Incorporation of a selective sigma-2 receptor ligand enhances uptake of liposomes by multiple cancer cells

Background: The sigma-2 receptor is an attractive target for tumor imaging and targeted therapy because it is overexpressed in multiple types of solid tumors, including prostate cancer, breast cancer, and lung cancer. SV119 is a synthetic small molecule that binds to sigma-2 receptors with high affinity and specificity. This study investigates the utility of SV119 in mediating the selective targeting of liposomal vectors in various types of cancer cells. Methods: SV119 was covalently linked with polyethylene glycol-dioleyl amido aspartic acid conjugate (PEG-DOA) to generate a novel functional lipid, SV119-PEG-DOA. This lipid was utilized for the preparation of targeted liposomes to enhance their uptake by cancer cells. Liposomes with various SV119 densities (0, 1, 3, and 5 mole%) were prepared and their cellular uptake was investigated in several tumor cell lines. In addition, doxorubicin (DOX) was loaded into the targeted and unmodified liposomes, and the cytotoxic effect on the DU-145 cells was evaluated by MTT assay. Results: Liposomes with or without SV119-PEG-DOA both have a mean diameter of approximately 90 nm and a neutral charge. The incorporation of SV119-PEG-DOA significantly increased the cellular uptake of liposomes by the DU-145, PC-3, A549, 201T, and MCF-7 tumor cells, which was shown by fluorescence microscopy and the quantitative measurement of fluorescence intensity. In contrast, the incorporation of SV119 did not increase the uptake of liposomes by the normal BEAS-2B cells. In a time course study, the uptake of SV119 liposomes by DU-145 cells was also significantly higher at each time point compared to the unmodified liposomes. Furthermore, the DOX-loaded SV119 liposomes showed significantly higher cytotoxicity to DU-145 cells compared to the DOX-loaded unmodified liposomes. Conclusion: SV119 liposomes were developed for targeted drug delivery to cancer cells. The targeting efficiency and specificity of SV119 liposomes to cancer cells was demonstrated in vitro. The results of this study suggest that SV119-modified liposomes might be a promising drug carrier for tumor-targeted delivery. © 2012 Zhang et al, publisher and licensee Dove Medical Press Ltd

Preliminary study on low-density polystyrene microplastics bead removal from drinking water by coagulation-flocculation and sedimentation

Microplastics (MPs), sized ~150 μm, have been found in tap water at levels of ~5 particles/L, suggesting that water treatment plants are not effectively removing MPs. Therefore, there is an urgent need to evaluate their fate in drinking water treatment processes. Coagulation-flocculation and sedimentation are applied in water treatment to primarily decrease turbidity, and MPs contribute to water turbidity. This study focuses on the removal of polystyrene (PS) beads of 100 μm with density 1.04–1.06 g/cm3. The low-density PS beads pose a removal challenge because they have similar density to the media. The effects of initial water pH and stirring speed on MPs removal by coagulation-flocculation and sedimentation were studied. The most effective conditions found for removing the PS beads from water, that led to removal rates up to 98.9 ± 0.94%, were 3.4 mg Al/L of coagulant, pH 5, flocculation time of 7 min and sedimentation time of 30 min. For the first time, floc breakage and regrowth following the addition of Al, has shown to favour the removal of the PS beads. Based on this research, coagulation-flocculation can play a very important role in removing MPs during drinking water treatment

Feedback-induced nonlinearity and superconducting on-chip quantum optics

Quantum coherent feedback has been proven to be an efficient way to tune the dynamics of quantum optical systems and, recently, those of solid-state quantum circuits. Here, inspired by the recent progress of quantum feedback experiments, especially those in mesoscopic circuits, we prove that superconducting circuit QED systems, shunted with a coherent feedback loop, can change the dynamics of a superconducting transmission line resonator, i.e., a linear quantum cavity, and lead to strong on-chip nonlinear optical phenomena. We find that bistability can occur under the semiclassical approximation, and photon anti-bunching can be shown in the quantum regime. Our study presents new perspectives for engineering nonlinear quantum dynamics on a chip.Comment: 10 pages, 9 figure

Application and improvement of conventional stress-wave-based non-destructive testing methods for the condition assessment of in-service timber utility poles

Timber utility poles represent a significant part of Australia’s infrastructure for power distribution and communication networks. Due to their advanced age, significant efforts are undertaken to prevent utility lines from failure. However, the lack of reliable tools for assessing the condition of in-service poles seriously jeopardizes the maintenance and asset management. Non-destructive testing (NDT) methods based on stress wave propagation can potentially offer simple and cost-effective tools for the condition assessment of in-service timber poles. Based on the impact direction and location, mainly two wave types can be excited in a pole, i.e. longitudinal and bending waves. A conventional stresswave- based method that analyses longitudinal waves is the Sonic Echo (SE) method; and a typical signal processing method for the analysis of bending waves (BW) is the Short Kernel Method (SKM). In this paper, firstly, the application of the conventional SE method and the BW method with SKM data analysis is investigated for the condition assessment of timber poles from a signal processing perspective. Secondly, to improve limitations of the current methods, the application of a multisensors array is proposed for more reliable and accurate results. The new method is validated on numerical data of a timber pole modelled with both isotropic and orthotropic material properties

