Decrease In Mean Diameter Research Articles

Morphofunctional evaluation of great saphenous vein's tributaries after thermoablation: A case series

ObjectiveThis study evaluates hemodynamic and anatomic changes in great saphenous vein (GSV) tributaries after endovenous laser ablation (EVLA). MethodsThis case series analyzed 112 areas in 28 lower limbs of 25 patients who underwent EVLA from April 2022 to June 2023 at the Hospital das Clínicas de Pernambuco/UFPE. All patients were evaluated by Doppler ultrasound preoperatively and 3 months after the surgical treatment. The parameters studied were GSV diameter and patency, GSV tributary diameter, patency and flow direction, and the Venous Clinical Severity Score after EVLA. The GSV characteristics were evaluated in four regions: saphenous-femoral junction, medium thigh, knee, and medium leg. The tributary veins were grouped in four areas: anterior thigh, posterior thigh, anterior leg, and posterior leg. ResultsThe results included 28 lower limbs from 23 patients; 18 patients (67.9%) were women, and the average age was 49 years; 2 patients were lost to follow-up. Ninety days after EVLA, all treated GSVs were occluded. The average diameter of GSV decreased in all four regions studied: saphenous-femoral junction, medium thigh, knee, and medium leg (P ≤ .001). We analyzed 101 GSV tributaries. In the analysis of GSV tributaries by area, we identified a mean diameter decrease in all groups of tributaries (P < .001). Considering the tributaries with reflux, we also identified a reduction in the number of tributaries with reflux in all four groups (P ≤ .001). All tributaries were patent preoperatively; at 3 months after the surgical treatment, GSV tributaries occlusion was infrequent, except for the anterior thigh group. There was a decrease from 9 to 5 points in Venous Clinical Severity Score after EVLA (P < .001). ConclusionsThis study demonstrated that, after GSV laser ablation, there was a statistically significant decrease in the diameters of all tributary groups, and the number of tributaries with decreased reflux; however, the occlusion of tributaries was not a frequent finding.

Investigation of Causal Relationships between Printing Parameters, Pore Properties and Porosity in Laser Powder Bed Fusion

This work reports on employing X-ray computed tomography (XCT) and optical microscopy to investigate the causal relationships between printing parameters, pore properties, and porosity in 316L stainless steel samples additively manufactured by Laser Powder Bed Fusion (LPBF). The porosity is very similar for both investigation methods. XCT provides more accurate results for large lack of fusion pores, while optical results are more accurate for small keyhole pores. These results were employed to develop mathematical models to determine how printing parameters influence pore properties and overall porosity. The developed optical and XCT mathematical models reveal that power is the most significant factor affecting pore properties and overall porosity. Pore number and mean diameter decrease and sphericity increases with increasing power. Overall porosity is negatively correlated with power, indicating that the higher the power, the lower the overall porosity. Attention should also be paid to the quadratic effects of power, velocity and hatch spacing on porosity, revealing an inverse change in porosity after a certain threshold. Power interacts with velocity and hatch spacing, suggesting that changes in power affect the influence of velocity and hatch spacing on porosity, and vice versa. The interaction of velocity and hatch spacing is not significant. Both models successfully predicted optimal printing parameter sets as validated by experimental measurements.

Oogenesis and expression of PCNA and vitellogenin in Geophagus native to the Amazon basin in pre- and post-hydroelectric dam periods

Oogenesis in fish is a process that involves cell proliferation, growth and maturation. In rivers blocked by hydroelectric dams, these factors can be altered and affect the reproduction mechanism of the species. Regarding this scenario, the present study aimed to describe oogenesis in two cichlids native to the Amazon basin, Geophagus argyrostictus and G. altifrons, during pre- and post-dam periods of the Xingu River. Females of both Geophagus species were captured and biometric measurements were taken. Afterwards, the fish were euthanized, and the gonads were removed and subjected to histological processing for light microscopy, scanning electron microscopy and immunoperoxidase staining. Oocyte diameter and zona radiata thickness were also measured. The ovaries appeared in pairs, where according to their shape, size, vascularization and cell organization, five stages were described for both species. In the post-dam period, there was a reduction in the mean diameter of the oocytes, especially type IV, and a decrease in the thickness of the zona radiata, mainly, in G. argyrostictus. In both species, there was a greater presence of oocyte atresia in the post-dam period. PCNA immunoreactivity was more intense in type I and II oocytes, while vitellogenin immunoreactivity occurred in the cytoplasm and follicular cells of oocytes III and IV. These data suggest that because of changes in the level/flow of the river, the gonads of these two species adjust to the new environment, with a decrease in mean diameter and zona radiata thickness of the oocytes, which can interfere with the reproduction of the animals.

