Induced expression of AMOT reverses adriamycin resistance in breast cancer cells.

Adriamycin (ADR) is widely used against breast cancer, but subsequent resistance always occurs. YAP, a downstream protein of angiomotin (AMOT), importantly contributes to ADR resistance, whereas the mechanism is largely unknown. MCF-7 cells and MDA-MB-231 cells were used to establish ADR-resistant cell. Then, mRNA and protein expressions of AMOT and YAP expressions were determined. After AMOT transfection alone or in combination with YAP, the sensitivity of the cells to ADR were evaluated in vitro by examining cell proliferation, apoptosis, and cell cycle, as well as in vivo by examining tumor growth. Additionally, the expressions of proteins in YAP pathway were determined in AMOT-overexpressing cells. In the ADR-resistant cells, the expression of AMOT was decreased while YAP was increased, respectively, and the nucleus localization of YAP was increased at the same time. After AMOT overexpression, these were inhibited, whereas the cell sensitivity to ADR was enhanced. However, the AMOT-induced changes were significantly suppressed by YAP knockdown. The consistent results in vivo showed that AMOT enhanced the inhibition of ADR on tumor growth, and inhibited YAP signaling, evidenced by decreased levels of YAP, CycD1, and p-ERK. Our data revealed that decreased AMOT contributed to ADR resistance in breast cancer cells, which was importantly negatively mediated YAP. These observations provide a potential therapy against breast cancer with ADR resistance.

Visible Light Enhancement of Biocarbon Quantum-Dot-Decorated TiO2 for Naphthalene Removal.

In this study, carbon-quantum-dot (CQD)-decorated TiO2 was prepared using an ultrasonic doping method and applied in the photocatalytic degradation of naphthalene under sunlight irradiation. The CQDs were synthesized from a typical macroalgae via diluted sulfuric acid pretreatment and hydrothermal synthesis using an optimal design, i.e., 3 wt% and 200 °C, respectively. The CQD/TiO2 composite remarkably enhanced the photocatalytic activity. The degradation of naphthalene under a visible light environment indicated that there is a synergistic mechanism between the CQDs and TiO2, in which the generation of reactive oxygen species is significantly triggered; in addition, the N that originated from the macroalgae accelerated the photocatalytic efficiency. Kinetic analysis showed that the photocatalytic behavior of the CQD/TiO2 composite followed a pseudo-first-order equation. Consequently, our combined experimental approach not only provides a facile pretreatment process for bio-CQDs synthesis, but also delivers a suitable TiO2 photocatalyst for the visible environment along with critical insights into the development of harmful macroalgae resources.

A Review of Ultrasonic Treatment in Mineral Flotation: Mechanism and Recent Development.

Ultrasonic treatment has been widely used in the mineral flotation process due to its advantages in terms of operational simplicity, no secondary pollutant formation, and safety. Currently, many studies have reported the effect of ultrasonic treatment on mineral flotation and shown excellent flotation performance. In this review, the ultrasonic mechanisms are classified into three types: the transient cavitation effect, stable cavitation effect, and acoustic radiation force effect. The effect of the main ultrasonic parameters, including ultrasonic power and ultrasonic frequency, on mineral flotation are discussed. This review highlights the uses of the application of ultrasonic treatment in minerals (such as the cleaning effect, ultrasonic corrosion, and desulfuration), flotation agents (such as dispersion and emulsification and change in properties and microstructure of pharmaceutical solution), and slurry (such formation of microbubbles and coalescence). Additionally, this review discusses the challenges and prospects of using ultrasonic approaches for mineral flotation. The findings demonstrate that the application of the ultrasonic effect yields diverse impacts on flotation, thereby enabling the regulation of flotation behavior through various treatment methods to enhance flotation indices and achieve the desired objectives.

Sulfur migration mechanism of pig manure in supercritical water: A combined experimental and DFT study.

