High Expansion Rate Research Articles

Experimental studies on the interfacial shear characteristics between joint concrete and foamed polymer in cross-river shield tunnel

The inadequate grouting performance in cross-river shield tunnels is primarily due to the insufficient bonding strength between the grouting material and the tunnel segments. In this study, a series of tests were conducted to compare foamed polymer and common grouting materials, focusing on the tangential bonding performance of the interface with tunnel segment concrete under varying humidity conditions. The applicability of polymer for treating leaks in cross-river shield tunnels was explored. The effects of polymer density, interfacial humidity, interfacial roughness, and normal stress on the shear strength of the polymer-concrete interface were investigated. A mathematical model reflecting the interface shear characteristics between polymer and concrete was established and validated. The test results have shown that, due to the fast reaction speed and high expansion rate, foamed polymer was found to be a feasible solution for addressing leakage in cross-river shield tunnels. Compared with common grouting materials, the density of foamed polymer is controllable, and the shear strength between foamed polymer and concrete segments is less affected by humid conditions. The minimum shear strength of the interface between foamed polymer and concrete is 1.2 MPa, while the maximum is 2.0 MPa. Foamed polymer can meet the needs of leakage treatment of cross-river shield tunnel. The interfacial shear strength between foamed polymer and concrete segments is directly proportional to the polymer density, interfacial roughness, and normal stress, and inversely proportional to the level of humid in the tunnel. The influence of various factors on interfacial strength is ranked as follows: polymer density > interfacial humidity > normal pressure > interfacial roughness. The residual error of linear regression mathematical model for the shear strength of interface between foamed polymer and segment concrete follows a normal distribution. The fitting results were proven to be accurate, allowing for the intuitive prediction of the quantitative relationship between shear strength and multiple influencing factors.

Measuring Changes in Temperature Rates due to Urban Expansion in Selected Municipalities of Baghdad using GIS Technology

The expansion of building blocks at the expense of agricultural land is one of the main problems causing climate change within the urban area of a city. The research came to determine these indicators, as a study was conducted on the expansion of the building blocks in three municipalities in the city of Baghdad for a period of four decades extended in the form of time cycles for the period (1981-2021) and using ArcMap GIS 10.7 technology. Then, the impact of this expansion on temperature rates was evaluated, as they are the most important climatic elements due to their significant effect on the rest of the elements. The results showed a clear, direct relationship between the increase in urban expansion rates and the corresponding rise in temperature rates, which results in urban heat islands. The results for the last time cycle showed high expansion rates for the municipalities of Al-Kadhimiya, Al-Shaala, and New Baghdad (62.2, 82.4, and 92.1), respectively, and were offset by high-temperature rates (25.2, 25.49, and 25.67) for the same municipalities, respectively, as the highest rates were recorded in the New Baghdad municipality, followed by the municipality of Al-Shaala, in second place, then the municipality of Al-Kadhimiya, with the lowest rates due to its location on the Tigris River.

Changing Pattern and Drivers of Land Use and Land Cover in Bagmati Province of Nepal

Land use and land cover (LULC) represents the physical component of the Earth's environment, and often changes as a result of natural and anthropogenic activities. This study carried out changing patterns and orientations of LULC types of Bagmati province of Nepal by using satellite images between 1996 and 2016. The study applied a classification scheme through support vector machines (SVM) for the period from 1996 to 2006, and 2006 to 2016. Our study explored that built-up area expansion was the major change witnessed which increased from 85.25 km2 in 1996 and sharply increased and labeled 250.06 km2 in 2016. Similarly, the forest land of the province increased by 329.02 km2 between 1996 and 2016. The status of cultivated land was found slightly decreasing trend, which was noted at 6113.50 km2 in 1996 and labeled at 5725.82 km2 in 2016. The shrubland of the province declined by 272.03 km2 from 1851.67 km2 in 1996 to 1579.64 km2 in 2016. However, the status of snow/ ice cover found at fluctuated form, which was noted 774.27 km2 in 1996, 1297.43 km2 in 2006, and 828.92 km2 in 2016. The increasing population trend is the main driver of the high rate of built-up area expansion and contraction of the cultivated land. Community forestry programs highly supported the expansion of forest cover. The proper implementation and improvement of the existing policy are the major concerns for sustainable LULC management in the province.

Strong Elastic Protein Nanosheets Enable the Culture and Differentiation of Induced Pluripotent Stem Cells on Microdroplets.

