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In this paper, we study the spatial bandwidth for line-of-sight (LOS) channels with linear large-scale antenna arrays (LSAAs) in 3D space. We provide approximations to the spatial bandwidth at the center of the receiving array, of the form $C R^{-B}$ , where $R$ is the radial distance, and $C$ and $B$ are directional-dependent and piecewise constant in $R$ . The approximations are valid in the entire radiative region, that is, for $R$ greater than a few wavelengths. When the length of the receiving array is small relative to $R$ , the product of the array length and the spatial bandwidth provides an estimate of the available spatial degree-of-freedom (DOF) in the channel. In a case study, we apply these approximations to the evaluation of spatial multiplexing regions under random orientation conditions. The goodness-of-fit of the approximations is demonstrated and some interesting findings about the DOF performance of the channel under 3D and 2D orientation restrictions are obtained, e.g., that, under some conditions, it is better to constrain the receiving array orientation to be uniform over the unit circle in the 2D ground plane rather than uniform over the 3D unit sphere.

In this letter, we investigate the air-to-ground (A2G) channel model and transmission performance for a cellular-connected massive multiple-input multiple-output unmanned aerial vehicle (UAV) swarm system. First, we propose a spatially and temporally correlated A2G channel model that focuses on non-isotropic scattering, line-of-sight (LoS) propagation, and moving scatterers. Second, we derive a novel closed-form signal-to-interference-and-noise ratio expression for uplink transmission, taking into account the effect of channel aging with strong LoS. The results show that the frame length, pilot overhead, and UAV swarm scale can be pre-designed in a fine-grained manner depending on the propagation environment and transmission task. For example, for a low-speed scenario, a long frame can be configured due to the negligible channel aging effect. Moreover, more pilots may mitigate the damage of channel aging, but it is no better when a short frame is needed for transmission such as ultra-reliable and low-latency communications.

Rhizoma coptidis has been clinically used for a long time for the treatment of various diseases in China, such as hypertension, diabetes, and inflammation. Previous studies have shown that alkaloid components of Rhizoma coptidis extract could be extensively metabolized and the metabolites were also considered to be the therapeutic material basis. However, until now, pharmacokinetic studies of the in vivo metabolites have not been revealed yet. The aim of the present study was to characterize the pharmacokinetics and excretions of five main alkaloids (berberine, jatrorrhizine, palmatine, epiberberine, and coptisine) and their seven metabolites (berberrubine, demethyleneberberine, jatrorrhizine-3- O - β -D-glucuronide, thalifendine-10- O - β -D-glucuronide, berberrubine-9- O - β -D-glucuronide, demethyleneberberine-2- O -sulfate, and demethyleneberberine-2- O - β -D-glucuronide) in rats after oral administration of Rhizoma coptidis extract. Meanwhile, comparative pharmacokinetics and excretions of these analytes in diabetic model rats were also investigated, since Rhizoma coptidis is widely used for the treatment of diabetes. Our results showed that the in vivo existing forms of alkaloid components were phase II metabolites, highlighting the glucuronidation metabolic pathway. In diabetic model rats, the utilization of Rhizoma coptidis alkaloids was significantly increased and the biotransformation of berberine into berberrubine was significantly inhibited. [ABSTRACT FROM AUTHOR]

Multifunctional drug delivery systems (DDSs) have shown great prospects in overcoming the heterogeneous barrier of delivery drugs to the complex tumor microenvironment (TME). In this study, multifunctional AS/Ge-pNAB microgels with dual-active targeting, triple environment responsiveness, and fluorescence imaging capability were prepared through a straightforward procedure. This was aimed to improve the antitumor therapeutic application of gambogic acid (GA) based on the biological characteristics of TME. The microgels have a uniform double-layer structure with aptamer in the outer layer which helps in recognizing receptors on the tumor cells. The GA loaded nano-herb exhibited environment-responsive drug release profiles under acidic pH, reductant and high temperature. The nano-herb significantly improved the accumulation of GA in tumor sites through the synergistic combination of the enhanced permeability and retention effect and dual-ligand mediated internalization. Then, it accelerated intracellular drug release and killed tumor cells. Therefore, the nano-herb had specific therapeutic effects on the tumor in vitroand in vivoas they remarkably inhibited tumor growth while depicting optimal biosafety and lower levels of off-target toxicity. Overall, these findings demonstrate the great potential of the multifunctional AS/Ge-pNAB microgels for precisely targeted GA delivery and open a new avenue for the facile preparation of multifunctional DDSs.