Numerical study of kerosene spray and combustion characteristics using an air-blast atomizer

In this study, a computational model for a cylindrical combustor with an air-blast atomizer was created to investigate the effect of changing air to liquid mass ratio (ALR) on spray characteristics without combustion and the effect of changing ALR on combustion characteristics under different swirl numbers with constant kerosene fuel mass flow rate using computational fluid dynamics (CFD) code. The study aim is to define the ALR at which the pollutants concentrations at combustion exhaust will be the least. Eight values of ALR were considered and these include 0.3, 0.5, 0.7, 0.9, 1.0, 1.2, 1.4 and 1.5. The cold spray characteristics including the number of droplets, Sauter Mean Diameter, droplets penetration length and droplets contours were obtained in addition to combustion characteristics that were studied by describing the reverse flow zone (RFZ) boundary, flow pathlines, temperatures maps, outlet temperatures at combustor exit and species concentrations. The results indicate that increasing ALR and consequently spray droplet diameter decrease does not always translate into superior emissions performance and it depends on several parameters including swirling intensity where the modernistic capabilities of CFD code including flow visualization and calculated recirculated mass flow ratio are used to justify the reasons behind this exceptional behavior. In addition, the results show that the spray Sauter Mean Diameter decreases by increasing ALR but the droplet diameter reduction effect was steeper at lower ALR than higher ones. The length of the RFZ is decreasing with the increase of ALR and shifts upstream closer to the combustor swirler. The recirculated flow mass ratio and the outlet average temperature are decreasing with the increase of ALR.

The Impact of Intermittent Fasting on Size Profile and Protein Cargo of Circulating Exosomes in High Fat Diet‐Induced Obese Mice

Extracellular vesicles (EVs) have emerged as a key regulator of intercellular and inter‐organ communications, playing an important role in mediating metabolic responses. Dysregulation of exosome secretion and exosome cargo composition has been associated with metabolic diseases. However, how EVs reflect diet‐induced metabolic responses remains unexplored. The objective of the study is to identify changes in the size profile and protein cargoes of circulating exosomes in diet‐induced obesity upon intermittent fasting, as well as to establish EV biomarkers for obesity‐related dietary responses.Male mice (8‐10 weeks of age) were all fed a high‐fat diet (HFD) for 18 weeks prior to being placed either in ad libitum group (HFD‐AL) or intermittent fasting group (HFD‐IF) for an additional 10 weeks. Mice on the normal chow ad libitum (NC‐AL) served as control. The IF group had food available for 10 hours and fasted for 14 hours per day. EVs were isolated from serum and size was measured using Nanoparticle Tracking Analysis. Additionally, quantitative proteomics was conducted to identify EV protein markers and FunRich Analysis Tool was used to identify pathways related to the identified proteins.On a long‐term HFD, the IF significantly altered the size profile of serum exosomes. The HFD‐AL mice had an increasing trend in mean diameter of serum EVs by 24nm compared to the NC‐AL mice. The 10 weeks of IF caused a significant decrease in mean diameter of serum EVs by 47.9nm (P= 0.03) when compared to the HFD‐AL mice. However, neither the HFD nor IF altered the overall particle amount per unit of serum. This suggests that the population composition of EVs may be changed in response to the HFD feeding or IF. To address this question, we analyzed the specific populations of EVs with different ranges of sizes. Intriguingly, we found the HFD altered the population composition of EVs (decreased small EVs and increased large EVs) and the IF was able to reverse these changes. The mean population of EVs/exosomes (30‐150nm in size) were increased in the HFD‐IF group by ~30% (P= 0.02), whereas the populations of larger EVs (200‐350nm) were decreased by ~15% (P= 0.02) when compared to the HFD‐AL mice. Proteomic Analysis of the protein abundance within the isolated EVs showed variance between the experimental groups. Compared to the NC‐AL, the HFD‐AL group had 15 upregulated proteins (involved in pathways such as blood coagulation, immune response, and others) and 18 downregulated proteins (involved in pathways such as cytolysis, classical and alternative pathway complement activation, and others). Between the HFD‐IF and HFD‐AL groups, 43 proteins were found to be significantly different in abundance. Of those 43 proteins, 10 proteins altered by HFD‐AL were reversed by implementing IF. FunRich analysis showed that these 10 proteins belonged to the pathways involving NADP metabolism, immune responses, lipoprotein metabolism, and cholesterol homeostasis.Together, this data suggests intermittent fasting significantly alters the profile and protein cargoes of circulating EVs which may serve as an important mechanism for the metabolic benefits of intermittent fasting in obesity as well as biomarkers for obesity‐related metabolic responses.