Advances in stem cell technologies, revolutionizing regenerative therapies and advanced in vitro testing, require novel cell manufacturing pipelines able to cope with scale up and parallelization. Microdroplet technologies, which have transformed single cell sequencing and other cell-based assays, are attractive in this context, but the inherent soft mechanics of liquid-liquid interfaces is typically thought to be incompatible with the expansion of induced pluripotent stem cells (iPSCs), and their differentiation. In this work, the design of protein nanosheets stabilizing liquid-liquid interfaces and enabling the adhesion, expansion and retention of stemness by iPSCs is reported. Microdroplet microfluidic chips are used to control the formulation of droplets with defined dimensions and size distributions. The resulting emulsions sustain high expansion rates, with excellent retention of stem cell marker expression. iPSCs cultured in such conditions retain the capacity to differentiate into cardiomyocytes. This work provides clear evidence that local nanoscale mechanics, associated with interfacial viscoelasticity, provides strong cues able to regulate and maintain pluripotency, as well as to support commitment in defined differentiation conditions. Microdroplet technologies appear as attractive candidates to transform cell manufacturing pipelines, bypassing significant hurdles paused by solid substrates and microcarriers.

Experimental Study on the Effects of Carbonated Steel Slag Fine Aggregate on the Expansion Rate, Mechanical Properties and Carbonation Depth of Mortar.

Steel slag is the main by-product of the steel industry and can be used to produce steel slag fine aggregate (SSFA). SSFA can be used as a fine aggregate in mortar or concrete. However, SSFA contains f-CaO, which is the main reason for the expansion damage of mortar and concrete. In this study, the carbonation treatment of SSFA was adopted to reduce the f-CaO content; the influence of the carbonation time on the content of f-CaO in the SSFA was studied; and the effects of the carbonated SSFA replacement ratio on the expansion rate, mechanical properties and carbonation depth of mortar were investigated through tests. The results showed that as the carbonation time increased, the content of f-CaO in the SSFA gradually decreased. Compared to the mortar specimens with carbonated SSFA, the specimens with uncarbonated SSFA showed faster and more severe damage and a higher expansion rate. When the replacement ratio of carbonated SSFA was less than 45%, the carbonated SSFA had an inhibitory effect on the expansion development of the specimens. The compressive strengths of the specimens with a carbonated SSFA replacement ratio of 60% and 45% were 1.29% and 6.81% higher than those of the specimens with an uncarbonated SSFA replacement ratio of 60% and 45%, respectively. Carbonation treatment could improve the replacement ratio of SSFA while ensuring the compressive strength of specimens. Compared with mortar specimens with uncarbonated SSFA, the anti-carbonation performance of mortar specimens with carbonated SSFA was reduced.

No difference in midterm outcomes and complication rate between retroperitoneal and transperitoneal open aortic aneurysm repair in females.

Abdominal Aortic Aneurysms (AAA) in females are less prevalent, have higher expansion rates and experience rupture at smaller diameters than in males. Studies have compared outcomes of the retroperitoneal (RP) and transperitoneal (TP) approach in open aortic aneurysm repair (OAR) with conflicting results. No study to date has compared the two approaches solely in females. In this study we compare midterm outcomes of the RP and TP approach in females undergoing OAR. Single-center, retrospective review of all females undergoing OAR from 2010 to 2021. Patients undergoing elective, symptomatic and ruptured OAR were included. The cohort was stratified by surgical approach RP versus TP and midterm outcomes were compared amongst the groups. Outcomes included mortality, graft related, and non-graft related complications. A total of 244 patients (RP n = 133; TP n = 111) were identified. Follow-up period was 28 ± 30.7months. Baseline perioperative characteristics were similar except that more people in the RP group had ejection fraction ((EF) > 50% (82% vs 68%), p = .037). Patients who underwent RP repair had longer visceral/renal ischemia time (p = .01), larger graft diameter (18 vs 16mm; p = <0.001), were more likely to have a suprarenal clamp placed(70.5 vs 48.2; p < .001), and had decreased autotransfusion volume (611 vs 861mL; p < .01) compared to those who underwent TP repair. Number of deaths was higher in the TP group during study follow-up period (36.4 vs 23.8; p = .035), but the difference of the time to event analysis was not significant. There was no difference in all-cause survival at 36 months between RP and TP (77.8 vs 76.8; p = .045). Overall midterm complications were 9.5% in both groups. Any graft related complication was 1.8% in TP versus 3% RP (p = .69). In a multivariable model, after adjusting for age, urgency, smoking, prior aneurysm repair, and ASA level, the hazard ratio decreases with the RP approach, however this did not reach significance (p = .052). In a 12-year period of OAR in females, TP and RP results were comparable at midterm analysis. The RP approach appeared to be used more often for OAR requiring suprarenal clamping. Although the TP group had increased mortality, the difference of the time to event analysis was not significant. Midterm postoperative complications in both groups were low. This suggests that both approaches are safe in the female population and decision should be driven by anatomy and surgeon's preference.

