bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro-fine Cellular Technology for the Appliance Industry
Authors: Rosbotham Dave , De Vos Rik , Deschaght Joris
Published: September 2023

When expanded with CFCs, rigid polyurethane foams display exceptional thermal insulation properties. The imminent phase-out of CFCs due to their environmental impact, however, has produced intensive research programmes throughout the polyurethanes industry. These aim to develop technologies, based on environmentally acceptable blowing agents, which produce foams with equivalent insulation performance to CFC 11 systems.

HCFC 22 has been considered as a possible alternative to CFC 11 because of its lower environmental impact. The gas's low boiling point of -40°C, however, results in processing problems which lead to distorted foam morphology, bad initial thermal conductivity X. values and rapid X value ageing.

The wide availability of HCFC 22, however, coupled with its low toxicity, non-flammability and high affinity to both polyol and isocyanate make it a strong candidate for replacing CFC 11, if the above problems can be overcome.

This paper reports developments with a novel technology based on HCFC 22. The technology results not only in improved X. value performance in rigid polyurethane foams, but also allows high HCFC 22 loadings whilst retaining a fine celled structure.

These higher loadings result in further improvements in thermal conductivity, better than production values actually obtained when using reduced CFC 11 systems. Different aspects of this novel technology, including lambda value performance, energy consumption data and relevant physical properties are discussed.
Recent Advances in AH-MDI-Based CFC-Free Flexible Foams
Authors: Murray Dennis , Sparrow David J. , Tab Aun
Published: September 2023

Since the introduction of CFC-free flexible foams in 1989, ICI Polyurethanes put significant effort into reducing density, so increasing competitiveness of all-MDI-based foams. This new generation of polyurethane systems not only makes it possible to produce low density flexible foams in large and increasingly complex moulds, but also demonstrates improved physical properties, exceeding the stringent requirements of the industry.

CFC -free combustion modified high resilience (CMHR) foams have now also been developed for the furniture industry capable of meeting even the most stringent large scale ignition tests.

As comfort properties of mouldings used for seating applications have always been of paramount importance, one area of concentrated effort has been in the development of vibration damping foams. While these foams were developed to meet low resilience requirements, they still maintain all the benefits of traditional MDI cold-cure systems - superior humid ageing and compression set properties, H-point retention and a wide hardness range.

The fast inherent reactivity of all-MDI-based cream foams not only allows for more rapid cure and thus shorter cycle times, but has also made it possible to develop systems containing low levels of catalysts - leading to excellent fogging performance in automotive applications. In addition, the new systems, which are suitable for both conventional and foam-in-fabric applications, have been designed with recycling in mind.
New Developments in Low Density Structural RIM
Authors: Schroeder J.M. , Mackey P.W.
Published: September 2023

Over the last two to three years, the automotive industry has recognised the benefits of low density structural reaction injection moulding (LDSRIM) materials in automotive interior applications. Low part weights, consolidation of parts, and improved design freedom associated with this technology help reduce material and labour costs, improve productivity and help engineers meet specific objectives such as CAFE standards.

ICI Polyurethanes has actively participated in the development of LDSRIM technology and has developed a series of resins designed for automotive interior application. These CFC-free polyurethane foams are processable on conventional RIM equipment. The resin systems are differentiated for open pour and closed mould processing techniques.

Unique processing features allow glass reinforced substrates to be moulded directly behind various vinyl composites, carpeting and fabrics, to produce parts with an aesthetically pleasing look and feel. Excellent adhesion to these substrates eliminates the need for secondary adhesive bonding operations, thereby improving productivity and lowering assembly costs. Composite door panels containing 20% by weight glass mat reinforcement weigh approximately half as much as competitive materials, such as ABS and polypropylene, with comparable physical properties. Typical door panel composite materials have flexural modulus 2370 MPa at 0.55 specific gravity. Unreinforced sections of the part, such as ribs and attachment points, are filled with a durable rigid foam material. Attachment inserts can be moulded in place to eliminate the need for post-mould assembly. Manufacturing mould residence times of 45 seconds are achievable in door panels.
Open Cell Isocyanurate Foams: A Novel Route to High Performance Thermal Insulation Panels
Authors: Ashida K. , Kashiwame J.
Published: September 2023

This paper discusses a novel type of rigid foam, open cell isocyanurate foam, and its use as a core material for vacuum insulation panels.

Due to the forthcoming phase-out of CFCs, alternative blowing agents are being studied worldwide.

It has been well recognised that the total thermal conductivity of closed cell foams consists of the factors as shown below:

λf = λg + λs + λc + λr

where

λf = total

λg = gas

λs = solid

λc = convection

λr = radiation

When open cell foams are used as core materials for insulation panels kept under vacuum, the total thermal conductivity of the panel consists of only two factors shown below:

λf = λs + λr

Therefore, the thermal conductivity of the panels could be far less than that of CFC-blown foams.

This paper describes the preparation, processing, properties and applications of open cell rigid isocyanurate foams.