Developing hemostatic agents with reliable biosafety and high efficiency has paramount clinical significance for saving lives. Herein, inspired from traditional Chinese medicine, a sponge (BC‐S) with hierarchical porous structure is proposed for the treatment of bleeding. The BC‐S is prepared by a simple self‐assembly method employing Bletilla Striata polysaccharide and quaternary amine alkaloids (QA) from Bletilla Striata and Coptidis Rhizoma. The ideal cation donor encapsulated in the helical structure of BSP enlarges the inter‐layer space of sponge by the action of electrostatic repulsion, forming wider channels which can accelerate the diversion speed of absorbed blood. Then, platelets and erythrocytes are trapped tightly in the reticular structure and extruded to deformation, activation. Subsequently, fibrin network forms and reinforces the internal multilayer mesh, blocks the outflow of blood. QA is released from the sponge skeleton mainly driven by a combination of surface erosion and potentially solution diffusion among pore to provide long‐term antibacterial activity. Benefiting from the well‐designed structure and the effective hemostatic mechanism, the BC‐S displays more excellent hemostatic performance in different models in vivo and in vitro compared with typical gelatin hemostatic sponge. This work is expected to boost the development of emerging hemostatic agents. A natural gel‐sponge is prepared by self‐assembly method employing polysaccharide and quaternary amine alkaloids from Bletilla Striata and Coptidis Rhizoma. The ideal cation donor encapsulated in the helical structure of polysaccharide enlarges the interlayer space of sponge by the action of electrostatic repulsion, forming wider channels which can accelerate the diversion rate of absorbed blood.

The highly-emulsified oily sludge in gas fields is complex in components and serious in emulsification, which makes effective reduction extremely difficult only by a single direct mechanical separation method such as microwave heating, ultrasonic treatment, chemical conditioning, etc. In view of this, this paper presented a new chemical–physical compounding conditioning technology for such highly emulsified oily sludge in gas fields. The experimental samples, from the Mizhi Natural Gas Processing Plant of PetroChina Changqing Oilfield Company, were treated through chemical conditioning, from which the optimal formula, dosages and dosing order were determined. On this basis, the compound technology of chemical–physical conditioning was applied to reduce the specific resistance to filtration (SRF) of the sludge, thus achieving a satisfactory result. The following results were obtained. (1) The chemical conditioning agent with the formula of the oxidant MN-S, calcium oxide and sodium hydroxide was proved to achieve the fastest dewatering speed, and the specific resistance of sludge can be reduced from 130.3 to 3.81 trillion m3per kg. (2) Comparison between microwave and ultrasonic conditioning methods shows that the latter is better in reducing the SRF (the ultrasonic frequency of 40 kHz was applied to reduce the SRF down to 14.01 trillion m3per kg after 4 min of conditioning treatment). (3) The ultrasonic treatment effect after chemical conditioning is the best; the SRF was reduced to 2.77 trillion m3per kg, and the moisture content of the sludge after mechanical dewatering was only 68.71%, decreased by 21.46% compared with the original content of 90.17%. In conclusion, this presented chemical–microwave–ultrasonic compound conditioning technology can reduce the sludge's SRF and the moisture content of filter cakes so as to achieve effective reduction of the highly-emulsified sludge in gas fields.

First, this letter presents a Minkowski reduction algorithm working directly on complex lattices. Then, a relaxation is proposed to Minkowski criterion by restricting the search of basis vectors within sublattices whose dimensions are determined by an integer parameter $\beta $ , and a reduction algorithm following the relaxed criterion is also developed. Simulation results show that when employed to assist linear equalization for multiple-input multiple-output systems, the proposed algorithms can achieve tremendous computational savings compared with the most efficient real-domain Minkowski reduction algorithm, without causing noticeable performance degradation.

Computational fluid dynamics (CFD) has evolved into a vital tool for advancing bubbling fluidized-bed reactors for biomass fast pyrolysis. However, due to the enormous computational burden of CFD simulations, optimizing working parameters over a broad range or simulating large/industrial units is still extremely time-consuming. Because deep learning (DL) is a promising method to attain both precision and speed, two new DL models, which added an attention mechanism or a convolutional neuron network (CNN) layer in the basic long short-term memory (LSTM) model, were established to predict instantaneous mass flow rates of major species for biomass fast pyrolysis in a bubbling fluidized bed. Historical mass flow rates from a multifluid model (MFM) simulation were considered as the time series of data for the model training process. Influencing factors, including sequence length, learning rate, convolutional kernel and stride sizes in the CNN layer, and number of neurons and layers in LSTM module, were examined to improve forecasting ability. The results demonstrated that the hybrid model including both CNN and LSTM outperforms other models in predicting instantaneous mass flow rates of biomass fast pyrolysis in bubbling fluidized beds.

Ten new guaiane-type sesquiterpenes (1–10), phaeocaulisins A–J, and 18 known guaiane derivatives were isolated from rhizomes of Curcuma phaeocaulis. Their structures were established on the basis of extensive spectroscopic analyses, X-ray crystallographic analysis, and comparison with literature data. Compound 10is the first example of a norsesquiterpene with this unusual skeleton isolated from the genus Curcuma. All of the isolated compounds were tested for inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages. Compounds 1, 2, 20, and 22–24inhibited nitric oxide production with IC50values less than 2 μM. Preliminary structure–activity relationships for these compounds are discussed.