Pig manure (PM) is a high concentration organic waste rich in sulfur, and its biofuel contains various sulfur-containing pollutants, which reduces the safety of the products. Supercritical water (SCW) can dissolve most organic matter, which is a technology worthy of further study. In order to reduce sulfur pollution in the process of PM resource utilization and better control the conversion path of sulfur, it is necessary to explore the migration mechanism of sulfur in the whole PM-SCW gasification process. The experimental results indicated that H2S was the only gaseous product. Only inorganic compounds (S2-, S2O32- and SO42-) were detected in the liquid. Sulfur in the solid mainly included thiol/thioether, thiophene and sulfone. The influence of different reaction conditions (temperature, residence time, PM concentration and catalysts) on sulfur migration was studied in a batch reactor. It was worth noting that the catalysts had a significant effect on H2S absorption. The lowest H2S yield was 3.2 * 10-4 mol/kg and more than 70% of the sulfur was distributed in the liquid under the condition of addition of K2CO3. While, the RTH2110 fixed most of the sulfur of PM (the maximum value reached 50.94%) in the solid. Thus, adding the catalysts flexibly can choose composition of the products. Furthermore, six possible pathways of sulfur migration in the solid were designed and the kinetic parameters were calculated by density functional theory (DFT). The results provided a basis for controlling sulfur in PM. Subsequently, the sulfur migration pathways during PM-SCW gasification process were comprehensively summarized through the combination of experiment and DFT. It provided a method for sulfur treatment in PM, which had guiding significance for the realization of pollution-free treatment of PM.

Phthalocyanine blue leaching and exposure effects on Microcystis aeruginosa (cyanobacteria) of photoaged microplastics.

Light-stabilizing additives may contribute to the overall pollution load of microplastics (MPs) and potentially enter the food chain, severely threatening aquatic life and human health. This study investigated the variation between polystyrene (PS) MPs and phthalocyanine blue (CuPC)-containing MPs before and after photoaging, as well as their effects on Microcystis aeruginosa. The presence of PS-MPs increased cell mortality, antioxidant enzyme activity, and the variation in extracellular components, while the presence of CuPC exacerbated these variations. CuPC-containing MPs caused different increasing trends in superoxide dismutase and malondialdehyde activities due to electron transfer across the membrane. Transcriptomic analysis revealed that the MPs and CuPC affected various cellular processes, with the greatest impact being on cell membranes. Compared with MPs, CuPC negatively affected ribosome and polysaccharide formation. These findings provide insights into the molecular mechanisms underlying the cellular response to MPs and their associated light-stabilizer pollution and imply the necessity for mitigating the pollution of both MPs and light-stabilizers.

Directional transformation and migration pathways of nitrogen during pig manure supercritical water gasification.

Nitrogen is a valuable nutrient element in pig manure. This work focuses on investigating the distribution, directional transformation, and migration pathways to facilitate the recovery of nitrogen from supercritical water gasification products. Results indicated that no nitrogen-containing gas was detected and 12.65 % of nitrogen remained in solid products. 82.49 % of nitrogen migrated into liquid products, which are predominated by ammonia. Catalysts were employed to promote the conversion of solid nitrogen to liquid nitrogen and organic nitrogen to ammonia. Finally, 85 % of nitrogen is enriched into liquid products and ammonia predominated the liquid nitrogen. The percentage of ammonia increased to 97.51 % at 620 °C in the presence of potassium carbonate. The migration pathways indicated that nitrogen was transformed into ammonia by various intermediates such as indole. The rest of the nitrogen remained in solid products with stable quaternary-nitrogen. These findings provide valuable insights into nitrogen management and recovery.

Deep convolutional neural networks for aged microplastics identification by Fourier transform infrared spectra classification.

