteria for traffic opening, respectively. Overall, this research confirms the potential benefits and optimal use of warm guss mastic asphalt in the construction process of mini-trenches.

18.
Polymers (Basel) ; 15(7)2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37050307

RESUMO

This paper proposes a performance-based mix design (PBMD) framework to support performance-related specifications (PRS) needed to establish relationships between acceptable quality characteristics (AQCs) and predicted performance, as well as to develop fatigue-preferred, rutting-preferred, and performance-balanced mix designs. The framework includes defining performance tests and threshold values, developing asphalt mix designs, identifying available performance levels, conducting sensitivity analysis, establishing the relationships between AQCs and predicted performance, and determining performance targets and AQC values for the three PBMDs using predicted performance criteria. Additionally, the framework recommends selecting the PBMD category for each asphalt layer to minimize pavement distresses. In this study, the proposed PBMD protocol was applied to FHWA accelerated loading facility (ALF) materials using asphalt mixture performance tester (AMPT) equipment coupled with mechanistic models. The study developed nine mix designs with varying design VMAs and air voids using the Bailey method. The cracking and rutting performance of the mix designs were determined by direct tension cyclic (DTC) fatigue testing, triaxial stress sweep (TSS) testing, and viscoelastic continuum damage (S-VECD) and viscoplastic shift models for temperature and stress effects. The study found that adjusting the design VMA was the primary way to achieve required performance targets. For fatigue-preferred mix design, the recommended targets were a cracking area of 0 to 1.9%, a rut depth of 10 mm, and a design VMA of 14.6 to 17.6%. For rutting-preferred mix design, the recommended targets were a cracking area of 18%, a rut depth of 0 to 3.8 mm, and a design VMA of 10.1 to 13.1%. For performance-balanced mix design, the recommended targets were a cracking area of 8.1 to 10.7%, a rut depth of 4.6 to 6.4 mm, and a design VMA of 12.6 to 14.3%. Finally, pavement simulation results verified that the proposed PBMD pavement design with fatigue-preferred mix in the bottom layer, performance-balanced mix in the intermediate layer, and rutting-preferred mix in the surface mix could minimize bottom-up cracking propagation without exceeding the proposed rutting performance criterion for long-life.

19.
J Natl Cancer Inst ; 115(7): 870-880, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37040087

RESUMO

BACKGROUND: Treatment patterns for intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) differ, but limited studies exist comparing them. This study examines differences in molecular profiling rates and treatment patterns in these populations, focusing on use of adjuvant, liver-directed, targeted, and investigational therapies. METHODS: This multicenter collaboration included patients with ICC or ECC treated at 1 of 8 participating institutions. Retrospective data were collected on risk factors, pathology, treatments, and survival. Comparative statistical tests were 2-sided. RESULTS: Among 1039 patients screened, 847 patients met eligibility (ICC = 611, ECC = 236). Patients with ECC were more likely than those with ICC to present with early stage disease (53.8% vs 28.0%), undergo surgical resection (55.1% vs 29.8%), and receive adjuvant chemoradiation (36.5% vs 4.2%) (all P < .00001). However, they were less likely to undergo molecular profiling (50.3% vs 64.3%) or receive liver-directed therapy (17.9% vs 35.7%), targeted therapy (4.7% vs 18.9%), and clinical trial therapy (10.6% vs 24.8%) (all P < .001). In patients with recurrent ECC after surgery, the molecular profiling rate was 64.5%. Patients with advanced ECC had a shorter median overall survival than those with advanced ICC (11.8 vs 15.1 months; P < .001). CONCLUSIONS: Patients with advanced ECC have low rates of molecular profiling, possibly in part because of insufficient tissue. They also have low rates of targeted therapy use and clinical trial enrollment. While these rates are higher in advanced ICC, the prognosis for both subtypes of cholangiocarcinoma remains poor, and a pressing need exists for new effective targeted therapies and broader access to clinical trials.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Humanos , Ductos Biliares Intra-Hepáticos/patologia , Estudos Retrospectivos , Colangiocarcinoma/genética , Colangiocarcinoma/terapia , Fatores de Risco , Prognóstico , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/terapia
20.
Polymers (Basel) ; 15(3)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36772029

RESUMO

The purpose of this research was to promote the recycling of pellet asphalt with Crumb Rubber Modifier (CRM) and Graphite Nanoplatelet (GNP) in pothole restoration. In this study, several laboratory tests were carried out on mixes containing CRM content ratios of 5%, 10%, and 20% and GNP content of 3% and 6% in order to identify the ideal mixing ratio of pellet-type asphalt paving materials. The Marshall stability test, the Hamburg wheel tracking test, and the dynamic modulus test were all performed to compare the effectiveness of the proposed method and heated asphalt combinations. Afterward, the full-scale testbed was conducted to verify the practical application between the proposed method and popular pothole-repairing materials. Both laboratory and field test findings confirmed that the asphalt pavement using 5% CRM and 6% GNP improved the resistance to plastic deformation and anti-stripping compared to the generally heated asphalt paving material, thereby extending road life. However, the resistance to fatigue cracking can be slightly reduced by incorporating these additives. Overall, the CRM and GNP asphalt pellet approach is a feasible solution for sustainable pavement maintenance and rehabilitation, particularly in small-scale damage areas such as potholes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA