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The central and eastern Qinghai-Tibet Plateau is the birthplace of the Yellow River, the Yangtze River and the Lancang River. It is also a climate change sensitive area and a key ecological protection area. Based on observations of 11 sorties conducted in summer and autumn of 2011 and 2013, the vertical distribution of aerosol number concentration and number spectrum at Golmud, and the transport characteristics as well as the horizontal distribution and nucleation characteristics of aerosol number concentration and cloud condensation nuclei (CCN) number concentration at mid-altitude of the central and eastern Plateau are analyzed. The results indicate that the vertical and horizontal distributions of aerosol number concentration (Na) and volume diameter (Dv) in the central and eastern Qinghai-Tibet Plateau are significantly different due to the influence of weather system, topography, and surface characteristics. The aerosol number concentration is high in the northwest and low in the southeast. The volume diameter is large in the lower layer, small in the upper layer, and there are dust layers in the middle and upper layers. Precipitation has clear effects on low-level aerosols when east wind prevails at Golmud, and the aerosol number concentration and volume diameter are significantly reduced. At the same time, due to plateau gale or convection, sand and dust layers also form at the middle and upper altitudes of 6.2 km and 7.2-7.4 km. The aerosol volume diameter of the lower layer is 1.8 μm mainly when westerly wind prevails, the number concentration increases with the increase of height and wind speed, the variation of aerosol volume diameter is small, and the sand and dust layer also appears at 6.2 km altitude. Under the influence of different weather systems over 6.5 km altitude, submicron particles are imported, and the number concentration even reaches 5×103 cm-3. Moreover, the aerosol number concentration and particle size imported at about 8.0 km altitude when east wind prevails are denser and smaller than those imported when west wind prevails, and the vertical distribution of spectrum also shows the same characteristics. The measurement of cloud condensation nuclei number concentration (Nccn) with different supersaturation shows that the mean nucleation rate is generally 1%-16%, except that the nucleation rate below 6 km altitude at Golmud is 21%-47%, and the nucleation rate at 6.0-8.5 km altitude is generally low. When the aerosol number concentration increases, the nucleation rate decreases significantly, and its value is relatively high with the supersaturation being 1%-2%, in the layer between -15 and -5℃ or the particle size of 1-3 μm.

A series of colon‐targeted, sustained‐release, sinomenine hydrochloride (SH) loaded shell/core electrospun nanofibers are reported. The fibers have shells made of Eudragit S100 (ES‐100), and drug‐loaded cores comprising of Eudragit RS100 (ERS‐100) and SH. The essential characteristics of membranes are evaluated by scanning electron microscopy, transmission electron microscope, Fourier transformed infrared spectroscopy, and x‐ray diffraction. In vitro release of SH show that the shell/core nanofiber membranes can block drug release in the HCl buffer (pH 1.2), and the release time of the hydrophilic drug SH exceed 240 min at pH 7.4 phosphate buffer solution. In vitro drug release kinetics consistent with the first‐order model. The shell/core nanofiber can achieve colon‐targeted and sustained‐release properties, which can better prevent the loss of SH and relieve the adverse effects on gastrointestinal tract. In addition, the hemolysis and cytotoxicity tests manifest that the nanofiber membrane display good hemocompatibility and cytocompatibility. These results suggest the SH‐containing nanofiber membranes have potential applications as a colon‐targeted drug delivery system that sustained release. They also offer a theoretical foundation for the development of novel dosage forms for SH. [ABSTRACT FROM AUTHOR]

Using CloudSat/CALIPSO satellite data and ERA5 reanalysis data from 2006 to 2010, the effects of aerosols on ice- and mixed-phase, single-layer, non-precipitating clouds over the Tibetan Plateau during nighttime in the MAM (March to May), JJA (June to August), SON (September to November), and DJF (December to February) seasons were examined. The results indicated the following: (1) The macrophysical and microphysical characteristics of ice- and mixed-phase clouds exhibit a nonlinear trend with increasing aerosol optical depth (AOD). When the logarithm of AOD (lnAOD) was ≤−4.0, with increasing AOD during MAM and JJA nights, the cloud thickness and ice particle effective radius of ice-phase clouds and mixed-phase clouds, the ice water path and ice particle number concentration of ice-phase clouds, and the liquid water path and cloud fraction of mixed-phase clouds all decreased; during SON and DJF nights, the cloud thickness of ice-phase clouds, cloud top height, liquid droplet number concentration, and liquid water path of mixed-phase clouds all decreased. When the lnAOD was >−4.0, with increasing AOD during MAM and JJA nights, the cloud top height, cloud base height, cloud fraction, and ice particle number concentration of ice-phase clouds, and the ice water path of mixed-phase clouds all increased; during SON and DJF nights, the cloud fraction of mixed-phase clouds and the ice water path of ice-phase clouds all increased. (2) Under the condition of excluding meteorological factors, including the U-component of wind, V-component of wind, pressure vertical velocity, temperature, and relative humidity at the atmospheric pressure heights near the average cloud top height, within the cloud, and the average cloud base height, as well as precipitable water vapor, convective available potential energy, and surface pressure. During MAM and JJA nights. When the lnAOD was ≤−4.0, an increase in aerosols may have led to a decrease in the thickness of ice and mixed-phase cloud layers, as well as a reduction in cloud water path values. In contrast, when the lnAOD was >−4.0, an increase in aerosols may contribute to elevated cloud base and cloud top heights for ice-phase clouds. During SON and DJF nights, changes in various cloud characteristics may be influenced by both aerosols and meteorological factors. [ABSTRACT FROM AUTHOR]