Amount Of Uptake Research Articles

Relationships between swelling temperature and shape memory properties of palmitic acid-based shape memory natural rubber

This article investigates the effect of swelling temperature on palmitic acid-based shape memory natural rubber (SMNR). SMNR has high storage modulus and excellent energy absorption capability which is suitable to replace the electronic parts in the lightweight machine. Although the swelling process increased the trigger temperature of palmitic acid-based SMNR, high thermal energy in swelling process might accelerate the degradation of the SMNR. To verify the swelling effect, two rubber sources were adopted in the sample preparation and immersed into molten palmitic acid. A custom-made elongation device which is introduced in the methodology section was used to measure the shape memory parameters under different deformation strains (100%, 200% and 300%). It was found that both swollen rubber sources stood their own beneficial shape memory parameters. For example, high shape fixation ($$>90\%$$) was found in natural rubber latex film (NRLF) specimen, while natural rubber (NR) specimens had outstanding shape recovery (100%). Swelling experiment revealed that the solvent diffusion rate was increased in higher swelling temperature, but crosslink density of rubber specimen limited the penetration of palmitic acid and maximum solvent uptake amount. Strain control mode test indicated that the swelling temperature accelerated the chain scission process which decreased the crosslink density of rubber specimens, but shape fixation was increased by high void formation. The DSC test clearly showed that trigger temperature varied with the solvent contents in the rubber specimens. Scanning electron microscopy images illustrated that the precoated palmitic acid was formed on the rubber molecules. The relationship between the swelling temperature and shape memory parameters of SMNR was established and the trigger temperature of SMNR was successfully increased near the melting temperature of fatty acid.

Global warming and acid atmospheric deposition impacts on carbonate dissolution and CO2 fluxes in French karst hydrosystems: Evidence from hydrochemical monitoring in recent decades

The long-term change in surface water chemistry over time in remote areas is usually related to global change, including several processes such as global warming and acid atmospheric pollution. These cumulative factors limit the quantitative interpretation of the global warming effect on surface water acidification in relation to the atmospheric CO2 sink. To quantitatively estimate the impact of global warming on the atmospheric/soil CO2 uptake by carbonate weathering, the approach proposed here involves discriminating the proportion of [Ca + Mg] in waters resulting from soil carbonic acid dissolution (equal to the amount of CO2 uptake from soil/atmosphere) from the proportion resulting from strong acid pollution. This approach was applied to 5 karst hydrosystems located in France, far from local pollution sources and with several decades of hydrochemical monitoring.[Ca + Mg] from acid deposition represented between 16 and 25% of the total [Ca + Mg] concentration and the flux was positively correlated with the atmospheric deposition flux. This [Ca + Mg] increase is associated with increasing [Mg] and was found to be driven by the acid pollution inputs. Equilibrating water with calcite in presence of carbonic acid will release [Ca + Mg] into solution. The input of strong acids from atmospheric pollution contributes more to magnesian calcite dissolution because its solubility is lower than that of calcite.Since the 1980s, the decrease in [Ca + Mg] production due to the decrease in acid atmospheric deposition has minimized the increase in [Ca + Mg] linked to CO2 partial pressure (pCO2) increasing with global warming. It was found that [Ca + Mg] from H2CO3 dissolution did not decrease with an increase in air temperature, as suggested by carbonate solubility. The annual fluxes of Ca + Mg from H2CO3 dissolution, calculated for an average flow, showed a positive gradient with air temperature, of about 0.061 mol m2 yr−1 °C−1 (±0.006). In low rainfall areas, the pCO2 increase with air temperature was stronger than in rainy areas. For an average specific discharge of 300 L m−2 yr−1, global warming is estimated to increase the CO2 uptake flux by about 204 micromol L−1 °C−1 (5.7% of the observed flux).