Infrared (IR) spectroscopy is a powerful technique for detecting and identifying Microplastics (MPs) in the environment. However, the aging of MPs presents a challenge in accurately identification and classification. To address this challenge, a classification model based on deep convolutional neural networks (CNNs) was developed using infrared spectra results. Particularly, original infrared (IR) spectra were used as the sample dataset, therefore, relevant spectral details were preserved and additional noise or distortions were not introduced. The Adam (Adaptive moment estimation) algorithm was employed to accelerate gradient descent and weight update, the Dropout function was implemented to prevent overfitting and enhance the generalization performance of the network. An activation function ReLu (Rectified Linear Unit) was also utilized to simplify the co-adaptation relationship among neurons and prevent gradient disappearance. The performance of the CNN model in MPs classification was evaluated based on accuracy and robustness, and compared with other machine learning techniques. CNN model demonstrated superior capabilities in feature extraction and recognition, and greatly simplified the pre-processing procedure. The identification results of aged commercial microplastic samples showed accuracies of 40 % for Artificial Neural Network, 60 % for Random Forest, 80 % for Deep Neural Network, and 100 % for CNN, respectively. The CNN architecture developed in this work also demonstrates versatility by being suitable for both limited data cases and potential expansion to include more discrete data in the future.

Saponin extract from Achyranthes bidentata Blume alleviates disuse-induced muscle atrophy through PI3K/Akt signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots of Achyranthes bidentata Blume are one of the regularly used herbal drugs in Chinese medicine, and has been applied for strengthening the muscle and bone for a long time. However, its effect on muscle remains unclear. AIM OF THE STUDY: This paper aims to explore the anti-muscle atrophy effect of A. bidentata, and to clarify the possible signaling pathways involved. MATERIALS AND METHODS: The saponin extract of the roots of A. bidentata (ABSE) was prepared and analyzed, and its activity on myoblast differentiation was assayed with C2C12 cell culture. ABSE was then orally administered at dosage of 35, 70 and 140 mg/kg/day to disuse-induced muscle atrophy mice. The studies on mice body weight and muscle quality were conducted, and Western blot was used for exploring the possible signaling pathways involved in the muscle protective action aided with transcriptome analysis. RESULTS: The total saponin content of ABSE was 59.1%. ABSE promoted the C2C12 cells differentiation to myotube in C2C12 differentiation assay. Further study with disuse-induced muscle atrophy mice model demonstrated that ABSE significantly increased muscle fiber diameter as well as the proportion of slow muscle fibers. Possible mechanism study aided with transcriptome analysis revealed that ABSE alleviated muscle atrophy at least through activation of PI3K/Akt pathway in vivo & vitro. CONCLUSIONS: The saponin extract of the root of A. bidentata (ABSE) has a protective effect on muscle atrophy, and showed a considerable potential in prevention and treatment of muscle atrophy.

Tibio-Femoral Contact Force Distribution of Knee Before and After Total Knee Arthroplasty: Combined Finite Element and Gait Analysis.

OBJECTIVE: To assess the tibio-femoral contact forces before and after total knee arthroplasty (TKA) in patients with knee osteoarthritis (KOA) by three-dimensional (3D) finite element analysis (FEA) models and gait analysis. METHODS: Two hospitalized patients with Kellgren-Lawrence grade IV varus KOA and two healthy subjects were enrolled in this study. Both patients underwent unilateral TKA. FEA models were established based on CT and MR images of the knees of the patients with KOA and healthy subjects. Gait analysis was performed using a three-dimensional motion capture system with a force plate. Three direction forces at the ankle joints were calculated by inverse dynamic analysis, which provided the load for the FEA models. The total contact forces of the knee joints were also calculated by inverse dynamic analysis to enable comparisons with the results from the FEA models. The total knee contact forces, maximum von Mises stress, and stress distribution of the medial plateau were compared between the patients and healthy subjects. The distributions of the medial plateau force at 2 and 6 months postoperatively were compared with the distributions of the forces preoperatively and those in the healthy subjects. RESULTS: During static standing, the medial plateau bore the most of the total contact forces in the knees with varus KOA (90.78% for patient 1 and 93.53% for patient 2) compared with 64.75 ± 3.34% of the total force in the healthy knees. At the first and second peaks of the ground reaction force during the stance phase of a gait cycle, the medial plateau bore a much higher percentage of contact forces in patients with KOA (74.78% and 86.48%, respectively, for patient 1; 70.68% and 83.56%, respectively, for patient 2) than healthy subjects (61.06% ± 3.43% at the first peak and 72.09% ± 1.83% at the second peak). Two months after TKA, the percentages of contact forces on the medial tibial plateau were 79.65%-85.19% at the first and second peaks of ground reaction forces during the stance phase of a gait cycle, and the percentages decreased to 53.99% - 68.13% 6 months after TKA. CONCLUSION: FEA showed that TKA effectively restored the distribution of tibio-femoral contact forces during static standing and walking, especially 6 months after the surgery. The changes in the gait were consistent with the changes in the contact force distribution calculated by the FEA model.