Intermittent Fasting Alters Serum Exosomes in Middle-Aged Male Mice on Long-Term High-Fat Diet

ObjectivesExtracellular vesicles (EVs), especially exosomes, have emerged as a critical regulator of intercellular and inter-organ communications. Dysregulation of exosome secretion and exosomal cargo composition has been associated with metabolic diseases. The objective of this study was to determine the effect of intermittent fasting (IF) on the size profile and cargoes of exosomes in diet-induced obesity. MethodsFemale and male mice (8–10 weeks old) were fed a high-fat diet (HFD) for 18 weeks prior to being placed either in an ad libitum feeding group (HFD-AL) or an IF feeding group (HFD-IF) for an additional 10 weeks. Mice on the normal chow ad libitum (NC-AL) for 28 weeks served as control. The IF group had food available for 10 hours and fasted for 14 hours daily. Serum EVs measured using Nanoparticle Tracking Analysis. ResultsHFD-AL mice had an increasing trend in mean diameter of serum EVs by 24 nm (P = 0.30) compared to the NC-AL mice. The IF caused a significant decrease in mean diameter of serum EVs by 47.9 nm (P < 0.03) when compared to the HFD-AL mice. However, neither HFD nor IF altered the overall particle amount per mL of serum when compared to NC-AL. The HFD-AL mice had a decreasing trend in the population of small-size EVs but an increase in large-size EVs compared to the NC-AL mice. Mice on long-term HFD with IF had a significant increase in the total amount of small EVs/exosomes (50–100 nm in size) per unit of serum, but a decrease in the amount of large EVs (250–500 nm in size). Moreover, the mean population (particles/ml) of small EVs/exosomes were increased in the HFD-IF mice by an average of 38% (P < 0.03), whereas the population of large-size micro-vesicles (250–300 nm in size) were decreased by an average of 4% (P < 0.01) when compared to the HFD-AL mice. In addition to exosome alterations, the weekly weigh-in differences were significantly higher in the HFD-IF mice compared to the HFD-AL mice (P < 0.02). Lastly, we found that IF could prevent the whitening of brown adipose tissue (BAT) and liver micro-vesicular steatosis induced by a long-term HFD. ConclusionsIF significantly alters the profile of serum EVs, which may serve as an important mechanism for the metabolic benefits of IF such as preventing the whitening of BAT and liver micro-vesicular steatosis in obesity. Funding SourcesThis work was supported by the General Mills Foundation Chair in Genomics for Healthful Foods to X.C.

Change in Collagen Fibril Diameter Distribution of Bovine Anterior Cruciate Ligament upon Injury Can Be Mimicked in a Nanostructured Scaffold

More than 200,000 people are suffering from Anterior Cruciate Ligament (ACL) related injuries each year in the US. There is an unmet clinical demand for improving biological attachment between grafts and the host tissue in addition to providing mechanical support. For biological graft integration, it is important to provide a physiologically feasible environment for the host cells to enable them to perform their duties. However, behavior of cells during ACL healing and the mechanism of ACL healing is not fully understood partly due to the absence of appropriate environment to test cell behavior both in vitro and in vivo. This study aims at (i) investigating the change in fibril diameter of bovine ACL tissue upon injury and (ii) fabricating nanofiber-based scaffolds to represent the morphology and structure of healthy and injured ACL tissues. We hypothesized that distribution and mean diameter of ACL fibrils will be altered upon injury. Findings revealed that the collagen fibril diameter distribution of bovine ACL changed from bimodal to unimodal upon injury with subsequent decrease in mean diameter. Polycaprolactone (PCL) scaffold fiber diameter distribution exhibited similar bimodal and unimodal distribution behavior to qualitatively represent the cases of healthy and injured ACL, respectively. The native ACL tissue demonstrated comparable modulus values only with the aligned bimodal PCL scaffolds. There was significant difference between mechanical properties of aligned bimodal and unaligned unimodal PCL scaffolds. We believe that the results obtained from measurements of diameter of collagen fibrils of native bovine ACL tissue can serve as a benchmark for scaffold design.