Long-term outcomes in patients with bicuspid valve stenosis and aortic dilation undergoing transcatheter valve implantation

BackgroundTo date, whether ascending aorta dilation (AAD) should be considered a contraindication for transcatheter aortic valve replacement (TAVR) remains a topic of debate.. ObjectiveThe study investigated the clinical outcome of TAVR in patients with bicuspid aortic valve stenosis (BAV-AS) complicated by AAD. MethodsWe included patients with BAV-AS who underwent TAVR between 2012 and 2019. We collected patient perioperative clinical data., tracked clinical outcomes for over four years post-TAVR, and obtained echocardiography images one year postoperatively. The Kaplan-Meier method was employed for analyzing both unadjusted and adjusted survival data, which was compared using the log-rank test. COX regression and nomograms were used to assess the impact of AAD on post-TAVR clinical outcomes in patients with aortic stenosis (AS), with all-cause mortality as the primary clinical endpoint. ResultsA total of 111 BAV patients were included in this study. Long-term follow-up showed an increased mortality risk in patients with BAV-AAD (adjusted Kaplan–Meier analysis: P = .02/0.001). Cox correlation analysis indicated that age (OR = 1.137; P = .034), AAD (OR = 3.51; P = .038), and postoperative left ventricular pressure (LVSP) (OR: 0.959; P = .044) were predictive factors for mortality more than four years after TAVR in patients with BAV. The area under the curve of the Nomogram predicting long-term survival for the training set of patients based on the above metrics was 0.845 (95% CI: 0.696–0.994). Short-term cardiac ultrasound follow-up showed a more rapid rate of AA expansion (0.29 [0–0.34] vs. -1 [−3.3–1] mm/month, P = .001) and a smaller proportion of AA diameter reduction (7.1% vs. 53.7%, P = .001) in patients who died. ConclusionsPatients with BAV-AAD-AS treated with TAVR have an increased risk of long-term mortality, and clinical prediction models, including AAD age and postoperative LVSP, may predict long-term patient survival. Condensed abstractThe study investigated the clinical outcome of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve stenosis (BAV-AS) complicated by ascending aorta dilation (AAD). Patients with BAV-AAD-AS treated with TAVR have an increased risk of long-term mortality. AAD, age and postoperative LVSP, may predict long-term patient survival. Short-term cardiac ultrasound follow-up showed a more rapid rate of AA expansion and a smaller proportion of AA diameter reduction in patients who died. A high postoperative AAD expansion rate may indicate an adverse clinical outcome. Surgery regimens for tolerable BAV-AADs and can be considered as a treatment option.

Extension mechanism of fracturing in liquid nitrogen fractured coal rock dominated by phase change expansion pressure

In this paper, the liquid nitrogen (LN2) fracturing test research using LN2 phase expansion instead of N2 pressurization was carried out in response to the neglected high phase expansion rate characteristic of LN2, an anhydrous fracturing medium. Expansion pressure measurements, infrared temperature measurements, DIC full-field strain measurements and acoustic emission (AE) signal measurements were used as measurement means. The phase change gas expansion pressure, specimen end-face field, internal fracture signal and end-face temperature changes during the fracturing process were explored. The experimental results show that there was a significant difference in the performance of LN2 cold shock damaged specimens and undamaged specimens during fracturing. The change rule of LN2 phase change expansion pressure under no peripheral pressure went through linearly increasing first and then stabilizing, the slope of the linear phase was 0.029 MPa/s, the expansion pressure in the stabilizing phase was 1.2 MPa and lasted for 12s, and then the specimen ruptured. The initiation pressure of the gas fractured specimen was 2.2 MPa. The surface strain of the specimen was significantly increased during the stabilization stage of expansion pressure, and the maximum values of transverse strain and longitudinal strain were 0.059% and 0.071%, respectively, which were increased by 43.9% and 73.2% within 12 s. At the same time, the number of AE localization points increased from 12 to 78, and the location of the localization points gradually expanded from the two sides of the horizontal slot to the top of the horizontal slot and the outer wall of the specimen. There was a low-temperature zone with obvious temperature gradient in the extended area and no such change existed in the gas fractured specimens. Therefore, the fracture initiation pressure of the damaged specimen is lower than that of the undamaged specimen, and the cracks are more likely to expand and become continuous during the fracturing process, thus producing complex cracks. The use of LN2 with high phase change expansion rate can replace the high-pressure pumping of N2, which is of great significance for the reduction of the implementation time and cost of the LN2 fracturing process.

