The influence of lateral forces on the cell stiffness measurement by optical tweezers vertical indentation

We studied the lateral forces arising during the vertical indentation of the cell membrane by an optically trapped microbead, using back focal plane interferometry to determine force components in all directions. We analyzed the cell-microbead interaction and showed that indeed the force had also lateral components. Using the Hertz model, we calculated and compared the elastic moduli resulting from the total and vertical forces, showing that the differences are important and the total force should be considered. To confirm our results we analyzed cells from two breast cancer cell lines: MDA-MB-231 and HBL-100, known to have different cancer aggressiveness and hence stiffness.     

Grain count in castings: theoretical background and experimental verification

In this work, a theoretical model is proposed for heterogeneous nucleation on substrates whose size distributions can be described by the Weibull statistics. In particular, the proposed model suggests that the size distribution for the various nucleation sites is exponential in nature. Measurements of grain count were carried out on experimental Al–1·3Si and Al–5·0Cu single phase alloys inoculated using an Al–5Ti–1B master alloy. In addition, experimental nodular and flake graphite iron castings were processed under various metallurgical conditions. In single phase alloys, the area of the equiaxed dendritic grain count was estimated from the electron backscattering diffraction analysis, whereas the graphite nodule and graphite eutectic cell count were estimated on polished cast iron surface sections by stereological means. In addition, maximum undercoolings were determined by thermal analysis. The experimental outcome indicates that the grain count can be properly described by a proposed exponential function of the maximum undercooling at the onset of alloy solidification. Finally, the magnitudes of the nucleation parameters were experimentally determined in this work.     

Applying particle swarm optimization-based decision tree classifier for cancer classification on gene expression data

BackgroundThe application of microarray data for cancer classification is important. Researchers have tried to analyze gene expression data using various computational intelligence methods.PurposeWe propose a novel method for gene selection utilizing particle swarm optimization combined with a decision tree as the classifier to select a small number of informative genes from the thousands of genes in the data that can contribute in identifying cancers.ConclusionStatistical analysis reveals that our proposed method outperforms other popular classifiers, i.e., support vector machine, self-organizing map, back propagation neural network, and C4.5 decision tree, by conducting experiments on 11 gene expression cancer datasets.     

Curcumin based nanomedicines as efficient nanoplatform for treatment of cancer: New developments in reversing cancer drug resistance,rapid internalization,and improved anticancer efficacy

BackgroundCancer is a group of diseases involving an abnormal growth of cells which tend to proliferate in an uncontrolled fashion and in some cases metastasize to the surrounding tissues (malignancy). Resistance to chemotherapy is typically intrinsic (heterogeneity); however, acquired resistance has also become prevelant due to multiple factors including expression of energy-dependent transporters causing expulsion of internalized drug contents extracellular, insensitivity of tumor cells to drug-induced apoptosis, and induction of drug-detoxifying mechanisms. Curcumin (CUR) has gained widespread recognition due to remarkable anticancer, anti-mutagenic, and anti-metastasizing potentials via downregulation of proliferation of cancer cells and induction of apoptosis. Nevertheless, pharmaceutical significance and therapeutic feasibility of CUR is restricted due to intrinsic physicochemical characteristics including poor aqueous solubility, inadequate biological stability, low bioavailability, and short half-life.Scope and approachOwing to these pharmaceutical limitations of CUR, nanodelivery systems have attained remarkable fascination in the recent years. Therefore, this review was aimed to overview and critically ponders recent developments in improving anticancer viability of CUR.Key findings and conclusionCritical analysis of the literature revealed that nanodelivery systems showed promising efficiency in achieving tumor specific targetability, maximizing internalization of drugs into cancer cells, mitigating tumor metastasis, as well as improving anticancer efficacy of CUR. Moreover, nanocarrier-mediated improved pharmacokinetics, drug accumulation, induced promising cytotoxicity, and enhanced anticancer efficacy by suppressing Egr-1 induction, Mitogen-activated protein kinase (MAPK) pathway, and protein tyrosine kinase (PTK) cascades while mitigating the progression of tumor, have also been discussed.     