Experimental comparison of the spray atomization of heavy and light fuel oil at different temperatures and pressures for pressure-swirl injector

In this study, the atomization of heavy fuel oil (Mazut) and diesel fuel at different pressures is compared experimentally. Also, the effects of temperature on the Mazut fuel atomization are investigated experimentally. Mass flow rate, discharge coefficient, wavelength, liquid film thickness, ligament diameter, spray angle, breakup length, and sature mean diameter are obtained for the Mazut and diesel fuel. Fuels spray images at different pressures and temperatures are recorded using the shadowgraphy method and analyzed by the image processing technique. Error analysis is performed for the experiments, and the percentage of uncertainty for each parameter is reported. The experimental results are compared with the theoretical results. Also, Curves are proposed and plotted to predict changes in the behavior of atomization parameters. Diesel fuel has less viscosity than Mazut fuel. Diesel fuel has shorter breakup length, wavelength, liquid film thickness, and sature mean diameter than Mazut fuel at the same pressure. Diesel fuel has a larger spray angle and a larger discharge coefficient than Mazut fuel at the same pressure. As the pressure and temperature increase, fuel atomization improves. The viscosity of Mazut fuel is decreased by temperature increase. As the fuel injection pressure and temperature increase, breakup length, wavelength, liquid film thickness, and sature mean diameter decrease; also, spray angle increases.

The Effects of Particle Segregation on Debris Flow Fluidity Over a Rigid Bed

ABSTRACTIt is essential to consider the fluidity of a debris flow front when calculating its impact. Here we flume-tested mono-granular and bi-granular debris flows and compared the results to those of numerical simulations. We used sand particles with diameters of 0.29 and 0.14 cm at two mixing ratios of 1:1 and 3:7. Particle segregation was recorded with a high-speed video camera. We evaluated the fronts of debris flows at 0.5-second intervals. Then we numerically simulated one-dimensional debris flows under the same conditions and used the mean particle diameter when simulating mixed-diameter flows. For the mono-granular debris flows, the experimental and simulated results showed good agreement in terms of flow depth, front velocity, and flux. However, for the bi-granular debris flows, the simulated flow depth was less, and both the front velocity and flux were greater than those found experimentally. These differences may be attributable to the fact that the dominant shear stress was caused by the concentration of smaller sediment particles in the lower flow layers; such inverse gradations were detected in the debris flow bodies. Under these conditions, most shear stress is supported by smaller particles in the lower layers; the debris flow characteristics become similar to those of mono-granular flows, in contrast to the numerical simulation, which incorporated particle segregation with gradually decreasing mean diameter from the front to the flow body. Consequently, the calculated front velocities were underestimated; particle segregation at the front of the bi-granular debris flows did not affect fluidity either initially or over time.

An experimental investigation on spray, performance and emission of hydrotreated waste cooking oil blends in an agricultural engine

Biomass-based fuels are gaining importance for operating a compression ignition engine as they can curb greenhouse gases and are a key for addressing the energy security. Hydrotreated oil is considered to be a potential drop-in fuel for the compression ignition engine as its cetane number is higher than fossil diesel. In this study, hydrotreated waste cooking oil and its blends (10%, 20%, 30%, 40% and 50% by volume) with diesel were prepared. The ignition probability of the test fuel samples was found using a hot-plate test setup. The neat hydrotreated fuel has higher ignition probability at a particular temperature than the other test fuels. The Sauter mean diameter of the test fuels was also observed using a Malvern Spraytec test setup. The results reveal that the neat hydrotreated fuel has higher Sauter mean diameter due to its high viscosity. As the percentage of the hydrotreated fuel in the blend decreases, the Sauter mean diameter decreases and diesel has the lowest Sauter mean diameter. The test fuels were also used to run a compression ignition engine. The results reveal a decrease in brake thermal efficiency with the increase in the hydrotreated fuel share in the blend. The heat release for the blends starts earlier than diesel and the peak heat release is also lower than diesel. The HC, CO and smoke emissions for the test blends decreases up to 30% blend. When the percentage of the hydrotreated oil is further increased, the emissions starts increasing. The NO emissions were lower than diesel for all the test samples. As compared to diesel, the maximum reduction in NO (neat), HC (30% blend), CO (30% blend) and smoke emissions (30% blend) is 23.2%, 14.4%, 13.83% and 13.3%, respectively.

