bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyureas for the Automotive Industry
Authors: Huygens E. , Cassidy E.F. 
Published: September 2023

Increasing use is being made of plastics and reinforced reaction injection moulded polymers for large and complex automotive parts. Polyurea RIM materials have become established in this market by fulfilling necessary technical and thermal resistance requirements - and by enabling dependable and consistent production of parts to be achieved at the rates required by industry. ICI has developed a range of polyurea systems capable of providing particularly high temperature and corrosion resistance and high impact strength. These systems may be processed on existing high-throughput RIM equipment, using relatively low clamping pressures. But machinery manufacturers are already extending their ranges with higher output dispensing units, more automated controls and gas nucleation of the chemical components. Because of their toughness at demould and excellent self-release character¬istics, RIM polyureas permit markedly shorter cycling on sophisticated automated lines. The addition of robotised part demoulding makes it possible to reduce overall cycle times to less than one minute. Polyurea RIM systems have progressed particularly rapidly over the past two years. A major car producer in Europe has already approved and commenced production with a RIMline® polyurea bumper system from ICI. Today's fast-reacting, self-releasing polyurea systems are not only suitable for fully auto¬mated production, but also offer the potential for on-line painting. The trend to decreasing production volumes as a consequence of greater model differentia¬tion will contribute to the economic competitiveness of polyurea for external body panel production.
Combustion Behaviour of Polyurethane Flexible Foams under Cone Calorimetry Test Conditions
Authors: Vanspeybroeck R. , Van Hees P. , Vandevelde P. 
Published: September 2023

The first part of this study focused on the effect of cone calorimeter test variables on polyurethane flexible foam properties such as ignitability, heat release rate, effective heat of combustion and mass loss. Three of the main commercial foam types were used; viz. conventional slabstock foams, high resilience slabstock foams and all-MDI moulded foams. A decrease in heat flux (down to. 40%) with increasing distance from the conical heater was measured. As a consequence, results were found to depend to a large extent on the thickness and the melting behaviour of the foam samples. To achieve a sufficiently constant and uniform heat flux exposure, sample thickness had to be limited to 2.5 cm. In addition, repeatability was found to be good under various conditions, with percentage standard deviations for effective heat of combustion, peak rate of heat release and mass loss below 10%. Levels of radiant flux above 25 kW/m2 were found to be very severe to test flexible polyurethane foams. Under such conditions, foams that show big differences in combustion performance in small scale flammability tests, performed almost identically in the cone calorimeter. In the second part of this study, the effects of foam variables, such as foam type, density and melamine content, were defined. These effects were clearly pronounced at radiant flux levels of 15 to 25 kW/m2. Density was found to be the key variable in controlling ignition resistance. In addition, high-resilience slabstock foams and all-MDI moulded foams performed better than conventional slabstock foams of the same density. Melamine addition resulted in a delay of ignition for all three foam types and an incomplete combustion, decreased heat release and effective heat of combustion, in case of HR slabstock and all-MDI moulded foams. However, melamine is not effective as a heat sink in conventional slabstock foams. The different performance of the foam types under study can be explained by a different melting behaviour.
The “Waterlily” Range of Quality Comfort Materials from Id's MDI-based Flexible Slabstock Technology
Authors: Casey Martin , Parfondry Alain , Muller Louis , Elliot Angela 
Published: September 2023

The flexible slabstock industry has been increasingly subjected to environmental pressures over the last five years, presenting challenges to seek new technologies. These challenges include the elimination of CFCs, careful scrutiny of alternative blowing agents, and constant tightening of fire ignition standards. ICI Polyurethanes has been at the forefront of MDI cold cure moulding technologies for some years, an area pioneered in the early 1980s. Building on its experience, ICI has developed a technology package for 100 percent water-blown MDI-based system for slabstock foams. Considerable investment in the project has included a production scale foaming unit, with a maximum output of 300 kg/min, and a dedicated project team. Deterioration of physical properties, normally associated with MDI formulations at low densities, has been overcome with the design of novel chemical intermediates, which has also required new formulation development and some equipment modification. The technology package allows a wide range of hardness/density combinations from a small number of raw material components, and produces foams with remarkable stability and fast cure times. This speed, and MDI's low vapour pressure, lead to much-improved working environments. In general, the new foams give a good balance of comfort properties with an excellent latex-like “feel”. Data is shown comparing their performance with that of existing high resilience foams.
The Use of Secondary Aromatic Diamines in Rigid Isocyanurate-Based Foams
Authors: Scott R.V. , House D.W. , Gattuso M.J. , Ashida K. , Frisch K.C. , Klempner D. , Mahdi S. , Parekh C. 
Published: September 2023