Smaller cities have large impacts on West Africa's expanding urban system

Urban expansion studies are often biased toward large cities with populations greater than 1 million, while small and medium cities with smaller populations are overlooked. We mapped and assessed the expansion of 1603 cities across Ghana, Togo, Benin, and Nigeria using impervious surface data generated from Landsat from 2001 to 2020. We classified pixels with >20 % impervious as developed with 93 % overall accuracy. Total developed area increased 2.3-fold from 4001 km² in 2001 to 9402 km² in 2020. Of the expanded area, more than half (54 %) occurred in small and medium cities, and 73 % was sprawl. The mean annual expansion rate was 4.6 %. Expansion rates and sprawl-to-infill ratios were higher in small and medium cities than in large cities, and the annual expansion rates of large cities decreased over time while those in small and medium cities were stable or increased. Proximity to large cities also increased smaller cities' expansion rates in Nigeria, but more remote cities had higher expansion rates in Benin and Togo. Although much attention is focused on large megacities, these results show that smaller and more numerous cities contribute substantially to urban expansion and need to be incorporated into regional assessments of urban growth and its impacts.

A two-step species distribution modeling to disentangle the effect of habitat and bioclimatic covariates on Psacothea hilaris, a potentially invasive species

Integrating host plants in distribution modeling of phytophagous species and disentangling the effect of habitat and bioclimatic variables are key aspects to produce reliable predictions when the aim is to identify suitable areas outside species’ native range. To this aim, we implemented a framework of Species Distribution Model aimed at predicting potential suitable areas of establishment for the beetle Psacothea hilaris across the world. Since habitat (including host plants) and bioclimatic variables affect species distribution according to processes acting at different geographical scales, we modeled these variables separately. For the species native range, we fitted a habitat (HSM) and a bioclimatic (BSM) suitability model calibrated on a local and a large scale, respectively; the overall suitability map was obtained as the spatial product of HSM and BSM projection maps. ROC, TSS and Cohen’s Kappa obtained in validation confirmed a good predictive performance of modeling framework. Within HSM, host plants played a substantial effect on species presence probability, while among bioclimatic variables, precipitation of the warmer quarter and isothermality were the most important. Native HSM and BSM models were used to realize an overall suitability map at world scale. At global scale, many areas resulted suitable for habitat, some for bioclimate, and few for both conditions; indeed, if the species would not be able to modify its bioclimatic niche, it might not be considered a major invasive species. However, the high rate of range expansion documented for P. hilaris in Northern Italy, a poorly suitable bioclimatic area, suggests a plasticity of the species that requires increasing the level of attention to its invasive potential.

Midterm Outcomes and Aneurysm Sac Dynamics Following Fenestrated Endovascular Aneurysm Repair after Previous Endovascular Aneurysm Repair