HA-20 prevents hepatocyte steatosis in metabolic-associated fatty liver disease via regulating Ca2+ relative signalling pathways.

Metabolic-associated fatty liver disease (MAFLD) is caused by hepatocyte steatosis and is associated with obesity, type II diabetes, and heart disease. There are currently no effective drugs to treat MAFLD. This study explored the effect of HA-20, an oleanolic acid derivative, on hepatocyte steatosis in MAFLD. HepG2, L02, and AML12 cells were developed using oleic acid for in vitro MAFLD cell assays, and a high-fat diet + high-fructose diet-induced (HFHF) MAFLD mouse model was established for in vivo studies. The results demonstrated that HA-20 prevented hepatocyte steatosis in cell assays and caused 26.3, 57.7 and 70.0% inhibition of triglyceride (TG) levels in the 5.0, 10.0 and 20.0 µM HA-20 groups, respectively. The EC50 values of HA-20 treatment in HepG2, L02 and AML12 cells were 9.7 ± 0.6 µM, 42.4 ± 3.5 µM and 71.0 ± 14.7 µM, respectively. HA-20 also prevented hepatocyte steatosis in the MAFLD mouse model, the liver triglyceride contents were 2.3 ± 0.4 and 1.5 ± 0.2 mmol/L in the 2.5 and 5.0 mg/kg/day HA-20 groups, lower than 6.2 ± 0.7 mmol/L in the HFHF group and 3.3 ± 0.4 mmol/L in the metformin group. Further mechanistic investigation revealed that HA-20 increased the phosphorylation of calmodulin-dependent protein kinase kinase (p-CaMKK) and the phosphorylation of AMP-activated protein kinase (p-AMPK), at least partially by increasing intracellular Ca2+ concentration, which suppressed lipogenesis and enhanced ß-oxidation. Our findings provide new insight into preventing MAFLD by increasing Ca2+ and suggest that HA-20 possesses therapeutic potential for MAFLD management.

Bioremediation of clay with high oil content and biological response after restoration.

The clay with high oil content form soil lumps, which is hard for microbes to repair. In this paper, the bioaugmentation and biostimulation technology  were applied to improve the bioremediation effect of the soil with high oil content, that modified by local cow dung and sandy soil, the ecological toxicity of the soil after restoration was further analyzed. After 53 days of bioremediation, the degradation efficiency with respect to the total petroleum hydrocarbons (TPH) content reached 76.9% ± 2.2%. The soil bacterial count of M5 group reached log10 CFU/g soil = 7.69 ± 0.03 and the results were better than other experimental groups. The relative abundances of petroleum-degrading bacteria added to M5 remained high (Achromobacter 9.44%, Pseudomonas 31.06%, and Acinetobacter 14.11%), and the proportions of some other indigenous bacteria (Alcanivorax and Paenibacillus) also increased. The toxicity of the bioremediated soil was reduced by seed germination and earthworm survival experiments.

Noncovalent Self-Assembly of Protein Crystals with Tunable Structures.