Commercial isocyanurate foams are generally modified with urethane groups. Other groups, such as amide, imide, carbodiimide, or oxazolidone linkages, have been used to modify such foams in order to improve physical properties (brittleness, friability). In the present work, urea modification was studied through the addition of a secondary aromatic diamine. The urea modification was studied in urethane-polyisocyanurate foams as well as foams in which the aromatic secondary diamine was the only source of active hydrogen. Exceptions were those foams in which water was used as the blowing agent. High isocyanate indices were employed so that the latter foams contained only urea and isocyanurate linkages. These foams were modified in the above manner in an effort to create a highly fire-resistant foam since the thermal stability and the rigidity of urea groups are known to be higher than that of urethane groups. The introduction of the aromatic secondary diamine into rigid foams has been shown to result in significantly improved compressive strength values, especially perpendicular to foam rise. This has led to the improvement of the isotropy of the foams. This improvement was verified by optical microscopy studies of the cell structure. These studies indicate that the incorporation of the additive resulted in much smaller cells with less elongation in the rise direction. As a result of the finer cells, slightly lower k-factors were obtained. This observation was true for freshly made foam samples as well as for samples aged at —20°C and 70°C. The dimensional stabilities of the aged samples were also consistent with these observations in that the addition of the aromatic diamine resulted in improved stabilities.
The Effect of Polymer Structure on the Gas Permeability of Model Polyurethanes
Authors: Kaplan W.A. , Tabor R.L. 
Published: September 2023

In the face of impending CFC elimination, a large variety of low-boiling alternate blowing agents have come under scrutiny for use in rigid foam insulation applications. The permeability of both the alternate blowing agent and atmospheric gases through the rigid foam thermoset polymer contributes to the rate at which the k-factor of the resulting foam deteriorates. In this study, a compression moulding method for synthesizing polymer films from polyurethane formulation components (a variety of diols with pure and polymeric methylenediphenyl diisocyanate) was developed and utilised to produce films containing distinct structural features. The permeabilities of the films to oxygen and carbon dioxide were then determined using a diffusion cell combined with either an infrared or coulombic detector. The effects on permeability of structural features such as diol molecular weight, alkylene oxide repeat unit, and isocyanate functionality are presented. Structural features determined to promote improved barrier performance in polymer films have been incorporated into a fully formulated foam system. Foam permeability and k-factor ageing comparisons were then made which demonstrate the improved foam barrier performance. The resulting structure/permeability correlations derived from these experiments will be useful in designing rigid foam polymers for use in alternate blowing agent applications.
Bedside placement of tunneled femorally inserted central catheters in pediatric patients on extracorporeal life support: A case series and discussion
Authors: Weber Mark D , Conlon Thomas , Connelly James , Himebauch Adam S 
Published: September 2023

Background: Pediatric patients requiring extracorporeal life support (ECLS) often need central venous access for extended periods of time. In this population, the placement of an upper extremity peripherally inserted central catheter (PICC) can be challenging due to the location and size of the venous ECLS cannula. Bedside placement of a tunneled femorally inserted central catheters (T-FICC) can be a viable alternative to a traditional PICC. Methods: In this case series we present five children who were on ECLS and had a T-FICC placed at the bedside. Results: In this series of five patients we successfully placed T-FICCs while the patients were on ECLS. The T-FICCs dwelled from 15 to 182 days. There were no events of central line associated blood stream infections or deep vein thrombosis. There was only one unintentional line dislodgement noted. Conclusion: The use of T-FICCs placed at the bedside is a safe and reliable alternative for secure long-term venous access in children who are on ECLS.
The Value of Neoadjuvant Anthracycline-Based Regimens for HER2-Positive Breast Cancer: A Systematic Review and Meta-analysis Including 1366 Patients
Authors: Ding Yuqin , Ding Kaijing , He Xiangming , Mo Wenju , Liang Chenlu , Gong Lijie , Huang Yuting , Ding Xiaowen 
Published: September 2023

