Polymers are known as thermally insulated materials with reported effective thermal conductivity (Keff) in the range of 0.1 to 0.5 Wm−1 K−1. However, increasing demand for smaller and more powerful ...electronics has created the need for thermally conductive polymers for use in heat exchangers and electronic packaging applications. Given this background, much research has been done over the past two decades to increase the Keff of polymers. Based on the strategy involved, those works can be divided into two main categories: (i) increasing the Keff of the neat polymer by aligning its chains orientation; and (ii) increasing polymer Keff by fabrication of polymeric composites with thermally conductive filler networks. Among these two strategies, the former is limited to nanoscale laboratory research and is difficult to scale up for mass production. Therefore, this work is mainly focused on the latter category, thermally conductive polymeric composites, which has a higher potential for large‐scale production. This work aims to summarize, evaluate, and highlight the successful strategies of the recent efforts in enhancing the thermal conductivity of polymer composites. The major achievements, future challenges, and the outlooks of high thermally conductive polymeric composites are presented by analyzing the results of about 300 works.
Polyethylene wear has been a concern for the longevity of total knee replacements (TKR). A characteristic wear feature often observed on the articular surfaces of retrieved polyethylene tibial ...inserts is a striated pattern of hills and troughs. This pattern is of interest because its surface area has been found to correlate with increased tibial insert wear. We therefore addressed the following two research questions: (1) What is the prevalence of the striated pattern on a contemporary tibial insert design made from conventional ultra-high-molecular-weight polyethylene (UHMWPE)? (2) Are the peaks and troughs of the striated pattern connected with differences in crystallinity developed during the wear process? The prevalence and area coverage of the striated patterns were determined on a set of 81 retrieved tibial inserts of a cruciate-retaining TKR design. The striated areas were mapped using an optical coordinate measuring machine. Differences in crystallinity between troughs and hills were determined on a representative tibial insert using Raman spectroscopy. The striated pattern was observed on 61 out of 81 (75%) of the retrieved tibial inserts, covering an average of 32% of the total articular area. In the representative insert that was evaluated, the hills exhibited higher crystallinity (68%) than the troughs (54%) (p = 0.001). Conversely, the troughs exhibited higher amorphous phase content (22%) than the hills (19%) (p = 0.04). In conclusion, this pattern of hills and troughs is another example of microstructural changes in UHMWPE stemming from tribological stresses.
•The prevalence of the striation pattern was high, reaching 75% in the cohort of 81 inserts that were examined.•The striated area occupied an average of 32% of the total area on inserts, similar between the medial and lateral sides.•The pattern was associated with a microstructural reorganization in the surface layer of the polyethylene.•The hills of the striated pattern exhibit higher crystallinity than the troughs leading to preferential wear in troughs.
With the rapid advancements in technology and growing aerospace applications, there is a need for effective low-weight and thermally insulating materials. Aerogels are known for their ...ultra-lightweight and they are highly porous materials with nanopores in a range of 2 to 50 nm with very low thermal conductivity values. However, due to hygroscopic nature and brittleness, aerogels are not used commercially and in daily life. To enhance the mechanical and hydrophobic properties, reinforcement materials such as styrene, cyanoacrylates, epoxy along with hydroxyl, amines, vinyl groups are added to the surface. The addition of organic materials resulted in lower service temperatures which reduce its potential applications. Polyimides (PI) are commonly used in engine applications due to their suitable stability at high temperatures along with excellent mechanical properties. Previous research on polyimide aerogels reported high flexibility or even foldability. However, those works' strategy was mainly limited to altering the backbone chemistry of polyimide aerogels by changing either the monomer's compositions or the chemical crosslinker. This work aims to summarize, categorize, and highlight the recent techniques for improving and tailoring properties of polyimide aerogels followed by the recent advancements in their applications.
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•Exploration of PI aerogels as new class of super thermally insulation materials•A detailed discussion on PI aerogel processing and polymerization steps•Summary of emerging techniques for improving the performance of PI aerogels•Perspectives on the opportunities and applications of PI aerogels
The purpose of this retrieval study was to determine the effect of implant positioning on wear, taking patient‐related factors into account. Therefore, the volumetric material loss of 59 retrieved ...tibial liners was quantitatively determined using a coordinate measuring‐machine. All retrievals were made of the same polyethylene and design by a single manufacturer. Using time in‐situ and linear regression, a wear rate for each liner was determined and corrected for bedding‐in. Backside damage was qualitatively scored. The following implant positioning parameters were obtained from radiographs: anatomical lateral‐distal femoral angle, anatomical medial‐proximal tibial angle, femoral tilt angle, and posterior tibial slope. The patella position was assessed by the Blackburne‐Peel index and the Insall‐Salvati ratio. Unlike the Insall‐Salvati ratio, the Blackburne‐Peel index is known to detect surgical joint line elevation. Using general linear modeling the most impactful factors on wear rate and backside damage was determined, thereby taking patient demographic factors into account. The mean volumetric wear rate was 11.6 mm3/y. Wear decreased with older age (P = .021) and female sex (P = .001). The wear rate increased with joint line elevation as indicated from a decreased Blackburne‐Peel index (P = .019), and increased with increased posterior tibial slope (P = .026). The backside damage score also increased with joint line elevation (P = .036). A Blackburne‐Peel index decrease of 0.1, signifying joint line elevation, was found to increase the wear rate by 1.8 mm3/y and increase back‐sided wear. A high tibial slope (>7°) led to a 9.3 mm3/y increase in wear rate compared with a low tibial slope (<3°). The results of this study demonstrate that tibial liner positioning has a significant impact on polyethylene wear with potential implications on osteolysis over time.
•Introducing a novel 3E function to optimize wall insulation.•Considering embodied energy and carbon in calculations.•Finding the optimum insulation by integrating EnergyPlus software with a 3E ...analysis.
One of the main challenges in the building industry is determining the thickness and material of insulations that are used in the external wall. The selection of the above-mentioned parameters depends upon various aspects, including energy, environment, and economy. In many cases, the analysis which is carried out based on each of these aspects leads to different results. In the present study, a comprehensive analysis was carried out based on energy, environment, and economy criteria where the energy, environment, and economic costs of producing insulations are also taken into account. Accordingly, material and optimum thickness of insulation for the external wall of an office building were determined. The results showed that Polyurethane with the thickness of 8 cm, EPS with the thickness of 20 cm, and Rockwool with the thickness of 7 cm were optimum states with regard to the aspects of energy, environment, and economy respectively. Finally, a novel function, which considered all three parameters simultaneously, was defined. Consequently, 3E (energy, environmental, and economic) analysis was carried out and led to the presentation of the Mineral wool insulation with the thickness of 11 cm as the optimum state of investigated cases according to the 3E criterion.
The increasing use of plastics has raised concerns about pollution of freshwater by these polymeric materials. Knowledge about their potential effects on environmental and public health is limited. ...Recent publications have suggested that the degradation of plastics will result in the release of nano-sized plastic particles to the environment. Therefore, it is of utmost importance to gain knowledge about whether and how nanoplastics affect living organisms. The present study aimed to analyse potential neurobehavioral effects of polystyrene nanoparticles (PS-NPs) after long-term exposure on rat. Potential effects of PS-NPs were investigated using four test dosages (1, 3, 6, and 10 mg PS-NPs/kg of body weight/day) administrated orally with adult Wistar male rats for five weeks. Neurobehavioral tests were chosen to assess a variety of behavioral domains. Particle diameters in test suspensions were determined through dynamic light scattering and showed an average hydrodynamic diameter of approximately 38.92 nm. No statistically significant behavioral effects were observed in all tests performed (p > 0.05). In the elevated plus maze, PS-NPs-exposed rats showed greater number of entries into open arms compared to controls. Also, PS-NPs had no significant influence on body weight of animals. Taking into account the subtle and transient nature of neurobehavioral consequences, however, these results underline the possibility of even pristine plastic nanoparticles to induce behavioral alteration in the rest of the food web, including for marine biota and humans. Indeed even though studied neurobehavioral effects in our study was not statistically significant, the observed subtle effects may be clinically considerable.