The open cellfoams were blown by using a blend of methylene chloride and n-pentane at specific ratios between 95/5 and 50/50 by weight.

The resulting foams had open cell contents of about 50-95%, depending upon the reaction conditions employed at densities of 30-50 kg/m3. When pour-in-place foams were further exposed to vacuum after foaming, the resulting foams had an increased open cell content.

This open cell foam technology suggests a variety of potential applications, not only for household refrigerators and deep freezers, but also for cryogenic liquidtank insulation, e.g. liquid hydrogen, liquid oxygen, liquid nitrogen, and liquefied natural gas.
Strongly Cosserat Elastic Lattice and Foam Materials for Enhanced Toughness
Authors: Lakes Roderic
Published: September 2023

Some foams exhibit size effects and other phenomena not describable by classical elasticity. These foams are describable by Cosserat elasticity, which is a continuum theory with more freedom than classical elasticity. Cosserat solids have a characteristic length which is greater than zero. Strongly Cosserat elastic materials are considered to be those materials for which the Cosserat characteristic length is substantially greater than the structure size and for which the coupling number is large. Such materials are predicted to exhibit superior toughness. A mechanically isotropic lattice model is presented for the study of foams. Ordinary open cell foams are shown to be weakly Cosserat elastic. If cell rib properties are modified, strongly Cosserat elastic effects can occur in the foam. Anisotropic laminate and fibrous materials can also be made to exhibit strongly Cosserat elastic effects.
Microcellular Polymers: Novel Materials for the 21st Century
Authors: Kumar Vipin
Published: September 2023

Microcellular polymer's produced by gas nucleation, refer to closed cell thermoplastic foams with a very large number of very small cells—typically 108 or more cells per cm3 of order 10μm in diameter. First produced in the early 1980's with the objective of reducing the amount of polymer used in mass produced items, these novel materials have the potential to revolutionize the way thermoplastic polymers are used today. Microcellular plastics have been produced from a number of polymers ranging in relative density from 0.1 to 1.0, containing 108 to 1011 cells per cm3, offering the engineer a new range of properties for design. The microcellular polymers appear to possess improved fatigue life and energy absorption characteristics as well as a higher specific strength. This paper reviews recent progress in this emerging technology and discusses the areas where this technology is likely to make an impact in the future.
Generation of Microcellular Polymers using Supercritical CO2
Authors: Goel S.K. , Beckman E.J.
Published: September 2023

Supercritical carbon dioxide is known to be a very good swelling agent and plasticiser for poly(methyl methacrylate), a consequence of an interesting combination of liquid-like and gas-like properties exhibited by supercritical fluids. Making use of this behaviour, we have studied a constant temperature process of generating microcellular polymers which employs a sudden pressure drop to induce phase separation in a solution of supercritical CO2 and poly-(methyl methacrylate). The method is different from commonly used temperature quench methods in that it makes use of the glass transition depression due to the presence of diluent in the polymer rather than heating the polymer to above its normal glass transition temperature. Typically, the process leads to a microcellular core structure encased by non-porous skin. Average cell sizes (0.5 to 15 (μm) and bulk densities (0.4 to 0.9 gm/cm3 compared with 1.2 gm/cm3of the starting material) can be varied by changing the process conditions such as saturation pressure, temperature, crosslinking, and time of saturation. Classical nucleation theory well describes the trends in observed cell density which increases very sharply with increasing pressure above 13.79 MPa (2000 psi), levelling out at approximately 27.59 MPa (4000 psi) (at 40°C). There is a corresponding decrease in the average cell size with increasing saturation pressure. The effect of temperature is rather small and gradual.
Structural Characterisation of Extruded Polyolefin Foams Made Using a Chemical Expansion System
Authors: Shishesaz M.R. , Hornsby P.R.
Published: September 2023

Consideration will be given to the structural characterisation of extruded foam profile made from polypropylene and polypropylene/polyethylene blends containing chemical blowing agents.

Emphasis will be given to the influence of blowing agent concentration on the melt rheology of foamable compositions combined with the effects of die geometry and processing conditions on the resulting density in the foamed state, before and after cooling of the melt. Cellular structure will be discussed in terms of the relative levels of open and closed cell content, the uniformity of cell distribution, determined by mercury penetration, porosimetry and microscopic techniques, and microstructural characterisation of the semi-crystalline polymeric phase.
The Thermal Decomposition of Azodicarbonamide (ADC)
Authors: Jaafar H.A.S. , Sims G.L.A.
Published: September 2023

Thermal decomposition of ADC depends on processing conditions and activators or “kickers” used empirically to adjust gas yield, rate of yield, and decomposition temperature. These parameters also have a profound effect on the foaming process and foam properties. This work attempts to establish some fundamental variables by studying the effect of time, temperature and formulation on the thermal decomposition of ADC (in the absence of polymer matrix). Gas evolution rate apparatus was used to study thermal decomposition of ADC as a function of particle size and to determine the effects of introducing varying proportions of ZnO, zinc stearate and stearic acid as activators. DSC measurements were also used to study decomposition temperatures. The effect of particle aggregation on total gas yield was also investigated.