Methoxylpoly(ethylene glycol)‐retinoic acid Micelles Loaded with Dimethylcurcumin for Efficient Castration‐Resistant Prostate Cancer Therapy

AbstractDimethylcurcumin (ASC−J9, DMC), a newly developed anti‐AR agent, suppresses androgen receptor (AR) signaling pathways by degradation of full‐length and splice variant of ARs, showing efficient growth inhibition effect on castration‐resistant prostate cancer (PCa). However, DMC is extremely hydrophobic, which significantly limits its applications. Here, we developed DMC‐loaded methoxylpoly (ethylene glycol)‐retinoic acid (DMC@mPEG2000‐RA) micelles in order to improve the solubility of DMC and its effect on growth inhibition of castration‐resistant PCa. DMC@mPEG2000‐RA micelles with hydrodynamic diameter around 200 nm and drug loading content of 6.0% were prepared by thin film hydration‐ultrasonic method. The as prepared micelles show good colloidal stability in PBS buffer and 10% FBS containing PBS buffer. The in vitro drug release study shows that DMC@mPEG2000‐RA micelles exhibit initially relative fast drug release followed by sustained drug release behaviors. The cellular uptake study reveals that the cellular uptake amount of DMC@mPEG2000‐RA micelles is significantly higher than that of free DMC and caveolae plays important roles in cellular uptake of DMC@mPEG2000‐RA micelles. Finally, DMC@mPEG2000‐RA micelles exhibit significantly enhanced in vitro antitumor activity against C4‐2 and 22Rv1 cells as compared to free DMC. DMC@mPEG2000‐RA micelles were proved to be an efficient formulation of DMC for suppression of castration‐resistant PCa.

Golden speaker builder – An interactive tool for pronunciation training

The type of voice model used in Computer Assisted Pronunciation Instruction is a crucial factor in the quality of practice and the amount of uptake by language learners. As an example, prior research indicates that second-language learners are more likely to succeed when they imitate a speaker with a voice similar to their own, a so-called “golden speaker”. This manuscript presents Golden Speaker Builder (GSB), a tool that allows learners to generate a personalized “golden-speaker” voice: one that mirrors their own voice but with a native accent. We describe the overall system design, including the web application with its user interface, and the underlying speech analysis/synthesis algorithms. Next, we present results from a series of listening tests, which show that GSB is capable of synthesizing such golden-speaker voices. Finally, we present results from a user study in a language-instruction setting, which show that practising with GSB leads to improved fluency and comprehensibility. We suggest reasons for why learners improved as they did and recommendations for the next iteration of the training.

Broad Spectrum of Antimicrobial Activity of Cotton Fabric Modified with Oxalic Acid and CuO/Cu2O Nanoparticles

This study discusses the possibility of fabrication of textile nanocomposites with antimicrobial activity against antibiotics-resistant bacterial strains and yeast. Modification of cotton fabric with oxalic acid solutions of different concentrations provided free carboxyl groups for binding of Cu2+ -ions from copper (II) sulfate solution which were further reduced with sodium borohydride in alkaline solution. An increase in the concentration of applied oxalic acid resulted in larger amounts of free carboxyl groups on the cotton fibers, Cu2+ -ions uptake and total amounts of Cu-based nanoparticles after reduction. XPS and XRD analyses suggested that nanoparticles mainly consisted of CuO with fractions of Cu2O. Fabricated textile nanocomposites ensured maximum reduction of Gram-negative E. coli ATCC 25922, E. coli NCTC 13846, E. coli ATCC BAA-2469, K. pneumoniae ATCC-BAA 2146 and P. aeruginosa ATCC 27853, Gram-positive bacteria S. aureus ATCC 25923 and S. aureus ATCC 43300 and yeast C. albicans ATCC 24433. Additionally, controlled release of Cu2+ -ions from fabrics into the physiological saline solution was obtained within 24 hours.

Central venous access device-related sheaths: a predictor of infective and thrombotic incidence?

Central vascular access device (CVAD)-related sheaths, sometimes described as 'fibrin sheaths', may result in minor or significant sequelae, from persistent withdrawal occlusion (PWO) to infective sheaths associated with increased morbidity and mortality. The authors studied 179 patients who underwent isotope scans, where isotope was infused via the CVAD. Isotope was found to bind to the sheaths around the catheters of some patients. The amount of uptake was taken to be an extent to which a sheath had developed around the CVAD. The degree of uptake of isotope was categorised into three groups: low uptake, moderate uptake and high uptake. Patients were then followed up from the date the CVAD was inserted to 12 months after the date of the isotope scan, until the device was removed or to the date the patient died, to identify incidence of infection, thrombosis and PWO. PWO incidence in all levels of uptake was around 5-7%. Bloodstream infection (BSI) incidence for low uptake was 7% (9/130), moderate uptake 10% (3/30) and for patients with significant uptake 16% (3/19). Thrombosis for no uptake was less than 1% (1/130), moderate uptake 7% (2/30), and significant uptake had no incidence of thrombosis. Total complications: no uptake 15%, moderate uptake 23% and significant uptake 21%. This single-centre study showed that patients with isotope-highlighted sheaths experienced higher incidence of infective, thrombotic and total complications.