Fenestrated endovascular aneurysm repair (FEVAR) represents a feasible option for aortic repair after endovascular aneurysm repair (EVAR), due to improved peri-operative outcomes compared with open conversion. However, little is known regarding the durability of FEVAR as treatment of failed EVARs. Since aneurysm sac evolution is an important marker for success after aneurysm repair, the aim of the study was to examine mid-term outcomes and aneurysm sac dynamics of FEVAR after prior EVAR. Patients undergoing FEVAR for complex abdominal aortic aneurysms from 2008 to 2021 at two hospitals in The Netherlands were included. Patients were categorised into primary FEVAR and FEVAR after EVAR. Outcomes included five year mortality, one year aneurysm sac dynamics (regression/stable/expansion), sac dynamics over time, and five year aortic related procedures. Analyses were done using Kaplan-Meier methods, multivariable Cox regression analysis, chi-square tests, and linear mixed effect models. In total, 196 patients with FEVAR were identified, of whom 27% (n = 53) had a prior EVAR. Patients with prior EVAR were significantly older (78 ± 6.7 years vs. 73 ± 5.9 years, p < .001). There were no significant differences in mortality. FEVAR after EVAR was associated with higher risk of aortic related procedures within five years (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.1 - 6.5, p = .037). Sac dynamics were assessed in 154 patients with available imaging. Patients with a prior EVAR showed lower rates of sac regression and higher rates of sac expansion at one year compared with primary FEVAR (sac expansion 48%, n = 21/44, vs. 8%, n = 9/110, p < .001)). Sac dynamics over time showed similar results, sac growth for FEVAR after EVAR, and sac shrinkage for primary FEVAR (p < .001). FEVAR after EVAR showed high rates of sac expansion and needed more secondary procedures than patients with primary FEVAR, although this did not affect mid-term survival. Future studies will have to assess whether FEVAR after EVAR is a valid intervention, and the underlying process that drives aneurysm sac growth following successful FEVAR after EVAR.

A Comparative Study on the Issues and Impacts of Land Use Planning in Indian and International Hill Cities

Abstract Land is the most important asset used by humans for existence and has been exploited since the dawn of civilization. Due to the unprecedently high rate of population expansion that has resulted in chaotic urban development, the land use pattern in most metropolitan areas has changed significantly in the recent past. The unplanned development and rapid urbanization are also occurring in India’s hill cities, and thus land use planning is becoming increasingly important. Moreover, due to geography, terrain, slope, climate, susceptibility to natural disasters, and other factors, planning in the hills is very difficult. This has led to several problems in hill towns, all of which require a well-thought-out framework for systematic urban development. The prime objective of the study is to get fully acquainted with the current processes of land use planning in India and abroad by examining a variety of instances, as well as analysing the efficacy of such processes in their respective hill cities. A comparative study of best land use practices being followed in hill towns in India and abroad is also carried out to identify any gaps and issues in the land use planning techniques being used in Indian hill towns.

Design of Ion Channel Confined Binary Metal Cu-Fe Selenides for All-Climate, High-Capacity Sodium Ion Batteries.

Exploring special anode materials with high capacity, stable structure, and extreme temperature feasibility remains a great challenge in secondary sodium based energy systems. Here, a bimetallic Cu-Fe selenide nanosheet with refined nanostructure providing confined internal ion transport channels are reported, in which the structure improves the pseudocapacitance and reduces the charge transfer resistance for making a significant contribution to accelerating the reaction dynamics. The CuFeSe2 nanosheets have a high initial specific capacity of 480.4mAhg-1 at 0.25Ag-1, showing impressively excellent rate performance and ultralong cycling life over 1000 cycles with 261.1mAhg-1 at 2.5Ag-1. Meanwhile, it exhibits a good sodium storage performance at extreme temperatures from -20°C to 50°C, supporting at least 500 cycles. Besides, the CuFeSe2||Na3V2(PO4)3/C full cell delivers a high specific capacity of 168.5mAhg-1 at 0.5Ag-1 and excellent feasibility for over 600 cycles long cycling. Additionally, the Na+ storage mechanisms are further revealed by ex situ X-ray diffraction (XRD) and in situ transmission electron microscopy (TEM) techniques. A feasible channelized structural design strategy is provided that inspires new instruction into the development of novel materials with high structural stability and low volume expansion rate toward the application of other secondary batteries.

Application of Satellite Images and Artificial Intelligence to Monitor Land Cover Changes in Hanoi Area During 2013-2023 Period

Artificial intelligence (AI) and remote sensing technology have now increasingly improved their efficiency and reliability in monitoring the changes in land cover. With the amendment of the Vietnamese Law on Land in 2013 and the administrative boundary expansion of Hanoi, Hanoi experiences significant changes in land use and land cover for the last ten years. To monitor the actual land use changes in the area, this study used the Random Forest (RF) machine learning algorithm to classify the basic land covers, monitor, and analyze the spatial variation of land use and land cover in the 2013 to 2023 period. The study findings indicate a relatively high rate of expansion of construction zone area and a decrease in land cover related to water bodies and vegetated area. Water bodies decrease by an average of 0.8% annually, whereas the construction zone area increased by 7% of the total area.&#x0D;