Background: The standard recommendation for neoadjuvant therapy for human epidermal growth factor receptor-2 (HER2)-positive breast cancer patients is trastuzumab in combination with chemotherapy, but there is no current standard recommendation for appropriate chemotherapy regimens. This meta-analysis evaluated the efficacy and cardiac safety of the concurrent use of anti-HER2 targeted drugs and anthracycline-based neoadjuvant chemotherapy (NAC) for HER2-positive breast cancers. Methods: The pooled odds ratio (OR) rate for pathologic complete response (pCR), the pooled hazard ratio (HR) of overall survival (OS), and the left ventricular ejection fraction (LVEF) decline events were all calculated. Differences in efficacy, prognosis, and cardiac safety were compared between patients receiving an anthracycline-containing regimen (AB) and those treated with non-anthracycline-based (nAB) NAC. Results: A total of 1366 patients in 4 prospective and 3 retrospective studies were included in the meta-analysis. The pooled OR for pCR rate was 0.73 with a 95% confidence interval (CI) of 0.43 to 1.24 ( P = .246). Subgroup analysis of low tumor burden cases showed no improvement in pCR rate for patients in the AB group compared with nAB, with the pooled OR rate being 0.73 with a 95% CI of 0.37 to 1.44 ( P= .357). The 3-year OS rate was 95.63% and 95.54% in the AB and nAB groups, respectively, with no statistical difference ( P= .157). There was a significant increase in the rate of LVEF decline of 19.07% in the AB group compared with 13.33% for the nAB group, with an HR of 1.62 and a 95% CI of 1.11 to 2.36 ( P = .013). Conclusions: The addition of anthracyclines did not improve pCR rates and survival after neoadjuvant and the increased cardiotoxicity of anthracyclines further limited their application. This study showed that it was feasible to use anti-HER2 drugs without anthracyclines in neoadjuvant therapy for HER2-positive breast cancer patients.
Windfall money and outbound tourism: A natural experiment from lottery winnings
Authors: Boto-García David , Muñiz-Fernández Alvaro , Pérez Levi 
Published: September 2023

Income is a relevant factor for explaining outbound tourism demand. However, when working with regional- or country-level data, it is difficult to disentangle the role of income in stimulating tourism travelling from other factors that correlate with greater income levels. This paper exploits a natural experiment from Spanish Christmas Lottery to estimate the causal effect of income shocks on outbound tourism. We leverage the staggered and quasi-random assignment of lottery winnings across Spanish regions to estimate the elasticity of outbound annual trips and expenditure to windfall gains. Using difference-in-differences with the amount of lottery prizes as an indicator of treatment intensity, we show that lottery winnings per capita increase both the annual number of tourism trips and expenditure per capita. This effect operates during the first 2 years following the draw, which is likely explained by bandwagon and income multiplier effects.
Higher perceived stress during the COVID-19 pandemic increased menstrual dysregulation and menopause symptoms
Authors: Garcia de leon Romina , Baaske Alexandra , Albert Arianne Y. , Booth Amy , Racey C. Sarai , Gordon Shanlea , Smith Laurie W. , Gottschlich Anna , Sadarangani Manish , Kaida Angela , Ogilvie Gina S. , Brotto Lori A. , Galea Liisa A.M. 
Published: September 2023

Background: The increased stress the world experienced with the coronavirus disease (COVID-19) pandemic affected mental health, disproportionately affecting females. However, how perceived stress in the first year affected menstrual and menopausal symptoms has not yet been investigated. Objectives: This study evaluates the effect that the first year of the COVID-19 pandemic had on female reproductive and mental health. Methods: Residents in British Columbia, Canada, were surveyed online as part of the COVID-19 Rapid Evidence Study of a Provincial Population-Based Cohort for Gender and Sex. A subgroup of participants (n = 4171), who were assigned female sex at birth (age 25–69 years) and were surveyed within the first 6–12 months of the pandemic (August 2020–February 2021), prior to the widespread rollout of vaccines, was retrospectively asked if they noticed changes in their menstrual or menopausal symptoms, and completing validated measures of stress, depression and anxiety. Design: This is a population-based online retrospective survey. Results: We found that 27.8% reported menstrual cycle disturbances and 6.7% reported increased menopause symptoms. Those who scored higher on perceived stress, depression and anxiety scales were more likely to report reproductive cycle disturbances. Free-text responses revealed that reasons for disturbances were perceived to be related to the pandemic. Conclusion: The COVID-19 pandemic has highlighted the need to research female-specific health issues, such as menstruation. Our data indicate that in the first year of the pandemic, almost one-third of the menstruating population reported disturbances in their cycle, which was related to percieved stress, depression and anxiety scores.
Experimenting With International Curricula in Shanghai: Policies, Practice, and a Network Ethnography Analysis
Authors: Jin (金津) Jin , Chen (陈佳颖) Jiaying 
Published: September 2023