Multifunctional periodic mesoporous benzene-silicas for evaluation of CO2 adsorption at standard temperature and pressure

Abstract Bi-functional periodic mesoporous organosilicas (PMOs) embedded with phenylene- and isocyanurate-bridging groups have been synthesized by a one-pot co-condensation method using 1,4-bis(triethoxysilyl)benzene and tris[3-(trimethoxysilyl)propyl]isocyanurate precursors in the presence of a poly(ethylene oxide)-poly( dl -lactic acid-co-glycolic acid)-poly(ethylene oxide) (PEO-PLGA-PEO) triblock copolymer named LGE54 under acidic conditions. Block copolymer template has been removed by solvent-extraction to get the template-free PMO whereas PLGA block chains from the copolymer template were also removed selectively by thermal treatment at 250 °C retaining PEO chains inside the silica framework. Furthermore, the bi-functional PMO and tri-functional PEO containing PMOs were modified with N-[3-(trimethoxysilyl)propyl]ethylenediamine to prepare amine-coated PMOs on the pore surface. The bi-, tri-, and tetra-functional PMO samples have been thoroughly characterized using small angle X-ray scattering (SAXS) and nitrogen adsorption isotherms to resolve the presence of ordered mesostructure and surface area of the PMOs. Also, solid-state 13C- and 29Si CP-MAS NMR studies have been performed to investigate significant chemical linkages from amine-containing modifiers and poly(ethylene oxide) group inside and on the surface of PMO samples. Scanning electron microscopic (SEM), elemental analysis, and thermogravimetric analysis (TGA) have been carried out to obtain the morphology, elemental percentage and thermal stability of the multi-functional PMO samples, respectively. CO2 capture has been investigated on multi-functional PMO samples at 25 °C and 1 atm using a mixed flow by 3:2 vol ratio of CO2 and N2 gas. Amine-functionalized PMO has shown significantly higher amount of CO2 uptake than those obtained using PMO itself and the respective PMOs modified with different functionalities.

Adsorptive recovery of Au(III) from aqueous solution using crosslinked polyethyleneimine resins.

Resin adsorption is considered as a promising method to recover gold ions from wastewater, but further reduction reaction is required to convert gold ions into particles. In this study, a crosslinked polyethyleneimine resin (CPEIR) was developed via a suspension polymerization of polyethyleneimine (PEI) and ethylene glycol diglycidyl ether (EGDE) for gold recovery. The Au(III) adsorption capacities of CPEIR were significantly impacted by solution pH and initial Au(III) concentrations but unaffected by co-existing metal ions. Compared with commercial anion-exchange resin IRA400, the CPEIR exhibited higher sorption amount and selectivity for Au(III) due to its high density of amine and hydroxyl groups on the surfaces. The adsorption isotherm of Au(III) on CPEIR was well described by the Langmuir equation, and the maximum uptake amount of Au(III) was high up to 943.5 mg/g, much higher than the reported sorbents. The adsorption kinetic data on the CPEIR were fitted well by the Pseudo-second-order equation, and the intraparticle diffusion was found to be the rate-controlling process of Au(III) adsorption. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis confirmed that Au(III) ions were adsorbed on the CPEIR via electrostatic attraction and chelating interaction, and subsequently the partial loaded Au(III) ions were reduced to elemental gold whereas the hydroxyl groups of CPEIR were oxidized to carbonyl groups.

Effect of the Metal within Regioisomeric Paddle-Wheel-Type Metal-Organic Frameworks.