It was shown that lowest decomposition temperatures of ADC alone, are achieved at lower heating rates (182°C at 0.25°C/min), whereas higher heating rates result in a significant increase of the decomposition temperature (260°C at 100°C/min). In addition, studies of total gas yield showed that the volume of gas liberated increased with increasing heating rate (from 250 cc/g at 2.5°C/ min to 350 cc/g at 11°C/min). The decomposition temperature, rate of gas yield and total gas yield are further complicated by particle size distribution, amount and type of additives used, degree of dispersion of the additives and the blowing agent, and together with processing conditions, produce a unique set of conditions controlling the decomposition behaviour.
Castor Oil - Glycerol Blends as Polyols for Rigid Polyurethane Foams
Authors: Baser S.A. , Khakhar D.V.
Published: September 2023

Castor oil is a relatively inexpensive and renewable source of hydroxyl groups. This makes use of castor oil in polyols for polyurethane very attractive. We have prepared a simple castor oil based polyol for rigid polyurethane foam application. The polyol is a physical blend of castor oil and glycerol. Glycerol acts as a cross-linker which gives the foam sufficient rigidity and reduces shrinkage. The foam samples are characterized by measuring density, % linear shrinkage, % closed cell content and compressive strength. Reaction injection moulding machine trials for the polyol are carried out. The amount of castor oil in the polyol which gives foams with properties comparable to commercial polyurethane foams, is about 76 % by weight of the base polyol, which is higher than the earlier reported values.
Friction and the Dynamic Mechanical and Thermal Properties of Polyurethane Elastomers. 1. Solid Polyurethanes
Authors: Hanhi K. , Stenberg B.
Published: September 2023

The results reported indicate that the properties of polyurethanes elastomers can be tailored to serve a wide variety of applications, for low temperature uses as well.

The glass transition temperatures of the soft segments (Tgs) which control the low temperature properties of polyurethane elastomers, ranged from -79°C to -27°C (DSC onset values).

The transitions observed in the range 75 to 125°C were attributed to hard segment glass transitions. The transitions at temperatures from 140 to 170°C, which were identified especially in the samples of over stoichiometric diisocyanate concentration, evidently arose from the dissociation of allophanate crosslinks and successive ordering processes.

The low temperature β” and γ transitions were observed at temperatures from -70°C to -125°C. In addition to the obvious Schatzki crankshaft mechanism, allophanate crosslinking may influence these transitions.

Samples that were annealed over the crystal melting temperature and subsequently quenched exhibited higher glass transition temperatures than the samples kept for a long time at room temperature. These results can be explained in terms of better phase separation in annealing and formation of small soft segment crystallites in quenching, in contrast to the formation of large crystalline and amorphous phases in the RT samples.
Experimental Study of Size Effects and Surface Damage in Closed-Cell Polymethacrylimide and Open-Cell Copper Foams
Authors: Anderson W.B. , Chen C.P. , Lakes R.S.
Published: September 2023

This article describes experimental investigations of size effects in torsion and bending of lathe cut closed-cell polymethacrylimide and open cell copper foams. Slender specimens were found to have a slightly smaller effective stiffness than thick ones. This behaviour is consistent with a model of surface damage to the outermost cells of the foam. The surface damage layer was inferred to be from 0.13 to 0.37 cell diameters for the polymethacrylimide, depending on the grade of foam, and from 0.3 to 0.4 cells in the copper foam. Effects of Cosserat (micropolar) elasticity, which would give rise to an effective stiffening of slender specimens, were not observed.
The Behaviour of Commercially Important Diisocyanates in Fire Conditions Part 2: Polymeric Diphenyl Methane-4,4’-diisocyanate(PMDI)
Authors: Marlair G. , Prager F.H. , Sand H.
Published: September 2023

The behaviour of polymeric diphenyl methane-4,4’-diisocyanate (PMDI) is described when examined in a laboratory small-scale test for its reaction to fire (ease of ignition; heat release and toxic gas production). Full-scale real fire scenarios have also been staged to predict events if (1) drumstock PMDI and (2) sizeable pools of liquid PMDI become enveloped in a fire. PMDI requires a stimulus (e.g. heat) before it will ignite from an applied flame. It then burns in a self-sustaining manner for a few minutes, during which main emissions take place. Then a polymerization reaction begins, producing a low density non-burning residue, which progressively dampens down the burning events by blanket action. Residues of 30–80% sample weight were recorded. The major toxic gas produced is carbon monoxide, though free isocyanate is to be expected in the early stages of the fire, and hydrogen cyanide could be important, especially in well-developed fire conditions. Firefighters should therefore wear full protective clothing and fresh-air breathing equipment. Events when drums of PMDI are exposed to fire depend heavily on the characteristics of the containers, with some rupture steps proceeding with considerable violence. Drumstock PMDI should be stored separately from easily ignitable materials.
Polyurethanes Recycling and Waste Management
Authors: Hicks D.A. , Krommenhoek M. , Soderberg D.J. , Hopper J.F.G.
Published: September 2023

Almost everybody in the urethanes industry is by now familiar with the different options for the recycling of urethane-based materials. Physical recycling (fillers in the polyol), chemical recycling (glycolysis, hydrolysis) and energy recovery are the main options under development. The actual process, however, is only a part of the equation. Disassembly, logistics, applications for recycled materials and market size are other vital elements for success.