Purpose Drawing on a study of international schools in Shanghai, this study explores how external experiences and curricula are mobilized as policy tools to inspire local educational innovations and how these experiences are enacted differently by schools. Design/Approach/Methods Based on a review of policy documents and interviews with school principals, senior management stakeholders, and teachers, this study identifies and compares the typologies of international schools in policy design and practice. Then, by deploying the network ethnography method following three key nodes, this study offers some explanations for the gaps between policy design and enactments. Findings This study demonstrates the complex relations, interests, and struggles involved in constructing and shaping the meanings of international curricula within local education. The findings show the autonomy of policy networks and the difficulties of ‘steering’ them in a clear-cut way. Originality/Value This study is one of the earliest attempts, if not the first, to experiment with the method of network ethnography in the context of China. These findings offer a nuanced account of the complex relations and ad hocery involved in policy learning.
Pre-Hospital and Post-Hospital Quality of Care in Traumatic Spinal Column and Cord Injuries in Iran
Authors: Zeinaddini-Meymand Arman , Baigi Vali , Mousavi-Nasab Mohammad Mehdi , Shool Sina , Sadeghi-Naini Mohsen , Azadmanjir Zahra , Jazayeri Seyed Behnam , Berchi Kankam Samuel , Dashtkoohi Mohammad , Shakeri Aidin , Fakharian Esmail , Kouchakinejad-Eramsadati Leila , Pirnejad Habibollah , Sadeghi-Bazargani Homayoun , Bagheri Laleh , Pourandish Yasaman , Amiri Malihe , Pour-Rashidi Ahmad , Harrop James , Rahimi-Movaghar Vafa 
Published: September 2023

Study design A retrospective study. Objectives The quality of care (QoC) for spinal column/cord injury patients is a major health care concern. This study aimed to implement the QoC assessment tool (QoCAT) in the National Spinal Cord/Column Injury Registry of Iran (NSCIR-IR) to define the current state of pre- and post-hospital QoC of individuals with Traumatic Spinal Column and Spinal Cord Injuries (TSC/SCIs). Methods The QoCAT, previously developed by our team to measure the QoC in patients with TSC/SCIs, was implemented in the NSCIR-IR. The pre-hospital QoC was evaluated through a retrospective analysis of NSCIR-IR registry data. Telephone interviews and follow-ups of patients with SCI evaluated the QoC in the post-hospital phase. Results In the pre-hospital phase, cervical collars and immobilization were implemented in 46.4% and 48.5% of the cases, respectively. Transport time from the scene to the hospital was documented as <1 hour and <8 hours in 33.4% and 93.9% of the patients, respectively. Post-hospital indicators in patients with SCI revealed a first-year mortality rate of 12.5% (20/160), a high incidence of secondary complications, reduced access to electrical wheelchairs (4.2%) and modified cars (7.7%), and low employment rate (21.4%). Conclusion These findings revealed a significant delay in transport time to the first care facilities, low use of immobilization equipment indicating low pre-hospital QoC. Further, the high incidence of secondary complications, low employment rate, and low access to electrical wheelchairs and modified cars indicate lower post-hospital QoC in patients with SCI. These findings imply the need for further planning to improve the QoC for patients with TSC/SCIs.
The Prevalence of Asymptomatic Cervical Spinal Cord Compression in Individuals Presenting With Symptomatic Lumbar Spinal Stenosis: A Meta-Analysis
Authors: Farahbakhsh Farzin , Khosravi Sepehr , Baigi Vali , Pourghahramani Koltapeh Masoud , Khayyamfar Amirmahdi , Eskandari Zahra , Ghodsi Zahra , Harrop James , Rahimi-Movaghar Vafa 
Published: September 2023