•The impacts of virgin nanoplastics on a suite of neurobehavioral responses in adult Wistar rats were investigated.•Exposure to plastic nanoparticles resulted in no measurable neurobehavioral consequences over the duration of the study.•Subtle and transient nature of effects highlight the potential of nanoplastics to have direct/indirect effects on human.
The PD-1 checkpoint pathway plays a major role in tumor immune evasion and the development of the tumor microenvironment. Clinical studies show that therapeutic antibodies blocking the PD-1 pathway ...can restore anti-tumor or anti-virus immune responses by the reinvigoration of exhausted T cells. Because of the promising results of anti-PD-1 monoclonal antibodies in cancer treatment, autoimmune disorders, and infectious diseases, the PD-1 has emerged as an encouraging target for different diseases. In the present study, we employed a human semi-synthetic phage library for isolation of some scFvs against the extracellular domain of PD-1 protein by panning process. After the panning, a novel anti-PD-1 scFv (SS107) was found that exhibited specific binding to PD-1 antigen and stimulated Jurkat T cells. The selected anti-PD-1 scFv could restore the production of IL-2 and IFN-gamma by Jurkat T cells that were co-cultured with PD-L1 positive tumor cells. This anti-PD-1 scFv with high specificity and the ability to reactivate exhausted T cells has the potential to be developed as an anti-cancer agent or to be used in combination with other therapeutic approaches.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The purpose of this clinical trial was to examine the effect of omega-3 fatty acids (W-3 FAs), nanocurcumin and their combination on serum levels and gene expression of VCAM in patients with episodic ...migraine. In this study, 80 patients were randomly divided in to 4 groups to receive for 2 months. Both serum levels and gene expression of VCAM showed remarkable decreases after single W-3 and after combined W-3 and nanocurcumin interventions. However, a borderline significant change and no remarkable change were observed after single nanocurcumin supplementation and in control group, respectively. While a significant difference between study groups in VCAM concentrations existed, there was no meaningful difference in VCAM gene expression among groups. It appears that the W-3 and combined W-3 and nanocurcumin can relieve VCAM serum level and its gene expression in patients with episodic migraine. Moreover, the combination of W-3 with nanocurcumin might cause more significant declines in VCAM level in the serum of migraine patients than when W-3 is administered alone.
Adoptive T-cell therapy (ACT) using autologous tumor-reactive T lymphocytes has considerable potential for cancer immunotherapy. In ACT, T cells are isolated from cancer patients and then stimulated ...and expanded in vitro by cytokines and costimulatory molecules. 4-1BB is an important costimulatory protein belonging to the TNF receptor superfamily. It is involved in T-cell survival, proliferation and activation. Agonistic anti-4-1BB monoclonal antibodies have been introduced as appropriate tools for ACT.
Here, various single-chain fragment variable (scFv) antibodies were used to activate T cells isolated from peripheral blood via immune magnetic isolation. The T cells were stimulated with IL-2 and anti-CD-3 mAb and then treated with agonistic anti-4-1BB scFvs. The results showed the remarkable effects of anti-41BB scFvs on the functional properties of T cells, including their activation, proliferation and cytokine production. The flow cytometry analysis revealed a considerable increase in the expression of the T-cell activation marker CD69. Moreover, T-cell proliferation was evidenced in treated cells by CFSE labeling compared to the control groups.
Anti-4-1BB scFvs significantly increased IFN-γ and IL-2 mRNA and protein expression in T cells, but exhibited no stimulatory effect on IL-4 expression. These findings show that anti-4-1BB scFvs could evoke a Type I immune response.
Our results demonstrate that targeting the 4-1BB molecule using agonistic scFvs could be an effective strategy for T-cell stimulation as part of an ACT approach to cancer treatment.
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