Engineering noncovalent interactions for assembling nonspherical proteins into supramolecular architectures with tunable morphologies and dynamics is challenging due to the structural heterogeneity and complexity of protein surfaces. Herein, we employed an anisotropic building block l-rhamnulose-1-phosphate aldolase (RhuA) to control supramolecular polymorphism in highly ordered protein assemblies by introducing histidine residues. Histidine-based π-π stacking interactions enabled thermodynamically controlled self-organization of RhuA to form three-dimensional (3D) nanoribbons and crystals. Self-assembly of different 3D crystal phases was kinetically modulated by the strong metal ion-histidine chelation, and double-helical protein superstructures were formed by engineering increased histidine interactions at the RhuA binding surface. Their structural properties and dynamics were determined via fluorescence microscopy, transmission electron microscopy, atomic force microscopy, and small-angle X-ray scattering. This work is aimed at expanding the toolbox for the programming of tunable, highly ordered, protein superstructures and increasing the understanding of the mechanisms of protein interfacial interactions.

The sludge-based adsorbent from oily sludge and sawdust: preparation and optimization.

Sludge-based adsorbent (S-AB) converted by oily sludge can make full use of the precious resource. In this paper, oily sludge and discarded sawdust are used to prepare adsorbent through chemical activation. The adsorbent prepared is used to adsorb raw petroleum. Firstly, the most reasonable chemical activator ZnCl2 is ascertained through parallel comparative experiments. The characterization results of N2-adsorption are consistent with adsorption experiment results, which shows that higher mesopore surface area and volume are benefitted by the adsorption process. Secondly, the optimization of preparation technology is investigated through orthogonal experiments after parallel comparative experiments. The adsorption capacity of S-AB-ZnCl2 is stronger when the preparation conditions are as follows: an activation temperature of 550°C, an activation time of 3.5 h, a solid-liquid ratio of 1:1.5, a sludge-sawdust ratio of 1:0.5 and the heating rate of 15°C/min. The maximum quantity adsorbed Q0 = 434.78 mg/g, calculated through the Langmuir adsorption isothermal models, of S-AB-ZnCl2 prepared under optimized condition is higher than that before optimization. In addition, the most reasonable kinetics fits were of the second-order model.

Precise Fabrication of De Novo Nanoparticle Lattices on Dynamic 2D Protein Crystalline Lattices.

The science of protein self-assembly has experienced significant development, from discrete building blocks of self-assembled nanoarchitectures to advanced nanostructures with adaptive functionalities. Despite the prominent achievements in the field, the desire of designing de novo protein-nanoparticle (NP) complexes and constructing dynamic NP systems remains highly challenging. In previous works, l-rhamnulose-1-phosphate aldolase (C98RhuA) tetramers were self-assembled into two-dimensional (2D) lattices via disulfide bond interactions. These interactions provided 2D lattices with high structural quality and a sophisticated assembly mode. In this study, we devised a rational design for RhuA building blocks to fabricate 2D functionalized protein lattices. More importantly, the lattices were used to direct the precise assembly of NPs into highly ordered and diverse nanoarchitectures. These structures can be employed as an excellent tool to adequately verify the self-assembly mode and structural quality of the designed RhuA crystals. The subsequent redesign of RhuA building blocks enabled us to predictably produce a novel protein lattice whose conformational dynamics can be controllably regulated. Thus, a dynamic system of AuNP lattices was achieved. Transmission electron microscopy and small-angle X-ray scattering indicated the presence of these diverse NP lattices. This contribution enables the fabrication of future NP structures in a more programmable manner with more expected properties for potential applications in nanoelectronics and other fields.

Designing Microfluidic Devices to Sort Haematopoietic Stem Cells Based on Their Mechanical Properties.