The effect of metal on the degree of flexibility upon evacuation of metal-organic frameworks (MOFs) has been revealed with positional control of the organic functionalities. Although Co-, Cu-, and Zn-based DMOFs (DMOF = DABCO MOF, DABCO = 1,4-diazabicyclo[2.2.2]octane) with ortho-ligands (2,3-NH2 Cl) have frameworks that are inflexible upon evacuation, MOFs with para-ligands (2,5-NH2 Cl) showed different N2 uptake amounts after evacuation by metal exchange. Considering that the structural analyses were not fully sufficiently different to explain the drastic changes in N2 adsorption after evacuation, quantum chemical simulation was explored. A new index (η) was defined to quantify the regularity around the metal based on differences in the oxygen-metal-oxygen angles. Within 2,5-NH2 Cl, the η value becomes larger as the metal are varied from Co to Zn. A large η value means that the structures around the metal center are less ordered. These results can be used to explain flexibility changes upon evacuation by altering the metal cation in this regioisomeric system.

Effects of Different Nitrogen and Irrigation Amount on Growth, Evapotranspiration and Water and Nitrogen Use Efficiency of Jatropha Curcas L.

In order to study the effects of different nitrogen and irrigation water patterns on water and nitrogen use efficiency of Jatropha curcas L., three water levels (W1:100% ET (ET as evapotranspiration), W2:80% ET, W3:60% ET), and three nitrogen application levels (N1:0g.kg-1, N2:0.4g.kg-1, N3:0.8g.kg-1) were designed. The results showed that compared with T1, each organ and total dry matter of Jatropha curcas L. decreased in T2 and T3. Besides, nitrogen application significantly increased each organ and total dry matter of Jatropha curcas L. Compared with W1N3(high water and nitrogen content), W2N2 treatment saved 20% water and 50% nitrogen fertilizer. Its irrigation water uses efficiency and total amount of nitrogen uptake in per plant increased by 26% and 64.88%. Therefore, W2N2 treatment is the best irrigation and nitrogen application pattern for the growth, the use efficiency of water and nitrogen of Jatropha curcas L.

Study on the dissolution of hollow mesoporous silica nanosphere-supported nanosized platinum oxide in biorelevant media for evaluating its potential as chemotherapeutics

Platinum oxide (PtOx) nanoparticles (NPs) have been shown to possess anticancer activity by releasing ionic Pt species under biological conditions. However, the dissolution kinetics and the changes in the chemical state of Pt during PtOx dissolution have not yet been studied. To fill this gap, we prepared a composite (designated as PtOx@MMT-2) containing PtOx NPs on hollow mesoporous silica nanospheres and studied the dissolution of the material in different biorelevant media. We found that the release of Pt was retarded due to the adsorption of biomolecules on PtOx NPs during the degradation of host silica. The biomolecules adsorption also lowered the accessibility of PtOx NPs, resulting in the reduced catalase-like activity of the NPs. In line with the results, the cytotoxicity of PtOx@MMT-2, which was positively correlated to the amount of Pt uptake, was reduced by biomolecules adsorption. Our findings should be applicable to other metal (oxide) NPs under biological conditions and may provide implications for the design of nanomaterials for practical therapeutic applications.

Inflammatory role of extracellular sphingolipids in Cystic Fibrosis

Ceramide is emerging as one of the players of inflammation in lung diseases. However, data on its inflammatory role in Cystic Fibrosis (CF) as part of the extracellular machinery driven by lung mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) are missing.We obtained an in vitro model of CF-MSC by treating control human lung MSCs with a specific CFTR inhibitor. We characterized EVs populations derived from MSCs (ctr EVs) and CF-MSCs (CF-EVs) and analyzed their sphingolipid profile by LC–MS/MS. To evaluate their immunomodulatory function, we treated an in vitro human model of CF, with both EVs populations.Our data show that the two EVs populations differ for the average size, amount, and rate of uptake. CF-EVs display higher ceramide and dihydroceramide accumulation as compared to control EVs, suggesting the involvement of the de novo biosynthesis pathway in the parental CF-MSCs. Higher sphingomyelinase activity in CF-MSCs, driven by inflammation-induced ceramide accumulation, sustains the exocytosis of vesicles that export new formed pro-inflammatory ceramide.Our results suggest that CFTR dysfunction associates with an enhanced sphingolipid metabolism leading to the release of EVs that export the excess of pro-inflammatory Cer to the recipient cells, thus contributing to maintain the unresolved inflammatory status of CF.