Biodegradable flexible foam: Novel material based on cassava TPS obtained by extrusion

Thermoplastic foams made from petrochemical polymers are commonly commercialized in the market, which, due to their chemical nature, require hundreds of years to degrade and therefore end up accumulating and polluting the environment. Therefore, the present research sought to develop a biodegradable foam from thermoplastic cassava starch, biodegradable polyester, and wheat gluten. Initially, an extreme vertex blend design was run, which comprised 60 to 70% thermoplastic starch (TPS), 30 to 40% biodegradable polyester, and 0 to 5% wheat gluten, the foam was obtained by extrusion and evaluated for expansion rate, bulk density, damping index, and morphology. A thin layer of rubber latex was applied to the foamed material with the most outstanding properties in order to reduce moisture adsorption, and its biodegradability was also evaluated. The results indicated that with the addition of 70% TPS, 30% polyester, and 0% wheat gluten, it was possible to obtain by extrusion a flexible thermoplastic foam with high radial expansion rate and low bulk density. Impregnation of the foam with natural rubber latex created an impermeable layer that helped to decrease moisture adsorption; however, there was an increase in compressibility. Also, it was found that this foam met the biodegradability condition since it presented a percentage of mineralization in relative terms of 97.59% in less than 180 days.

Research on casing damage mechanism and prevention and control under creep behavior of salt-gypsum layer

As a good cap rock, the salt-gypsum layer often contains abundant oil and gas resources, but it has strong plastic flow and creep properties, resulting in frequent casing damage problems. Therefore, a new method is proposed to prevent and control casing failure in creep formation by using solid expandable tubular (SET). Based on the Heard model, the creep behavior of formation was described. The expansion experiment of the SET, the material tensile experiment of casing and SET with different expansion rates were carried out. The three-dimensional mechanical model and finite element model of casing-cement sheath- (SET) -formation were established. Numerical simulation of creep behavior of salt-gypsum layer under non-uniform in-situ stress was carried out. Comparative study of casing damage mechanism in two cases with or without SET prevention and control. The influence of sensitive factors such as SET wall thickness and expansion rate on the failure behavior of casing prevented and controlled by SET were analyzed. The results show that (1) In the direction of the maximum horizontal in-situ stress, the stress on the outer surface of the casing is large. In the direction of the minimum horizontal in-situ stress, the stress on the inner surface of the casing is the largest, and the material yield failure occurs first at this position of the casing. The compression deformation of casing is greater than the tensile deformation. The casing is oval after deformation. (2) By increasing steel grade and wall thickness of casing, the service time of the casing under creep behavior of salt-gypsum layer can be prolonged. However, while increasing cost and reducing diameter, it has not played a role in preventing casing failure. (3) By using the method of SET prevention and control, the casing stress is more evenly distributed, the maximum stress is effectively reduced, the stress growth rate is slowed down, and the external collapse resistance ability is significantly enhanced. The maximum stress of the casing is reduced by up to 24.96 %. The larger the wall thickness of the SET, the better the prevention and control effect, and the longer the service time of the casing. The increase of the ultimate wall thickness of the SET with high expansion rate can effectively make up for its poor prevention and control effect. (4) The new method of adding the SET between salt-gypsum layer and cement sheath has the advantages of increasing casing inner diameter, optimizing wellbore structure, reducing cost and wellbore risk. The research results can provide some reference value for the prevention and control of casing failure in creep salt-gypsum layer.

Super thermal-insulation PS/PMMA/CNTs composite foams with shape recovery property formed by the synergy of ultrasound and H2O in scCO2 foaming

For polymer foams, a high expansion rate is often required to obtain a low thermal conductivity. However, polymer foams with high expansion ratio faces a difficulty of shape recovery. In this work, polystyrene (PS)/polymethyl methacrylate (PMMA)/carbon nanotubes (CNTs) composite foams were prepared by the synergy of ultrasound and H2O in supercritical carbon dioxide (scCO2) foaming. The introduction of ultrasound and H2O is beneficial to improving expansion ratio. CNTs can enhance the melt strength of PS/PMMA, which also absorb part of the thermal radiation. Therefore, the PS/PMMA/CNTs foams with 0.5 wt% CNTs exhibits the high expansion ratio (80.7 times), low thermal conductivity (25.98 mW/mK) and 100% compression recovery in water at 85 °C after one compression. In addition, with the increasing of filler contents, the reusability of the foam is further improved. After ten compressions, the PS/PMMA/CNTs foams with 2 wt% CNTs still achieve the 99% recovery. This work provides a new way to prepare polymer foams with super-insulation and reusability.