In this paper, progress is presented on the different recycling options, in conjunction with a cost model which has been developed especially for the purpose.
Mechanical Behaviour of a New Stress Dissipating Composite Sandwich Structure
Authors: Richardson M.O.W. , Robinson A.M. , Eichler K. , Branco C. Moura
Published: September 2023

In this paper the mechanical properties of a new composite sandwich structure are presented. Two composite plates are connected by a polymer foam. This connection is reinforced with composite tubes (ties) of braided glass fibre (Figure 1). With this system the shear deformation of the sandwich panel is substantially reduced. The panels were tested at room temperature in bending, torsion and shear with a constant loading rate first in the elastic range and also in the plastic range with the object of obtaining information on the resilience and energy absorbing capability of the panels.
Latest Manufacturing Solutions for Slabstock Foams
Authors: Fiorentini Carlo , Taverna Max , Griffiths Tony
Published: September 2023

As environmental pressure increases worldwide, it is becoming necessary for foamers to eliminate chlorinated products - such as chloro fluoro carbons (CFCs), methylene chloride, 1.1.1 trichloroethane - or any type of volatile organic compounds (VOC's) from their production. In some countries these additives have already been banned: the impact on the flexible foam industries would be to increase foam prices and to eliminate certain soft grades.

The use of liquid carbon dioxide (CO2) as an expanding agent in a polyurethane foam is a good and well accepted idea. Handling this liquid, which gasses off at room temperature, has always been one of the main problems. Its use - although the subject of various patents - has been scarcely put into current practice, mostly because of inherent problems linked with the formation of typical “chimneys” in the foam, i.e. long, narrow cavities oriented in the rise sense, generated by the uncontrolled expansion of carbon dioxide.

Possible solutions to this problem can be found by investigating several aspects of the process: chemicals selection, CO2 dispersion into the formulation, gas nucleation, metering equipment, mixing chamber's geometry, foam's lay-down, rise profile, but until now no suitable method was available and this interesting opportunity was left aside.

Cannon started investigating this matter after having spent several years in the development of a suitable pre-mixing device for LBBA's (Low Boiling Point Blowing Agents). The original program started in 1989 when liquid carbon dioxide was tried for the expansion of low-density rigid foams for insulation applications (refrigerators, panels etc). Heavy frothing effect was noticed when loading high amounts of CO2 in conventional polyols. Cell structure was acceptable, but frequent “chimneys” were still present. On top of that, the lambda value of a CO2-blown foam was still not attractive for most of the applications.

The project was temporarily put on hold, giving priority to other more promising alternative blowing agents (HCFC 22, 142b, HFC 134a, etc) because of their higher insulation capacity and better solubility in conventional polyols.

Now (after having successfully solved the problem of metering and mixing gaseous blowing agents with the EasyFroth™ unit and cyclopentane with the Multi EasyFroth™ version) Cannon have developed and patented a proprietary method for the addition of liquid CO2 to flexible foam formulations for slabstock. This revolutionary new process - for which a patent is pending - is named CarDio™ from carbon dioxide: it enables foamers to continue producing their existing foam grades at a lower chemical cost, due to the significant price differential between CFC's, ABA's and CO2. Its peculiar foaming method can also - if one likes - dramatically reduce the size of the foaming plants, thereby deriving the advantages of reduced floor space and plant volume.
The Use of Pentanes as Blowing Agent in Rigid Polyurethane Foam for Lamination
Authors: Fleurent Hilde
Published: September 2023

Pentanes tend to be considered as long-term alternative blowing agents for rigid polyurethane foams. They are environmentally friendly, non-toxic and economically feasible. A major drawback of the use of pentanes is their flammability and their relatively high thermal conductivity, compared to CFC-11. As pentane processing techniques have improved considerably, safety can now be insured at a reasonable price. In this paper the overall performance of pentane blown laminates in terms of processing, insulation value, mechanical properties and flammability is demonstrated. The ageing characteristics are compared to those of CFC-11 blown foams. The low vapour pressure of both n-pentane and cyclopentane is shown to induce condensation effects. The consequences of condensation in terms of thermal conductivity and dimensional stability are discussed. The problem of pentane solubility in the polymer matrix and its influence on the long-term foam performance is addressed. Possible solutions are presented.
Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass?
Authors: Rijpkema Marije , Vlot Eline A , Stehouwer Marco C , Bruins Peter
Published: September 2023

Background

Heparin rebound is a common observed phenomenon after cardiac surgery with CPB and is associated with increased postoperative blood loss. However, the administration of extra protamine may lead to increased blood loss as well. Therefore, we want to investigate the relation between heparin rebound and postoperative blood loss and the necessity to provide extra protamine to reverse heparin rebound.

