We propose a sensor based on spectral as well as angular interrogation of lossy mode resonance between absorbing thin film lossy modes and the evanescent wave for measurement of variation in the ...refractive index of the bulk media. It is shown that a low index dielectric matching layer introduced between the prism and the lossy waveguiding layer can produce an efficient refractive index sensor. The obtained sensitivity (4000–5000nm/RIU) is comparable to some of the best surface plasmon resonance (SPR) sensors. Unlike the SPR sensor in which surface plasmons can be excited only by p-polarized (TM) light, the proposed sensor can operate at either of these polarizations. Detailed theoretical analysis of the proposed sensor based on Fresnel reflection coefficients and transfer matrix method is presented. Effect of losses (imaginary part of refractive index) on the sensor parameters is also presented in sufficient details. Various parameters such as resonance angle, film thickness and refractive index of various layers are optimized for maximum evanescent field enhancement and increased sensitivity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Most cancer patients die as a result of metastasis, thus it is important to understand the molecular mechanisms of dissemination, including intra- and extravasation. Although the mechanisms of ...extravasation have been vastly studied in vitro and in vivo, the process of intravasation is still unclear. Furthermore, how cells in the tumor microenvironment facilitate tumor cell intravasation is still unknown. Using high-resolution imaging, we found that macrophages enhance tumor cell intravasation upon physical contact. Macrophage and tumor cell contact induce RhoA activity in tumor cells, triggering the formation of actin-rich degradative protrusions called invadopodia, enabling tumor cells to degrade and break through matrix barriers during tumor cell transendothelial migration. Interestingly, we show that macrophage-induced invadopodium formation and tumor cell intravasation also occur in patient-derived tumor cells and in vivo models, revealing a conserved mechanism of tumor cell intravasation. Our results illustrate a novel heterotypic cell contact-mediated signaling role for RhoA, as well as yield mechanistic insight into the ability of cells within the tumor microenvironment to facilitate steps of the metastatic cascade.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
An efficient and green route to access diverse functionalized ketones via dehydrogenative–dehydrative cross-coupling of primary and secondary alcohols is demonstrated. Selective and tunable formation ...of ketones or alcohols is catalyzed by a recently developed proton responsive ruthenium phosphine–pyridone complex. Light alcohols such as ethanol could be used as alkylating agents in this methodology. Moreover, selective tandem double alkylation of isopropanol is achieved by sequential addition of different alcohols.
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IJS, KILJ, NUK, PNG, UL, UM
In the past decade nanotechnology has developed in many directions. Nanofluid is a mixture of nanosized particles dispersed in fluids. Nanofluids are new generation heat transfer fluids used in heat ...exchangers for energy conservation. Viscosity is an important property particularly concerning fluids flowing in a tube in heat exchangers. In this regard, an attempt has been made to review the available empirical and theoretical correlations for the estimation of viscosity of nanofluids. The review also extended to preparation of nanofluids, nanoparticle volume concentration, nanofluid temperature, particle size and type of base fluid on viscosity of nanofluids. The available experimental results clearly indicate that with the dispersion of nanoparticles in the base fluid viscosity increases and it further increases with the increase in particle volume concentration. Viscosity of nanofluid decreases with increase of temperature.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary
This systematic review and meta‐analysis appraises the utility of point‐of‐care platelet function tests for predicting blood loss and transfusion requirements in cardiac surgical patients, ...and analyses whether their use within a transfusion management algorithm is associated with improved patient outcomes. We included 30 observational studies incorporating 3044 patients in the qualitative assessment, and nine randomised controlled trials including 1057 patients in the meta‐analysis. Platelet function tests demonstrated significant variability in their ability to predict blood loss and transfusion requirements. Their use within a blood transfusion algorithm demonstrated a reduction in blood loss at longest follow‐up (mean difference −102.9 ml (95% CI −149.9 to −56.1 ml), p < 0.001), and transfusion of packed red cells (RR 0.86 (95% CI 0.78−0.94), p = 0.001) and fresh frozen plasma (RR 0.42 (95% CI 0.30−0.59), p < 0.001). Viscoelastic methods used in combination with other platelet function tests achieved greater reduction in blood loss (mean difference −111.8 ml (95% CI −174.9 to −49.1 ml), p = 0.0005) compared with their use alone (mean difference −90.6 ml (95% CI 166.1−15.0 ml), p = 0.02). We conclude that incorporation of point‐of‐care platelet function tests into transfusion management algorithms is associated with a reduction in blood loss and transfusion requirements in cardiac surgery patients.