Unveiling the role of differential growth in 3D morphogenesis: An inference method to analyze area expansion rate distribution in biological systems

The three-dimensional (3D) morphologies of many organs in organisms, such as the curved shapes of leaves and flowers, the branching structure of lungs, and the exoskeletal shape of insects, are formed through surface growth. Although differential growth, a mode of surface growth, has been qualitatively identified as 3D morphogenesis, a quantitative understanding of the mechanical contribution of differential growth is lacking. To address this, we developed a quantitative inference method to analyze the distribution of the area expansion rate, which governs the growth of surfaces into 3D morphology. To validate the accuracy of our method, we tested it on a basic 3D morphology that allowed for the theoretical derivation of the area expansion rate distribution, and then assessed the difference between the predicted outcome and the theoretical solution. We also applied this method to complex 3D shapes and evaluated its accuracy through numerical experiments. The findings of the study revealed a linear decrease in error on a log–log scale with an increase in the number of meshes in both evaluations. This affirmed the reliability of the predictions for meshes that are sufficiently refined. Moreover, we employed our methodology to analyze the developmental process of the Japanese rhinoceros beetle Trypoxylus dichotomus, which is characterized by differential growth regulating 3D morphogenesis. The results indicated a notably high rate of area expansion on the left and right edges of the horn primordium, which is consistent with the experimental evidence of a higher rate of cell division in these regions. Hence, these findings confirm the efficacy of the proposed method in analyzing biological systems.

The effect of serum origin on cytokines induced killer cell expansion and function

BackgroundCytokine-induced killer (CIK) cells have shown promising results in adoptive immunotherapy. However, serum may play a determining role in the large-scale expansion of these cells for clinical applications. According to Good Manufacturing Practice (GMP) guidelines to reduce the use of animal products in cell-based therapies; therefore, this study sought to investigate the impact of serum origin and the reduced serum concentration on the pattern of cell expansion and function.MethodsPeripheral blood mononuclear cells (PBMCs) isolated from a healthy donor were expanded based on the CIK cell expansion protocol. The cell culture medium was supplemented with three types of sera comprising fetal bovine serum (FBS), human serum (HS), or human-derived platelet lysate (hPL) at different concentrations (10%, 5%, and 2.5%). The proliferation kinetics for each group were investigated for 30 days of cell culture.ResultsCell proliferation in 10% concentration of all sera (hPL, FBS, HS) was higher than their lower concentrations. Moreover, hPL was significantly associated with higher expansion rates than FBS and HS in all three concentrations. Furthermore, cells cultured in hPL showed higher viability, cytotoxicity effect, and CIK CD markers expression.ConclusionhPL at a concentration of 10% showed the best effect on CIK cell proliferation and function.

Partial replacement of fish meal by cottonseed protein concentrate and the effects of preconditioning water content and die temperature on pellet physical quality of extruded floating fish feed

A two-factorial central composite design was performed to investigate the effects of preconditioning water content (PCwater: 21, 22.5, 26, 29.5 or 31%) and die temperature (Dtemp: 115, 119.4, 130, 140.6 or 145 ℃) on the physical properties of extruded floating fish feed. This design was applied to two separate diet formulas to study the effect of cottonseed protein concentrate (CPC) inclusion (replacing 67% of fish meal-FM in the diet). A total of 26 batches of diets were prepared. Response surface methodology was used for regression and parameter optimization. Averaged over all PCwater and Dtemp combinations, CPC-pellets had a lower bulk density, oil leakage, higher expansion rate, oil absorption, hardness, pellet durability index and a longer hydration time than FM-pellets. A negative correlation between oil absorption and oil leakage was presented in the CPC-pellets but not in the FM-pellets. Moreover, the influence of PCwater on the PPQ was uniform across both formulas except for oil leakage. However, the effect of Dtemp on the PPQ differed between the formulas. For oil leakage, it was maximal at both the highest PCwater and Dtemp combination in the FM-pellets, while it was maximized at both the lowest PCwater and Dtemp combination in the CPC-pellets. Furthermore, exchanging fish meal with CPC improved the optimal processing conditions and enlarged the operating window to produce the desired feed. This reduces water and energy consumption in feed production.