Methods

We searched PubMed, Cochrane, EMBASE, Google Scholar and Web of Science to review the question: “Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass.” Combination of search words were framed within four major categories: heparin rebound, blood loss, cardiac surgery and cardiopulmonary bypass. All studies that met our question were included. Quality assessment was performed using the Cochrane risk of bias (RoB2) tool for randomized controlled trials and the risk of bias in non-randomized studies of intervention (ROBINS-I) for non-randomised trials.

Results

4 randomized and 17 non-randomized studies were included. The mean incidence of heparin rebound was 40%. The postoperative heparin levels, due to heparin rebound, were often below or equal to 0.2 IU/mL. We could not demonstrate an association between heparin rebound and postoperative blood loss or transfusion requirements. However the quality of evidence was poor due to a broad variety of definitions of heparin rebound, measured by various coagulation tests and studies with small sample sizes.

Conclusion

The influence of heparin rebound on postoperative bleeding seems to be negligible, but might get significant in conjunction with incomplete heparin reversal or other coagulopathies. For that reason, it might be useful to get a picture of the entire coagulation spectrum after cardiac surgery, as can be done by the use of a viscoelastic test in conjunction with an aggregometry test.
Group-based cardiac telerehabilitation interventions and health outcomes in coronary patients: A scoping review
Authors: Jacobsson Renuka J , Oikarinen Anne , Krogell Jenni , Kankkunen Päivi
Published: September 2023

Objective

To explore the extent and type of evidence in relation to group-based cardiac telerehabilitation interventions and health outcomes in coronary artery disease patients.

Data sources

A literature search was conducted in August 2022 and July 2023 in databases including PubMed, CINAHL, Scopus and PsycINFO. The search process followed the scoping review methodology guided by the Joanna Briggs Institute for scoping reviews.

Methods

The inclusion criteria were a peer-reviewed journal article published in English between 1 January 2017 and 15 August 2022 and updated to cover until 15 July 2023 concerning group-based cardiac telerehabilitation in adult coronary artery disease patients. All group-based cardiac telerehabilitation interventions and health outcome types were charted and summarized.

Results

The researcher screened a total of 2089 articles, of which 22 were retained with a total of 1596 participants. Group-based cardiac telerehabilitation interventions were particularly useful for patients with multi-faceted technological applications and social support. The patients received guidance regarding cardiovascular disease risk factors. Physical fitness, psychological complaints and quality of life were often measured outcomes in the included studies.

Conclusions

This scoping review indicates the success of various rehabilitation interventions utilizing different technologies for coronary patients. Coronary patients were guided in making lifestyle changes, and positive findings were observed in the health outcomes measured after the telerehabilitation intervention. The findings of this review can provide valuable guidance for developing and evaluating sustainable group-based cardiac telerehabilitation programs that aim to benefit coronary patients.
Evaluation of the Earth Pressure Acting on Concrete Box Culverts
Authors: Sanderson Tristan , Phares Brent M. , Freeseman Katelyn S. , Liu Zhengyu
Published: September 2023

Earth pressure on concrete box culverts is a key component of design and load-rating decisions. The American Association of State Highway and Transportation Officials has revised the design guidelines over the years to impose greater design/rating earth pressures for buried structures. Currently, the Iowa Department of Transportation uses the maximum and minimum lateral earth pressure of 36/18 lb/ft3 specified for load factor design (LFD) and allowable stress design (ASD) and 60/30 lb/ft3 for load and resistance factor design (LRFD). The objective of this research is to monitor and evaluate the real earth pressures acting on deep-buried culvert structures. To achieve this objective, two concrete box culverts–one in Ida County and the other in Crawford County–were monitored for more than 2.5 years and 1 year, respectively, to identify the realistic design soil pressure. The captured pressure, strain, and temperature data were analyzed to find the relation between the temperature and earth pressure experienced by the culverts. The measured vertical and lateral pressures were compared with the specified design pressure loading. The monitoring results from both culverts led to the consistent conclusion that the earth pressure experienced by the culverts was two to six times that of the design values with the LRFD and LFD/ASD methods. This paper revealed that the earth pressure acting on the deeply embedded culvert could be higher than the design-specified value. Further research was recommended to investigate the relation between the soil weight and culvert vertical/lateral pressure for Iowa design specifications.
Down-regulation of interleukin-2 predicts poor prognosis and associated with immune escape in lung adenocarcinoma
Authors: Hou Yongwang , Xiang Baoli , Yang Zhicong , Liu Jiangmin , Xu Dandan , Geng Lina , Zhan Minghua , Xu Yuhuan , Zhang Bin
Published: September 2023