Study Design Systematic review and meta-analysis. Objective The aim of this study was to determine the prevalence of asymptomatic cervical spinal cord compression (CSCC) in individuals with lumbar spinal stenosis (LSS). Methods A systematic electronic search was conducted in Medline, EMBASE, Scopus, and Web of Science without language restriction, with no starting date limit to June 8, 2023, to define the prevalence of asymptomatic CSCC in symptomatic LSS patients. Asymptomatic CSCC was defined based on radiographic studies. All types of studies were included in the review. Meta-analysis was performed on the reported prevalence of asymptomatic CSCC in LSS. Results The database search yielded 10,272 articles. After a full-text review, five studies were included in the final review, comprising a total of 1043 cases. Two studies had a low risk for bias, two moderate, and one estimated to be high risk. The range of prevalence of asymptomatic CSCC in LSS in the five included studies was between 24% and 61%. Meta-analysis on the reported prevalence of asymptomatic CSCC patients with symptomatic LSS demonstrated that the random pooled prevalence was 35% (95% CI: 23 to 48). Conclusions Asymptomatic CSCC appears to occur in a high number of patients, with this study noting its presence in one-third of patients with LSS. Based on these findings, we strongly recommend that spine surgeons exercise particular caution during the positioning of patients who are undergoing surgery for lumbar stenosis. Furthermore, it is imperative to monitor individuals with symptomatic LSS closely for any potential signs of emerging myelopathy.
Clinical characteristics of chylothorax: results from the International Collaborative Effusion database
Authors: Porcel José M. , Bielsa Silvia , Civit Carmen , Aujayeb Avinash , Janssen Julius , Bodtger Uffe , Fjaellegaard Katrine , Petersen Jesper Koefod , Welch Hugh , Symonds Jenny , Mitchell Michael A. , Grabczak Elżbieta Magdalena , Ellayeh Mohamed , Addala Dinesh , Wrightson John M. , Rahman Najib M. , Munavvar Mohammed , Koegelenberg Coenraad F.N. , Labarca Gonzalo , Mei Federico , Maskell Nick , Bhatnagar Rahul 
Published: September 2023

BackgroundChylothorax is an uncommon medical condition for which limited data are available regarding the contemporary aetiology, management and outcomes. The goal of this study was to better define these poorly characterised features.MethodsThe medical records of adult patients diagnosed with chylothorax at 12 centres across Europe, America and South Africa from 2009–2021 were retrospectively reviewed. Descriptive and inferential statistics were performed.Results77 patients (median age 69 years, male to female ratio 1.5) were included. Subacute dyspnoea was the most typical presenting symptom (66%). The commonest cause of chylothorax was malignancy (68.8%), with lymphoma accounting for 62% of these cases. Other aetiologies were trauma (13%), inflammatory/miscellaneous conditions (11.7%) and idiopathic cases (6.5%). At the initial thoracentesis, the pleural fluid appeared milky in 73%, was exudative in 89% and exhibited triglyceride concentrations >100 mg·dL−1in 88%. Lymphangiography/lymphoscintigraphy were rarely ordered (3%), and demonstration of chylomicrons in pleural fluid was never ascertained. 67% of patients required interventional pleural procedures. Dietary measures were infrequently followed (36%). No patient underwent thoracic duct ligation or embolisation. Morbidity included infections (18%), and thrombosis in malignant aetiologies (16%). The 1-year mortality was 47%. Pleural fluid protein >3.5 mg·dL−1(sub-distribution hazard ratio (SHR) 4.346) or lactate dehydrogenase <500 U·L−1(SHR 10.21) increased the likelihood of effusion resolution. Pleural fluid protein ≤3.5 mg·dL−1(HR 4.047), bilateral effusions (HR 2.749) and a history of respiratory disease (HR 2.428) negatively influenced survival.ConclusionChylothoraces have a poor prognosis and most require pleural interventions. Despite the standard recommendations, lymphatic imaging is seldom used, nor are dietary restrictions followed.