Experimental and Numerical Study on Flow Resistance and Bubble Transport in a Helical Static Mixer

Flow resistance and bubble transport in a helical static mixer were studied experimentally and numerically. The inline mixer increases the volume fraction of gas in liquids by breaking bubbles into smaller sizes with a micrometer size in the flow experiments. The gas–liquid flow was simulated by a combination of computational fluid dynamics and Taylor expansion methods of moments. The friction factor of the helical static mixer is much smaller than that of the Kenics static mixers. The pressure drop increases with the Reynolds number, and the increment is larger when the Reynolds number is higher. The equidistant pressure drop increases with the argument of Reynolds number, and increases when the pitch decreases from upstream to downstream. The energy expenditure increases significantly when the variable-pitch coefficient is too small. The bubble geometric mean diameter decreases and the geometric standard deviation increases when the gas–liquid fluid flows through the mixer. The variable pitch structure enhances the bubble breakup effectively. The change of the bubble size decreases with the argument of the Reynolds number. The effect of the mixer has a limitation on breaking the bubbles.

Fast Evolution of Sulfuric Acid Aerosol Activated by External Fields for Enhanced Emission Control.

Sulfuric acid aerosol (SAA) can considerably deteriorate air visibility, which poses a threat to human health. Pretreatment methods that enlarge SAA sizes are crucial to enhanced emission control from industrials. This study provides an insight into SAA growth in terms of aerosol dynamics simulation and growth experiments under simulated flue gas conditions. Results show that SAA growth dynamics are dominated by coagulation and condensation mechanisms for small and large aerosols, respectively. The two mechanisms are coupled mainly in SAA sizes smaller than 0.05 μm. A large amount of time was allotted for the SAA distribution to grow into an approximately log-normal form without the use of any activation methods. Cooling gas and corona discharge can both enhance SAA growth. Cooling gas is in charge of condensation, whereas corona discharge mainly acts on coagulation. They exhibited 14.3% and 12.3% increases in mean diameter and 12.3% and 69.1% decreases in number concentration. In contrast, adding vapor led to a 1.58% decrease in mean diameter and a 9.4% increase in number concentration. Findings suggest that combining cooling gas and corona discharge to simultaneously promote coagulation and condensation and reduce SAA emission from humid flue gas is possible.

On the cumulative dam impact in the upper Changjiang River: Streamflow and sediment load changes

Climate change and anthropogenic activities such as dam construction alter basin-scale hydrological regime of a river. The upper Changjiang River (uCR) stands out as one of the most heavily dammed rivers in the world after the construction of the Three Gorges Dam (TGD) and other large dams in its mainstem. Quantification of the cumulative dam impact is prerequisite for better river management. In this work, we provide a rigorous appraisal of the changes in streamflow, sediment load, and sediment composition at multiple time scales throughout the uCR based on data in 1950–2017. We observed that a decreasing trend in annual streamflow has emerged since 2015 at Yichang, the outlet of the uCR basin, although the changes were statistically insignificant for the first 65 years. The annual sediment load has decreased progressively and substantially, e.g., by 97% in 2010s compared to 1950s at Yichang. The Three Gorges Dam and the new large dams in the upstream mainstem accelerated the sediment load reduction in 2003 and 2014, respectively. As a result, the suspended sediment became finer, with a decrease in mean diameter from 17 μm in the 1960s to 8 μm in the 2010s at Yichang. We established a reservoir storage capacity index, which is the ratio of the total reservoir storage capacity to annual streamflow, and identified a threshold of 4% larger than which the cumulative dam impact will induce profound sediment load reduction. We concluded that climate change and anthropogenic activities, in particular the large dams in the mainstem, have transformed the uCR system from a turbulent and muddy river to a placid one, which can affect fluvial processes as well as aquatic ecosystems by altering sediment and nutrient concentrations and ratios. These hydro-morphological changes merit the urgent attention of concerned authorities.