Background and Objective: Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer and has a poor prognosis. Interleukin-2 (IL2) is a cytokine that stimulates lymphocyte proliferation. However, its role in LUAD remains unclear. Methods: The UALCAN, human protein atlas (HPA), and tumor immune estimation resource (TIMER) databases were used to investigate IL2 expression in samples from patients with LUAD. The HPA, PrognoScan, and Kaplan–Meier plotter databases were used to examine the prognostic value of IL2 in LUAD. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to analyze IL2-interacting genes identified through the GeneMANIA database. TIMER was used to analyze the correlation of IL2 expression with immune cell infiltration and immune checkpoint expression levels in LUAD. Results: Bioinformatic analysis using the TIMER, The University of Alabama at Birmingham Cancer data analysis Portal (UALCAN), and HPA public databases showed that IL2 expression was lower in patients with LUAD than in the normal control group. Moreover, patients with low IL2 expression exhibited poor overall survival. Furthermore, IL2 expression was significantly positively correlated with various immune cells, including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells, in patients with LUAD. Additionally, IL2 expression was markedly positively associated with the above-mentioned immune cells. Furthermore, IL2 expression was positively correlated with PD-1, PD-L1, and CTLA-4 expression. Conclusion: Our results indicate that down-regulation of IL2 predicts poor prognosis and is associated with immune escape in LUAD, and IL2 could serve as a potential novel prognostic biomarker of LUAD.
Determinants of Technological Interventions for Children With Autism - A Systematic Review
Authors: Hasan Nazmul , Nene Manisha J.
Published: September 2023

Children with Autism face several significant challenges, including deficits in both verbal and nonverbal communication, difficulties with concentration, limited interest in their surroundings, non-responsiveness, and struggles with adapting to new situations. It is imperative to consider and address these challenges when implementing technological interventions aimed at enhancing the skills of children with Autism. This study aims to identify the research emphasis on the following four determinants of technological interventions for children with Autism - (i) involvement of caregivers, (ii) design considerations, (iii) persuasive technology, (iv) psychological and physiological effects of technologies. These determinants address their deficiencies in communication, coping with new situations, responsiveness and effects of using technologies respectively. A total of seventy six review articles from 2010 to 2022 have been selected through PRISMA guidelines for this study. Most of the selected review articles have not evaluated these four determinants in their studies. This study discusses this research scope and presents future research directions to bridge this gap to develop effective technological solutions to upskill the children with Autism.
COVID-19 and the “Golden Era”: Turning the page on rural, weekly newspaper production
Authors: Smith Christina C. , Miller Kyle J.
Published: September 2023

The rural weekly newspaper industry rooted in traditional geographically bounded U.S. communities was long thought to have been shielded from industry dilemmas—revenue and circulation—at larger mainstream daily newspapers. However, recent data show a shift in these rural community journalism trends, particularly since the COVID-19 pandemic. Using normative theory and diffusion of innovations, this study examines how rural weekly newspaper publishers perceived, nearly 18 months after the onset of the pandemic, how COVID-19 impacted their newspapers’ advertising, news, technology, and community involvement. Survey results reveal short-term and long-term content and financial challenges plague U.S. rural grassroots information sources with circulation less than 3,000—indicating the end of the “golden era” of weekly newspapers. Despite the constraints, publishers remain optimistic and dedicated to their audiences, albeit reluctant to swift change, as they perceive themselves as the only reliable information source for their rural communities.
On-board radio communication and its development in a historical perspective
Authors: Rey Charlo Raquel Esther
Published: September 2023

This article presents an explanation of the incorporation of on-board radio communication as a consequence of the growing concerns for maritime safety. It focuses on the economic, political and social characteristics that influenced its incorporation and evolution, and a legislative change in safety. The article demonstrates how the evolution of radio communication has been very important as the only emerging means to request and provide assistance on the high seas. In addition, the study provides evidence of the technological leap that has improved radio communication, with a new system with a high degree of reliability: the Global Maritime Distress and Safety System.
Healthcare Providers’ Knowledge of Evidence-Based Treatment for Tobacco Dependence, DocStyles 2020
Authors: Golden Thomas , Courtney-Long Elizabeth , VanFrank Brenna
Published: September 2023

Purpose

Although smoking cessation reduces the risk of all-cause mortality, evidence-based cessation treatments are underused. This study examined healthcare provider knowledge of evidence-based cessation treatments and associations between knowledge and clinical practice characteristics.

Design

Cross-sectional survey.

Setting

2020 DocStyles.

Subjects

1480 U.S. healthcare providers.

Measures

Provider knowledge of availability of tobacco use disorder diagnostic criteria, clinical practice guideline availability, treatment efficacy, evidence-based counseling modalities, and medications approved by the U.S. Food and Drug Administration (FDA).

Analysis

Adjusted odds ratios (aORs), adjusted for personal and clinical practice characteristics.