Investigation into Deep Breathing through Measurement of Ventilatory Parameters and Observation of Breathing Patterns.

In this protocol, two deep breathing patterns were shown to 15 participants to determine an easy yet effective method of breathing exercise for future application in a clinical setting. The women in their twenties were seated comfortably in a chair with back support. They were fitted with an airtight mask connected to agas analyzer. Three electrodes were placed on the chest connected to a wireless transmitter for relaying to the electrocardiograph. They executed a 5 min rest phase, followed by 5 min of deep breathing with a natural breathing pattern, terminating with a 5 min rest phase. This was followed by a 10 min intermission before commencing the second instruction phase of substituting the natural breathing pattern with the diaphragmatic breathing pattern. Simultaneously, the following took place: a) continuous collection, measurement and analysis of the expired gas to assess the ventilatory parameters on a breath-by-breath basis; b) measurement of the heart rate by an electrocardiograph; and c) videotaping of the participant's thoracoabdominal movement from a lateral aspect. From the video capture, the investigators carried out visual observation of the fast-forward motion-images followed by classification of the breathing patterns, confirming that the participants had carried out the method of deep breathing as instructed. The amount of oxygen uptake revealed that, during deep breathing, the work of breathing decreased. The results from the expired minute ventilation, respiration rate and tidal volume confirmed increased ventilatory efficiency for deep breathing with the natural breathing pattern compared to that with the diaphragmatic breathing pattern. This protocol suggests a suitable method of instruction for assessing deep breathing exercises on the basis of oxygen consumption, ventilatory parameters, and chest wall excursion.

Corrosion protection of steel by Mg-Al layered double hydroxides in simulated concrete pore solution: Effect of SO42-

This paper aims to evaluate the effect of SO42− ions on the corrosion protection of steel by Mg-Al layered double hydroxides (LDHs), which was synthesized by traditional co-deposition method. The results show that the presence of SO42− ions greatly affects the uptake amount of Cl- ions. The prepared Mg-Al LDHs has an obvious corrosion inhibition effect on steel. With the increase of SO42− content, the steel corrosion is initially decreased and then increased. The microstructure characterization demonstrates the uptake of Cl- and SO42− on Mg-Al LDHs, which mainly contribute to the corrosion inhibition of LDHs.

Quantification and micro-mechanisms of CO2 sequestration in magnesia-lime-fly ash/slag solidified soils

The combined use of CO2 and industrial by-products offers a novel alternative to traditional Portland cement in soil stabilization, sequestering permanently CO2 emissions and producing low-carbon cementitious materials in an accelerated carbonation environment. This study attempts to propose two approaches to evaluate the CO2 uptake amount of reactive magnesia-lime-fly ash/slag solidified soils, rather than soil improvement proved by previous findings. The CO2 uptake efficiency, pore structure and micro-mechanisms are examined, and the carbon footprint of each designed mixture is evaluated based on life cycle assessment. The key outcomes from accelerated carbonation, mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) tests reveal that: (i) CO2 uptake amount and uptake efficiency estimated by direct weight gain are largely greater than that defined by indirect thermogravimetric analysis, (ii) CO2 uptake amount and uptake efficiency tend to increase with carbonation duration, binder content and mass ratio of magnesia/lime, (iii) accelerated carbonation induces reduced total pore volume, smaller pore size and denser microstructure and reactive magnesia contributes more than lime in filling pore spaces, (iv) magnesium and calcium carbonates are formed in magnesia-lime-fly ash/slag solidified soils storing permanently CO2, and (v) carbon emissions for magnesia-lime-fly ash/slag blends are greatly reduced during their whole product life cycle in comparison to Portland cement.