Abstract 5157: Comparison of exosomes shed by breast cancer cell lines with varying metastatic potential

Abstract Exosomes are endosomal secreted vesicles containing a variety of genetic and non-genetic material that can be transferred between cells (DNA, RNA, protein, lipid, etc.). Cancer derived exosomes have been implicated in a wide range of cancer mechanisms such as promotion of tumor growth, tumor angiogenesis, immune evasion, drug resistance, and metastasis. In addition to functional significance, cancer exosomes may possess novel biomarkers with potential uses for non-invasive liquid biopsies for cancer detection and monitoring of disease progression. Here we examined differences that may exist in extracellular vesicles or exosomes (EVs) shed by cancer cell lines with various metastatic potential (MDA-MB-231, highly metastatic; MCF-7, weakly metastatic; MCF-10a, normal breast epithelial cells). Morphological analysis of EVs was performed using fluorescent Nanosight Tracking Analysis and revealed decreased mean diameter of EVs derived from MCF-7 cells compared to the other two cell lines, there was also increased exosome particle yield in this cell line. Small RNAs from EVs cargo were also analyzed via sequencing (exoRNA-Seq). The majority of sequenced RNA aligned to coding regions of the human genome (~60%) across all cell lines. Non-coding RNA classification also showed little variability across cell lines examined regardless of metastatic potential, with ~38% of RNA reads corresponding to non-coding RNAs. Pairwise comparison of these cell lines demonstrated that each line packaged unique cargos into their shed exosomes. The non-coding regions corresponded to a variety of small RNAs (miRNA, snoRNA, snRNA, miscRNA, rRNA) but included other RNA features such as pseudogenes and antisense RNAs. We found 304 genes significantly up-regulated and 150 genes significantly down-regulated when comparing metastatic cancer exosomes (MCF-7 and MDA-MB-231) to normal, non-tumorigenic exosomes (MCF-10A). Among examined microRNAs we found several miRNAs associated with metastatic behavior that have previously been implicated in cancer biology, which will be prioritized for validation. Also, 21 RNAs were upregulated at high levels in exosomes shed by metastatic cells, and their expression level was directly proportional with the metastatic character, suggesting that these RNAs may be tested for their potential as biomarkers. Future research will expand upon these newly identified genetic signatures of metastatic exosomal cargo and further validate their influence in driving metastasis. This study received funding from DOD grant BC151687. This work was conducted under the auspices of the USDOE by LLNL (DE-AC52-07NA27344). IM number: LLNL-POST-758941 Citation Format: Kelly A. Martin, Nicholas R. Hum, Aimy Sebastian, Gabriela G. Loots. Comparison of exosomes shed by breast cancer cell lines with varying metastatic potential [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5157.

Dual-targeting and microenvironment-responsive micelles as a gene delivery system to improve the sensitivity of glioma to radiotherapy

Dbait is a small double-stranded DNA molecule that has been utilized as a radiosensitizer to enhance the sensitivity of glioma to radiotherapy (RT). However, there is no effective drug delivery system to effectively overcome the bloodbrain barrier (BBB). The aim of this study was to develop a gene delivery system by using the BBB and glioma dual-targeting and microenvironment-responsive micelles (ch-Kn(s-s)R8-An) to deliver Dbait into glioma for RT. Angiopep-2 can target the low-density lipoprotein receptor-related protein-1 (LRP1) that is overexpressed on brain capillary endothelial cells (BCECs) and glioma cells. In particular, due to upregulated matrix metalloproteinase 2 (MMP-2) in the tumor microenvironment, we utilized MMP-2-responsive peptides as the enzymatically degradable linkers to conjugate angiopep-2. The results showed that ch-Kn(s-s)R8-An micelles maintained a reasonable size (80–160 nm) with a moderate distribution and a decreased mean diameter from the cross-linking as well as exhibited low critical micelle concentration (CMC) with positive surface charge, ranging from 15 to 40 mV. The ch-K5(s-s)R8-An/pEGFP showed high gene transfection efficiency in vitro, improved uptake in glioma cells and good biocompatibility in vitro and in vivo. In addition, the combination of ch-K5(s-s)R8-An/Dbait with RT significantly inhibited the growth of U251 cells in vitro. Thus, ch-K5(s-s)R8-An/Dbait may prove to be a promising gene delivery system to target glioma and enhance the efficacy of RT on U251 cells.