Results

Less than half of respondents demonstrated high knowledge of availability of diagnostic criteria (36.8%), cessation treatment efficacy (33.2%), evidence-based counseling modalities (5.6%), and FDA-approved medications (40.1%). Significant differences were found between specialties: compared to internists, family physicians were less likely to have low knowledge of medications (aOR = .69, 95% CI = .53, .90) and obstetricians/gynecologists were more likely to have low knowledge of medications (aOR = 2.62, 95% CI = 1.82, 3.76). Overall, few associations between knowledge and clinical practice characteristics were identified.

Conclusion

Most providers had low knowledge of the topics of interest, with little variation across clinical practice characteristics, indicating room for improvement. Efforts to improve provider knowledge of evidence-based treatments are an important component of a comprehensive approach to improving delivery and use of cessation interventions and increasing tobacco cessation.
Decentralized legislative oversight of bureaucratic policy making
Authors: King Janna , Gailmard Sean , Wood Abby
Published: September 2023

Congressional oversight is a potentially potent tool to affect policy making and implementation by executive agencies. However, oversight of any agency is dispersed among several committees across the House and Senate. How does this decentralization affect the strategic incentives for oversight by each committee? And how do the strategic incentives of oversight committees align with the collective interest of Congress as a whole? We develop a formal, spatial model of decentralized oversight to investigate these questions. The model shows that when committees have similar interests in affecting agency policy, committees attempt to free ride on each other, and oversight levels are inefficiently low. But if committees have competing interests in affecting agency policy, they engage in “dueling oversight” with little overall effect, and oversight levels are inefficiently high. Overall, we contend that committee oversight incentives do not generally align with the collective interests of Congress, and the problem cannot be easily solved by structural changes within a single chamber.
Investigation and optimization of energy absorption of squared-section thin-walled structure under lateral dynamic loading
Authors: Kazemi M , Aryaie M , Nouri D
Published: September 2023

In many engineering structures, especially transportation systems, energy-absorbing structures are used to prevent or reduce collision damage. Thin wall structures are an important category of these systems. The present study investigates the level of energy absorption and crushing behavior of thin-walled aluminum structures with multi-cell square sections under lateral impact loading. The material used to produce the samples is AL-6061. The samples were subjected to lateral impact loading by combining different wall thicknesses to determine the optimal cross-section geometry. For this purpose, numerical simulation was conducted using Abaqus software. Firstly, the simulation method was validated, and after validation, different combinations of multi-cell square sections with varying wall thicknesses were designed using the Design of Experiment (DOE) method. Additionally, due to the assumption of thin walls in the structures, the wall thicknesses of the samples were considered in the range of 1 to 3 mm. The mass and initial velocity of the impactor are 35.7 kg and 6.26 m/s, respectively. The results showed that the wall thickness of the structures and their different combinations can have a significant effect on their energy absorption parameters. These effects are generally nonlinear, with severe effects observed in some cases. Finally, through the analysis of the energy absorption process of the structures and the use of the response surface method (RSM), an optimal sample was designed and simulated. The results indicate an increase of approximately 246% in the specific energy absorption of the optimal sample compared to the sample with the same wall thickness.
Self-Esteem and Income Over Time
Authors: Bleidorn Wiebke , Kretzschmar André , Rauthmann John F. , Orth Ulrich , Denissen Jaap J. A. , Hopwood Christopher J.
Published: September 2023

There is robust evidence that people with higher incomes tend to have higher self-esteem, but little is known about how changes in income and self-esteem are related within individuals. Some theories predict that increased earnings lead to higher self-esteem, others that increased self-esteem leads to higher earnings, and still others that there should be no within-person associations between these variables. We tested these theories in 4-year longitudinal data from more than 4,000 adult participants from a Dutch representative sample. Results indicated significant between-person associations between income and self-esteem, consistent with prior research. Within-person effects suggested that increases in self-esteem are a function of previous increases in income more than the other way around. These links held when analyses controlled for employment status, and they generalized across gender, age, and educational background. Overall, the findings provide evidence for theories that consider self-esteem as both a source and a consequence of personal earnings.
A multi-period analysis of a water management arena in the Italian Alps, circa 1951–2007: The territorialisation of environmental concerns
Authors: Maran Laura , Schneider Thomas , Andreaus Michele
Published: September 2023

Water exploitation is at the centre of current social and environmental sustainability discourses, one form of which is hydropower. Intense damming of rivers and natural basins occurred in nineteenth and twentieth century Europe (and elsewhere). Following Miller and Power's concept of territorialisation and Foucault's notion of visibility, this study sheds light on the water management arena, read through changes in stakeholder objectives and accountabilities. Its focus is on the ‘accounts’ of environmental concerns, from post WWII to the new millennium. The analysis focuses on the case of the Santa Giustina dam in Northern Italy, using archival and oral-history approaches. It is shown how an increasing visibility of environmental concerns translated into a higher degree of ‘territorialisation’ through their itemisation in water quality and quantity parameters. This historical evolution informs policy makers, managers and society in general, about how to address profits and environmental issues regarding current water exploitation.
Hybridity and Multiscale Compatibility in Landscape Infrastructure for Mountain River Restoration: A Pathway Toward Environmental and Socio-Ecological Sustainability
Authors: Li Rong , Shi Qijie , Sun Wenxin , Zhai Jun
Published: September 2023