Development of drug-coated balloon for the treatment of multiple peripheral artery segments

ObjectivePeripheral artery disease is the second most common cardiovascular disease. It can often occur in complex form when there is a presence of long, diffuse, and multiple lesions. Current treatments use either single long drug-coated balloons (DCBs) or multiple DCBs; however, treatment success is limited. The purpose of this study was to investigate the preclinical feasibility of our multiple-release Tailored Medical Devices DCB (MR-TMD-DCB) to treat multiple arterial segments using a single DCB. MethodsThe MR-TMD-DCBs were developed using a two-layer coating approach. The DCBs were developed in a certified Current Good Manufacturing Practices facility using presterilized materials and reagent and then characterized for coating morphology, thermal and chemical changes, and in vitro particulate shedding. The drug loss, tissue uptake, and undelivered drug amounts were analyzed using an in vitro peripheral artery flow model and explanted pig arteries. Then, an in vivo survival study was performed using a healthy porcine model to measure the short-term drug uptake (seven swine; 14 treatments at day 1) and retention (seven swine; 14 treatments at day 7) in two different arterial segments after treatment with a single MR-TMD-DCB. ResultsThe coating on the MR-TMD-DCB was smooth and homogeneous with paclitaxel molecularly dispersed in its amorphous state. A negligible number of particulates were shed from the MR-TMD-DCB coating. A similar amount of drug was accurately delivered into two separate explanted arteries using a single MR-TMD-DCB during the in vitro flow model testing (707 ± 109 ng/mg in the first explanted artery and 783 ± 306 ng/mg in the second explanted artery). The MR-TMD-DCB treatment resulted in equivalent drug amounts in the two arterial segments at day 1 (63 ± 19 ng/mg in the first treatment site and 59 ±19 ng/mg in the second treatment site) and at day 7 (9 ± 6 ng/mg in the first treatment site and 10 ± 6 ng/mg in the second treatment site). In addition, the drug levels at each time point were in the clinically relevant range to prevent neointimal hyperplasia. ConclusionsThe MR-TMD-DCBs provided equivalent and clinically relevant drug retention levels into two different arterial segments. Thus, MR-TMD-DCBs can be used to accurately deliver drug into multiple arterial segments with the use of a single DCB. The clinical outcomes of these findings need further investigation. Future long-term pharmacokinetics and safety studies will be performed to evaluate the safety and efficacy of the MR-TMD-DCB.

Lethality and kinetic of diatomaceous earth uptake by the bean weevil (Acanthoscelides obtectus [Say] Coleoptera: Bruchinae): Influence of short-term exposure period

Laboratory bioassays were carried out to assess the lethal effect of the diatomaceous earth (DE) formulation Fossil-Shield® against males and females of adult bean weevils (Acanthoscelides obtectus [Say]). Kinetics of the DE uptake experiment was determined by using manganese as a trace element. The adherence of DE to the common bean was also measured in this study. The mortality of weevils was evaluated after exposure to eight different DE dosages (400–4000 mg/kg) after 1, 2 and 4 days, respectively. DE dust was more lethal to male than female weevils within shorter exposure period at low DE dosages (<2400 mg/kg). However, LD99 values did not show a significant difference (P > 0.05) between sexes. DE adherence ratio ranged between 73% and 98% at the highest (3600 mg/kg) and the lowest (400 mg/kg) DE dosages, respectively. The maximum saturated amount of DE retention on the bean surface was approximately 7.14 μg/mm2. The amount of DE uptake by a weevil was significantly increased (P < 0.05) with DE dosage and exposure time. The two-compartment kinetic model fitted well to the experimental data as a two-site reaction model over the range of DE dosage between 500 and 2000 mg/kg. According to the model, bean weevils can take-up 2.3–3.1 μg/mm2 of DE based on their corresponding LD99 values depends on the exposure period. It was observed that DE particles were incorporated into the epicuticle lipid layer at a rate of 1.18 × 10−3 μg mm−2 min−1 during DE uptake by a weevil. This indicates that from the total body weight, approximately 2% of DE taken-up by an insect within a given exposure period was more decisive for insect mortality than the rate of DE application.

Trehalose uptake and dehydration effects on the cryoprotection of CHO–K1 cells expressing TRET1