Green acid-free one-step hydrothermal ammonium persulfate oxidation of viscose fiber wastes to obtain carboxylated spherical cellulose nanocrystals for oil/water Pickering emulsion

Textile manufacturing industries produce large amounts of viscose fiber wastes (VFW), causing serious environmental pollution. This study presents an acid-free approach to prepare spherical cellulose nanocrystals (SCNs) with carboxyl groups from industrial VFW by one-step hydrothermal ammonium persulfate (APS) oxidation. Novel double-response surface methodology was employed to optimize the reaction conditions. A maximum yield (37.89%) of carboxylated SCN was obtained at reaction time of 4 h, APS concentration of 1 M and temperature of 80 °C, while the SCNs showed gradual size reductions along with increase of carboxyl contents as reaction time and APS concentration increased. Interestingly, it was possible to obtain carboxylated SCNs in only 2 h of reaction with an increase of 16.5% in the crystallinity index, which was attributed to efficient swelling of cellulose chains and oxidation interaction of surface groups under hydrothermal condition. Compared with SCN-2 h, the crystallinity index and maximum degradation temperature of SCN-10 h were improved by 5.5% and 17.9 °C, respectively. Moreover, SCN-10 h exhibited excellent emulsifying capacity to stabilize soybean oil/water Pickering emulsion droplets and emulsion volume were increased with decreased mean diameter of emulsion droplets as SCN-10 h concentration increased. These results indicate that VFW is an attractive source to produce carboxylated SCNs by APS oxidation, making SCN extraction as value-added alternatives to recycle this waste. Such carboxylated SCNs have great potentials as green food Pickering emulsion stabilizers and nanofillers in high-performance composites.

Influence of Milling parameters in the morphology of nanostructured CrC-30wt%NiCr

Nanostructured CrC-30wt%NiCr powders were synthesized by high energy ball milling in a planetary ball mill. Two ball-to-powder ratios, four milling times and two milling speeds were used. Morphology, average grain diameter, and phase transformation of the powders were characterized by scanning electron microscopy (SEM), particle size analysis, and X-ray diffraction (XRD). Crystallite size and mean diameter decrease with increase in BPR, milling time and speed. The results show that with the use of a ball-to-powder weight ratio of 1:20, a milling time of 1h and a milling speed of 500 rpm, the average particle size and crystallite size were respectively 5.6µm and 8.3nm.

Synthesis and properties of polyacrylamide by nanoparticles, effect nanoclay on stability polyacrylamide solution

Polyacrylamide (PAM)-encapsulated clay nanoparticles (NPs) were successfully synthesised by conventional emulsion polymerisation for solving the aggregation matter of nanoscaled clay. A novel nanofluid based on PAM has been developed and its' attributes have been experimentally tested as an optimised solution. The frequency, sonication time effect, NPs and polymer concentration on the constant salinity and particle size (PS) distribution of samples was investigated. The solutions of polymer at different frequencies (10, 20 and 30 kHz) were treated with ultrasound for different times (5 and 15 min). The results showed that increasing sonication time decreased mean diameter of nanoclay mass and also showed with an increment range of frequency in specified range improved rheology and dispersion of the solution. Clay NPs were found to have a positive effect on the stability of samples.

Liquid–Liquid Mixing Studies in Annular Centrifugal Contactors Comparing Stationary Mixing Vane Options

Comparative studies of multiphase operation of an annular centrifugal contactor show the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported for operation of a 12.5 cm engineering-scale contactor unit. Fewer straight vanes give greater mixing-zone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugal contactors.

Small angle neutron scattering analyses and high temperature mechanical properties of nano-structured oxide dispersion-strengthened steels produced via cryomilling

Three oxide dispersion-strengthened (ODS) steels are produced in order to investigate the effect of the mechanical alloying (MA) temperature on the microstructural evolution and high temperature mechanical properties. The microstructural evolution with different MA conditions is examined using small angle neutron scattering. As the MA temperature decreases, the density of the nanoclusters below 10 nm increases and their mean diameter decreases. A low temperature during MA leads to a high strength in the compression tests performed at 500 °C; however, this effect disappears in testing at 900 °C. The milling process at −70 °C exhibits excellent high fracture toughness, which is better than the benchmark material 14YWT-SM10. However, the −150 °C milling process results in significantly worse fracture toughness properties. The reasons for this strong temperature dependency are discussed.