River rehabilitation has traditionally focused on hard-engineering projects, which often fail to address environmental protection concerns and social-ecological services in a larger territorial context. In particular, mountain rivers pose unique challenges due to their diverse hydrological and morphological conditions, which are often overlooked by traditional restoration methods. Consequently, water quality deteriorates and social-ecological imbalances arise. To address these challenges, we propose a holistic solution that integrates landscape infrastructure (LI), a soft-engineered biophysical structure and process. Our approach combines hydrological analysis, ecological sensitivity assessment, and ecological design solutions to develop an LI framework for the Xiaojiahe basin in the Chongqing Mountain range in southwest China. This framework emphasizes integration across the spatial scale of landscape networks and corridors. Our study reveals the existence of fragmented river systems and limited connectivity among green spaces in the research area. The adoption of a comprehensive Landscape Infrastructure (LI) framework facilitates the execution of culturally sensitive and practical design solutions for Mountain Urban River Restoration (MURR) at different levels. This approach reinstates the multifaceted environmental and socio-ecological benefits of the basin. We believe that our approach can be applied to other cases with similar contexts and challenges.
White Fortressing: How Racial Threat and Conservatism Lead to the Formation of Local Governments
Authors: Godinez Puig Luisa
Published: September 2023

A large body of research has shown that American politics have been highly influenced by conservative movements born in American White suburbia. Yet, suburbs are also moving left and becoming more diversified. I argue that this context has led to new cityhood movements in unincorporated areas of some regions of the US. By forming cities, unincorporated communities detach themselves from shared county-level authorities and the wider populations served in these jurisdictions. What triggers municipal incorporations today and how are recent incorporation movements different from those of the postwar era? To answer these questions, I conduct fieldwork in Georgia. I find that municipal incorporations are a modern type of segregation triggered by sentiments of racial threat and conservatism, which I call White fortressing. I update the study of government formation by analyzing a new wave of municipal incorporations and contribute to the literature works on White flight, racial threat, and residential segregation.
‘Let Us Hold Hands’: Lived Practices of Intimacy Among Gay Youth in Urban India
Authors: Mukherjee Utsa , Pradhan Anil
Published: September 2023

This article contributes to the growing literature on youth sexualities and intimacy, by centring the lived experiences of self-identified gay youth in the eastern Indian city of Kolkata. It draws on interview narratives of thirteen gay youth between the ages of 19 and 26, living in Kolkata, to unpack two inter-locking ways in which these sexual minority youth co-construct intimacy within the urban space: (a) intimacy as verbal and non-verbal disclosure and (b) embodied intimacy. The findings underline how studying gay youth’s practices of intimacy offer a unique window into sexual politics and urban life in twenty-first-century India.
Early, Forme Fruste keratoconus and normal thin cornea, evaluation of sensitive parameters by combined Placido Scheimpflug topography
Authors: Gharieb Hesham Mohamed , Abdelatif Mona Kamal , Gharieb Hani Mohamed , Othman Ihab Saad
Published: September 2023

Purpose

To determine the sensitive indices distinguishing forme-fruste keratoconus (FFKC) and early keratoconus (early KC) from thin normal corneas, and their cutoff values using Sirius topography.

Methods

156 eyes with normal thin corneas < 500 um (group 1), 99 eyes with early KC (group 2) and 41 eyes with FFKC (group 3), were assessed retrospectively for: corneal keratometric indices, pachymetry indices, corneal aberrations, elevation indices; thinnest corneal point elevation, Q value, root mean square (RMS) withRMS/ area (RMS/A); and KC summary indices of front and back surfaces; surface asymmetry index (SIf, SIb), elevation at KC vertex (KVf, KVb), Baiocchi-Calossi-Versaci index (BCVf, BCVb) and summation of its vector (BCV). Cutoff values were calculated.

Results

Keratometry indices were significantly different between early KC and thin normal cases (apex front curvature had the highest area-under-the-ROC-curve (AUROC) (0.926) in early KC, while only apex curvature and coordinates were significant in FFKC cases. Pachymetry indices did not show any significance in differentiating either early KC or FFKC from normal thin corneas. KC summary indices were highly significant among the 3 groups. The highest AUROC was observed with KVb in early KC (0.987) and with KVf in FFKC (0.831). Vertical coma and vertical trefoil showed the highest significance of all aberration parameters differentiating the 3 groups. Thinnest point elevation, RMS and RMS/A showed the highest AUROC in differentiating early KC and FFKC cases from thin normal corneas.

Conclusion

Comparing early KC and FFKC to thin normal corneas, Sirius provided high precision in prediction.