Chinese hamster ovary cells (CHO–K1 cells) in which the trehalose transporter (TRET1) is expressed can have greater cryoprotection than ordinary CHO–K1 cells. This study examines the uptake characteristics of trehalose into cells via TRET1 and determines the influence of intracellular trehalose on the freeze–thaw viabilities. In our experiments, the intracellular trehalose concentration is controlled by the extracellular trehalose concentration and the immersion time in a freezing solution. In this freezing solution, both kinds of CHO–K1 cells are independently dispersed with various amount of trehalose, and then put into the CO2 incubator for 0–6 h. After a set immersion time, the cell-suspended sample is cooled to 193 K, stored for 1 week, then quickly thawed at 310 K and its viability measured. The uptake amount of intracellular trehalose is measured before freezing. We find an upper limit for the uptake amount of trehalose when the extracellular trehalose concentration is about 400 mM, at which the freeze–thaw viability is the highest. When the extracellular trehalose concentration exceeds 400 mM, shorter immersion times are needed to obtain the maximum freeze–thaw viability. Also, longer immersion weakens the cells. Our analyses indicate that when the extracellular trehalose-concentration is less than 400 mM, the trehalose uptake occurs more slowly with less dehydration, resulting in less stress on the cell. When the extracellular trehalose concentration exceeds the saturation level, the cell is stressed by the excess dehydration due to the remaining osmotic pressure, with apoptosis occurring before freezing.

Decoding Live Cell Interactions with Multi-Nanoparticle Systems: Differential Implications for Uptake, Trafficking, and Gene Regulation.

Surface modification with oligonucleotides renders gold nanoparticles to endocytose through very different pathways as compared to unmodified ones. Such oligonucleotide-modified gold nanoparticles (OGNs) have been exploited as effective nanocarriers for gene regulation therapies. Notably, in an effort to reduce overall dosage and provide safer transition to the clinic, cooperative systems composed of two or more discrete nanomaterials have been recently proposed as an alternative to intrinsically multifunctional nanoparticles. Yet, our understanding of such systems designed to synergistically cooperate in their diagnostic or therapeutic functions remains acutely limited. Specifically, cellular interactions and uptake of OGNs are poorly understood when the cell simultaneously interacts with other types of nanoparticles. Here, we investigated the impact of simultaneous uptake of similar-sized iron oxide nanoparticles (IOPs) on the endocytosis and gene regulation function of OGNs, whose analogues have been proposed for sensitization, targeting, and treatment of tumors. We discovered that both the OGN uptake amount and, remarkably, the gene regulation function remained stable when exposed to a very wide range of extracellular concentrations of IOPs. Additionally, the co-localization analysis showed that a proportion of OGNs was co-localized with IOPs inside cells, which hints at the presence of similar trafficking pathways for OGNs and IOPs following endocytosis. Taken together, our observations indicate that while the OGN endocytosis is highly independent of the IOP endocytosis, it shares transport pathways inside cells-but does so without affecting the gene regulation behavior. These results provide key insights into concomitant interactions of cells with diverse nanoparticles and offer a basis for the future design and optimization of cooperative nanomaterials for diverse theranostic applications.

Eosin Removal by Cetyl Trimethylammonium-Cloisites: Influence of the Surfactant Solution Type and Regeneration Properties.

The effect of the counteranion of hexadecyltrimethylammonium salts on the physico-chemical properties of organoclays was investigated, using a selected natural clay mineral with a cation exchange capacity of 95 meq/100 g. The uptake amount of C16 cations was dependent on the hexadecyltrimethylammonium (C16) salt solution used, the organoclay prepared from C16Br salt solution exhibited a value of 1. 05 mmole/g higher than those prepared from C16Cl and C16OH salt solutions. The basal spacing of these organoclays was in the range of 1.81 nm to 2.10 nm, indicating a similar orientation of the intercalated surfactants, and could indicated that the excess amount of surfactants, above the cation exchange capacity of 0.95 meq/g could be adsorbed on the external surface of the clay mineral sheets. These organoclays were found to be stable in neutral, acidic, and basic media. The thermal stability of these organoclays was carried out using thermogravimetric analysis and in-situ X-ray diffraction (XRD) techniques. The decomposition of the surfactant occurred at a maximum temperature of 240 °C, accompanied with a decrease of the basal spacing value close to 1.42 nm. The application of these organoclays was investigated to remove an acidic dye, eosin. The removal amount was related to the initial used concentrations, the amount of the surfactants contents, and to the preheated temperatures of the organoclays. The removal was found to be endothermic process with a maximum amount of 55 mg of eosin/g of organoclay. The value decreased to 25 mg/g, when the intercalated surfactants were decomposed. The reuse of these organoclays was limited to four regeneration recycles with a reduction of 20 to 30%. However, noticeable reduction between 35% to 50% of the initial efficiency, was achieved after the fifth cycle, depending of the used organoclays.