Effect of single and double strap backpacks on lung function

Carrying heavy and moderate military loads in backpacks or as body armour compresses the chest, causing a change in lung function that is typical of a restrictive ventilatory impairment. It is not known if a lighter backpack load of only 6?kg, such as is typical of loads carried by students, will have a similar effect on lung function. There have been no studies examining whether backpacks of different strapping styles have an effect on lung function. Several designs of student backpack have recently been introduced to the market. One of the most popular is a single-strap backpack. This study examined Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV₁), FEV₁.FVC^???1% and Peak Expiratory Flow (PEF) in 13 participants (4 males, 9 females) wearing each of two 6?kg backpacks, one with two shoulder straps (a Double Strap Backpack (DSB)) and the other with a single strap (a Single Strap Backpack (SSB)) worn across the shoulder and chest. In comparison with the control of no pack (N), SSB significantly reduced FVC (by 3.94%, p?=?0.006) but there were no significant differences in FEV₁, FEV₁. FVC^???1% and PEF. The DSB also significantly reduced FVC (by 1.97%, p?=?0.034) but no significant differences were found in FEV₁, FEV₁. FVC^???1% and PEF measures. In comparison with DSB, the SSB was associated with a significantly lower FVC (by 2.05%, p?=?0.049) and FEV₁ (by 1.88%, p?=?0.029) but there were no significant changes in FEV₁. FVC^???1% and PEF. It is concluded that a backpack load of 6?kg could produce a mild restrictive type of ventilatory impairment in lung function. This effect was greater for a single cross-chest strap than for a more conventional double strap harness.     

Antifungal activity of citral,octanal and α-terpineol against Geotrichum citri-aurantii

This study investigated the antifungal activity and potential antifungal mechanisms of three volatile compounds (i.e., citral, octanal, and α-terpineol) against Geotrichum citri-aurantii, one of the main postharvest pathogens in citrus. Results showed that the volatile compounds exhibited strong antifungal activity against the targeted pathogens, with minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 0.50 μL/mL and 1.00 μL/mL for citral, 0.50 μL/mL and 2.00 μL/mL for octanal, and 2.00 μL/mL and 4.00 μL/mL for α-terpineol. The volatile compounds alter the morphology of G. citri-aurantii hyphae by causing loss of cytoplasm content and distortion of the mycelia. The membrane permeability of the G. citri-aurantii increased with increasing concentrations of the three volatile compounds, as evidenced by cell constituent release, extracellular conductivity, and pH. Moreover, the volatile compounds induced a decrease in the total lipid content of G. citri-aurantii cells, indicating the destruction of cell membrane structures. These results suggest that the antifungal activity of citral, octanal, and α-terpineol against G. citri-aurantii could be attributed to the disruption of cell membrane integrity and leakage of cell components.     

In vitro and in silico (IVIS) flow characterization in an idealized human airway geometry using laser Doppler anemometry and computational fluid dynamics techniques

The air flow in idealized human airway geometry was studied using computational and experimental methods. A computational fluid dynamics model developed to determine the air flow characteristics in airways was validated by comparison of the experimental velocity profiles obtained with laser Doppler anemometric measurements with numerical data. A good correlation was found between the values obtained with the two methods. Both the measurements and the calculations showed the flow to be laminar in the trachea region of the airway model, but it is affected by the airway geometry in subsequent airways.     

An insight into the inhibitory activity of dihydromyricetin against Vibrio parahaemolyticus

The objective of this study is to investigate the antibacterial activity of dihydromyricetin (DMY) against Vibrio parahaemolyticus. The dilution method indicated that the minimum inhibitory concentration (MIC) of DMY against V. parahaemolyticus was at 0.625 mg/mL. The inhibitory effects of DMY against V. parahaemolyticus was further studied by analyzing cell morphology, cell injury, cell permeability, cell surface hydrophobicity (CSH) and antibacterial rate. The results showed bacterium cells are completely inactivated in a higher concentration (10 MIC). DMY treatment also lead to an increase in cell membrane permeability, cell injury as well as CSH. A good correlation between antibacterial rate and CSH was also observed. These findings indicated DMY could be used as a new alternative natural antibacterial agent for control pathogen growth in aquatic food.     

DMA thermal analysis of different parts of potato tuber

Dynamic mechanical analysis (DMA) was applied to three potato tissues (‘cortex’, ‘pith’, and ‘side’ surface) of two cultivars (more waxy ‘Nicola’ and more mealy ‘Saturna’) in temperature scans in the range 30–90 °C and constant air humidity of 90%. The obtained scans indicate peaks in both storage and loss module of elasticity (SM and LM, respectively) at temperatures higher than 70 °C – so called ‘starch’ peak (SP) – as was observed previously. The peak value increase with increasing potato dry matter (DM) content, below DM content approximately 14% no SP is observed (‘Nicola pith’). Slope analysis of the basic parameters: SM, LM, and loss tangent (LT) was performed and further characteristic points on the temperature plots were found: (i) in temperature range A (30–40 °C) maximum of SM and LM and minimum of LT, (ii) in temperature range B (40–50 °C) minimum of SM and LM slopes corresponding to point of inflection on SM-T and LM-T plots, (iii) at about 50 °C, big peak in LT in side tissue only, (iv) at about 70 °C just prior the ‘starch’ peak, big peak in LT that is more marked in ‘pith’; this peak denoted as ‘I’ influenced the ‘starch’ peak ‘II’. It was found that both cultivar and part of the tuber influences the DMA temperature plots.