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Vitamin E behaves as an antioxidant and is well known for its protective properties of the lipid membrane. The most biologically active form of vitamin E in the human organism is α-tocopherol (aToc). ...Very recently (Marquardt, D.; et al. J. Am. Chem. Soc. 2014, 136, 203–210) it has been shown that aToc resides near the center of dimyristoylphosphatidylcholine (DMPC) bilayer, which is in stark contrast with other PC membranes, where aToc is located near the lipid–water interface. Here we report an unusual effect of this exceptional location of aToc on the dynamical behavior of DMPC membrane probed by incoherent elastic and quasielastic neutron scattering. For pure DMPC vesicles, elastic scan data show two step-like drops in the elastic intensity at 288 and 297 K, which correspond to the pre- and main phase transitions, respectively. However, inclusion of aToc into DMPC membrane inhibits the step-like elastic intensity drops, indicating a significant impact of aToc on the phase behavior of the membrane. This observation is supported by our differential scanning calorimetry data, which shows that inclusion of aToc leads to a significant broadening of the main phase transition peak, whereas the peak corresponding to the pretransition disappears. We have performed quasielastic neutron scattering (QENS) measurements on DMPC vesicles with various concentrations of aToc at 280, 293, and 310 K. We have found that aToc affects both the lateral diffusion and the internal motions of the lipid molecules. Below the main phase transition temperature inclusion of aToc accelerates both the lateral and the internal lipid motions. On the other hand, above the main phase transition temperature the addition of aToc restricts only the internal motion, without a significant influence on the lateral motion. Our results support the finding that the location of aToc in DMPC membrane is deep within the bilayer.
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In spite of their well-known side effects, the nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications for their antipyretic and anti-inflammatory actions. ...Interaction of NSAIDs with the plasma membrane plays a vital role in their therapeutic actions and defines many of their side effects. In the present study, we investigate the effects of three NSAIDs, aspirin, ibuprofen, and indomethacin, on the structure and dynamics of a model plasma membrane using a combination of small angle neutron scattering (SANS) and neutron spin echo (NSE) techniques. The SANS and NSE measurements were carried out on a 1,2-dimyristoyl-
sn-glycero
-3-phosphocholine (DMPC) membrane, with and without NSAIDs, at two different temperatures, 11 °C and 37 °C, where the DMPC membrane is in the gel and fluid phase, respectively. SANS data analysis shows that incorporation of NSAIDs leads to bilayer thinning of the membrane in both the phases. The dynamic properties of the membrane are represented by the intermediate scattering functions for NSE data, which are successfully described by the Zilman and Granek model. NSE data analysis shows that in both gel and fluid phases, addition of NSAIDs results in a decrease in the bending rigidity and compressibility modulus of the membrane, which is more prominent when the membrane is in the gel phase. The magnitude of the effect of NSAIDs on the bending rigidity and compressibility modulus of the membrane in the gel phase follows an order of ibuprofen > aspirin > indomethacin, whereas in the fluid phase, it is in the order of aspirin > ibuprofen > indomethacin. We find that the interaction between NSAIDs and phospholipid membranes is strongly dependent on the chemical structure of the drugs and physical state of the membrane. Mechanical properties of the membrane can be quantified by the membrane's bending rigidity. Hence, the present study reveals that incorporation of NSAIDs modulates the mechanical properties of the membrane, which may affect several physiological processes, particularly those linked to the membrane curvature.
Incorporation of drugs makes membranes softer, and the magnitude of the effect depends on the drug and the phase of the membrane.