Robustness trade-offs and host–microbial symbiosis in the immune system

The immune system provides organisms with robustness against pathogen threats, yet it also often adversely affects the organism as in autoimmune diseases. Recently, the molecular interactions involved in the immune system have been uncovered. At the same time, the role of the bacterial flora and its interactions with the host immune system have been identified. In this article, we try to reconcile these findings to draw a consistent picture of the host defense system. Specifically, we first argue that the network of molecular interactions involved in immune functions has a bow-tie architecture that entails inherent trade-offs among robustness, fragility, resource limitation, and performance. Second, we discuss the possibility that commensal bacteria and the host immune system constitute an integrated defense system. This symbiotic association has evolved to optimize its robustness against pathogen attacks and nutrient perturbations by harboring a broad range of microorganisms. Owing to the inherent propensity of a host immune system toward hyperactivity, maintenance of bacterial flora homeostasis might be particularly important in the development of preventive strategies against immune disorders such as autoimmune diseases

Remarks on the method of comparison equations (generalized WKB method) and the generalized Ermakov-Pinney equation

The connection between the method of comparison equations (generalized WKB method) and the Ermakov-Pinney equation is established. A perturbative scheme of solution of the generalized Ermakov-Pinney equation is developed and is applied to the construction of perturbative series for second-order differential equations with and without turning points.Comment: The collective of the authors is enlarged and the calculations in Sec. 3 are correcte

Graphene electrode modified with electrochemically reduced graphene oxide for label-free DNA detection.

A novel printed graphene electrode modified with electrochemically reduced graphene oxide was developed for the detection of a specific oligonucleotide sequence. The graphene oxide was immobilized onto the surface of a graphene electrode via π-π bonds and electrochemical reduction of graphene oxide was achieved by cyclic voltammetry. A much higher redox current was observed from the reduced graphene oxide-graphene double-layer electrode, a 42% and 36.7% increase, respectively, in comparison with that of a bare printed graphene or reduced graphene oxide electrode. The good electron transfer activity is attributed to a combination of the large number of electroactive sites in reduced graphene oxide and the high conductivity nature of graphene. The probe ssDNA was further immobilized onto the surface of the reduced graphene oxide-graphene double-layer electrode via π-π bonds and then hybridized with its target cDNA. The change of peak current due to the hybridized dsDNA could be used for quantitative sensing of DNA concentration. It has been demonstrated that a linear range from 10(-7)M to 10(-12)M is achievable for the detection of human immunodeficiency virus 1 gene with a detection limit of 1.58 × 10(-13)M as determined by three times standard deviation of zero DNA concentration

The origin of galaxy scaling laws in LCDM

It has long been recognized that tight relations link the mass, size, and characteristic velocity of galaxies. These scaling laws reflect the way in which baryons populate, cool, and settle at the center of their host dark matter halos; the angular momentum they retain in the assembly process; as well as the radial distribution and mass scalings of the dark matter halos. There has been steady progress in our understanding of these processes in recent years, mainly as sophisticated N-body and hydrodynamical simulation techniques have enabled the numerical realization of galaxy models of ever increasing complexity, realism, and appeal. These simulations have now clarified the origin of these galaxy scaling laws in a universe dominated by cold dark matter: these relations arise from the tight (but highly non-linear) relations between (i) galaxy mass and halo mass, (ii) galaxy size and halo characteristic radius; and (iii) from the self-similar mass nature of cold dark matter halo mass profiles. The excellent agreement between simulated and observed galaxy scaling laws is a resounding success for the LCDM cosmogony on the highly non-linear scales of individual galaxies.Comment: Contribution to the Proceedings of the Simons Conference "Illuminating Dark Matter", held in Kruen, Germany, in May 2018, eds. R. Essig, K. Zurek, J. Fen

Search for K_S K_L in psi'' decays

K_S K_L from psi'' decays is searched for using the psi'' data collected by BESII at BEPC, the upper limit of the branching fraction is determined to be B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is compared with the prediction of the S- and D-wave mixing model of the charmonia, based on the measurements of the branching fractions of J/psi-->K_S K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur

Study of psi(2S) decays to X J/psi

Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) -> pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026 \pm 0.055.Comment: 13 pages, 8 figure