AIM: Few haematopoietic stem cells (HSCs) injected systemically for therapeutic purposes actually reach sites of injury as the vast majority become entrapped within pulmonary capillaries. One promising approach to maintain circulating HSC numbers would be to separate subpopulations with smaller size and/or greater deformability from a heterogeneous population. This study tested whether this could be achieved using label-free microfluidic devices. METHODS: 2 straight (A-B) and 3 spiral (C-E) devices were fabricated with different dimensions. Cell sorting was performed at different flow rates after which cell diameter and stiffness were determined using micromanipulation. Cells isolated using the most efficient device were tested intravitally for their ability to home to the mouse injured gut. RESULTS: Only straight Device B at a high flow rate separated HSCs with different mechanical properties. Side outlets collected mostly deformable cells (nominal rupture stress/σ R = 6.81 kPa; coefficient of variation/CV = 0.31) at a throughput of 2.3 × 105 cells/min. All spiral devices at high flow rates separated HSCs with different stiffness and size. Inner outlets collected mostly deformable cells in Devices C (σ R = 25.06 kPa; CV = 0.26), D (σ R = 22.21 kPa; CV = 0.41), and E (σ R = 29.26 kPa; CV = 0.27) at throughputs of 2.3 × 105 cells/min, 1.5 × 105 cells/min, and 1.6 × 105 cells/min, respectively. Since Device C separated cells with higher efficiency and throughput, it was utilized to test the homing ability of separated cells in vivo. Significantly more deformable cells were observed trafficking through the injured gut-interestingly, increased retention was not observed. CONCLUSION: This study applied microfluidics to separate subpopulations from one stem cell type based on their intrinsic mechanical heterogeneity. Fluid dynamics within curved devices most effectively separated HSCs. Such devices may benefit cellular therapy.

Characterising the mechanical properties of haematopoietic and mesenchymal stem cells using micromanipulation and atomic force microscopy.

BACKGROUND: Improving stem cell (SC) deformability using pre-treatment strategies, or isolating more deformable sub-populations, may prevent non-specific entrapment of injected cells, maintain circulating numbers and thus increase the likelihood of capture by microvessels in injured organs. However, nothing is currently known about the basic mechanical properties of SCs, particularly with regards their elastic characteristics. This study therefore aimed to determine the mechanical characteristics of haematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) with comparisons made to neutrophils. METHODS: Micromanipulation and atomic force microscopy (AFM) were used to quantitate mechanical properties following large and small deformations respectively of neutrophils, MSCs and naïve and stromal cell-derived factor-1α (SDF-1ɑ) or hydrogen peroxide (H2O2) pre-treated HSCs. RESULTS: Neutrophils and HSCs underwent rupture at ∼80% deformation. Nominal rupture stress (σR), nominal rupture tension (TR) and the Young's/elastic modulus at large deformations was significantly higher for neutrophils indicating they were stiffer and less deformable than HSCs. Surprisingly, MSCs did not rupture and were as deformable as HSCs despite their large size. Pre-treatment increased HSC deformability as indicated by lower rupture force, σR, TR and Young's modulus at large deformations. AFM demonstrated that pre-treatment increased the Young's modulus at smaller deformations indicating the HSC surface stiffened. This was accompanied by increased F-actin accumulation and its localisation in the cell cortex. CONCLUSION: This is the first study to precisely demonstrate that mechanical distinctions exist amongst different therapeutic SCs with regards their deformability and rupture response to applied stress. This can potentially be utilized as label-free markers in microfluidic cell sorting systems to separate sub-populations of potentially more therapeutic SCs.

Precise Self-Assembly of Nanoparticles into Ordered Nanoarchitectures Directed by Tobacco Mosaic Virus Coat Protein.