Ionic liquids (ILs) are potential candidates for new antimicrobials due to their tunable antibacterial and antifungal properties that are required to keep pace with the growing challenge of bacterial ...resistance. To a great extent their antimicrobial actions are related to the interactions of ILs with cell membranes. Here, we report the effects of ILs on the nanoscopic dynamics and phase behaviour of a dimyristoylphosphatidylcholine (DMPC) membrane, a model cell membrane, as studied using neutron scattering techniques. Two prototypical imidazolium-based ILs 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) and 1-decyl-3-methylimidazolium tetrafluoroborate (DMIMBF4), which differ only in terms of the alkyl chain length of cations, have been used for the present study. Fixed Elastic Window Scan (FEWS) shows that the incorporation of ILs affects the phase behaviour of the phospholipid membrane significantly and the transition from a solid gel to a fluid phase shifts to lower temperature. This is found to be consistent with our differential scanning calorimetry measurements. DMIMBF4, which has a longer alkyl chain cation, affects the phase behaviour more strongly in comparison to BMIMBF4. The pressure-area isotherms of the DMPC monolayer measured at the air-water interface show that in the presence of ILs, isotherms shift towards higher area-per lipid molecule. DMIMBF4 is found to shift the isotherm to a greater extent compared to BMIMBF4. Quasielastic neutron scattering (QENS) data show that both ILs act as a plasticizer, which enhances the fluidity of the membrane. DMIMBF4 is found to be a stronger plasticizing agent in comparison to BMIMBF4 that has a cation with a shorter alkyl chain. The incorporation of DMIMBF4 enhances not only the long range lateral motion but also the localised internal motion of the lipids. On the other hand, BMIMBF4 acts weakly in comparison to DMIMBF4 and mainly alters the localised internal motion of the lipids. Any subtle change in the dynamical properties of the membrane can profoundly affect the stability of the cell. Hence, the dominant effect of the IL with the longer chain length on the dynamics of the phospholipid membrane might be correlated with its cytotoxic activity. QENS data analysis has provided a quantitative description of the effects of the two imidazolium-based ILs on the dynamical and phase behaviour of the model cell membrane, which is essential for a detailed understanding of their action mechanism.
Ionic liquids (ILs) are potential candidates for new antimicrobials due to their tunable antibacterial properties. Effects of ILs on lipid membranes are investigated to address the growing challenge of bacterial resistance.
This paper aims to investigate the dynamic stability of a multi-area power system. A three-degree-of-freedom-based fractional order proportional integral derivative-proportional resonant (FOPID-PR) ...controller is designed and implemented in the multi-area power system to stabilize the frequency and the fluctuations of power after the disturbance occurs. For improving the system dynamics, the parameters of the three degrees of the FOPID-PR controller are optimized using an artificial humming bird (AHB) optimization. AHB optimization is used in the controllers to fine-tune the gain. It will identify any minor adjustments in the FOPID-PR controller’s value. The proposed methods are implemented in the five-area power system. Five areas, diesel generator, aqua electrolyzer, fuel cell (FC), wind turbine, hydro, and bio-mass-based power generator, are given with their dynamic responses by conceding frequency deviations in each area. The results are obtained under random, stochastic, and step loads, including the frequency and tie-line characteristics. The proposed method results in reduced ITAE of 61.04%, 70.76%, 81.9% and 86.42% for SSA, DE, GWO and PSO, respectively.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Aqueous mixtures of deep eutectic solvents (DESs) have gained traction recently as an effective template to tailor their physicochemical properties. But detailed microscopic insights into the effects ...of water on the molecular relaxation phenomenon in DESs are not entirely understood. DESs are strong network-forming liquids due to the extensive hydrogen bonding and complex formation between their species, and therefore, water can behave as a controlled disruptor altering the microscopic structure and dynamics in DESs. In this study, the role of water in the diffusion mechanism of acetamide in the aqueous mixtures of DESs synthesized using acetamide and lithium perchlorate is investigated using molecular dynamics (MD) simulation and quasielastic neutron scattering (QENS). The acetamide dynamics comprises localized diffusion within transient cages and a jump diffusion process across cages. The jump diffusion process is observed to be strongly enhanced by about a factor of 10 as the water content in the system is increased. Meanwhile, the geometry of the localized dynamics is unaltered by addition of water, but the localized diffusion becomes significantly faster and more heterogeneous with increasing water concentration. The accelerating effects of water on localized diffusion are also substantiated by QENS experiments. The water concentration in the DES is observed to control the solvation structure of lithium ions, with the ions becoming significantly hydrated at 20 wt % water. The formation of interwater and water–acetamide hydrogen bonds is observed. The increase in water concentration is found to increase the number of H-bonds; however, their lifetimes are found to decrease substantially. Similarly, the lifetimes of acetamide–lithium complexes are also found to be diminished by increasing water concentration. A power-law scaling relationship between lifetimes and diffusion constants is established, elucidating the extent of coupling between diffusive processes and hydrogen bonding and microscopic complexation. This study demonstrates the ability to use water as an agent to probe the role of structural relaxation and complex lifetimes of diffusive processes at different time and length scales.
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