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Lipid nanoparticles (LNPs) coated with functional and biocompatible polymers have been widely used as carriers to deliver oligonucleotide and messenger RNA therapeutics to treat diseases. Poly(ethylene glycol) (PEG) is a representative material used for the surface coating, but the PEG surface-coated LNPs often have reduced cellular uptake efficiency and pharmacological activity. Here, we demonstrate the effect of pH-responsive ethylenediamine-based polycarboxybetaines with different molecular weights as an alternative structural component to PEG for the coating of LNPs. We found that appropriate tuning of the molecular weight around polycarboxybetaine-modified LNP, which incorporated small interfering RNA, could enhance the cellular uptake and membrane fusion potential in cancerous pH condition, thereby facilitating the gene silencing effect. This study demonstrates the importance of the design and molecular length of polymers on the LNP surface to provide effective drug delivery to cancer cells. IMPACT STATEMENT: The study presents the unique characteristics of small interfering RNA (siRNA)-loaded lipid nanoparticles (LNPs) with different lengths of PGlu(DET-Car), revealing the length of PGlu(DET-Car) critically affects the formation of a stable LNP, the cellular uptake, membrane fusion, and gene silencing abilities. [ABSTRACT FROM AUTHOR]

Laser-beam-intensity fluctuations between an uplink (ground to satellite) and a downlink (satellite to ground) are described. The dependence of the beam radius on log-intensity variance in the uplink and the dependence of receiving-aperture diameter on the log-intensity variance in the downlink using a known theory were calculated. Statistical analysis of the experimental data on the laser links was performed, and high correlation coefficients of 0.94 between the normalized intensity variances of the uplink and those of the stellar scintillation were obtained. The beam-pointing error in the satelliteborne laser transmitter chiefly caused fluctuations in the downlink. 2005 Optical Society of America OCIS codes: 010.1300, 010.3310, 010.7060

A method that uses two quadrant detectors (QDs) for sensing wave-front tilt is described. The detectors are set at the front and back of the focal plane of the focusing optics. When the intensity distribution at the aperture of a telescope is not uniform because of atmospheric turbulence, the wave-front tilt can be measured more accurately with our two-QD method than with a conventional single-focal-plane QD. We proved this method to be effective by using it for fixed-star observation. Application of the method to a ground-to-satellite laser beam pointing system showed that it increases the intensity of the laser beam that is transmitted to a satellite. OCIS codes: 010.1080, 010.3310, 010.7350.

The titania pulp—a semi product received from the industrial production of titania white—was submitted for the thermal heating at 400–600 °C under Ar and H2 to obtain TiO2 with different structure and oxygen surface defects. Heating of titania in H2 atmosphere accelerated dehydration and crystallisation of TiO2 compared to heating in Ar. TiO2 prepared at 500 and 600 °C under H2 had some oxygen vacancies and Ti3+ centres (electron traps), whereas TiO2 obtained at 450 °C under H2 exhibited some hole traps centres. The presence of oxygen vacancies induced adsorption of atmospheric CO2. It was evidenced, that ethylene reacted with TiO2 after UV irradiation. Formic acid was identified on TiO2 surface as the reaction product of ethylene oxidation. Hydroxyl radicals were involved in complete mineralisation of ethylene. TiO2 prepared at 500 °C under H2 was poorly active because some active sites for coordination of ethylene molecules were occupied by CO2. The most active samples were TiO2 with high quantity of OH terminal groups. At 50 °C, the physically adsorbed water molecules on titania surface were desorbed, and then photocatalytic decomposition of ethylene was more efficient. TiO2 with high quantity of chemisorbed OH groups was very active for ethylene decomposition. The acidic surface of TiO2 enhances its hydroxylation. Therefore, it is stated that TiO2 having acidic active sites can be an excellent photocatalyst for ethylene decomposition under UV light. [ABSTRACT FROM AUTHOR]

A technique for transmitting a narrow laser beam from a ground station to a satellite has been developed. The principle of pointing a laser beam to a distant target in a scattering medium by use of a backscattered laser beam image is described. We calculated the intensity distribution of the image by using a typical model of atmospheric coefficients. The method was applied to transmit a laser beam from a ground station to Engineering Test Satellite-VI. The accuracy of pointing the laser beam to the satellite was approximately 10 [micro] rad in this experiment. OCIS codes: 010.1310, 010.3310.