Self-assembly guided by biological molecules is a promising approach for fabricating predesigned nanostructures. Protein is one such biomolecule possessing deterministic 3D crystal structure and peptide information, which acts as a good candidate for templating functional nanoparticles (fNPs). However, inadequate coordination efficacy during the establishment of interfacial interactions with fNPs makes it highly challenging to precisely fabricate designed nanostructures and functional materials. Here, a facile and robust strategy is reported for the hierarchical assembly of fNPs into ordered architectures, with unprecedentedly large sizes up to tens of micrometers, using a hollow cylinder-shaped tobacco mosaic virus coat protein (TMV disk). The rational design of the site-specific functional groups on the TMV disk not only demonstrates the powerful capability of directing various discrete fNP assemblies with high controllability but also assists in precise assembly of a TMV monolayer sheet structure for further organizing homogeneous and heterogeneous fNP periodic lattices by varying the types of fNPs. The high precision and adjustability of the pattern fashions of different fNPs unambiguously corroborate the validity of this innovative strategy, which provides a convenient route to design and assemble protein-based hierarchical ordered architectures for use in nanophotonics and nanodevices.

The dynamic behaviors of complementary correlations under decoherence channels.

Complementary correlations can reveal the genuine quantum correlations present in a composite quantum system. Here, we explore an effective method to identify the entangled Bell diagonal states by means of Pearson correlation, one of the complementary correlations. Then, we extend this method to expose the dynamic behavior of complementary correlations under various kinds of decoherence channels. The sudden death and revival of entanglement can be explained by the idea of Pearson correlation. The threshold that is used to identify entanglement is proposed. Furthermore, we put forward a new method to expound the underlying physical mechanisms for which classical and quantum correlations suffer a sudden change in the decoherence process.

Biomechanical properties of human T cells in the process of activation based on diametric compression by micromanipulation.

A crucial step in enabling adoptive T cell therapy is the isolation of antigen (Ag)-specific CD8+ T lymphocytes. Mechanical changes that accompany CD8+ T lymphocyte activation and migration from circulating blood across endothelial cells into target tissue, may be used as parameters for microfluidic sorting of activated CD8+ T cells. CD8+ T cells were activated in vitro using anti-CD3 for a total of 4 days, and samples of cells were mechanically tested on day 0 prior to activation and on day 2 and 4 post-activation using a micromanipulation technique. The diameter of activated CD8+ T cells was significantly larger than resting cells suggesting that activation was accompanied by an increase in cell volume. While the Young's modulus value as determined by the force versus displacement data up to a nominal deformation of 10% decreased after activation, this may be due to the activation causing a weakening of the cell membrane and cytoskeleton. However, nominal rupture tension determined by compressing single cells to large deformations until rupture, decreased from day 0 to day 2, and then recovered on day 4 post-activation. This may be related to the mechanical properties of the cell nucleus. These novel data show unique biomechanical changes of activated CD8+ T cells which may be further exploited for the development of new microfluidic cell separation systems.

Quantitative nucleation and growth kinetics of gold nanoparticles via model-assisted dynamic spectroscopic approach.

Lacking of quantitative experimental data and/or kinetic models that could mathematically depict the redox chemistry and the crystallization issue, bottom-to-up formation kinetics of gold nanoparticles (GNPs) remains a challenge. We measured the dynamic regime of GNPs synthesized by l-ascorbic acid (representing a chemical approach) and/or foliar aqueous extract (a biogenic approach) via in situ spectroscopic characterization and established a redox-crystallization model which allows quantitative and separate parameterization of the nucleation and growth processes. The main results were simplified as the following aspects: (I) an efficient approach, i.e., the dynamic in situ spectroscopic characterization assisted with the redox-crystallization model, was established for quantitative analysis of the overall formation kinetics of GNPs in solution; (II) formation of GNPs by the chemical and the biogenic approaches experienced a slow nucleation stage followed by a growth stage which behaved as a mixed-order reaction, and different from the chemical approach, the biogenic method involved heterogeneous nucleation; (III) also, biosynthesis of flaky GNPs was a kinetic-controlled process favored by relatively slow redox chemistry; and (IV) though GNPs formation consists of two aspects, namely the redox chemistry and the crystallization issue, the latter was the rate-determining event that controls the dynamic regime of the whole physicochemical process.